Factors Influencing the Citrus Nematode and Its Control On Citrus Replants in Arizona1 )

Abstract

A preplanting soil fumigation experiment was done under hot desert conditions in Arizona to study citrus nematode control and response of young grapefruit trees planted in place of old infected trees. D-D was applied at the rates of 425 and 850 liters per hectare. Untreated plots served as controls. Almost complete control of citrus nematodes over a 3-year period was obtained at both levels of fumigation and also in the unfumigated plots. Control in the untreated plots was probably due to the high soil temperature on unshaded soil around the young trees. As the trees grew and provided shade, the nematode population increased in the untreated plots. Tree measurements taken annually for 6 years showed a steady growth rate but no differences in rate of growth of differently treated trees.