doi: 10.14720/aas.2018.111.3.19
Review article / pregledni znanstveni članek
On-farm seed priming interventions in agronomic crops
Neha CHATTERJEE1, Deepranjan SARKAR2, Ardith SANKAR1, Sumita PAL3, H. B. SINGH3, Rajesh Kumar
SINGH1, J. S. BOHRA1, and Amitava RAKSHIT2*
Received May 07, 2018; accepted November 12, 2018. Delo je prispelo 07. maja 2018, sprejeto 12. novembra 2018.
ABSTRACT
Priming techniques are gaining importance in agriculture with the increase in environmental stresses. Resource-poor farmers are in urgent need of such techniques as they are simple, economical, and value-added intervention associated with low-risk bearing factors. Seed enhancement methods are key to improve seed performance and achieve a good stand establishment. Worldwide beneficial effects of priming are recorded. But these technologies have still not reached most farmers. This review highlights the importance of on-farm priming strategies in modern crop production system to yield better productivity and obtain higher economic returns. Stimulation of the pre-germination metabolic changes by priming is necessary to overcome the environmental challenges that a plant can encounter. Thus, the study also focuses on mechanisms associated with priming-induced stress tolerance of crops. Various safe practical methods of seed priming can be easily adopted by the farming community to alleviate the levels of different stresses which can hamper productivity. Simultaneously they can produce good quality seeds and use them further for the next crop cycle cutting the costs of seed purchase.
Key words: priming methods; priming agents; stress; stress tolerance; plant growth
IZVLEČEK
UVAJANJE PREDSETVENE OBDELAVE SEMEN POLJŠČIN NA KMETIJAH
Tehnike predsetvene obdelave semen pridobivajo na pomenu v kmetijstvu s povečevanjem okoljskih stresov. Zaradi preprostosti uporabe, ekonomičnosti in dodane vrednosti zaradi zmanjšanja tveganja so te metode nujno potrebne za revne kmete. Metode pospeševanja kalitve semen so ključne za izboljšanje setve in za vzpostavitev dobrih posevkov. Blagodejni učinki predsetvene obdelave semen so zabeleženi širom po svetu, vendar te tehnologije še vedno niso dosegle večine kmetov. Ta pregled osvetljuje pomen teh postopkov na kmetijah v modernih sistemih pridelovanja poljščin za boljšo produktivnost in doseganje večjih iztržkov. Vzpodbujanje predkalitvene presnovne aktivnosti semen z njihovo predsetveno obdelavo je potrebno za preseganje okoljskih izzivov s katerimi se soočajo rastline. Raziskava se osredotoča tudi na mehanizme, povezane s predsetveno obdelavo semen vzpodbujene tolerance na stres pri kmetijskih rastlinah. Različne varne in praktične metode predsetvene obdelave semen bi lahko bile z lahkoto uporabljene pri kmetovalcih za zmanjševanje okoljskih stresov, ki ovirajo produktivnost rastlin. Hkrati bi tako pridelali kvalitetna semena za naslednjo setev in s tem zmanjšali stroške njihovega nakupa.
Ključne besede: metode predsetvene obdelave semen;
sredstva za predsetveno obdelavo; stres; toleranca na stres; rast rastlin
1	Department of Agronomy, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi 221005, Uttar Pradesh, India
2	Department of Soil Science and Agricultural Chemistry, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi 221005, Uttar Pradesh, India; *corresponding author: amitavar@bhu.ac.in
3	Department of Mycology and Plant Pathology, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi 221005, Uttar Pradesh, India
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1 INTRODUCTION
Farmers in developing countries often encounter poor crop establishment in crop production practices. The reasons for this failure might be due to some basic factors like availability of good quality seeds, knowledge of seed technology, proper sowing techniques, or climate change and various environmental stresses (Figure 1). The extra costs in labour, draft power, and materials hinder the small and marginal farmers to alleviate these constraints efficiently. Therefore, we need to popularize the seed enhancement technologies which could be easily adopted by all farmers, irrespective of their socioeconomic conditions. Because successful crop production depends on good quality seeds.
Abiotic and biotic stresses are the norm for any plant while completing its phenology (Suzuki et al., 2014). Among others, the predominant abiotic stresses include extremes of temperature, drought, high salinity, nutrient, and oxidative stress. While pathogens (fungi, bacteria, viruses, and nematodes) and pests (insects, arachnids, herbivores, and weeds) are threats to plants as biotic stress. These stresses are known to cause physiological, biochemical, and metabolic changes in crop plants affecting the metabolism, performance, and ultimately adversely reducing the yield of plants (Anjum et al., 2011; Rejeb et al., 2014).
High salt stress is the cause for disruption of water relations and ionic distribution in plants (Munns & Tester, 2008). Basically, salinity has a negative impact on seed germination and seedling establishment either by inhibiting water uptake with development of high external osmotic potential or through accumulation of toxic ions (Na+ and Cl-) in the system (Nasri et al., 2015; Negrao et al., 2017). Water is a primary factor of production, and hence drought stress, particularly at the critical growth stages is one of the major environmental limiting factor affecting crop growth and productivity (Araus et al., 2002). The negative consequences of drought stress can be seen in every aspect of plant life (Rahman et al., 2004). Drought stress is known to bring about a series of adverse effect in biochemical and
physiological processes of plants, viz., disturbance in ion homeostasis and enzymatic activities, increased levels of reactive oxygen species (ROS), decreased cell division, leaf parameters (area, size, and chlorophyll contents), CO2 assimilation, photosynthesis, root proliferation, stem elongation, and water use efficiency, and consequently reduction in grain yield (Farooq et al., 2009; Anjum et al., 2011; Farooq et al., 2012; Nikju et al., 2015). Moreover, seeds sown in dry soil often delays in germination as they absorb too little water from the soil, following delay in several imbibition processes. If a method of germination could be devised to overcome with this time lag in germination by pre-soaking of the seeds in water, germination would occur swiftly ensuing in a better crop stand.
Another major global constraint in productivity of agricultural crops is the inaccessibility of nutrients by plants due to their deficiency in soil, commonly known as nutrient stress (Baligar et al., 2001; Sun et al., 2011). Both macro- and micronutrients have great roles in meeting crops demands and improving the yield levels. Micronutrient deficiency has already been found in the food chain; proper management strategies focusing on nutritional quality is a serious concern in sustainable agriculture (Khoshgoftarmanesh et al., 2010). Several other abiotic stresses like cold, heat, light, or irradiation can adversely alter the plant physiology and govern the occurrence of biotic stresses in the environment (Suzuki et al., 2014; Pandey et al., 2017).
Plants in response to multiple environmental stresses activate various defense mechanisms and signaling pathways regulated by ROS, hormones (salicylic acid, abscisic acid, jasmonic acid, ethylene, gibberellic acid, auxins, and cytokinins), proteins, and transcription factors (Verma et al., 2016; Gimenez et al., 2018). Understanding these mechanisms will not only help in saving important crops but also preventing economic losses. Searching suitable priming agents can significantly contribute to acclimation pathways of plants developed against the threats of stress-induced infections.
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Slow and non-uniform germination
Biotic and abiotic stresses
* *
Poor sowing techniques
Figure 1: Basic issues in low productivity of crops
While attempting to maintain an optimum external environment for crops, the overdependence on natural resources and fossil fuel-based technology, over the years, has led to the gradual depletion of global water resources, escalating greenhouse gas emissions, and a gradual decline in productivity particularly in the high input-intensive agriculture systems. This scenario is likely to worsen and the brunt of the menace will supposedly be faced by rainfed agriculture systems globally on account of their inherent resource limitation. While 40 % of the world's and 68 % of Indian
agriculture is rainfed, 42 % of the Indian food requirement is met through dryland agriculture (Singh et al., 2004). Climate change is a real intimidation to the developing world which unchecked, will become a major hindrance to poverty eradication. Besides, the contamination of the natural water bodies and soil strata through excessive agrochemical use coupled with improper irrigation techniques in intensive-irrigated agriculture systems call for alternative options under low-input sustainable agriculture systems with the ultimate aim of acquiring global food security.
2 POSSIBLE ALTERNATIVES
Throughout the history of agriculture, several methods have been adopted to achieve better crop tolerance to stresses and production in unfavorable environmental conditions. These entail breeding strategies (selection and hybridization, molecular breeding, genetic engineering) (Athar & Ashraf, 2009; Waqar et al., 2014), agronomic strategies (variety selection, date of sowing, soil management, irrigation) (Mariani & Ferrante, 2017; Lamaoui et al., 2018), physiological approaches (seed priming, foliar spray) (Bakhtavar et al., 2015), etc. The success of breeding techniques is often limited due to huge requirement of skilled manpower and energy, complexity associated with stress tolerance traits, tedious and costly methods, and ethical regulations. These drawbacks have forced the researchers to go for the alternatives which are simple
and low-cost solution so that they are easily introduced at the field scale by resource-poor farmers.
