Hydro Priming Research Articles

Seed Biopriming– A Review

There are various seed priming methods such as hydro priming, osmo priming, solid matrix priming, hormo-priming, chemo-priming, nutri-priming and biopriming being useful for enhancing the seed germination, seedling vigour and to overcome abiotic stress. Moreover to these advantages, of all priming methods only biopriming method gives an extra advantage of biotic stress management and thus gain special attention. Solubilisation or mobilization of soil macro and micronutrients, siderophore production, induction of plant growth promoting activities, induction of useful biochemicals, phytoalexin and defense-related enzymes and induced systemic resistance are the mechanisms involved in seed biopriming. Range of fungal or bacterial bio agents viz., Azotobacter, Rhizobium, Arthrobacter, Agrobacterium, Azospirillum, Enterobacter, Streptomyces, Bacillus, Burkholderia, Klebsiella, PSB, Pseudomonas fluorescence, Trichoderma viride, Trichoderma harzianum and Vesicular Arbuscular Mycorhiza, whether they are biofertilizer or biopesticide, may be useful as biopriming agents. Seed biopriming is useful in almost all the crops over the globe and is an eco-friendly substitute to chemical fungicides.

Effect of seed priming on growth behaviour of French bean <em>Phaseolus vulgaris</em> L.

An experiment entitled “Effect of seed priming on growth behaviour of French bean Phaseolus vulgaris L.” was conducted during Rabi 2018-19 in the Vegetable Research field of Department of Vegetable Science, College of Agriculture, OUAT, Bhubaneswar. The trial was conducted in Randomized Block Design with three replications and ten treatments. The treatments were T1 (Hydro priming), T2 (GA3 50 ppm),T3 (KCl 2%),T4 (Sodium Molybdate 500 ppm),T5 (Vitavax 2g/kg), T6 (Pseudomona fluorescens 10%), T7 (Trichoderma viride 10%), T8 (GA3 50 ppm+ T .viride 10%), T9 (Sodium Molybdate 500 ppm +Pseudomonas fluorescens 10%), T10 (Control) Good quality seeds of French bean variety Harsha was taken and different priming treatments were done in the laboratory followed by growing the crop in the field as per recommended package of practices. However days to 1st flowering & 50% flowering were found non-significant. Days to 50% flowering varied from 45.5 in T6 to 48.7 in T4. The average leaf area of the trifoliate compound leaves were taken which was highest in T3 (148.30) followed by T8 (140.40 cm2) and was lowest (105.8 cm2) in control. The highest stem girth (2.8 cm) was recorded in KCl (2%) primed seeds closely followed by GA3 (50PPM) + T. viride (10%) (2.7cm) and vitavax treatment @ 2g/kg (2.6 cm). The number of primary branches per plant was maximum in T3 (4.52) and minimum in T10 (2.87) and this character differed significantly among the treatments. The treatments T3 (4.52), T8 (4.32), T6 (4.14), T5 (4.01) produced more branches and they are at par.

Hydro and osmo priming effects on phenolics, essential oil and fatty acid composition of Pimpinella anisium seeds for medicinal purposes

Hydro and osmo priming effects on phenolics, essential oil and fatty acid composition of Pimpinella anisium seeds for medicinal purposes

Combined effect of hydro priming and root pruning on plant dry matter of tomato (Lycopersicon esculentum) seedlings

Combined effect of hydro priming and root pruning on plant dry matter of tomato (Lycopersicon esculentum) seedlings

The Effects of Hydro Priming Intervals on the Germination and Yield of Kidney Beans (Phaseolus vulgaris L.) in the Humid Forest Zone of Cameroon

