Pest Infestation and Recovering in Coconut Orchards in Kui Buri, Prachuap Khiri Khan Province

Abstract

Weather at Kui Buri District is variability with low precipitation and long drought. This weather can cause a risk of pest infestation in various plants including coconut. Thus, effective pest control is required. The current study was conducted during July 2012- July 2015. One hundred and twenty coconut fields were studied for level of infestation of coconut black-headed caterpillar (BHC) and coconut hispine beetle (CHB) every 2 months. The coconut fields were then grouped by level of pest infestation and monitored to determine the recovering of infested coconut. The results showed that 57% of coconut fields were grown in monocrop system. Most of the coconut fields were in rainfed area. In July 2012, BHC was the key pest which severely found in Tambol Khoa Dang, Sam Kratai, Don Yainu, Northern and Southern Kui Buri, Northern Kui Nuen and Eastern Had Kam. While CHB infestation was lightly found in this study. The most CHB infestation area was only in the Middle and Eastern Kui Nuen. CHB infestation was fluctuated 4 months interval. Severity of attacked leaves depended on precipitation levels, the more dry weather the higher severely infestation. Infested coconut plant could be recovering by good cultural practices. Application of chemical injection and fertilizer to tall coconut tree cultivar (>12 m) for at least 8 months could increase non-infested leaves (n>13) and for 1.5 years to reach the normal yield. Effective control could remain non-infested leaves (n>13) after chemical injection for 23 months. While releasing Goniozus nephantidis in the short coconut tree cultivar could recover and reduce in number of BHC. The dead BHC larva was found but G. nephantidis adults emerge from larva sampled from the field was not found.