Pre-sowing seed treatment (seed priming, seed coating, and seed pelleting), in this regard, is an effective strategy to overcome different stresses. This pragmatic and short-term approach is basically used as seed enhancement aimed at value adding or upgrading the quality of seed (Taylor et al., 1998). Such intervention involves the application of physical, chemical, and/or biological agents to stimulate seed germination, seedling vigour, and crop yield in a sustainable manner (Sharma et al., 2015). Seed priming is an effective pre-germination physiological method that mends seed performance and delivers quicker and synchronized seed germination (Matsushima & Sakagami, 2013; Nawaz et al., 2015) by prior exposure of seed to a stress
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situation, which endows plant to better withstand the future stress imposition (Yadav et al., 2011; Ibrahim, 2016). It involves soaking of seeds in water (hydropriming) or solutions of lower water potential (osmotic solutions) composed of polyethylene glycol (PEG) (osmopriming) or salts (CaCl2, CaSO4, KH2PO4, KCl, NaCl, etc.) (halopriming) prior to germination (Jisha et al., 2013; Paparella et al., 2015; Wojtyla et al., 2016). In priming, controlled imbibition is provided so as to induce the metabolic process of germination without actual germination and seminal root emergence (Binang et al., 2012; Nejad & Farahmand, 2012). Seed coating is a process of application of adhesive polymers with active ingredients (nutritional elements, plant growth regulators, insecticides, fungicides, and other
chemicals) to the seed surface without altering its original shape or size (Avelar et al., 2012; Mandal et al., 2015; Pedrini et al., 2017). Seed pelleting came out as an advanced form of seed coating technology. The method includes enclosing of seed in a layer of inert material that may change the shape and size of raw seed, but produce a standard product (uniform round seeds) to facilitate improved planting (Mandal et al., 2015; Mei et al., 2017 ). Seed coating technologies are sophisticated and expensive (Sharma et al., 2015). Seed priming emerged as the most common method of pre-sowing treatments (Parera & Cantliffe, 1994; Jisha et al., 2013; Soleimanzadeh, 2013; Paparella et al., 2015; Lutts et al., 2016; Wojtyla et al., 2016).
3 ON-FARM PRIMING OPTIONS
In ' 'on-farm'' seed priming, seeds are soaked in water, surface dried, and sown in the field (Rashid et al., 2002). The term on-farm is used to differentiate it from the intensive agricultural systems using high input and advance technology for seed priming (Harris et al., 1999). This practice is very common in tropical environments or semi-arid agricultural lands as a low-cost and low-risk intervention. A plethora of priming techniques has been developed to enhance and stabilize field emergence, and those are categorized according to the priming agents used. The efficiency of these approaches is dependent upon certain factors like aeration and water potential of priming solution, light, temperature, priming duration, post-hydration drying, seed and storage condition, and plant species (Parera & Cantliffe, 1994; Wojtyla et al., 2016). Thus, it is essential to evaluate the efficacy of various priming options in different crops and agro-climatic conditions, and optimize our chosen priming technique.
3.1 Hydropriming
Slow and non-uniform germination of seeds induced the requirement of water-based seed priming. Hydropriming is a very simple, cost-effective, and eco-friendly technique which basically involves soaking seeds in water for a pre-determined time followed by re-drying to their initial moisture content (Farooq et al., 2006; Lutts et al., 2016). Submergence can also be performed in distilled water with or without aeration. Earlier, this practice was known as hardening, which was done by alternate soaking of seeds in water and drying before sowing. The process of seed germination occurs in three phases, viz., rapid water uptake or imbibition (phase I), lag or plateau phase (phase II), and protrusion of seminal root and resumption of growth (phase III) (Bewley, 1997). Hydropriming reduces the lag period,
and ensures rapid and uniform germination for good stand establishment (Ahammad et al., 2014). Controlled seed hydration as a pre-sowing strategy triggers pre-germination metabolic activities in the form of cellular physiological, biochemical, and molecular changes (Figure 2) (Ibrahim, 2016; Wojtyla et al., 2016). Improved germination of hydroprimed seeds is a result of activation of enzymes (amylase, protease, phosphatase, lipase, etc.), ATP production, RNA and protein synthesis, DNA replication, detoxification of ROS and lowering of lipid peroxidation by antioxidant enzymes [superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), and glutathione reductase (GPx)], accumulation of germination enhancing metabolites (proline, soluble sugars, etc.), higher utilization of seed reserves (proteins, carbohydrates, lipids, and phosphorus compounds), and other metabolic repairing mechanisms (McDonald, 2000; Ghassemi-Golezani & Hosseinzadeh-Mahootchi, 2013; Vaz Mondo et al., 2016).
Information on duration (maximum length of time) (Table 3) of hydration treatment can bring success at the farmer's level. Mahmoodi et al. (2011) evaluated four hydropriming durations (6, 12, 18 and 24 h) to improve seedling vigour and field establishment of maize, and found 18 h to be the most effective priming period. In case of pinto bean, Ghassemi-Golezani et al. (2010) reported 7 and 14 h priming is sufficient to augment seed and seedling vigour, stand establishment, and grain yield instead of soaking the seeds for 21 h. For optimizing duration of hydropriming in mung bean, Shukla et al. (2018) chose five intervals of time viz., 2, 4, 6, 8, 24 h, and concluded 6 h of priming to be optimum as the germination responses were almost similar if the duration was increased after this priming treatment.
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The major limitations associated with this technique include uncontrolled water uptake, which cannot be regulated because it is a property of seeds; and nonuniform hydration of seeds may result in unsynchronized germination (Taylor et al., 1998; McDonald, 2000; Di Girolamo & Barbanti, 2012). To overcome these challenges, drum priming is often used, where major focus is given on duration, temperature, and volume of water.
3.2 Osmopriming
Osmopriming is alternatively known as osmotic priming, osmotic conditioning or osmoconditioning. In this technique, seeds are soaked in osmotic solutions of organic compounds like PEG, mannitol, glycerol, sorbitol, etc. having low water potential so as to restrict the water uptake by seeds and allow the pre-germinative metabolic events to continue, but prevent the seminal root protrusion (Ashraf & Foolad, 2005). PEG with a molecular weight of 6000-8000 daltons having some osmotic potential (¥s) is dissolved in water for seed treatment. Out of the different concentrations (5, 10, 15, and 20 %) of PEG solutions, Faijunnahar et al. (2017) reported 10 % is sufficient to improve the germination, seedling growth, and water relation behaviour of wheat genotypes. Sadeghi et al. (2011) tested the efficacy of PEG-6000 with different levels of osmotic potentials (0.4, -0.8, -1.2, -1.6, and -2 MPa) and priming durations (6, 12, 24, and 48) on germination behaviour (percentage, mean time, index) and vigour of soybean seeds. Better results were observed in the seeds primed with -1.2 MPa for 12 h.
This technique is further classified as halopriming when the seeds are soaked in low water potential solutions composed of inorganic salts. Osmopriming/halopriming are also used for developing stress tolerances in plants (Table 2 and 3). Eivazi (2012) found wheat seeds primed with 2.5 % KCl for 16 h developed drought tolerance in plants besides increasing the grain yield. Rice seeds primed with NaCl @ 50 and 75 mM performed higher seedling vigor, osmotic stress tolerance potential, and overall crop growth than hydropriming (Jisha & Puthur, 2014). However, both of the priming treatments were able to modulate antioxidant enzyme activities, reduce lipid peroxidation of biomembranes, and increase the protein, carbohydrate, photosynthetic pigment, photochemistry, and mitochondrial activities of rice seedlings under salt stress conditions. A similar study of Goswami et al. (2013) revealed that rice seedlings conferred drought resistance by seed priming with 5 % of PEG-6000 and NaCl, which strengthened GPx activity and reduced peroxidative damage of the crop. Interestingly, priming effects of NaCl and PEG was not visible in chickpea under water deficit stress conditions (Kaur et al., 2002); priming with mannitol (4 %) and water gave better
results in growth by modulating enzymes (amylase, invertase, sucrose synthase, and sucrose phosphate synthase) of sucrose metabolism (Kaur et al., 2002, 2005). Seed pretreatment with NaCl (50 mM) moderated the adverse effect of salt stress by modifying the antioxidant enzymes like SOD, CAT, and catechol peroxidase (CPX), enhancing accumulation of osmolytes (proline), lowering malondialdehyde (MDA) and H2O2 contents of plants, and improving growth and photosynthetic pigments (total chlorophyll, chlorophyll-a, chlorophyll-b, and carotenoids) (Saha et al., 2010). Application of PEG may cause disruption in aeration of solution due to its high viscosity (Paparella et al., 2015).
3.3	Solid Matrix Priming
In solid matrix priming (SMP) or matric conditioning, solid or semi-solid medium is used instead of liquid medium (Copeland & McDonald, 1995). This technique is accomplished by mixing seeds with a solid or semisolid medium and specified amounts of water. By the virtue of the physical and chemical characteristics of the matrix, the water uptake by the seeds is restricted. In SMP, a small amount of liquid per unit of seed and solid particles is used. During SMP, water is slowly provided to the seeds and thus, slow or controlled imbibition occurs, allowing cell repair mechanisms to function (Jisha et al., 2013). Predominant solid matrices are exfoliated vermiculite, expanded calcined clay, bituminous coal, sodium polypropionate gel or synthetic calcium silicate (Kubik et al., 1988). Some locally available materials that are generally utilized as solid matrices are sawdust, charcoal and volcanic cinder and they offer the scope for reducing priming costs (Lorenzo, 1991). In the study of Lorenzo (1991) on SMP using sawdust, ground charcoal and volcanic cinder, soybean seeds responded favorably to shorter incubation periods, i.e., 1, 2, and 5 days. The longer incubation periods and higher water levels were harmful to the seeds because they encouraged fungal growth. SMP was also found to be effective in improving soybean germination by Mercado & Fernandez (2002).