The aim of this research was to evaluate the appropriate hydro-priming interval on germination, growth and yield of kidney beans (Phaseolus vulgaris L.).
 The experiment was conducted in a Completely Randomized Block Design, with five treatments, replicated thrice.
 This study was conducted at the agricultural research farm of Pan African Institute for Development – West Africa (PAID-WA), Buea from August to October 2017.
 The Five treatments were: T1 (Unprimed or control), T2 (Hydro-primed for 6 hours), T3 (Hydro-primed for 12 hours), T4 (Hydro-primed for 18 hours), and T5 (Hydro-primed for 24 hours). Data were collected on percentage germination, plant height, stem diameter, number of leaves per plant, number of pods, pod weight and grain yield.
 The result revealed there was a significant increase in days (P < 0.05) in the germination percentage of some primed seeds and unprimed seeds across the treatment. There was not any significant difference (P > 0.05) in plant height, number of leaves, plant girth from T1 to T5. There was a significant difference (P < 0.05) in the number of pots among the primed treatments. Yield of beans also showed a significant difference (P < 0.05) with unprimed and primed plants. Seeds of T2, T3, T4, T5 produced the following yields 11.1 kg/ha, 22.3 kg/ha, 172.3 kg/ha, 277.8 kg/ha more than unprimed seeds (control) respectively.
 This study showed that hydro primed seeds for 6 hours produced the best growth and development aspect as well as the yield, despite the low germination percentage as compared to the unprimed and the other primed seeds.

From Emergence to Flowering: Four Beet (Beta vulgaris ssp.) Cultivars’ Phenological Response to Seed Priming

Beta vulgaris comprise various variety groups that are cultivated for vegetative or reproductive production. As a biennial crop, beets have a photothermal induction requirement for the transition from the vegetative to the reproductive stage. Bolting and flowering are not desirable when beets are cultivated for vegetative production and are suppressed during breeding programs, though these structures are important in seed production. Therefore, the potential of seed hydro priming as an enhancement technique to partially induce vernalization in seeds was evaluated. Following hydro priming, seeds were sown in October 2018 and evaluated during three selected phenological stages. Treating seeds with hydro priming significantly improved the emergence rate in all four tested cultivars. Moreover, treatments significantly lowered the required growing degree days (GDD) for transition to the reproductive stage in all four tested cultivars. Regardless of the treatment effect on an individual developmental stage, the treatment efficiency should be evaluated on the whole production process, depending on the purpose of production. The focus of this study was mainly on improvement of seed production performance. The outcome showed the potential of priming to influence the reproductive stages of the plant life cycle rather than just the germination.

Effect of osmo priming on sucrose metabolism in spring maize, during the period of grain filling, under limited irrigation conditions.

The present study was undertaken to study the effect of osmo priming on sucrose metabolism of spring maize, under limited irrigation conditions. Osmo priming increased the activities of acid invertase, alkaline invertase and sucrose synthase (cleavage) and the contents of reducing sugars and starch in the grains of stressed plants. There was also an increase in sucrose phosphate synthase activity with a parallel increase in sucrose content in leaves of stressed plants in comparison with those of hydro priming treatment. It showed that osmo priming helped in improving sucrose phosphate synthase activity in leaves of plants, leading to higher sucrose content, under stress conditions.

Effects of Seed Priming with Gibberellic, Salicylic Acids and Mycorrhizal Inoculation on Lentil (Lens culinaris L.) Yield and its Components

A field experiment was conducted to study the effect of mycorrhizal inoculation and seed priming with plant growth regulators on yield and yield components of lentil as factorial base on the randomized complete block design in four replications at the research farm of Gonbad Kavous University of Iran during 2013–2014. First factor included application of the mycorrhiza at three levels (control, inoculated soil using Glomus intraradices and Glomus mosseae) and seed priming at five levels (hydro-priming with distilled water, seed priming with GA3 100 ppm, priming with SA 100 ppm, priming with GA3 100 ppm + SA 100 ppm and non-primed seed as control was the second factor. On the basis of results, days to 50% flowering was significantly decreased with the application of mycorrhizal inoculation along whole treatments of priming except G.mosseae in combination with both hormones level. It was also observed that combined treatments of Glomus intraradical inoculation with hydro priming caused most early flowering, the number of pods in the plant, ratio of the filled pod, grain weight of lentil eventually higher yields and harvest index of lentil over other treatments. Thus mycorrhizal inoculation can help to minimize synthetic herbicides and develop biofertilizer in sustainable agriculture.

