Jae-Kwon Ko

Response of the Resistant Biotype of Echinochloa oryzoides to ACCase and ALS inhibitors, and Effect of Alternative Herbicides

*, Bon-Il Ku, Sin-Koo Kang, Min-Kyu ChoiHong-Kyu Park, Kyong-Bo Lee and Jae-Kwon KoABSTRACT Cyhalofop-butyl and penoxsulam, known for respective acetyl CoA carboxylase (ACCase) and acetolactate synthase (ALS) inhibitor, have been widely using as a post-emergence foliar application for many years in wet-seeded rice field in Korea. Since 2009, control of Echinochloa oryzoides with cyhalofop-butyl and penoxsulam was no longer satisfactory. Greenhouse and experiment in rice field were conducted to confirm E. oryzoides resistance to ACCase and ALS inhibitors and to compare herbicide treatments for control of the resistant E. oryzoides to ACCase and ALS inhibitors. Three resistant E. oryzoides to ACCase and ALS inhibitors accessions were tested for levels of resistance to cyhalofop-butyl and penoxsulam, base on survival rate. Iksan and Kimje accessions were not any affected to the survival by treatment with recommended doses of two herbicides tested. Buan accession displayed an intermediate response of 62 and 72% survival at recommended doses of cyhalofop-butyl and penoxsulam, respectively. Survival rates to herbicides mixed with ACCase and ALS inhibitors at 3.5 leaf stage of E. oryzoides was over 80%. Benzobicyclon+fentrazamide+bensulfuron SC, benzobicyclon+mefenacet+bensulfuron SC, benzobicyclone +cafenstrole+pyrazosulfuron-ethyl GR controlled effectively by 2 leaf stage of resistant E. oryzoides to ACCase and ALS inhibitors. In the field experiment, single treatment of benzobicyclon+ fentrazamide+bensulfuron SC and benzobicyclon+mefenacet+bensulfuron SC failed to control E. oryzoides, but squential treatment of benzobicyclon+thiobencarb SE and benzobicyclon+ mefenacet+

Multiple Disease Resistant Early Maturing Rice Cultivar 'Joil' with High Grain Quality Adaptable to Early Transplanting Cultivation in the Southern Plain Area

Joil’ is a multiple disease resistant early maturing rice cultivar with high grain quality. ‘Joil’ was derived from a single cross between ‘Unbong37’ (cultivar name ‘Unmi’) and ‘HR23156-26-2-3-5’. ‘Unmi’ is an early maturing rice cultivar with high grain quality and resistance to rice blast and stripe virus. ‘HR23156-26-2-3-5’ is an early maturing elite rice line with lodging resistance and cold tolerance. ‘Joil’ was selected through the pedigree method, yield trials, and local adaptability tests. ‘Joil’ was an early maturing rice. The heading date of ‘Joil’ was July 16 in early transplanting cultivation, which was 2 days later than that of ‘Jopyeong’. ‘Joil’ was a lodging resistance rice with a short culm and showed better tolerance to viviparous germination than that of ‘Jopyeong’. ‘Joil’ was a multiple disease resistant rice with resistance against rice blast, bacterial blight, and stripe virus. ‘Joil’ showed higher yield in both early and late-transplanting cultivations than those of the standard rice cultivars ‘Jopyeong’ and ‘Geumo’. ‘Joil’ had enhanced grain quality under high temperature ripening conditions in early transplanting cultivation. The cooked rice had good grain appearance and taste attributes, and this cultivar had a higher head rice ratio than that of ‘Jopyeong’. ‘Joil’, a multiple disease resistant early maturing rice cultivar with high grain quality, would be suitable for early transplanting cultivation in the southern plain area (Registration No. 6792).

Bacterial Blight Resistant Mid-late Maturing Rice ‘Manbaek’ with High Grain Quality

‘Manbaek’ is a bacterial blight resistant mid-late maturing rice cultivar with high grain quality. ‘Manbeak’ was derived from anther culture using the backcross combination, Hopum*2/SR30075. ‘Hopum’ is a mid-late maturing rice cultivar with high grain quality and ‘SR30075’ is a pyramid line carrying three bacterial blight resistance genes. ‘Manbaek’ was selected through the pedigree method, yield trials, and local adaptability tests. ‘Manbeak’ carrying two bacterial blight resistance gene Xa3 and xa5 showed high-level and broad-spectrum resistance against bacterial blight. ‘Manbaek’ was resistant to K3a, mostly virulent race in Korea, and exhibited resistance reaction against 16 Korean bacterial blight isolates. ‘Manbaek’ was a mid-late maturing rice. The heading date of ‘Manbaek’ was August 19th, which was 5 days later than that of ‘Nampyeong’. Manbaek’ was a lodging-tolerant rice with short culm and dark green leaf. Due to the low viviparous germination, ‘Manbaek’ could be a useful material to prevent pre-harvest sprouting. ‘Mabeak’ was resistant to bacterial blight and rice stripe virus, but susceptible to other virus diseases and insect pests. The yield of ‘Manbaek’ was similar to ‘Nampyeong’. ‘Manbaek’ showed excellent grain appearance and good tastes of cooked rice, so that it could contribute to improving the quality of bacterial blight resistant cultivars. ‘Manbaek’, bacterial blight resistant cultivar with high grain quality, is suitable for the cultivation at bacterial blight prone area and has been utilized in the breeding programs for enhancing the resistance against bacterial blight (Registration No. 6069).

Effect of Seedling Raising Shelf Size on Seedling Growth of Rice

Rice seedling raising in shelf apparatus not only saves time but also reduces labor input. However. it sometimes gives weak seedling because of light shading during the seedling growth in shelf. To develop technology for healthy seedling growth in seedling raising shelf, the effect of seedling raising shelf width and Interlayer on seedling growth of rice(cv.Gumyoung) at 95 cm and 125 cm 1n width such as 35 cm, 50 cm and 65 cm Interlayer, respectively was investigated. The seedling quality of rice and occurrence of abnormal seedling on rice seedling were not greatly different in shelf widths, but those were significantly different among shelf Interlayers. As shelf hight was rising, the seedling quality of rice and occurrence of abnormal seedling on rice seedling were increasing and decreasing, respectively. And the rice seedling grown in the seedling raising shelf making with 95cm and 125cm in width by 50cm and 65cm in Interlayer gave better seedling quality and lower occurrence of abnormal seedling on the rice seedling than that grown in the conventional seeding raising shelf with 65cm in width by 20cm in Interlayer. The making shelf with 95cm in width by 65cm in Interlayer and that with 125cm in width by 65cm in Interlayer reduces the cost and expense for shelf body-making and re-moving of growing box etc. based on 1,000 boxes by 24~78% versus the conventional seedling shelf.