3.4	Biopriming
Biopriming or biological seed treatment is the application of beneficial microbes in seed-plant-soil system to enhance plant productivity and simultaneously maintain the ecological balance. The process is accomplished by controlled seed hydration followed by coating of seeds with biological agents (Sarkar et al., 2017). The priming agents help in plant growth promotion by supplying nutrients to crops, enhancing resistance of plants to biotic and abiotic stresses, improving soil diversity (Singh, 2016), ameliorating soil structure, bioremeding the polluted soils (Mahmood et al., 2016). The technology basically
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aims at reduction of chemical inputs in our production system.
Farmers can treat the seeds with microbial formulations at the rate of 10 g kg-1 seed after soaking the seeds for 12 h and incubate at room temperature for 48 h to obtain microbial coating of seeds (Reddy, 2013). Carboxymethyl cellulose (CMC), gum arabic, rice water, etc. are used for adhesion of inoculums. The seeds are air-dried after incubation, and then used for sowing. Liquid formulations can also be used by the farmers as they mix well over the seed surface without any sticking agent. Root dipping of the seedlings for few hours before transplanting is also a common practice now-a-days. Biopriming agents are potential in promoting germination, controlling
Table 1: Some field experiments carried on biopriming
pathogens, and favouring growth and development in plants (Table 1). Microbial consortium of compatible microbes can also be used for better effects. Selection of microbes is an important step in biopriming as the growth-promoting abilities of microbes are highly specific to certain plant species, cultivars, and genotypes (Rakshit et al., 2015). Further, it can also promote synergistic interaction between microbes (e.g., Trichoderma and arbuscular mycorrhiza) (Meena et al., 2017). Arbuscular mycorrhizal fungi (AMF) (e.g., Glomus sp.) are getting special attention in biopriming techniques because of their multi-functional nature stimulating the growth and development of plants (Dhawal et al., 2016). Biopriming is a suitable tool to enhance the nutrient use efficiency in soil-plant-environment system (Meena et al., 2016).
Crop
Biological agent
Method
Major effect
References
Boro rice
Trichoderma sp.
Seed inoculation @ 4 % of seed weight before 4 h of sowing
Higher grain yield
Rahman et al. (2015)
Maize
Trichoderma
harzianumRifai,
(1969)
Seed inoculation @ 10 g kg-1 seed
Reduction of Fusarium verticillioides (Sacc.) Nirenberg (1976) and fumonisin infection, increased seed germination, vigour index, field emergence, yield, 1000 seed mass
Chandra Nayaka et al. (2010)
Barley
Azospirillum sp.
Seed inoculation @ 7 g kg-1 seed
Increased plant height, spike length, number of spike per area, grains per spike, 1000 grain mass, grain yield
Shirinzadeh et al. (2013)
Soybean
Rhizobium sp.
Seed inoculation @ 7.5 x 106 cells seed-1
Increased	germination,
nodulation, seed yield, harvest index, nitrogen harvest index
Amule et al. (2017)
Pearl millet Pseudomonas	Seed inoculation
fluorescens (Flügge 1886) Migula, 1856
Enhanced germination, seedling vigour, plant height, leaf area, tillering capacity, 1000 seed weight, grain yield, induction of resistance against downy mildew
Niranjan Raj et al. (2004)
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3.5	Nutrient priming
Nutrient priming has been proposed as a novel technique that combines the dual benefits of seed priming with an improved nutrient supply (Al-Mudaris & Jutzi, 1999). In nutrient priming, seeds are primed in solutions containing the limiting nutrients instead of being soaked just in water (Arif et al., 2005). Of the mineral nutrients, potassium plays an important role in imparting stress tolerance to plants (Cakmak, 2005). Seed priming in Zn2+ solutions improves grain yield of chickpea and wheat (Arif et al., 2007). Micronutrients are required in traces however, their deficiencies are quite common in crop plants (Abd El-Wahab, 2008). There are mainly 3 methods of micronutrient application in crops: application to soil, through foliar sprays and seed treatment (Johnson et al., 2005). Each method may affect plant growth distinctly. The use of micronutrient enriched seeds (seed priming) has been reported to be an easier and cost-effective strategy in overcoming micronutrient deficiencies (Harris et al., 1999; Rakshit et al., 2013). Seed priming has been shown to enhance the speed of germination (Deering & Young, 2006), reduce the emergence time, enhance seedling vigour (Harris, 1996) and obtain better stand establishment (Diniz et al., 2009), and increase yield (Yilmaz et al., 1998) in wheat, rice, maize, sorghum, chickpea, and soybean. There is evidence that sowing seeds enriched with micronutrients is also agronomically beneficial (Welch, 1986).
3.6	Redox priming
The cell processes are largely determined by "redox state". While redox state can categorically imply to the ratio of interconvertible oxidized and reduced species in a redox pair, lately this term is also correlated to define the cellular redox environment (Krebs, 1967; Schaefer & Buettner, 2001). It is opined that if the reduced redox state of a cell is possible to maintain, the extent of stress-induced damage can be significantly mitigated (Mittler, 2002). Srivastava et al. (2009) found that thiourea treatment to the seeds of Indian mustard (Brassica juncea (L.) Czem.) was helpful in maintaining the integrity and functioning of mitochondria in seeds as well as seedlings under salinity stress conditions. Srivastava et al. (2010b) treated Brassica juncea seeds with thiourea and observed different signaling and effector mechanisms to be regulated in a synchronized manner.
Seed priming with hydrogen peroxide was also reported in wheat (Wahid et al., 2007). Manjunatha et al. (2008) reported notable enhancement of seed germination and seedling vigour due to exogenous application of nitric oxide (NO) donors through seed treatment in pearl millet. Recently, Barba-Espin et al. (2012) reported that
hydrogen peroxide could act as signaling molecule during the initiation of seed germination involving certain specific changes at proteomic, trancriptomic and hormonal levels. In the opinion of Draganic & Lekic (2012), priming with antioxidant substances like ascorbic acid, glutathione and tocopherol (vitamin E) was beneficial in increasing the vigour of sunflower seeds exposed to low temperatures. In sorghum, seed priming with cysteine reduced the injury caused by gamma radiations and the effects of cysteine were most prominent in primary root elongation (Reddy & Smith, 1978).
3.7 Hormonal priming
Plant growth regulators like auxins, cytokinins, and gibberellins can be utilised as a pre-sowing seed treatment to improve their germination and emergence in stress situations (Lee et al., 1998; Jisha et al., 2013). Particularly, abscisic acid (ABA) is extensively involved in plant responses to abiotic stresses such as drought, low temperature, and osmotic stress (Fujita et al., 2006). Besides inducing the expression of many salt-responsive genes (Chandler & Robertson, 1994), exogenous ABA application was found in some experiments to increase salt tolerance of the treated plants or plant tissues (Xiong & Zhu, 2002). At the molecular level, ABA is known to induce the expression of numerous plant genes (Rock, 2000). ABA priming showed increased rate of germination as compared to nonprimed seeds in Indian mustard (Srivastava et al. 2010a, b). The beneficial effects of gibberellic acid (GA3) on germination are well known (Angrish et al., 2001; Radi et al., 2001). GA3 (100 mg l-1) applied as presowing treatment resulted in the highest K+ and Ca2+ content in the shoots of faba beans (Vicia faba L.) and cotton (Gossypium barbadense L.) (Harb, 1992). Auxin has also been used for priming. In wheat seed germination, auxin treatments increased the hypocotyl length, fresh and dry mass of seedlings and hypocotyl dry mass (Akbari et al., 2007).
Improved replication in root tips has been found by hormonal and vitamin priming (Shakirova et al., 2003) which could be attributed to rapidly dividing root apical meristem, consequently leading to better growth. Moreover, hormone applications maintain the auxin and cytokinin ratios in the tissues, which inadvertently are responsible for enhancing cell division (Sakhabutdinova et al., 2003). Hormonal priming, specifically ethylene (ET) and chloroethylphosphonic acid (CEPA) has also been found to impart tolerance to cadmium toxicity (50 ^M cadmium chloride (CdCl2) to pigeon pea (Cajanus cajan (L.) Mill.) (Sneideris et al., 2015).
Some seed priming options adopted in various crops over time are presented in Table 2. Detailed description of seed priming agents and their respective
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concentrations along with the treatment durations are mentioned in Table 3. The major events of seed priming
responsible for improved plant performances are shown in Figure 2.