INFLUENCES OF PRE-SOWING TREATMENTS ON THE GERMINATION AND EMERGENCE OF DIFFERENT MULBERRY SPECIES SEEDS

Morus genus includes more than 20 species, some of which are commercially important mulberries with different fruit color and shape. Even though the trees of those species are propagated by rooting of cuttings in practice, mulberry seeds are of importance for breeding studies and rootstock seedling propagation. For that reason, this study was conducted to improve the seed performance of four mulberry species by different pre-sowing treatments including; 3% KNO3, GA3 at 500 ppm, organic priming with herbal tea brewed from marigold flowers petals and hydro priming. Results of the parameters of emergence characteristics and seedling vigor were evaluated. According to the results that varied between different species and pre-treatments, since emergence percentage and time, and seedling vigor were improved by the treatments, it was concluded that pre-sowing applications, especially GA3 and hydro priming, were beneficial in improving the seed performance of mulberry species included in the study.

Combined seed enhancement technique involving seed priming and coating for improvised anatomical potential and vigour of okra seeds (Abelmoschus esculentus L.)

The study was conducted to standardize the methodology of humid priming for improving the seed germination and vigour of okra seeds and to compare the efficacy of different enhancement techniques such as hydro priming, spin priming, seed coating and the combination of ‘humid priming + seed coating’ in improving the seed vigour characteristics of okra (Abelmoschus esculentus L.). In order to standardize the humid priming technique, okra seeds were subjected to humid priming for four different duration’s viz., 2, 4, 6 and 8 h, shade dried to original moisture content and subjected to evaluation of seed germination under shade net conditions in raised beds. The results revealed that 4 h of humid priming was statistically significant to the rest of the durations, with respect seed germination and seedling growth. With respect to anatomical potential, the radicle length (3.39mm), cotyledon length (6.69mm) and cotyledon width (6.30mm), recorded by humid priming (4 h) was 62.2 %, 6.4 % and 2.6 % higher than control seeds. The second experiment conducted to compare the efficacy of hydro priming, spin priming, polymer coating and combination of humid priming + seed coating. The study revealed that seeds subjected to combination of humid priming (4 h) + seed coating (3g kg-1) recorded highest physiological potential in terms of germination percentage (87 %), seedling length (20.2 cm), dry matter production (421.3 mg), vigour index (1765), root volume (3.5 cm3) and root sheath (2.560 g) while the control recorded only 70 %, 15.1 cm, 328.7 mg, 1055, 2.0 cm3 and 1.532 g, respectively.

Effects of Storage and Priming on Seed Emergence in Soil and Embryo Culture of Musa acuminata Calcutta 4

Aims: Effects of 3 storage durations, 3 hydro priming protocols and 6 chemical priming protocols on emergence in soil (in vivo) and embryo culture (in vitro) of Musa acuminata Calcutta 4 were investigated.
 Study Design: The experimental design was a completely randomised with three replicates. Analysis of variance was used (P=.05) to test treatment effects in a Completely Randomised design. Mean comparison was by LSD.
 Place and Duration of Study: This study was carried out for a period of 10 months at the International Institute of Tropical Agriculture High Rainfall Station, Onne, in Rivers State, Nigeria.
 Methodology: Seed pre-sowing treatments consisted of 3 storage protocols, 3 hydro priming and 6 chemical treatment protocols. After which treated seeds were divided into two sets. One set was sown directly in soil and the other set subjected to embryo culture technique.
 Results: Seeds sown in soil immediately they were extracted had significantly higher emergence than stored seeds. Emergence declined by 20% and 23% after 2 weeks and 4 weeks of storage respectively. For embryo culture, seeds stored for 2 weeks had significantly higher germination (40%) than seeds that were not stored or seeds stored for 4 weeks (38%). Emergence in vivo was significantly higher for seeds that were not hydro primed than for seeds hydro primed for 4 days or 8 days. Emergence declined by 33% and 38% in seeds hydro primed for 4 days and 8 days respectively. Hydro priming for embryo culture for 4 days increased germination significantly by 60% compared to those without hydro priming. All the chemicals reduced emergence in both soil and in vitro procedures except that of Copper oxychloride in embryo culture which increased germination by 18%, compared to the control achieving 47% germination.
 Conclusion: Higher germination was recorded with in vitro than in vivo procedures irrespective of the treatments applied. Perhaps inherent factors in the seed coat and possible interactions in soil may account for the poor emergence exhibited in vivo and will require further investigation.

