• Korean Journal of Organic Agriculture
• /
• v.25 no.2
• /
• pp.345-355
• /
• 2017

This study was conducted to evaluate rice seed disinfection efficacy of loess-sulfur for the suppression of Bakanae disease caused by Fusarium fujikuroi. Rice seeds were treated at different concentrations of loess-sulfur, soaking time and temperature, and combination of hot-water treatment. Rice cultivar, Shindongjin harvested from Bakanae disease-infested area in 2015, was used. Loess-sulfur was treated as follows; concentration of undiluted solution, 2%, 1% and 0.5%; soaking time of 24 and 48 hours; treatment temperature of $20^{\circ}C$ and $30^{\circ}C$; hot water treatment or not. Optimal conditions of rice seed disinfection were selected soaking time of 48 hours and the suspension of 0.5% and 1% loess-sulfur by investigating seed germination and isolation frequency of Fusarium spp. on Komada agar medium in vitro, and were established 3 disinfection conditions as hot water ($60^{\circ}C$, 10 min.) + 1% loess-sulfur ($20^{\circ}C$, 48 hours), 1% loess-sulfur only ($30^{\circ}C$, 48 hours) and 1% loess-sulfur only ($20^{\circ}C$, 48 hours) through additional test in greenhouse. Above 3 conditions were verified by rice seedling box and paddy field test in the way of investigating Bakanae diseased plants (%) and healthy plants (%). Consequently, most effective rice seed disinfection conditions on Bakanae disease were combination of hot water and 1% loess-sulfur and loess-sulfur only at $30^{\circ}C$. Furthermore, treatments with these conditions showed control value of 100% were maintained from seedling to the heading stage in the field. However, treatment of 1% loess-sulfur only at $20^{\circ}C$ showed low control value of 78.2% in paddy field. Hot water only treatment turned out to be an effective disinfection method when conducted thoroughly with $60^{\circ}C$, 10 min. However, it was thought additional soaking process with loess-sulfur after hot water treatment served more high control effect against Bakanae disease when rice seeds were disinfected on a large scale. This results expected rice seed disinfection with loess-sulfur were effectively and easily usable method if farmers had only one of either hot water-disinfector or seed-disinfector. In addition, loess-sulfur is well-known to farmers, simple to manufacture method and cheap.

• The Korean Journal of Pesticide Science
• /
• v.7 no.3
• /
• pp.216-222
• /
• 2003

In order to develop effective control methods for Bakanae disease caused by Gibberella fujikuroi (Saito) Ito during rearing of rice seedlings, we investigated the disease resistance of 15 rice varieties to G. fujikuroi and control effect of six seed disinfectants, and tried to improve the using methods of the seed disinfectants. Disease resistance was tested by investigating the disease incidence on each rice cultivar grown in rice seedling box infested with or not infested with G. fujikuroi at 30 days after sowing seeds and 20 days after heading date. The results showed that Hwayongbyeo, Dongjinbyeo, Hwoanbyeo, Nonghobyeo, Nampyeongbyeo, and Hwojinbyeo were resistant G. fujikuroi, meanwhile Keulubyeo, Sobibyeo, Odaebyeo, Junambyeo, Samchonebyeo, Sangjubyeo, and Hwabongbyeo were susceptible. Three seed disinfectants, prochloraz, fludioxonil, and carproamid + thiram + fludioxonil controlled Bakanae disease of rice very well, while bonomyl + thiram, thiophanate-methyl + thiram and thiophanate-methyl + triflumizole did not suppress the disease enough. Water temperature was turned to be an important factor for controlling the disease by treating seed disinfectants. Prochloraz showed 61% control value on the disease at $10^{\circ}C$, but it showed above 95% control value at the range of $30-35^{\circ}C$. It was confirmed that the control effect of seed disinfectants increased with increasing water temperature. Meanwhile soaking period of rice seeds in the suspension of seed disinfectants and chemical dosage had no high relation to control the disease. This results suggest that rice varieties, water temperature, and optimal selection of suitable seed disinfectants are very important to control Bakanae disease effectively.

• Journal of Forest and Environmental Science
• /
• v.35 no.4
• /
• pp.223-231
• /
• 2019

Castanopsis indica (Sil Batna) is an ecologically valuable multipurpose indigenous tree species of Bangladesh. Considering its high value but poor natural regeneration due to seed dormancy, the authors conducted an experiment at the Institute of Forestry and Environmental Sciences Chittagong University (IFESCU) during 2012-2013 to find out effective pre-sowing treatments. Ten pre-sowing seed treatments were applied on mature, even-sized seeds namely-control; sandpaper rubbing; nail clipping; immersion in normal water (at room temperature: 24℃) for 24 hrs., 48 hrs. and 72 hrs.; immersion in hot water (80℃) for 1 minute; soaking in 10% dilute H₂SO₄; soaking in 10% HCl for 5 minutes; and sowing in propagator house. Seeds sown after sandpaper rubbing at the distal end revealed best performances by providing highest germination percent (66.7%), germination energy (30%), germination index (0.17), germination rate (0.0145), germination value (30%) and plant percent (66.7%) within shortest period (38 days). The treatment also produced most vigor seedlings with 20.9 cm shoot height, 15 node number, and largest leaves (11.1 cm×2.9 cm). Hence, it is recommended to adopt sandpaper rubbing method for maximum germination and quality seedlings.