Table 2: Seed priming methods developed for various agro-ecologies and their effect on imparting stress tolerance in agronomic crops
Crop	Agro-ecology	Treatment	Effect	and References
			protective	
			mechanism	
Cereals				
Rice
Rainfed
Halopriming (NaCl, KH2PO4), osmopriming (PEG), hydropriming
Drought and salinity tolerance	by
increasing carbohydrate, protein,	and
photosynthetic pigment content, modulating antioxidant enzyme activities (SOD, POD,	GPx),
reducing lipid peroxidation of biomembranes, enhancing
photochemistry and mitochondrial activities of rice seedlings
Goswami et (2013); Jisha Puthur (2014)
al. &
Subtropics
Se and SA priming
Chilling resistance by increasing membrane stability, antioxidant activity, starch metabolism (a-amylase activity, total soluble sugar contents) of primed seedlings
Wang et al. (2016a,b)
Wheat
Arid and semi-arid
Halopriming (CaCl2), hydropriming, chemical priming	(H2O2),
hormonal priming (auxin), choline priming
Salt tolerance by increasing antioxidant activity (SOD, CAT), leaf water relations, nutritional status (K+, Ca2+, NO3-, PO43), improving K+:Na+	ratio,
reducing toxic elements (Na+, Cl), RMP leakage of ions, enhancing root
Afzal et al. (2006); Wahid et al. (2007); Akbari et al. (2007); Salama et al. (2011)
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growth
Hormonal (ascorbic acid)
priming Drought resistance due to accumulation of proline and phenolics leading to membrane stability, tissue	water
maintenance, reduced oxidative damages
Farooq et al. (2013)
Barley
Arid
Nutrient	priming
(KH2PO4, ZnSO4)
Drought nutrient tolerance increase
and stress due to in root
Ajouri et al. (2004)
biomass influencing nutrient uptake, water use efficiency
Maize
Sub-tropical semi- Halopriming (CaCl2) arid
Drought resistance Khan et al. (2015)
due to well-
developed root
system facilitating
higher water and
nutrient supplies
Triticale
Rainfed
Hydropriming, halopriming (KH2PO4)
Drought and salt Yagmur	and
tolerance is related Kaydan (2008)
with higher water
uptake ability of
seeds enhancing the
relative water
content of shoot,
increased root and
shoot growth
Pulses
Mung bean
Subtropics
Halopriming (NaCl)
Salt stress tolerance by	enhancing
growth, photosynthetic pigments (chlorophyll, carotenoids), activities	of
antioxidant enzymes (SOD, CAT,	CPX),
accumulation of osmolytes (proline), lowering MDA and H2O2 contents of
Saha et al. (2010)
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plants				
Chickpea	Semi-arid	Osmopriming	Drought tolerance	Kaur et al. (2002,
		(mannitol),	by rapid hydrolysis	2005)
		hydropriming	of transitory starch	
Soybean	Dryland	Nutrient priming	Soda saline-alkali Dai et al. (2017)
		(ZnSO4), halopriming	stress tolerance by
		(CaCl2), vitamin	better osmotic
		priming (betaine	adjustment,
		hydrochloride),	antioxidant defense
		hormonal priming (GA3)	system, membrane
			integrity, higher
			photosynthetic
			pigment contents,
			starch accumulation
Alfalfa	Arid and semi-arid Hydropriming,	Salinity tolerance Amooaghaie (2011)
	osmopriming (mannitol)	with higher activity
		of antioxidant
		enzymes (POD,
		CAT, SOD),
		accumulation of
		proline, stabilizing
		membranes by
		reducing MDA
		accumulation and
		electrolyte leakage
Sugar crops
Sugarcane
Tropics	and Halopriming (NaCl),
subtropics	osmopriming (PEG)
Salt and drought tolerance	by
osmotic adjustment, antioxidant defense system
Patade et al. (2011)
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Table 3: Seed priming agents and treatment durations applied for developing tolerances in some crops under drought and salinity stress
Crop species	Seed priming treatment	References
Rice	Halopriming (NaCl @ 50 and 75 mM) for 12 h; hydropriming with distilled water for 24 h; biopriming with Trichoderma harzianum @ 10 g kg-1 of seed for 24 h;	Jisha and Puthur (2014); Yuan-Yuan et al. (2010); Rawat et al. (2012); Zheng et
	spermidine (0.5 mM) priming for 24 h	al. (2016)
Wheat	Hydropriming (16 h); halopriming (2.5 % KCl) for 16 h; osmopriming (10 % PEG) for 12 h; hormonal priming (2 mM ascorbic acid solution) for 10 h; choline priming (5 mM choline chloride) for 24 h	Patra et al. (2016); Eivazi (2012); Faijunnahar et al. (2017); Farooq et al. (2013); Salama et al. (2011)
Barley	Hydropriming for overnight (12 to 16 h)	Rashid et al. (2006)
Maize	Osmopriming with aerated solution of CaCl2 (ys -1.25 MPa) for 24 h	Khan et al. (2015)
Mung bean	Hydropriming (6 h); chemical priming with p-amino butyric acid solution (1.0 mM) for 6 h	Shukla et al. (2018); Jisha and Puthur (2016)
Pea	Halopriming with KCl and KOH @ 250 and 500 ppm (1 h)	Naz et al. (2014)
Soybean	Hydropriming (12 h) and hormonal priming (gibberlic acid @ 50 ppm) for 14 h; biopriming with Trichoderma harzianum @ 10 g kg-1 of seed	Langeroodi & Noora (2017); Khomari et al. (2018)
Indian mustard	Hydropriming with distilled water (18 h)	Srivastava et al. (2010a)
Sunflower	Hydropriming with distilled water (18 h)	Kaya et al. (2006); Moghanibashi et al. (2013)
Sugarcane	Halopriming (NaCl @ 100 mM) for 8 days	Patade et al. (2009)
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Neha CHATTERJEE et al.
Figure 2: Schematic representation of the major processes induced by seed priming during pre- and post-germination stages
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4 CHALLENGES IN ADOPTION OF SEED PRIMING
Many of the experiments which showed better results were practiced in greenhouse or controlled conditions, especially in the rainfed regions of Bangladesh, Pakistan, Nepal, Africa, and India. Their validation in field conditions is still unexplored. However, this customised method is gaining popularity, and emerged as a smart intervention across diversified agro-ecological regions. Harris et al. (1999, 2001) suggested on-farm seed priming can be revived through farmer-participatory approaches. Farm walks, group discussions, and other tools of extension should be adapted by the researchers/scientists. If the duration of priming is exceeded, then it may lead to seed or seedling damages. Special care is needed while transporting liquid inoculants and applying to the fields (Mahmood et al., 2016). Higher concentrations of priming agents may hamper or delay seed germination. The longevity of low vigour seeds are improved, but
reduced in high vigour seeds (Varier et al., 2010). Reduced storability of primed seeds enhances the maintenance costs of farmers (Lutts et al., 2016). In hydropriming, the activation of the physiological processes are non-uniform because seeds are not equally hydrated (Girolamo & Barbanti, 2012). Heavy rainfall after sowing decays primed seeds in soils remaining saturated for a longer period of time (e.g., black soils) (Ramamurthy et al., 2005). Contamination of priming agents can heavily impair seed germination. The efficiency of the biological agents is often low or variable due to unfavourable environmental conditions (e.g., relative humidity, temperature, etc.), shorter shelf-life, low quality, and/or competition with local microbes (O'Callaghan, 2016). For better implementation of seed priming processes, crop species, location, duration of priming, priming agents, temperature, and storage conditions must be considered.
5 CONCLUSION
On-farm seed priming is an apt technology for the predominantly resource-poor farmers of the developing world. It is a simple, low-cost intervention which shows quick results in varied eco-systems ranging from arid and semi-arid tropics in India, Africa, the Middle East as well as in highly controlled temperate agriculture systems. Pre-sowing water hardening of seeds has been an age-old practice in several dryland agro-ecosystems. However, the recent advances in halopriming, chemical priming with KNO3, KH2PO4, ZnSO4, MnSO4, etc., solid matrix priming, ascorbate priming, and redox priming have given this technique an added edge over the traditional system of seed hardening. Coupled with the success of modern science in agriculture, our understanding of the priming-induced responses of crops will open new vistas regarding their stress tolerance abilities, and devise further integrated and sustainable approach applicable in diverse agro-ecosystems. Biopriming with potent strains of Trichoderma spp. and Pseudomonas spp. among others is a stratagem of not only alleviating moisture stress but also imparting much needed biotic stress tolerance. Seed
priming is known to activate certain signaling pathways during the early stages of plant phenology and result in quicker plant defence responses. Thereby, upon subsequent or future exposure to these biotic and abiotic stresses, a second signaling event would excite/stimulate the signaling proteins consequently amplifying the signal transduction, and therefore leading to more rapid and/or more intense activation of previously acquired defence responses (Conrath et al., 2006).
A better and refined transition from laboratory to field adaptability of the different seed priming methods is also needed, which essentially should be adjudged to extensive farmer participatory trials. While seed priming is indeed ascertained as a potential technology to mitigate the adverse effects of climate change and the ensuing alterations in water availability, extremes of temperatures, salinity stress, etc.; future work is needed on the usability of various priming options for varied agro-ecosystems and different crops.
6 ACKNOWLEDGEMENT
Sumita Pal is thankful to DST, New Delhi(SR/WOS-A/LS-1199/2015(G))for financial support.
Ill
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7 REFERENCES
Abd El-Wahab, A.M., & Mohamed, A. (2008). Effect of some trace elements on growth, yield and chemical constituents of Trachyspermum ammi L. plants under Sinai conditions. Research Journal of Agriculture and Biological Sciences, 4, 717-724.
Afzal, I., Basra, S. M. A., Hameed, A., & Farooq, M.
(2006).	Physiological enhancements for alleviation of salt stress in wheat. Pakistan Journal of Botany, 38(5), 1649-1659.
Ahammad, K. U., Rahman, M. M., & Ali, M. R. (2014). Effect of hydropriming method on maize (Zea mays) seedling emergence. Bangladesh Journal of Agricultural Research, 39(1), 143-150. doi:10.3329/bjar.v39i1.20164
Ajouri, A., Asgedom, H., & Becker, M. (2004). Seed priming enhances germination and seedling growth of barley under conditions of P and Zn deficiency. Journal of Plant Nutrition and Soil Science, 167,	630-636.
doi: 10.1002/jpln.200420425
Akbari, G., Sanavy, S. A. M. M., & Yousefzadeh, S.