Evaluation of different seed priming methods for improvement of seedling growth of barnyard millet (Echinochloa frumentacea L.) cv. MDU1

The present investigation was carried out to study the effect of different priming methods on improvement of seedling growth. Pre-sowing seed priming helps to improve germination and stand establishment. Seeds of barnyard millet were primed with different priming methods viz., hydro priming(H2O), hormo priming(GA3 10ppm), organic priming(vermiwash 10%), botanical priming (Calotropis leaf extract 15%), halo priming (KH2PO41%) and chemo priming (succinic acid 100ppm). Barnyard millet seeds were soaked in double the volume of priming media for 12hours and evaluated the seed quality parameters. Among these methods, hormo priming (GA310ppm) recorded higher values in germination (100%), shoot length (10.85 cm) and vigour index (2353) compared to other priming treatment methods. The percentage increase over control was by 5, 12.22, 16.87, 50 and 18.66 for germination percentage, root length, shoot length, dry matter production and vigour index I, respectively.

Consequences of Seed Priming with Salicylic Acid and Hydro Priming on Smooth Vetch Seedling Growth under Water Deficiency

Due to low rainfall at early autumn, smooth vetch seedling growth in rain-fed lands often is limited by water deficit stress yet the data regarding the reactions of smooth vetch to water deficit at early growth stages are pretty rare. The objective of current study was to examine possibility of using priming treatments (hydro priming and priming salicylic acid) to alleviate the inhibitory effect of water deficiency during early growth of Smooth Vetch. In this respect, seeds were soaked in distilled water (hydro priming) or 0.5 mM solution of SA for 36 h at 10 °C then dried back to original moisture content. Pots were irrigated for 25 days at four levels of available water containing field capacity (FC), 75% FC, 50% FC and 25% FC. In general, seedling emergence and early growth were markedly limited by increasing water deficiency. However, priming treatments particularly with SA caused considerable improvement in either emergence or growth of seedlings (dry weight, length). The obtained results showed that primed samples exhibited higher accumulation of proline, glycine betaine (GB) under all levels of available water except 100% FC and also higher total soluble sugars (TSS) and trehalose under severe water deficit (25% FC). SA primed samples had higher relative water content especially under higher levels of water deficiency. The more balanced water status within SA primed samples also was accompanied with higher accumulation of proline and glycine betaine. There were significant differences between two priming treatments in terms of proline and GB content within seedlings and SA priming considerably increased proline and GB accumulation. In contrast to proline and GB, TSS and trehalose content wasn’t influenced by SA treatment and both hydro and SA primed samples showed statistically similar quantities.