• The Plant Pathology Journal
• /
• v.36 no.5
• /
• pp.476-490
• /
• 2020

The parasitic weed, Orobanche crenata, is one of the most devastating constraint for faba bean production in Mediterranean regions. Plant host defense induction was reported as one of the most appropriate control methods in many crops. The aim of this study was to elucidate the effect of salicylic acid (SA) and indole acetic acid (IAA) on the induction of faba bean resistance to O. crenata under the field and controlled experimental conditions. Both hormones were tested on two contrasting faba bean genotypes: Giza 843 (partially resistant to O. crenata) and Lobab (susceptible) at three different application methods (seed soaking, foliar spray, and the combination of both seed soaking and foliar spray). Soaking seeds in SA or IAA provided the highest protection levels reaching ~75% compared to the untreated control plants. Both elicitors limited the chlorophyll content decrease caused by O. crenata infestation and increased phenolic compound production in host plants. Phenylalanine ammonia lyase, peroxidase, and polyphenol oxidase activities were stimulated in the host plant roots especially in the susceptible genotype Lobab. The magnitude of induction was more obvious in infested than in non-infested plants. Histological study revealed that both SA and IAA decreased the number of attached O. crenata spikes which could be related to specific defense responses in the host plant roots.

• Journal of Bio-Environment Control
• /
• v.10 no.4
• /
• pp.251-257
• /
• 2001

This experiment was conducted to investigate the effect of chitosan on the growth and yield of fall-planted potatoes. The research was carried out in fall-planted potatoes from August 2000 to Aprial 2001 at the height of 250m above sea level in Jeju Island. Soaking for 30 min. of seed potatoes in 200 times diluted solution of 3% liquid chitosan shortened days to emergence by 4 to 6 days. Stem length, number of stems and number of stolons per plant were 56.5 cm, 4.3, and 19.0, respectively, when seed potatoes were soaked for 30 min. in 200 times diluted solution of 3% liquid chitossan. Total potato yield in this treatment reached 2,963 kg per 10a and was significantly greater than in other treatments. Yield of marketable tubers (greater than 30g) per 10a for treatment of seed potatoes soaking in 200 times diluted solution of 3% liquid chitosan and for treatment of foliage spray with 200 times diluted solution of 3% liquid chitosan plus chitosna power (10 kg per 10a) miximg with soil was 2,761 kg and 2,628 kg, respectively. Contents of Mg, Fe and B were the greatest in the treatment of 30 min. soaking of seed potatoes in 200 times diluted solution of 3% liquid chitosanm. The increased contents of these elements are considered to have caused yield increase as a result of increased chlorophyll content for photosynthesis.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.39 no.2
• /
• pp.158-164
• /
• 1994

These experiment were conducted to evaluate the environmentally acceptable polymers, and 10 polymers were used in these study, and to investigate conductivity, germination percentage, water uptake of polymeric coating soybean seed. The conductivity of polymeric coating seed is higher than that of none coating seed and the highest conductivity was obtained with waterlock coating seed among the 10 polymer coating seed. As the soaking time was long, the conductivity was increased. The conductivity of large seed was higher than that of small seed, and that of long period storage seed was higher than that of short period storage seed. The effects of seed coating polymers on uptake water were various, and daran 8600 inhibited uptake water of low quality seed. The waterlock, captan, klucel and sacrust was rised germination percentage, and daran 8600 was declined germination percentage, and the effect of coating polymers on germination percentage of low quality seed was higher than that of high quality seed.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.59 no.2
• /
• pp.188-193
• /
• 2014

Seed viability testing provides valuable information for assessing seed lot germinability. However, most testing methods require destruction of seed prior to test. Because the dissected seeds for viability test cannot be used further evaluation, the nondestructively X-ray photography technique that can be applied for the evaluation of seed quality has been developed. In order to know the validity and accuracy of X-ray photography technique in seed evaluation test that conducted to remove the abnormal seed from a seed lot, we have compared the results from tetrazolium viability test, germination test and X-ray contrast method in cotton. Metallic salts treatment increased the efficiency of X-ray photographic method by enhancing the penetration of X-ray in abnormal or damaged seeds rather than normal seeds that have strong and well-organized tissues in seed. Cotton seeds presoaked for 16 hr in distilled water followed by soaking into metallic salt solution (5% NaI in water) for 60 min were easily classified seeds into dead seed and viable seed based on the radiography images obtained by X-ray radiation. We concluded that soft X-ray photography was reliable to find out the various defective characters due to heat and mechanical damage of seeds.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.43 no.3
• /
• pp.147-151
• /
• 1998