(2007).	Effect of auxin and salt stress (NaCl) on seed germination of wheat cultivars (Triticum aestivum L.). Pakistan Journal of Biological Sciences,	10(15),	2557-2561. doi:10.3923/pjbs.2007.2557.2561
Al-Mudaris, M. A., & Jutzi, S. C. (1999). The influence of fertilizer based seed priming treatment on emergence and seedling growth of Sorghum bicolor and Pennisetum glaucum in pot trials under greenhouse conditions. Journal of Agronomy & Crop Science, 182, 135-141. doi:10.1046/j.1439-037x.1999.00293.x
Amooaghaie, R. (2011). The effect of hydro and osmopriming on alfalfa seed germination and antioxidant defenses under salt stress. African Journal of Biotechnology, 10(33), 6269-6275.
Amule, F. C., Rawat, A. K., & Rao, D. L. N. (2017). Mono and co-inoculation response of Rhizobium and PGPR on soybean in central India.
International Journal of Plant & Soil Science, 20(6), 1-13. doi:10.9734/IJPSS/2017/36997
Angrish, R., Kumar, B., & Datta, K. S. (2001). Effect of gibberellic acid and kinetin on nitrogen content and nitrate reductase activity in wheat under saline condition. Indian Journal of Plant Physiology, 6, 172-177.
Anjum, S. A., Xie, X. -Y., Wang, L. -C., Saleem, M. F., Man, C., & Lei, W. (2011). Morphological, physiological and biochemical responses of plants
to drought stress. African Journal of Agricultural Research, 6(9), 2026-2032.
Araus, J. L., Slafer, G. A., Reynolds, M. P., & Royo, C. (2002). Plant breeding and drought in C3 cereals: what should we breed for? Annals of Botany, 89(7), 925-940. doi: 10.1093/aob/mcf049
Arif, M., Ali, S., Shah, A., Javed, N., & Rashid, A. (2005). Seed priming maize for improving emergence and seedling growth. Sarhad Journal of Agriculture, 21, 239-243.
Arif, M., Waqas, M., Nawab, K., & Shahid, M. (2007). Effect of seed priming in Zn solutions on chickpea and wheat. African Crop Science Conference Proceedings, 8, 237-240.
Ashraf, M., & Foolad, M. R. (2005). Pre-sowing seed treatment—a shotgun approach to improve germination, plant growth, and crop yield under saline and non-saline conditions. Advances in Agronomy, 88, 223-271. doi:10.1016/S0065-2113(05)88006-X
Athar, H. R., & Ashraf, M. (2009). Strategies for crop improvement against salinity and drought stress: an overview. In M. Ashraf, M. Ozturk, & H. R. Athar (Eds.), Salinity and water stress (pp. 1-16). Springer, Netherlands. doi:10.1007/978-1-4020-9065-3_1
Avelar, S. A. G., de Sousa, F. V., Fiss, G., Baudet, L., & Peske, S. T. (2012). The use of film coating on the performance of treated corn seed. Revista Brasileira de Sementes, 34(2), 186-192. doi: 10.1590/S0101 -31222012000200001
Baligar, V. C., Fageria, N. K., & He, Z. L. (2001). Nutrient use efficiency in plants. Communications in Soil Science and Plant Analysis, 32(7-8), 921950. doi:10.1081/CSS-100104098
Barba-Espín, G., Hernández, J.A., Diaz-Vivancos, P. (2012). Role of H2O2 in pea seed germination.
Plant Signaling and Behavior, 7, 193-195. doi:10.4161/psb.18881
Bakhtavar, M. A., Afzal, I., Basra, S. M. A., Ahmad, A-u-H, & Noor, M. A. (2015). Physiological strategies to improve the performance of spring maize (Zea mays L.) planted under early and optimum sowing conditions. PLoS ONE, 10(4), e0124441. doi:10.1371/journal.pone.0124441
Bewley, J. D. (1997). Seed germination and dormancy. The Plant Cell, 9, 1055-1066. doi:10.1105/tpc.9.7.1055
728 Acta agriculturae Slovenica, 111 - 3, december 2018
On-farm seed priming interventions in agronomic crops
Binang, W. B., Shiyam, J. O., & Ntia, J. D. (2012). Effect of seed priming method on agronomic performance and cost effectiveness of rainfed, dry-seeded NERICA rice. Research Journal of Seed Science, 5(4),	136-143.
doi:10.3923/rjss.2012.136.143
Cakmak, I. (2005). The role of potassium in alleviating detrimental effects of abiotic stresses in plants.
Journal of Plant Nutrition and Soil Science, 168, 521-530. doi:10.1002/jpln.200420485
O'Callaghan, M. (2016). Microbial inoculation of seed for improved crop performance: issues and opportunities. Applied Microbiology and Biotechnology,	100,	5729-5746.
doi:10.1007/s00253-016-7590-9
Chandler, P. M., & Robertson, M. (1994). Gene expression regulation by abscisic acid and its relation to stress tolerance. Annual Review of Plant Physiology and Plant Molecular Biology, 45, 113141. doi: 10.1146/annurev.pp.45.060194.000553
Chandra Nayaka, S., Niranjana, S. R., Uday Shankar, A. C., Niranjan Raj, S., Reddy, M. S., Prakash, H. S., & Mortensen, C. N. (2010). Seed biopriming with novel strain of Trichoderma harzianum for the control of toxigenic Fusarium verticillioides and fumonisins in maize. Archives of Phytopathology and Plant Protection, 43(3), 264-282. doi:10.1080/03235400701803879
Copeland, L. O., & McDonald, M. B. (1995). Principles of seed science and technology. 3rd Edn. USA, Chapmann and Hall.
Dai, L. Y., Zhu, H. D., Yin, K. D., Du, J. D., & Zhang, Y. X. (2017). Seed priming mitigates the effects of saline-alkali stress in soybean seedlings. Chilean Journal of Agricultural Research, 77(2), 118-125.
Deering, R. H., & Young, T. P. (2006). Germination speeds of exotic annual and native perennial grasses in California and the potential benefits of seed priming for grassland restoration. Grasslands, 16, 14-15.
Dhawal, S., Sarkar, D. R., Yadav, R. S., Parihar, M., & Rakshit, A. (2016). Bio-priming with Arbuscular mycorrhizae for addressing soil fertility with special reference to phosphorus. International Journal of Bioresource Science, 3(2), 35-40. doi:10.5958/2454-9541.2016.00013.X
Di Girolamo, G., & Barbanti, L. (2012). Treatment conditions and biochemical processes influencing seed priming effectiveness. Italian Journal of Agronomy, 7, e25. doi:10.4081/ija.2012.e25
Diniz, K. A., Silva, P. A., Oliveira, J. A., & Evangelista, J. R. E. (2009). Sweet pepper seed responses to
inoculation with microorganisms and coating with micronutrients, amino acids and plant growth regulators. Scientia Agricola, 66, 293-297. doi:10.1590/S0103-90162009000300002
Draganic, I., & Lekic, S. (2012). Seed priming with antioxidants improves sunflower seed germination and seedling growth under unfavorable germination conditions. Turkish Journal of Agriculture and Forestry, 36, 421-428.
Eivazi, A. (2012). Induction of drought tolerance with seed priming in wheat cultivars (Triticum aestivum L.). Acta agriculturae Slovenica, 99(1), 21-29. doi:10.2478/v10014-012-0003-6
Faijunnahar, M., Baque, A., Habib, M. A., & Hossain, H. M. M. T. (2017). Polyethylene glycol (peg) induced changes in germination, seedling growth and water relation behavior of wheat (Triticum aestivum L.) Genotypes. Universal Journal of Plant Science, 5(4), 49-57.
Farooq, M., Basra, S. M. A., Afzal, I., & Khaliq, A. (2006). Optimization of hydropriming techniques for rice seed invigoration. Seed Science and Technology, 34,	507-512.
doi: 10.15258/sst.2006.34.2.25
Farooq, M., Irfan, M., Aziz, T., Ahmad, I., & Cheema, S. A. (2013). Seed priming with ascorbic acid improves drought resistance of wheat. Journal of Agronomy and Crop Science, 199, 12-22. doi:10.1111/j.1439-037X.2012.00521.x
Farooq, M., Wahid, A., Kobayashi, N., Fujita, D., & Basra, S. M. A. (2009). Plant drought stress: effects, mechanisms and management. Agronomy for Sustainable Development, 29(1), 185-212. doi: 10.1051/agro:2008021
Farooq, M., Hussain, M., Wahid, A., & Siddique, K. H. M. (2012). Drought stress in plants: an overview. In R. Aroca (Ed.), Plant responses to drought stress: from morphological to molecular features (pp. 1 -33). Springer-Verlag, Berlin, Heidelberg. doi:10.1007/978-3-642-32653-0_1
Fujita, M., Fujita, Y., Noutoshi, Y., Takahashi, F., Narusaka, Y., Yamaguchi-Shinozaki, K., & Shinozak, K. (2006) Crosstalk between abiotic and biotic stress responses: a current view from the points of convergence in the stress signaling networks. Current Opinion in Plant Biology, 9, 436-442. doi:10.1016/j.pbi.2006.05.014
Ghassemi-Golezani, K., Chadordooz-Jeddi, A., Nasrollahzadeh, S., & Moghaddam, M. (2010). Effects of hydro-priming duration on seedling vigour and grain yield of pinto bean (Phaseolus vulgaris L.) Cultivars. Notulae Botanicae Horti Agrobotanici Cluj-Napoca, 38(1), 109-113.