English

A laboratory experiment was carried out to assess the possibility of decreasing the negative effects of salinity on seed germination and early seedling growth of canola by hydro-priming of seeds. A 7×5 factorial experiment based on completely randomized design was employed to compare the treatments. Seed priming comprised 0.0, 4.0, 8.0, 12.0, 16.0, 18.0 and 24.0 h seeds soaking in distilled water, and salinity stress was simulated by the solutions of 0.0, 25.0, 50.0, 75.0 and 100.0 mM NaCl. Germination percentage and uniformity, germination speed and seedling dry weight were measured as germination performance indicators. Results showed that all traits were significantly affected by salinity stress and seed priming. Germination uniformity and seedling dry weight were affected by the interaction of salinity × seed priming. Germination percentage and speed were slightly affected by the interaction of salinity × seed priming. However, it was not significant. Increasing in salinity stress from control to the highest level (125 mM NaCl) resulted in 26% reduction of germination percentage of rapeseed. However, germination speed was a trait showing higher sensitivity to the salinity stress. The difference between control treatment and the highest salinity stress in terms of germination speed was 45%. Hydro-priming improved germination percentage and speed of rapeseed seeds. The highest germination percentage and speed was observed in the treatment of 24 h which was not significantly different with 20 h hydro-priming. Germination percentage and speed of rapeseed improved 25 and 30 by hydro-priming of seeds, respectively. Generally, the length of hydro-priming solutions improved the performance of seeds and seedlings of rapeseed. Higher levels of hydro priming duration reduced negative effects of sever salinity stress, where there was no significant difference between two last salinity levels in terms of salinity. Key words: Germination, rapeseed, salinity, seedling dry weight.

COMPARISON BETWEEN HYDRO- AND OSMO-PRIMING TO DETERMINE PERIOD NEEDED FOR PRIMING INDICATOR AND ITS EFFECT ON GERMINATION PERCENTAGE OF AEROBIC RICE CULTIVARS (Oryza sativa L.)

This study compared hydro- and osmo-priming to determine period needed for seed priming indicator to emerge and its effect against water stress on germination percentage of some aerobic rice cultivars ( Oryza sativa L.). Experiments were arranged in completely randomized design using three aerobic rice cultivars and PEG with four replications. Rice varieties (Inpago-8, IR64 and Situ Bagendit) were combined with four different PEG concentrations. Drought stress was simulated by different PEG solutions and with distilled water as control. Results indicated differentiations between hydro and on priming indicator time, while varietal difference was not significant. Fastest recorded time was obtained between 30-36 hours under hydro priming, PEG 100 g L -1 (63-69 hours) and 83-93 hours in PEG 200 g L -1 solution. Thus showing increased solution concentration led to prolonged priming indicator time. The highest germination percentage was obtained in Situ Bagendit treated with PEG 200 mg L -1 (90.25%) and the lowest obtained in Inpago-8 (75.75%) under control. It is better to use osmo-priming (PEG 200 g L -1 ) for teaching aerobic rice seed against drought stress. More research is needed to confirm benefits of seed treatment with PEG to cultivated crops under water stress, drought and salinity conditions.

Effect of priming and different initial soil moisture on desi chickpea ICCV 95107 (Cicer arietinum L.) dry matter production (kg/ha)