The conductivity test is a measure of electrolytes leakage from plant tissue. The shorter the maturation period after heading was the greater electrical conductivity (EC) of rice seed. The polymer-coated seed was not different in EC compared with non-coated seed. As soaking time of rice seed increased, EC increased gradually. The EC varied from 9.9 to 20.7$\mu$S $cm^{-1}g^{-l}$ for control plots and from 21.3 to 41.7$\mu$S $cm^{-1}g^{-l}$ for heat-killed seeds which were produced by autoclaving seeds at 121$^{\circ}C$ for 20 minutes. The germination speed (the rate of 5th day) of rice seed was 94% at control plot, 83% at low temperature and 20% at high temperature. Besides, germination percentage was 95% for the control, 92% for the low temperature treatment and 39% for the high temperature treatment. The EC was negatively correlated (r=-0.771$^{**}$) with germination percentage at low temperature. Water uptake in seeds of 30, 40, 50 days after heading (DAH) was greater than that of 20 DAH. Plant height of seedlings was 9.84 cm for the control but 4.32 cm for the high temperature treatment, and the tallest for polymer-coated seed. Dry weight of seedlings was 0.841 g for the control and 0.287 g at high temperature. Besides, the polymer-coated seed was heavier than non-coated seed. The number of roots was largest from 40 to 50 DAH and polymer-coated seed, but was decreased from 20 to 30 DAH. The length of roots was 20.52 cm at control plot and 19.89 cm polymer-coated seed but 8.68 cm for the low temperature treatment and 7.28 cm for the high temperature treatment.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.13
• /
• pp.73-76
• /
• 1973

Protein spectra from 6 species of Gossypium were obtained by disc electraphoresis of seed extracts. Protein extracts were made by soaking 0.5g. of seed in 15ml of Tris-glycine buffer for 24 hours. Gels 24 hours. Gels were stained in 0.5% Amido Black solution for 1 hour, and destained in 7% acetic acid for 72 hours. Nine to 15 bands were visible in each gel. Homologies of Protein bands among the species were determined by migration velocity. Evidences obtained from electrophoretic separation of seed Protein were consistent with those from genetic, cytological, morphological and Phenogenetic methods regarding the origin of New World cultivated cottons. Possibility, however, does not exist to exclude Gossypium herbaceum from one of the Progenitors of New World cultivated cottons from electrophoretic evidences alone.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.60 no.1
• /
• pp.123-137
• /
• 2015

This study was carried out to investigate the effect of pre-germination soaking on germination in 90 Korean soybean varieties and identification of protein in seeds of 7 soybean varieties. The results obtained that germination rate of soybean seeds was decreased as amount of soaking water and soaking duration in number of days. Difference in germination rate of soybean seeds was significant at three days soaking with water volume of 90 ml. Water absorption of seeds was rapidly increased during the first 6 hours, followed by slow increase until 24 hours and then decreased 24 to 48 hours after soaking soybean varieties for bean sprout soaked the lowest amount of water, while soybean varieties for cooking with rice showed the lowest seed water content. Dissolved oxygen (DO) in soaking water was rapidly decreased during the first 3 hours after soaking, and then slowly decreased. Soybean varieties for vegetable and early maturity showed the lowest DO during early soaking periods, but showed higher DO after 24 hours than other groups of soybean varieties. Electrical conductivity and Total Dissolved Solid (TDS) were increased as number of soaking days increased. Soybean varieties for vegetable and early maturity showed the highest electrical conductivity and TDS, followed by those for sauce and paste or cooking with rice, while showed the lowest electrical conductivity and TDS, varieties for bean sprout. Among 90 Korean soybean varieties, varieties which showed the highest germination rate were Jangsu-kong for sauce and paste, Sobaegnamul-kong for bean sprout, Seonheuk-kong for cooking with rice, Seunnokkong for vegetable and early maturity. On the ather hand varieties which showed the lowest germination rate were Iksan and Songhak-kong for sauce and paste, Pangsa-kong for bean sprout, Jinyeul-kong for cooking with rice, Sinlok-kong for vegetable and early maturity. Germination rates of soybean seeds were higher when electrical conductivity, TDS and water absorption of seeds were lower. There were negative correlations between electrical conductivity, TDS and water absorption of seeds and germination rate, while there were positive correlations among electrical conductivity, TDS and soybean seed weight.