Acta agriculturae Slovenica, 111 - 3, december 2018 729
Neha CHATTERJEE et al.
Ghassemi-Golezani, K., & Hosseinzadeh-Mahootchi, A. (2013). Influence of hydro-priming on reserve utilization of differentially aged chickpea seeds.
Seed Technology, 35(1), 117-124.
Gimenez, E., Salinas, M., & Manzano-Agugliaro, F. (2018). Worldwide research on plant defense against biotic stresses as improvement for sustainable agriculture. Sustainability, 10, 391. doi:10.3390/su10020391
Goswami, A., Banerjee, R., & Raha, S. (2013). Drought resistance in rice seedlings conferred by seed priming. Protoplasma, 250,	1115-1129.
doi:10.1007/s00709-013-0487-x
Harb, E. Z. (1992). Effect of soaking seeds in some growth regulators and micronutrients on growth, some chemical constituents and yield of faba bean and cotton plants. Bulletin of Faculty of Agriculture University of Cairo, 43, 429-452.
Harris, D. (1996). The effects of manure, genotype, seed priming, depth and date of sowing on the emergence and early growth of Sorghum bicolor (L.) Moench in semi-arid Botswana. Soil & Tillage Research, 40, 73-88.
Harris, D., Joshi, A., Khan, P. A., Khan, P. A., Gothkar, P., & Sodhi, P. S. (1999). On-farm seed priming in semi-arid agriculture: development and evaluation in maize, rice and chickpea in India using participatory methods. Experimental Agriculture, 35, 15-29. doi:10.1017/S0014479799001027
Harris, D., Pathan, A. K., Gothkar, P., Joshi, A., Chivasa, W., & Nyamudeza, P. (2001). On-farm seed priming: using participatory methods to revive and refine a key technology. Agricultural Systems, 69, 151-164. doi:10.1016/S0308-521X(01)00023-3
Ibrahim, E. A. (2016). Seed priming to alleviate salinity stress in germinating seeds. Journal of Plant Physiology, 192,	38-46.
doi:10.1016/j.jplph.2015.12.011
Jisha, K. C., & Puthur, J. T. (2014). Seed halopriming outdo hydropriming in enhancing seedling vigour and osmotic stress tolerance potential of rice varieties. Journal of Crop Science and Biotechnology,	17(4),	209-219.
doi:10.1007/s12892-014-0077-2
Jisha, K. C., & Puthur, J. T. (2016). Seed priming with BABA (P-amino butyric acid): a cost-effective method of abiotic stress tolerance in Vigna radiata (L.) Wilczek. Protoplasma, 253, 277-289. doi:10.1007/s00709-015-0804-7
Jisha, K. C., Vijayakumari, K., & Puthur, J. T. (2013). Seed priming for abiotic stress tolerance: an
overview. Acta Physiologiae Plantarum, 35, 1381— 1396. doi:10.1007/s11738-012-1186-5
Johnson, S. E., Lauren, J. G., Welch, R. M., & Duxbury, J. M. (2005). A comparison of the effects of micronutrient seed priming and soil fertilization on the mineral nutrition of chickpea (Cicer arietinum), lentil (Lens culinaris), rice (Oryza sativa) and wheat (Triticum aestivum) in Nepal. Experimental Agriculture,	41,	427-448.
doi: 10.1017/S0014479705002851
Kaur, S., Gupta, A. K., & Kaur, N. (2002). Effect of osmo- and hydropriming of chickpea seeds on seedling growth and carbohydrate metabolism under water deficit stress. Plant Growth Regulation,	37,	17-22.
doi: 10.1023/A:1020310008830
Kaur, S., Gupta, A. K., & Kaur, N. (2005). Seed priming increases crop yield possibly by modulating enzymes of sucrose metabolism in chickpea. Journal of Agronomy & Crop Science, 191,	81-87.	doi: 10.1111/j.1439-
037X.2004.00140.x
Kaya, M. D., Okcu, G., Atak, M., Cikili, Y., & Kolsaric, O. (2006). Seed treatments to overcome salt and drought stress during germination in sunfower
(Helianthus annuus L.). European Journal of Agronomy,	24,	291-295.
doi:10.1016/j.eja.2005.08.001
Khan, M. B., Hussain, M., Raza, A., Farooq, S., & Jabran, K. (2015). Seed priming with CaCl2 and ridge planting for improved drought resistance in maize. Turkish Journal of Agriculture and Forestry, 39(2), 193-203. doi:10.3906/tar-1405-39
Khomari, S., Golshan-Doust, S., Seyed-Sharifi, R., & Davari, M. (2018). Improvement of soybean seedling growth under salinity stress by biopriming of high-vigour seeds with salt-tolerant isolate of
Trichoderma harzianum. New Zealand Journal of Crop and Horticultural Science, 46(2), 117-132. doi:10.1080/01140671.2017.1352520
Khoshgoftarmanesh, A. H., Schulin, R., Chaney, R. L., Daneshbakhsh, B., & Afyuni, M. (2010). Micronutrient-efficient genotypes for crop yield and nutritional quality in sustainable agriculture. A review. Agronomy	for	Sustainable
Development, 30(1),	83-107.
doi: 10.1051/agro/2009017
Krebs, H. A. (1967).The redox state of nicotinamide adenine dinucleotide in the cytoplasm and mitochondria of rat liver. Advances in Enzyme Regulation, 5, 409-434. doi:10.1016/0065-2571(67)90029-5
7^0
730 Acta agriculturae Slovenica, 111 - 3, december 2018
On-farm seed priming interventions in agronomic crops
Kubik, K. K., Eastin, J. A., & Eskridge, K. M. (1988). Solid matrix priming of tomato and pepper. In
Proceedings of the international conference on stand establishment for horticultural crops (pp. 8696). Lancaster, Pennsylvania, USA.
Lamaoui, M., Jemo, M., Datla, R., & Bekkaoui, F. (2018). Heat and drought stresses in crops and approaches for their mitigation. Frontiers in Chemistry, 6, 26. doi:10.3389/fchem.2018.00026
Langeroodi, A. R. S., & Noora, R. (2017). Seed priming improves the germination and field performance of soybean under drought stress. The Journal of Animal and Plant Sciences, 27(5), 1611-1621.
Lee, S. S., Kim, J. H., Hong, S. B., Yuu, S. H., & Park, E. H. (1998). Priming effect of rice seeds on seedling establishment under adverse soil conditions. Korean Journal of Crop Science, 43, 194-198.
Lorenzo, M. C. B. (1991). Seed invigoration of soybean and corn through solid matrix priming. BS, Philippines.
Lutts, S., Benincasa, P., Wojtyla, L., Kubala, S., Pace, R., Lechowska, K., Quinet, M., & Garnczarska, M. (2016). Seed priming: new comprehensive approaches for an old empirical technique. In S. Araujo & A. Balestrazzi (Eds.), New challenges in seed biology - basic and translational research driving seed technology (pp. 1-46). InTechOpen. doi:10.5772/64420
Mahmood, A., Turgay, O. C., Farooq, M., & Hayat, R. (2016). Seed biopriming with plant growth promoting rhizobacteria: a review. FEMS Microbiology	Ecology, 92(8).
doi:10.1093/femsec/fiw 112
Mahmoodi, T. M., Ghassemi-Golezani, K., Habibi, D., Paknezhad, F., & Ardekani, M. R. (2011). Effect of hydro-priming duration on seedling vigour and field establishment of maize (Zea mays L.). Research on Crops, 12(2), 341-345.
Mandal, A. B., Mondal, R., & Dutta, P. M. S. (2015). Seed enhancement through priming, coating and pelleting for uniform crop stand and increased productivity. Journal of the Andaman Science Association, 20(1), 26-33.
Manjunatha, G., Raj, S. N., Shetty, N. P., & Shetty, H. S. (2008). Nitric oxide donor seed priming enhances defense responses and induces resistance against pearl millet downy mildew disease.
Pesticide Biochemistry and Physiology, 91, 1-11. doi:10.1016/j.pestbp.2007.11.012
Mariani, L., & Ferrante, A. (2017). Agronomic management for enhancing plant tolerance to
abiotic stresses—drought, salinity, hypoxia, and lodging. Horticulturae, 3,	52.
doi:10.3390/horticulturae3040052
Matsushima, K. -I., & Sakagami, J. -I. (2013). Effects of seed hydropriming on germination and seedling vigor during emergence of rice under different soil moisture conditions. American Journal of Plant Sciences, 4,	1584-1593.
doi:10.4236/ajps.2013.48191
McDonald, M. B. (2000). Seed priming. In M. Black & J. D. Bewley (Eds.), Seed technology and its biological basis (pp. 287-325). Sheffield Academic Press, Sheffield.