Technologies such as seed priming have been reported to result in early and uniform crop germination, enhancing optimum crop stand and establishment, eventually leading to optimal crop yields in the Arid and Semi-Arid Lands (ASALs). This study, therefore, was initiated to evaluate the dry matter production of chickpea under different priming methods, varying priming durations and different initial soil moisture levels. Field experiments were carried out at Mwea Irrigation Agricultural Development Centre (MIAD) farm Kirinyaga County, Kenya during 2012/2013 seasons. A split plot experimental design was used to test effects of no priming, hydro priming and halo priming at 0.1, 0.2 and 0.3 % NaCl2 concentration) and at 8, 10 and 12 hours priming duration on germination and growth of desi chickpea ICCV 95107. Altogether, the trial comprised 13 treatment combinations replicated three times with pre-sowing irrigation to soils at field capacity (FC) (100%), 75 %, 50 % and 25 %. Data was collected at growth stages of 25,50,75,90 and 105 days after sowing (DAS). The highest dry matter (DM) yields of 5001.1 and 3973.0 kg/ha was realized under 100 % FC at 105 DAS in season I and II, respectively. Dry matter accumulation (kg/ha) increased from 25 DAS to 105 DAS in both season under all pre sowing irrigation conditions, which correlates to growth stages. Dry matter also increased with increased pre sowing irrigation from 25% FC to 100% FC, and at every stage of growth. Halo priming for 8 hours with 0.2% NaCl2 distilled water solution gave the highest DM at all stages of growth (P ≤ 0.05). Significantly higher DM yields (P ≤ 0.05) were produced at 25% FC pre sowing irrigation with no priming (6500.0 kg/ha) and 0.2% NaCl2 for 12 hours (5900.0 kg/ha) by 90 DAS D during the wet season (SI). Dry matter ranged from 6440.0kg/ha at 50% FC- 0.2% NaCl2 for 8 hours to 6713.0kg/ha at 75% FC- 0.1% NaCl2 for 10 hours 6970.0 kg/ha at 0.2% NaCl2 for 8 hours. During the drier season (SII), the highest DM yields of 5017.0 and 4285.0 kg/ha were realized from 100% FC pre-sowing irrigation and priming of 0.2% NaCl2 for 12 hours and 0.2% NaCl2 for 10 hours, respectively. Therefore, adequate soil moisture of over 75% FC is necessary if effectiveness of priming 0.1 to 0.2% NaCl2 for 8 to 12 hours is to be realized under clay ASALs sandy loam soils of Mwea where droughts lead to prolonged seed emergence period, leading to deterioration of the seedbed and increased soil compaction, that eventually result in poor crop emergence, establishment and poor crop yields.

Season wise analysis of productivity of maize hybrid COHM (5) with the influence of seed and crop management techniques

The Studies were initiated to evaluate the influence of seed priming technique (15 per cent Azospirillum + 15 per cent phosphobacteria, 10per cent P. fluorescens + 20per cent Humic acid, 15 per cent Azophos + 10 per cent P. fluorescens and hydro priming technique) in conjunction with crop management techniques viz., nutrient supplementation as basal (humic acid @ 10kg ha−1, micronutrient 5kg ha−1) and foliar (diammonium phosphate 2 per cent, humic acid 0.1per cent, sea weed extract 0.5per cent) along with NPK application. The results revealed that seeds primed with 20 per cent humic acid + 10 per cent P. flurescense, applied with humic acid @ 10 kg ha−1 as basal application and sprayed with 0.5% sea weed extract improved the productivity of maize and the grain recovery. On comparison of seed and crop management techniques the contribution of seed management technique was higher than crop management techniques. The evaluated seed and crop management techniques were further test verified at Bhavanisagar both during Kharif and Rabi season, which conformed the influence of identified seed and crop management techniques on enhanced productivity and nutrient status of the grain, recommending it as package for commercial hybrid production irrespective of season and location.

Seed priming Enhanced Seed germination traits of Wheat under water, salt and heat stress

Abiotic or physicochemical stresses affect plant’s internal mechanisms as well as external morphology. Seed priming can be an effective tool to minimize effects of the abiotic stress on plant growth and wheat seed priming used as stress tolerance mechanism. The study was conducted to evaluate effects of seed priming on germination of two wheat varieties under drought, high salt levels and high temperature stress. Hydro priming (distilled water), Osmopriming (5milli molar KNO3, 10 mM KNO3) and halo priming (5 mM NaCl, 10 mM NaCl) were used. Under drought and heat stress, hydro priming resulted in the highest germination index to increase up to 70 and 65 percent as compared to stressed seeds while under salt stress, 5 mM KNO3 priming showed highest germination index up to 75 percent. Under salt stress, 5mM KNO3 priming resulted in highest seedling vigor index with 86% increase as compared to stressed seeds. Under water and heat stress, hydro primed seeds showed highest percentage i.e. 50% and 45% increase in germination stress tolerance index as compared to stressed seeds. Under salinity stress, 5mM KNO3 primed showed 51% increase in germination tolerance index as compared to stressed seeds. Seed priming was proved as an effective technique to increase abiotic stress tolerance. Keywords: Wheat seed priming; Abiotic stress; Germination http://dx.doi.org/10.19045/bspab.2015.44025

