| Survey in paddy field in 2013 amount 54 fields as follow : Mueang Chai Nat 13 fields, Manorom 6 fields, Watsing 5 fields, Sapphaya 7 fields, Sankaburi 9 fields, Hankha district 10 fields, Nakhonsawan 1 field, Uthithani 1 field, Singburi 1 field and Suphanburi province 1 field. We begin survey at 15 days after planting to 90 days and used outbreak data sets by week from Department of Agricultural Extension for decision. The survey results show that brown planthopper high in 2 times per year. The first time is in February to March in Mueang Chai Nat and Hankha district because of brown planthopper outbreak in Suphanburi, migrated to Hankha district and influence of southern wind. The second time is in July to August in Mueang Chai Nat, Hankha and Sankaburi... |
