Results of 7 years' experiments conducted in South China indicated that root-zone application of systemic insecticides effectively controlled nearly all the potential insect pests of rice—the yellow stem-borer, the striped stem-borer, the pink borer, the rice leaf folder, the rice gall midge, the brown planthopper, the greem leafhopper, the rice thrip and the rice weevil. Altogether, 16 compounds have been evaluated for the control of various species. Applications of carbofuran mixed with derivatives of nereistoxin (padan, thiocyclam or dimehypo) in the root-zone were found to be most effective against the major insect pests. The merits and demerits of root-zone applications has been discussed in this paper.
