Effects of Different Seeding Rates on Disease Incidences of Wheat Sharp Eyespot and Selection of Fungicides

Research in Plant Disease 2012;18(1):10-16.
Published online March 30, 2012.

밀 잎집눈무늬병의 발생에 파종량이 미치는 영향과 방제 약제 선발

박종철 ( Jong Chul Park ) , 이은숙 ( Eun Sook Lee ) , 조광민 ( Kwang Min Cho ) , 이미자 ( Mi Ja Lee ) , 강천식 ( Chun Sik Kang ) , 최재성 ( Jae Seong Choi )

Effects of Different Seeding Rates on Disease Incidences of Wheat Sharp Eyespot and Selection of Fungicides

Jong-Chul Park*, Eun-Sook Lee1, Kwang-Min Cho, Mi-Ja Lee, Chun-Sik Kang and Jae-Seong Choi

Department of Rice and Winter Cereal Crop, National Institute of Crop Science, Rural Development Administration, Iksan 570-080, Korea
¹Biological Research Team, Agricultural Research Center, Hankook Samgong Co. Ltd., Kimje 576-942, Korea

Received: August 11, 2011 Revised: January 27, 2012 Accepted: February 28, 2012

Abstract

This study was conducted to examine the effects of the seeding rate on the disease incidence of sharp eyespot (Rhizoctonia cerealis) on three different varieties and to select effective chemicals to control the disease. When the seeds were sown twice as many as the recommendation, the disease incidence increased by approximately 13%. However, the susceptible variety ‘Jopummil’ alone showed the significantly enhanced disease incidence at a two-fold seeding rate. Two chemicals such as Hexaconazole EC and Tebuconazole EC highly inhibited the fungal growth on agar medium. However, two strobilurin fungicides such as Pyraclostrobin EC and Trifloxystrobin SC were relatively weak. The fungicides tested displayed the similar in vivo antifungal activities as in vitro activities. Hexaconazole EC and Tebuconazole EC showed the strongest both protective and curative activities and the protective activities of the chemicals were generally higher than the curative activities. Hexaconazole EC and Tebuconazole EC controlled the disease by 64% and 73%, respectively, and the two chemicals reduced the disease by 45% and 39%, respectively, when they were applied one day after pathogen inoculation. These results indicate that both Hexaconazole EC and Tebuconazole EC could be used to control sharp eyespot on wheat.

Key Words: Chemical control, Seeding rate, Sharp eyespot, Wheat