No abstract

Fruit maturity for seed production can occur at various times because of the continual flowering of pepper plants. Accordingly, seeds with different maturity are acquired as the fruits are collected in a single harvest. Immature seeds obtained in this harvest may lead to a decrease in the quality of seed lots. Therefore, this research aimed to evaluate the influence of four different endophytic bacteria strains (Pseudomonas fluorescens strain L5b, Pseudomonas gessardii strain L13, Bacillus subtilis strain Bs1 and Bacillus mojavensis strain ApBm) on germination and seedling vigor of immature and mature bell pepper seeds. To obtain seeds with different maturity levels, fruits were collected 45–49 days after flowering for immature seeds and 65–69 days for mature seeds. The effectiveness of these bacteria strains was examined by coating seeds with four different endophytic bacteria strains separately. Additionally, to see the activity of endophytic bacteria more clearly, a mock treatment with sterile water was added to the experiment as a control (+) group. Bio-priming (especially strain Bs1 and L13) improved germination and seedling emergence characteristics of both immature and mature seed lots compared to control groups (p < 0.05). The results demonstrate that bio-priming with beneficial endophytic bacteria can be used to stimulate the quality of both immature and mature seeds from the pepper.

This study was carried out to determine seed longevity in organic and conventionally produced pepper seeds from four different pepper cultivars. Seeds were stored at 20± 2 oC with 7.5±0.5 seed moisture over 48 months. Longevity of seeds were evaluated with Ki (initial seed quality), P50 (half-viability period), σ (standard deviation of distribution of seed deaths in time), and regression coefficient values. The highest longevity was observed in ‘Corbaci’ and ‘Yaglik’ cultivars, while ‘Surmeli’ and ‘K. Dolma’ were found to have shorter longevity. P50 was 43.4 and 40.2 months for ‘Corbacı’ and 34.9 and 39.7 months for ‘Yaglık’ organic and conventional cultivars, respectively, whereas it was about 21.4 and 23.7 months in ‘K. Dolma’ and ‘Surmeli’ cultivars. Similarly, the highest σ and regression coefficient values were observed for ‘Corbaci’ and the lowest for ‘Surmeli’ cultivars. Organic and conventional pepper seed longevity was not different in the same species. Regression coefficient values were 0.043 in organic and 0.046 in conventional seeds for ‘Corbaci’. Very close values were found between the two production systems for the other cultivars too. Results indicate that organic seeds had similar longevity to conventional ones. The main differences originated from the cultivars, not from the production system.

High quality seed production is essential in organic production as well as in conventional production. Fruit maturity can be observed at different times due to the continuous flowering of pepper plant. Consequently, seeds with different maturity are obtained as the fruits are collected during once over-harvesting period. Immature seeds collected in once over-harvest may cause quality losses in the seed lot. Hence, this study was conducted to determine the effect of after-ripening on mature and immature pepper seeds produced in organic and conventional production systems. To see the effect of after-ripening treatment, seeds were harvested in two different periods (immature 45-50 day after anthesis(DAA) and mature 60-65DAA). After-ripening(AR) was performed by keeping the seeds in fruits for 7 days after harvesting the fruits. Effect of production systems and after-ripening on immature and mature pepper seed lots were assessed for four cultivars harvested in 2015 and 2016. After-ripening increased germination (AR:76.3%, C:28% for organic and AR:88%, C:53.8% for conventional), seedling emergence (AR:70.8%, C:44.3% for organic and AR:82.5%, C:53.8% for conventional) percentages and mean weight of 1000 seeds (AR:6.5, C:6.0g for organic and AR:6.5, C:6.2g for conventional) in both production systems of immature seed lots compared to control (C)(P<0.05) but did not have a similar effect on mature ones. Moreover, organically-produced seed lots have the same quality as conventionally-produced seeds. Consequently, obtained results indicate that after-ripening can be used to enhance the quality of immature seeds of pepper cultivars and seeds can be produced organically without any loss of quality.

This study was carried out to test the effect of vacuum and open-air storage on seed germination, oil content, and sugar contents of four pepper cultivars. Seeds were stored at 13°C with 35% relative humidity over 48 months in vacuum packets or in perforated cheese cloth in a storage room. Seed samples were examined at 12, 24, 36 and 48 months. Seed germination, oil content and sugar contents were determined. Seed germination declined gradually as storage time extended. Vacuum storage had significantly higher (P<0.05) germination than oxygen storage after 48 months of storage for all cultivars. Differences between the two storage methods were not significant for the other samples, except Yaglik in which vacuum storage had higher values from 24 months onwards during storage. Total oil content declined in all cultivars but the decline was faster in seeds stored in the open air. A similar trend was also observed for sugar contents. Seeds stored in the presence of oxygen lost sugar content faster than vacuum-stored seeds. Results indicated that storage with vacuum conditions (no oxygen) extended the longevity of pepper seeds.

This study was carried out to test the use of raw zeolite material in drying freshly harvested pepper seeds. Seeds of three pepper cultivars (Carliston, Kandil Dolma, and Yalova Yağlık) were harvested at maturity (65-70 days after anthesis) in two runs (run 1 and 2) in 2019 and dried at 45°C (machine-drying), in the sun (sun-dried) and with zeolite (1:1, seed, zeolite, rate) until seed moisture was reduced to lower than 10%. The time to safe drying was about 20, 40 and 60-100 hours for machine, sun and zeolite drying, respectively. Germination percentages were not significantly different between the drying methods (P&lt;0.05) for all three cultivars. Mean germination time was not affected by drying methods in Yalova Yağlık, but was in both runs for Kandil Dolma and in the second run for Carliston. Drying methods showed insignificant differences (P&gt;0.05) in seedling emergence for Carliston and Yalova Yağlık, but were significant (P&lt;0.05) for Kandil Dolma in both runs. Mean seedling emergence time (d) also changed among the cultivars. Results indicated that raw zeolite has the potential to be used for safe drying of freshly harvested pepper seeds.

The main objective of this study was to improve seed quality by using magnetic field (MF) as a priming method to increase germination percentages (GP) and seedling emergence percentages (SEP) in onion and lettuce seeds. MF treatments on pre-hydrated seeds, significantly increased GP (up to 80% for onion, 87% for lettuce) and SEP (up to 76% for onion, 86% for lettuce) in both species. Magnetic treatments in other saying magnetopriming helped to increase germination and seedling emergence speed in treated seeds as well. The shortening of mean germination time allowed the treatments to establish uniform and well-developed seedlings. Our findings indicate that magnetopriming could be used as a pre-germination treatment before sowing.