The effects of stigma removal from floral organ and treatment of auxin on those regions were evaluated on the fruit growth and quality in strawberry (Fragaria ananassa Duch.). The removal of stigma reduced the fruit weight, fruit length, and fruit width, while fruit growth declined as the number of removed stigma increased. The removal of stigma also resulted in reduced fruit firmness, sugar content, and total anthocyanin content, and decreased value of Hunter a for red color and increased value of Hunter b for yellow. The number of seeds deceased as the regions of removed stigma increased. The treatment of auxin on the region of removed stigma improved fruit size, while it reduced fruit firmness, sugar content, and anthocyanin content. The delay in fruit ripening was observed from both stigma removal and auxin treatment. The incidence of malformed fruits increased as the regions with removed stigma increased. The treatment of auxin also promoted fruit malformation.

This study was conducted to investigate changes in seed vigor based on temperature of dry heat and duration treatment of watermelon seeds and examine the effect on percent of emergence and seedling vigor. When the upper limit temperature of dry heat treatment was raised to 80℃, the percent of the germination decreased. Moreover, T50 was delayed as the upper limit temperature of dry heat treatment increased. The higher the upper limit temperature of dry heat treatment and the longer the treatment period, the higher the percentage of abnormal seedlings. The optimum upper limit temperature for dry heat treatment was 72℃, and the treatment period was five days. Seed vigor was better maintained at 30℃, 45℃, and 52℃, followed by stepwise exposure to high temperatures of 72℃, the upper limit of dry heat treatment, rather than dry heat treatment at a high temperature of 72℃ for 5 days from the initial stage of treatment. When the fungicide was added during the dry heat treatment process, the germination percentage decreased and the percent of the abnormal seedling percentage increased. However, the addition of 10 mg/kg fungicide did not significantly reduce seed vigor.

Kadsura coccinea (Lem.) A.C. Smith is used as a medicinal plant and cosmetic material in China and Southeast Asia. To mass-produce Kadsura coccinea seedlings, the effects of gibberellic acid (GA3) and cold stratification treatments on seed germination were investigated. Seed germination rate with GA3 treatment was most effective at concentrations of 250 or 500 mg/L. With respect to mean germination time (MGT), mean daily germination, and T50 (days to reach 50% seed germination), the germination-promoting effect was improved as the concentration of GA3 increased. Stem growth of seedlings was the highest following GA3 treatments of 250 and 500 mg/L, and the growth promoting effect gradually decreased as the concentration of GA3 decreased. Root growth was stimulated at GA3 concentrations of 250–1,000 mg/L. Examination of the effect of stratification treatment for 15, 30 and 60 days at temperatures of 0, 5 and 10℃ on the germination rate revealed that the most stratification treatment temperature was 10℃, and the results improved with longer treatment periods. Altogether, GA3 and stratification treatments improved the seed germination rate, shortened the MGT, improved germination uniformity, and produced healthy seedlings.

The purpose of this study was to identify for extenders, adhesives, colorants, and fungicides suitable for the production of high-quality film-coated seeds of Chinese cabbage. In addition, the effect of various additives used for film coating on the germination of coated seeds and seedling vigor was investigated to establish appropriate treatment conditions for film coating efficiency. The germination rate and germination speed in Chinese cabbage film-coated seeds did not differ significantly depending on the type and concentration of the extender, while the use of Talc resulted in superior granulation capacity and adhesion of the seed coat in comparison to Zeolite. There was no significant difference in the germination rate depending on the type of adhesive used for film coating of Chinese cabbage seeds, but the germination rate was slightly slower in the film-coated seeds using carboxymethyl cellulose as an adhesive. On the other hand, the seeds coated with a film using 1% PVA as an adhesive not only maintained hardness enough to withstand external pressure, but also showed a high germination rate. In addition, the suitable disinfectant for film coating was venoram, and the treatment concentration was good at 250 mg·L-1. The type of colorant used in the film-coated seeds of Chinese cabbage did not significantly affect the germination rate, germination speed, and seedling vigor. The seeds film-coated using the liquid colorant were superior in appearance to the seeds film-coated with the solid colorant, which implies the possibility of reduction in the manufacturing costs by using the water-soluble paints as colorants for film-coated seeds.

