Effect of Oxamyl, Fenamiphos and Carbofuran on an Important Plant Parasitic Nematode in Declined Longan Orchard

Abstract

Rotylenchulus reniformis was prevalent among the plant parasitic nematodes observed in the soil around the root system of longan in declined longan orchards. It's approximately represented 80% among the other. Three differentkinds of nematicides namely oxamyl, fenamiphos and carbofuran were then selected to apply into the soil of three declined orchards, one in Chiang Mai and two in Lam Phun. The three nematicides were applied to experimental sites only one time at the beginning of the study. Oxamyl with the rate of 4.32 liters of active ingredient (a.i.) per 1,600 square meters were mixed with water and thoroughly applied to 900 square meters of tested area. Then 320 grams of a. i. of fenamiphos and carbofuran per 1,600 square meters were mixed with sand and similarly applied to 900 squared meters of tested areas. After the soil samples were collected 5-7 times and extracted for nematodes, it was revealed that the number of nematodes especially R. reniformis were not reduced at all in all treatments of study. During a period of 4-5 months, all nematicides were not effectively reduced the number of population of R. reniformis in declined longan orchards.