Evaluation of Seed Nut Size as Index of Selection for Superior Seed Quality Attributes in Two Biotypes of Cashew (Anacardium occidentale)

Abstract Quality seed nuts are germane to propagation of the cashew plant. Seed nut fraction and genotypes have been identified to influence seed quality of crop plant. Unexpectedly, seed size effect has not been well documented in Brazilian and local biotypes of cashew grown in Nigeria. An experiment was initiated to investigate the effect of three nut sizes and two biotypes of cashew on seed quality (physical and physiological) traits. Seed nut were collected from three cashew plants of the same age of each of the biotypes and were allowed to stay for 60 days after collection. The experiment was carried out in a factorial arrangement laid out in a completely randomized design with three replicates using two factors (nut size and biotypes) in 2011 cropping season in both laboratory and screen house tests. Data were collected on physical characters such as seed length, seed width, 100 seed weight and seed imbibition rate while physiological characters were seed germination and early vigour traits. Data obtained were analysed statistically using Tukey HSD test at 5% probability level. The result revealed that some of the characters were significantly different from one another. Seed nut fraction and biotype had considerable effect on seed length, seed width, seed imbibition rate and 100 seed weight. The two factors (nut size and biotype) interaction had profound effect on seed width only. On seed physiological quality, biotype effect was significant on seedling fresh and dry weights and seedling growth rate whereas seed nut size had considerable effect on seed germination, seedling vigour index, seedling fresh weight and seedling growth rate. The interaction effect of nut size and biotype recorded significant effect on the above four characters. Brazilian biotype had superior physical characters (seed length, width and weight) but with low imbibitions rate while medium and large nut sizes gave the highest seed germination and seedling vigour. Also, medium and large nuts had the highest seedling fresh weight whereas the highest seedling growth rate was recorded with small size seed. However, large, medium and small nut sizes of local biotype had the highest imbibition rate, whereas small, medium and large nut size of Brazilian biotype gave the highest 100 seed weight. On seedling emergence, large nuts of local biotype recorded the highest seedling emergence and seedling vigour index. Medium nuts of the two biotypes of cashew are recommended for cashew seed multiplication. Further research on physiology of cashew nut sizes during storage and osmo and hydro priming treatment effect are necessary and therefore advocated.

Effects of hydropriming treatments on the invigoration of aged Dodonaea viscosa seeds and water‐holding polymer on the improvement of seedling growth in a lava field

Restoration requires techniques similar to those used in agriculture to improve germination and seedling vigor. We treated 6‐year‐old (collected in 2003, S‐2003) and 1‐month‐old (S‐2009) seeds of Dodonaea viscosa with hydropriming (HP). Seeds were made permeable with hot water prior to hydration for 24 or 48 hours (HP‐24 and HP‐48, respectively) followed by dehydration. The resulting seedlings exposed to both HP treatments were sown in a lava field in soil mixed with hydrogel (HG) under the shade projected by five vegetation patches. The effects of these treatments on germination, seedling field survival, and growth were assessed. HP‐24 in S‐2009 and HP‐48 in S‐2003 increased the germination percentage from 22.5 and 31.7% in control seeds (permeable seeds) to 63.3 and 98.3%, respectively. The seedlings‐2009 (from S‐2009) with HG maintained high survival in all vegetation patches. Seedlings‐2003, however, had low survival. The lack of HG was negatively related to the photon flux in each patch. Survival of seedlings‐2009 increased with HG of up to 398.41 µmol m−2 s−1; after which survival decreased. During the rainy season, HP enhanced seedling growth, except the basal diameters and number of leaves in the seedlings‐2003 with HP‐24. During the dry season, the effects of HG and HP were similar for all the seedlings. In the following rainy season, the priming effect was lost while HG continued to promote seedling growth. The combined use of HP and HG and the shade projected by the patches resulted in a successful vegetation recovery strategy.