The Outbreaking of Rice Blast (Pyricularia oryzae Cav.) in Chia-Nan Area
S. C. Hwang and C. C. Tu
Rice blast (Pyricularia oryzae Cav.) mainly attacked on the first crop of rice in Chia-Nan area. The second crop of rice could be attacked by rice blast but not serious. There were 8600 ha and 3500 ha of rice attacked by leaf blast and panicle blast, and occupied 12.63% and 4.96% of the total cultivated acreage, respectively. There were 730 ha and 340 ha for leaf blast and panicle blast, and occupied 0.71% and 0.33% of the total cultivated acreage, respectively in second crop of rice.
The outbreak of rice blast was much serious in mountain area or general cultivated area, but less in seashore area. The right outbreak seasons for leaf blast were from mid of February to mid of April but the panicle blast was from mid of April to June.