This study was conducted to determine the optimum conditions for the treatment of polyamine to promote pollen germination and improve the fruiting rate by overcoming fertilization defects in low-temperature strawberry cultivation. The optimum temperature for pollen germination of strawberries was 30 for Seolhyang and 25 for Maehyang, and Seolhyang had a higher pollen germination rate than that of Maehyang. The addition of polyamines, namely spermine and putrescine to the medium improved the pollen germination rate and spermine treatment showed a better effect than putrescine treatment. The proper polyamine type and treatment concentration for enhancing the potency of pollen germination was 500 μM of spermine for both Seolhyang and Maehyang, which improved the pollen germination rate by 19-23% compared with that of the control. However, combined treatment of spermine and putrescine, resulted in a lower germination rate lower than that of the single treatment. Our results indicated that the treatment of polyamines during flowering in protected cultivation of strawberrise can improve the fruiting rate by overcoming the problem of poor pollen germination due to low temperature.

The purpose of this study was to investigate the effects of defoliation treatment on the growth and yield of strawberries. There was a remarkable growth in the above-ground part and root of untreated strawberry plants possibly due to higher amount of photosynthesis, while overall plant growth was suppressed as the level of defoliation treatment increased. In both the “Seolhyang” and “Maehyang” cultivars examined, defoliation treatment resulted in small fruits and a low number of fruits per plant. Notably, 50% defoliation significantly reduced the number of fruits per plant to 8.2, compared to 13.8 in untreated plants. Defoliation treatment also negatively influenced the fruit quality including color, sugar content, and solid-acid rate. However, no significant changes in fruit firmness was observed in either cultivar. Therefore, retaining enough leaves without defoliation treatment can be important to increasing fruit yield, producing high quality fruits and saving labor required for defoliation.

The purpose of this study was to investigate the effect of shading on the growth and productivity of strawberries. Photosynthesis was normally achieved under natural light without shading treatment, and vegetative growth of under- and aboveground part of strawberry plants were excellent. Strawberry fruit productivity and quality were different depending on shading conditions. In natural light, they were improved possibly by balanced vegetative and reproductive growth. However, under light-shading conditions with insufficient sunshine, photosynthetic activity deteriorated and carbohydrate production was therfore inadequate; this adversely affected plant height and quality. The negative effects were more pronounced at 50% shading condition. Shading treatments resulting in insufficient sunshine had a detrimental impact on plant productivity and growth; this implies that proper shading conditions could heip improve yield and fruit quality.

In this study, we investigated the influences of abnormal high temperature on growth, yield and physiologically active substances of the strawberry. General strawberry cultivars in the 20℃ growth condition showed much better growth of leaf number, length, diameter along with plant height, compared with those in 22.5℃ or 25℃. But the cultivars of both ‘Sulhyang’ and ‘Mehyang’ showed good growth and development at 25℃ with the roots showing great growth at 20℃. The quality and yield of the strawberry were best in the 20℃ growth condition, but the merchantability deteriorated in the 25℃ high temperature condition. As for the content of the physiologically active substances of the strawberry, it increased at 20℃, the optimum growth temperature, but decreased at 25℃. The physiologically active substances in the strawberry differed among the cultivars, the contents of cyanidin-3-glucoside, cinchonine, ellagic acid and cinnamic acid higher in the ‘Mehyang’, whereas the content of fisetin is higher in the ‘Sulhyang’ cultivar.Consequentially, the high temperature in summer has a negative effect on the physiological active ingredients of the strawberry, which was increased in the strawberry cultivated at proper temperature, and high quality strawberry production was possible.