Meena, S. K., Rakshit, A., & Meena, V. S. (2016). Effect of seed bio-priming and N doses under varied soil type on nitrogen use efficiency (NUE) of wheat (Triticum aestivum L.) under greenhouse
conditions. Biocatalysis and Agricultural Biotechnology, 6,	68-75.
doi:10.1016/j.bcab.2016.02.010
Meena, S. K., Rakshit, A., Singh, H. B., & Meena, V. S. (2017). Effect of nitrogen levels and seed bio-priming on root infection, growth and yield attributes of wheat in varied soil type. Biocatalysis and Agricultural Biotechnology, 12, 172-178. doi:10.1016/j.bcab.2017.10.006
Mei, J., Wang, W., Peng, S., & Nie, L. (2017). Seed pelleting with calcium peroxide improves crop establishment of direct-seeded rice under waterlogging conditions. Scientific Reports, 7, 4878. doi:10.1038/s41598-017-04966-1
Mercado, M. F. O., & Fernandez, P. G. (2002). Solid matrix priming of soybean seeds. Philippines Journal of Crop Science, 27, 27-35.
Mittler, R. (2002). Oxidative stress, antioxidants and stress tolerance. Trends in Plant Science, 9, 405410. doi:10.1016/S1360-1385(02)02312-9
Moghanibashi, M., Karimmojeni, H., & Nikneshan, P. (2013). Seed treatment to overcome drought and salt stress during germination of sunflower
(Helianthus annuus L.). Journal of Agrobiology, 30, 89-96.
Munns, R., & Tester, M. (2008). Mechanisms of salinity tolerance. Annual Review of Plant Biology, 59, 651-681.
doi:10.1146/annurev.arplant.59.032607.092911
Nasri, N., Saïdi, I., Kaddour, R., & Lachaâl, M. (2015). Effect of salinity on germination, seedling growth and acid phosphatase activity in lettuce. American Journal of Plant Sciences, 6, 57-63. doi:10.4236/ajps.2015.61007
Acta agriculturae Slovenica, 111 - 3, december 2018 731
Neha CHATTERJEE et al.
Nawaz, J., Hussain, M., Jabbar, A., Nadeem, G. A., Sajid, M., Subtain, M. U., & Shabbir, I. (2013). Seed priming a technique. International Journal of Agriculture and Crop Sciences, 6(20), 1373-1381.
Naz, F., Gul, H., Hamayun, M., Sayyed, A., Khan, H., & Sherwani, S. (2014). Effect of NaCl stress on Pisum sativum germination and seedling growth with the influence of seed priming with potassium (KCL and KOH). American-Eurasian Journal of Agricultural and Environmental Sciences, 14(11), 1304-1311.
Negrao, S., Schmockel, S. M., & Tester, M. (2017). Evaluating physiological responses of plants to salinity stress. Annals of Botany, 119(1), 1-11. doi:10.1093/aob/mcw191
Nejad, H. A., & Farahmand, S. (2012). Evaluating the potential of seed priming techniques in improving germination and early seedling growth of Aeluropus macrostachys under salinity stress
condition. Annals of Biological Research, 3(11), 5099-5105.
Nikju, M. B., Mobasser, H. R., & Ganjali, H. R. (2015). Influence of variety on biological yield, harvest index, percent of protein in Zea mays. Biological Forum - An International Journal, 7(1), 662-667.
Pandey, P., Irulappan, V., Bagavathiannan, M. V., & Senthil-Kumar, M. (2017). Impact of combined abiotic and biotic stresses on plant growth and avenues for crop improvement by exploiting physio-morphological traits. Frontiers in Plant Science, 8, 537. doi:10.3389/fpls.2017.00537
Paparella, S., Araujo, S. S., Rossi, G., Wijayasinghe, M., Carbonera, D., & Balestrazzi, A. (2015). Seed priming: state of the art and new perspectives. Plant Cell Reports, 34, 1281-1293. doi:10.1007/s00299-015-1784-y
Parera, C. A., & Cantliffe, D. J. (1994). Presowing seed priming. Horticultural Reviews, 16, 109-141. doi:10.1002/9780470650561.ch4
Patade, V. Y., Bhargava, S., & Suprasanna, P. (2009). Halopriming imparts tolerance to salt and PEG induced drought stress in sugarcane. Agriculture, Ecosystems and Environment, 134, 24-28. doi:10.1016/j.agee.2009.07.003
Patade, V. Y., Bhargava, S., & Suprasanna, P. (2011). Salt and drought tolerance of sugarcane under iso-osmotic salt and water stress: growth, osmolytes accumulation, and antioxidant defense. Journal of Plant	Interactions, 6(4),	275-282.
doi:10.1080/17429145.2011.557513
Patra, S. S., Mehera, B., Rout, S., Tomar, S. S., Singh, M., & Kumar, R. (2016). Effect of hydropriming
and different sowing dates on growth and yield attributes of Wheat (Triticum aestivum L.). Journal of Applied and Natural Science, 8(2), 971-980.
Pedrini, S., Merritt, D. J., Stevens, J., & Dixon, K. (2017). Seed coating: science or marketing spin?
Trends in Plant Science, 22(2), 106-116. doi:10.1016/j.tplants.2016.11.002
Radi, A. F., Shaddad, M. A. K., El-Enany, A. E., & Omran, F. M. (2001). Interactive effects of plant hormones (GA3 or ABA) and salinity on growth and some metabolites of wheat seedlings. In W. J. Horst, M. K. Schenk, A. Urkert , N. Claassen, H. Flessa, W. B. Frommer, H. Goldbach, H. W. Olfs, & V. Romheld (Eds.), Plant nutrition, food security and sustainability of agro-ecosystems through basic and applied research. 14th international plant nutrition colloquium (pp. 436-437). Hannover, Germany. doi: 10.1007/0-306-47624-X_211
Rahman, M. U., Gul, S., & Ahmad, I. (2004). Effects of water stress on growth and photosynthetic pigments of corn (Zea mays L.) cultivars. International Journal of Agriculture & Biology, 6(4), 652-655.
Rahman, M., Ali, J., & Masood, M. (2015). Seed priming and Trichoderma application: a method for improving seedling establishment and yield of dry direct seeded boro (winter) rice in Bangladesh.
Universal Journal of Agricultural Research, 3(2), 59-67.
Ramamurthy, V., Gajbhiye, K. S., Venugopalan, M. V., & Parhad, V. N. (2005). On-farm evaluation of seed priming technology in sorghum (Sorghum bicolor L.). Agricultura Tropica et Subtropica, 38(1), 34-41.
Rakshit, A., Pal, S., Rai, S., Rai, A., Bhowmick, M. K., & Singh, H. B. (2013). Micronutrient seed priming: a potential tool in integrated nutrient management.
Satsa Mukkhapatra- Annual Technical Issue, 17, 77-89.
Rakshit, A., Sunita, K., Pal, S., Singh, A. & Singh, H. B. (2015). Bio-priming mediated nutrient use efficiency of crop species. In A. Rakshit, H. B. Singh, & A. Sen (Eds.), Nutrient use efficiency: from basics to advances (pp. 181-191). Springer, India. doi:10.1007/978-81-322-2169-2_12
Rashid, A., Harris, D., Hollington, P. A., & Khattak, R. A. (2002). On-farm seed priming: a key technology for improving the livelihoods of resource-poor farmers on saline lands. In R. Ahmad & K. A. Malik (Eds.), Prospects for saline agriculture (pp. 423-431). Springer, Dordrecht. doi:10.1007/978-94-017-0067-2 44
200 Acta agriculturae Slovenica, 111 - 3, december 2018
On-farm seed priming interventions in agronomic crops
Rashid, A., Hollington, P. A., Harris, D., & Khan, P. (2006). On-farm seed priming for barley on normal, saline and saline-sodic soils in North West Frontier Province, Pakistan. European Journal of Agronomy,	24,	276-281.
doi:10.1016/j.eja.2005.10.006
Rawat, L., Singh, Y., Shukla, N., & Kumar, J. (2012). Seed biopriming with salinity tolerant isolates of Trichoderma harzianum alleviates salt stress in rice: growth, physiological and biochemical characteristics. Journal of Plant Pathology, 94(2), 353-365.
Reddy, P. P. (2013). Bio-priming of seeds. In P. P. Reddy (Ed.), Recent advances in crop protection (pp. 83-90). Springer, India. doi:10.1007/978-81-322-0723-8
Reddy, C. S., & Smith, J. D. (1978). Effects of delayed post treatment of gamma-irradiated seed with cysteine on the growth of Sorghum bicolor seedlings. Environmental and Experimental Botany, 18, 241-243. doi:10.1016/0098-8472(78)90050-3
Rejeb, I. B., Pastor, V., & Mauch-Mani, B. (2014). Plant responses to simultaneous biotic and abiotic stress: molecular mechanisms. Plants, 3, 458-475. doi:10.33 90/plants3040458
Rock, C. D. (2000). Pathways to abscisic acid regulated gene expression. New Phytologist, 148, 357-384. doi:10.1046/j. 1469-8137.2000.00769.x
Sadeghi, H., Khazaei, F., Yari, L., & Sheidaei, S. (2011). Effect of seed osmopriming on seed germination behavior and vigor of soybean
(Glycine max L.). ARPN Journal of Agricultural and Biological Science, 6(1), 39-43.
Saha, P., Chatterjee, P., & Biswas, A. K. (2010). NaCl pretreatment alleviates salt stress by enhancement of antioxidant defense system and osmolyte accumulation in mungbean (Vigna radiata L. Wilczek). Indian Journal of Experimental Biology 48, 593-600.
Sakhabutdinova, A. R., Fatkhutdinova, D. R., Beazrukova, M. V., & Shakirova, F. M. (2003). Salicylic acid prevents the damaging action of stress factor of wheat plants. Bulgarian Journal of Plant Physiology, Special Issue, 314-319.
