• 한국약용작물학회:학술대회논문집
• /
• 2011.09a
• /
• pp.374-375
• /
• 2011

• 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.

• Research in Plant Disease
• /
• v.13 no.3
• /
• pp.157-163
• /
• 2007

Hot water treatment that is the most appropriate seed disinfection method for organic vegetable farming was evaluated in this study. Among the leafy vegetable seeds lettuce that was the most sensitive to hot water was suitable to treat at $45^{\circ}C$ for 25 min, while Chinese cabbage and radish seeds were optimally treated at $50^{\circ}C$ for 25 min. The treatments resulted in similar or higher seed germination rate than non-treated seeds and promoted plant growth. In addition, fungi such as Alternaria, Aspergillus, Penicillium, or Mucor grown on the seeds were suppressed over 90% and the bacterial growth on lettuce seeds reduced 98.5% by the treatment. Among the fruit vegetable seeds pumpkin that was vulnerable to hot water was suitable to treat at $50^{\circ}C$ for 15 min, while cucumber and hot pepper seeds revealed optimum treatment at $50^{\circ}C$ for 25 min as chinese cabbage and radish. The treatment also showed similar or higher seed germination rate and growth than non-treated seeds. Furthermore, fungi such as Rhizopus, Aspergillus, Penicillium or Mucor grown on the seeds reduced from 72.0% to 95.4%. The bacterial growth on cucumber and red pepper seeds was suppressed from 65.5% to 86.0% by the treatment. Results indicated that the hot water treatment is practical for disinfection of organic vegetable seeds and the optimum temperature and soaking time varied among the seeds.

• Journal of Radiation Industry
• /
• v.17 no.2
• /
• pp.199-207
• /
• 2023

Since seeds can be directly used as food resources as well as for crop cultivation or preservation of genetic resources, it is essential to develop high-quality seed processing technology to increase agricultural productivity. Seed treatment means processing technologies of seeds through physical or chemical treatment processes from after harvesting seeds to before sowing of seeds to improve germination and growth rate, durability, and immunity, etc. Since chemical seed treatment technology using pesticides or plant growth regulators has problems of environmental pollution and human toxicity, it is desired to develop an alternative technology. As a physical seed treatment method, various technologies such as ionizing radiation, plasma, microwave, and magnetic field are being developed, and some of them are being used practically. In this paper, I will summarize the mechanism of seed priming and disinfection, and the advantages and disadvantages of application, focusing on these physical seed treatment methods. Low dose or moderate intensity ionizing radiation, microwave, low-temperature plasma, and magnetic field treatments often promoted seed germination and seedling growth. However, effective removal of direct seed pathogens at these treatment intensities appears to be difficult. And it has been shown that relatively high-dose electron beam treatment using low-energy electron beams kills microorganisms on the seed surface and hull layer while not damaging the inner tissue of the seed, and is also effectively used for seed treatment on a commercial scale. In order to put the physical seed treatment technology to practical use in Korea, it is necessary to develop an economical scale treatment device along with the development of individual treatment technology to each crop.

• Research in Plant Disease
• /
• v.10 no.2
• /
• pp.87-93
• /
• 2004

Rhizome rot of ginger, caused by Pythium myriotylum, a major limiting factor for its production, has occurred annually, but become severe, especially in hot and humid years with frequent rainfalls in Korea. Most studies on rhizome rot have been carried out since 1980s in the National Institute of Agricultural Sciences and Technology, Honam Crop Experimental Station and Choongnam Provincial Rural Development Administration. Many aspects of rhizome rot, such as survey of the disease incidence, taxonomy, pathogenicity and physiology of pathogen, and ecology of soilborne inocula have been studied in the researches. However, intensive studies have been concentrated on management technologies of the disease including seed-rhizome disinfection, soil sterilization, evaluation of cultivar resistance, and fungicide application, and most developed technologies have been used in commercial farmings. In future, development of resistant varieties and simple soil disinfection technologies applicable in Korean condition and economically feasible fungicide application technology have to be developed for better management.

• Korean Journal Plant Pathology
• /
• v.14 no.3
• /
• pp.253-259
• /
• 1998

Effects of soil disinfection, fungicide application, and narrow ridge cultivation on ginger rhizome rot development were examined in two naturally-infested fields at Seosan, Choongnam province. Soil disinfection treatments were assigned to main plots, and fungicide and ridge treatments to sub-plots in a split plot design with three replications. The rhizome rot started in late July, and progressed rapidly until late September with the peak incidence in mid-august to early September. Soil disinfection by dazomet application showed the most prominent inhibition effects in both fields, where the disease was reduced by the treatment from 17.5% to 4.8% in one field, and from 51.0% to 2.2% in the other field. Three to five applications of fungicide metalaxyl-copper during the growing season inhibited the disease by 89.7% in one field, but less effectively in the other field. Narrow ridge cultivation reduced the disease effectively by 78.1% and 63.9%, compared to the unridged control plots in each field, respectively. Germination rate of seed-rhizomes and growth of ginger plants were similar between treatments, except when the plots received improper aeration after applying dazomet, and then the germination rate was significantly reduced. The greatest yields were obtained in the disinfected plots, regardless of rhizome rot incidence, except one control plot with very little disease. Ginger yield was negatively correlated with disease severity. However, the yield of ridge plots averaged 58∼59% compared to those of the unridged plots, due mainly to the half planting rate of the ridge plots. In spatial progress, the disease in the disinfected plots started from a single focus of the inoculum, and spread into the adjacent areas only, whereas in the untreated plots, the disease started from many foci that were distributed over the plot, and rapidly progressed to make an epidemic during the season. The soil density of P. myriotylum in the disinfected plots was not changed or, if not, increased slightly during the season. However, in the untreated plots it increased rapidly to reach the density 3 to 5 times greater by the end of the season.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2005.04a
• /
• pp.126-127
• /
• 2005

• Korean Journal of Plant Resources
• /
• v.19 no.2
• /
• pp.204-208
• /
• 2006

Soybean sprout decay during its culture should be one of serious problems. The study was carried out to clarify the effect of water imbibition and acetic acid treatments on growth and morphological characters of the soybean sprouts. The soybean seeds of 3 cultivars (cv. Eunhakong, Pungsannamulkong and Junjery) imbibed in pure water or 0.l% acetic acid for 3 minutes before soaked for 6 hours into 1 ppm BA solution and aerated for 3 hours immediately before 6 day culture. On the 6th day, the sprouts were classified into 4 categories on the base of hypocotyl length; > 7cm, 4 to 7cm, > 4cm and not germinated and seed floating rate, their morphological characters, fresh fraction weights and productivity were measured. The best water imbibition for seed cleaning was to soak the seeds for 5 minutes and then to aerate soak them for 40 minutes. In Pungsannamulkong and Junjery, percentage of the sprouts with hypocotyls of longer than 4 cm was higher in water imbibition than in acetic acid treatment for seed disinfection although in Eunhakong there was no significant difference between the two treatments. Eunhakong and Junjery had greater lateral root formation rate and its number per sprout in water imbibition than in acetic acid treatment but Pungsannamulkong showed reverse result. Eunhakong and Pungsannamulkong, furthermore, had more total fresh weight in acetic acid treatment than in water imbibition but Junjery showed reverse result, although there was no significant difference between the two treatments in productivity of mass production system.

• Mycobiology
• /
• v.51 no.4
• /
• pp.195-209
• /
• 2023

The seed borne disease such as bakanae is difficult to control. Crop yield loss caused by bakanae depending on the regions and varieties grown, ranging from 3.0% to 95.4%. Bakanae is an important disease of rice worldwide and the pathogen was identified as Fusarium fujikuroi Nirenberg (teleomorph: Gibberella fujikuroi Sawada). Currently, four Fusaria (F. fujikuroi, F. proliferatum, F. verticillioides and F. andiyazi) belonging to F. fujikuroi species complex are generally known as the pathogens of bakanae. The infection occurs through both seed and soil-borne transmission. When infection occurs during the heading stage, rice seeds become contaminated. Molecular detection of pathogens of bakanae is important because identification based on morphological and biological characters could lead to incorrect species designation and time-consuming. Seed disinfection has been studied for a long time in Korea for the management of the bakanae disease of rice. As seed disinfectants have been studied to control bakanae, resistance studies to chemicals have been also conducted. Presently biological control and resistant varieties are not widely used. The detection of this pathogen is critical for seed certification and for preventing field infections. In South Korea, bakanae is designated as a regulated pathogen. To provide highly qualified rice seeds to farms, Korea Seed & Variety Service (KSVS) has been producing and distributing certified rice seeds for producing healthy rice in fields. Therefore, the objective of the study is to summarize the recent progress in molecular identification, fungicide resistance, and the management strategy of bakanae.

• Korean Journal of Agricultural Science
• /
• v.20 no.1
• /
• pp.18-24
• /
• 1993

This experiment was focused on determining the potential of sodium hypochlorite (NaOCl) as fungicide against seed-borne fungi. Effects of NaOCl to control seed-borne fungi were compared to the those of Benlate T in several crop seeds. 1. The effect of NaOCl on disinfection of sesame seeds without imparing germination was highest in the range of 1-2% solution for 10 min. Also, a 30 min immersion of rice seed in 1-2% solution reduced incedence of seed-borne fungi. 2. Alternaria spp. in seeds of radish and chinese cabbage and Colletoricum spp. in pepper were significantly reduced by a 10 min immersion of seeds in 1% NaOCl. 3. The effective control range of NaOCl for seed-borne fungi was much wider than that of Benlate T in sesame seeds. No clear difference between chemicals was found in rice seeds. However, germination of seeds were impaired at 1-2% NaOCl immersion for more than 1 hour.