Salama, K. H. A., Mansour, M. M. F., & Hassan, N. S. (2011). Choline priming improves salt tolerance in wheat (Triticum aestivum L.). Australian Journal of Basic and Applied Sciences, 5(11), 126-132.
Sarkar, D., Pal, S., Singh, H. B., Yadav, R. S., & Rakshit, A. (2017). Harnessing bio-priming for integrated resource management under changing
climate. In H.B. Singh, B.K. Sarma, & C. Keswani (Eds.), Advances in PGPR Research (pp. 349-363). CAB International, UK.
Schaefer, F. Q., & Buettner, G. R. (2001). Redox environment of the cell as viewed through the redox state of the glutathione disulfide/glutathione couple. Free Radical Biology and Medicine, 30(11), 1191-1212. doi:10.1016/S0891-5849(01)00480-4
Shakirova, F. M., Sakhabutdinova, A. R., Bezrokuva, M. V., Fatkhutdinova, R. A., & Fatkhutdinova, D. R. (2003). Changes in the hormonal status of wheat seedlings induced by salicylic acid and salinity. Plant Science, 164, 317-322. doi:10.1016/S0168-9452(02)00415-6
Sharma, K. K., Singh, U. S., Sharma, P., Kumar, A., & Sharma, L. (2015). Seed treatments for sustainable agriculture-a review. Journal of Applied and Natural	Science, 7(1),	521-539.
doi:10.31018/jans.v7i1.641
Shirinzadeh, A., Soleimanzadeh, H., & Shirinzadeh, Z. (2013). Effect of seed priming with plant growth promoting rhizobacteria (PGPR) on agronomic traits and yield of barley cultivars. World Applied Sciences Journal, 21(5), 727-731.
Shukla, N., Kuntal, H., Shanker, A., & Sharma, S. (2018). Hydro-priming methods for initiation of metabolic process and synchronization of germination in mung bean (Vigna radiata L.) Seeds. Journal of Crop Science and Biotechnology, 21(2),	137-146.
doi:10.1007/s12892-018-0017-0
Singh, H. B. (2016). Seed biopriming: a comprehensive approach towards agricultural sustainability. Indian Phytopathology, 69(3), 203-209.
Singh, H. P., Sharma, K. D., Reddy, G. S., & Sharma, K. L. (2004). Dryland agriculture in India. In S. C. Rao & J. Ryan (Eds.), Challenges and strategies of dryland agriculture (pp. 67-92). Madison, WI (USA), Crop Science Society of America, American Society of Agronomy.
Sneideris, L. C., Gavassi, M. A., Campos, M. L., D'Amico-Damiao, V., & Carvalho, R. F. (2015). Effects of hormonal priming on seed germination of pigeon pea under cadmium stress. Anais da Academia Brasileira Ciencias, 87(3), 1847-1852. doi:10.1590/0001-3765201520140332
Soleimanzadeh, H. (2013). Effect of seed priming on germination and yield of corn. International Journal of Agriculture and Crop Sciences, 5(4), 366-369.
Acta agriculturae Slovenica, 111 - 3, december 2018 733
Neha CHATTERJEE et al.
Srivastava, A. K., Lokhande, V. H., Patade, V. Y., Suprasanna, P., Sjahril, R., & D'Souza, S. F. (2010a). Comparative evaluation of hydro-, chemo-, and hormonal priming methods for imparting salt and PEG stress tolerance in Indian mustard (Brassica juncea L.). Acta Physiologiae Plantarum, 32, 1135-1144. doi: 10.1007/s11738-010-0505-y
Srivastava, A.K., Ramaswamy, N. K., Mukopadhyaya, R., Chiramal Jincy, M. G., & D'Souza, S. F. (2009). Thiourea modulates the expression and activity profile of mtATPase under salinity stress in seeds of Brassica juncea L. Annals of Botany, 103, 403-410. doi: 10.1093/aob/mcn229
Srivastava, A.K., Suprasanna, P., Srivastava, S., & D'Souza, S.F. (2010b). Thiourea mediated regulation in the expression profile of aquaporins and its impact on water homeostasis under salinity stress in Brassica juncea roots. Plant Science, 178, 517-522. doi:10.1016/j.plantsci.2010.02.015
Sun, C. -X., Cao, H. -X., Shao, H. -B., Lei, X. -T., & Xiao, Y. (2011). Growth and physiological responses to water and nutrient stress in oil palm. African Journal of Biotechnology, 10(51), 10465-10471. doi: 10.5897/AJB 11.463
Suzuki, N., Rivero, R. M., Shulaev, V., Blumwald, E., & Mittler, R. (2014). Abiotic and biotic stress combinations. New Phytologist, 203, 32-43. doi: 10.1111/nph. 12797
Taylor, A. G., Allen, P. S., Bennett, M. A., Bradford, K. J., Burris, J. S., & Misra, M. K. (1998). Seed enhancements. Seed Science Research, 8, 245-256. doi:10.1017/S0960258500004141
Varier, A., Vari, A.K., & Dadlani, M. (2010). The subcellular basis of seed priming. Current Science, 99(4), 450-456.
Vaz Mondo, V. H., Nascente, A. S., Neves, P. D. C. F., Taillebois, J. E., & Oliveira, F. H. S. (2016). Seed hydropriming in upland rice improves germination and seed vigor and has no effects on crop cycle and grain yield. Australian Journal of Crop Science, 10(11),	1534-1542.
doi:10.21475/ajcs.2016.10.11.PNE70
Verma, V., Ravindran, P., & Kumar, P. P. (2016). Plant hormone-mediated regulation of stress responses. BMC Plant Biology, 16(1), 86. doi:10.1186/s12870-016-0771-y
Wahid, A., Perveen, M., Gelani, S., & Basra, S. M. A. (2007). Pretreatment of seed with H2O2 improves salt tolerance of wheat seedlings by alleviation of oxidative damage and expression of stress proteins. Journal of Plant Physiology, 164, 283-294. doi:10.1016/j.jplph.2006.01.005
Wang, W., Chen, Q., Hussain, S., Mei, J., Dong, H., Peng, S, Huang, J., Cui, K., & Nie, L. (2016a). Pre-sowing seed treatments in direct-seeded early rice: consequences for emergence, seedling growth and associated metabolic events under chilling stress. Scientific	Reports, 6,	19637.
doi:10.1038/srep19637
Wang, W., Peng, S., Chen, Q., Mei, J., Dong, H., & Nie, L. (2016b). Effects of pre-sowing seed treatments on establishment of dry direct-seeded early rice under chilling stress. AoB Plants, 8, plw074. doi: 10.1093/aobpla/plw074
Wojtyla, L., Lechowska, K., Kubala, S., & Gamczarska, M. (2016). Molecular processes induced in primed seeds—increasing the potential to stabilize crop yields under drought conditions. Journal of Plant Physiology, 203,	116-126.
doi:10.1016/j.jplph.2016.04.008
Waqar, K., Surriya, O., Afzal, F., Kubra, G., Iram, S., Ashraf, M., & Kazi, A. G. (2014). Modern tools for enhancing crop adaptation to climatic changes. In P. Ahmad (Ed.), Emerging technologies and management of crop stress tolerance, volume 1 (pp. 143-157). Elsevier Inc. doi:10.1016/B978-0-12-800876-8.00007-2
Welch, R. M. (1986). Effects of nutrient deficiencies on seed production and quality. Advances in Plant Nutrition, 2, 205-247.
Xiong, L., & Zhu, J.K. (2002). Molecular and genetic aspects of plant responses to osmotic stress. Plant, Cell & Environment, 25, 131-139. doi:10.1046/j.1365-3040.2002.00782.x
Yadav, P. V., Kumari, M., & Ahmed, Z. (2011). Seed priming mediated germination improvement and tolerance to subsequent exposure to cold and salt stress in capsicum. Research Journal of Seed Science, 4(3),	125-136.
doi:10.3923/rjss.2011.125.136
Yagmur, M., & Kaydan, D. (2008). Alleviation of osmotic stress of water and salt in germination and seedling growth of triticale with seed priming treatments. African Journal of Biotechnology, 7(13), 2156-2162.
Yilmaz, A., Ekiz, H., Gultekin, I., Torun, B., Barut, H., Karanlik, S., & Cakmak, I. (1998). Effect of seed zinc content on grain yield and zinc concentration of wheat grown in zinc-deficient calcareous soils.
Journal of Plant Nutrition, 21, 2257-2264. doi:10.1080/01904169809365559
Yuan-Yuan, S., Yong-Jian, S., Ming-Tian, W., Xu-Yi, L., Xiang, G., Rong, H., & Jun, M. (2010). Effects of seed priming on germination and seedling
734
4 Acta agriculturae Slovenica, 111 - 3, december 2018
On-farm seed priming interventions in agronomic crops
growth under water stress in rice. Acta Agronomica Sinica, 36(11), 1931-1940. doi:10.1016/S1875-2780(09)60085-7
Zheng, M., Tao, Y., Hussain, S., Jiang, Q., Peng, S., Huang, J., Cui, K., & Nie, L. (2016). Seed priming
in dry direct-seeded rice: consequences for emergence, seedling growth and associated metabolic events under drought stress. Plant Growth	Regulation, 78,	167-178.
doi:10.1007/sl0725-015-0083-5
Acta agriculturae Slovenica, 111 - 3, december 2018 735