Rate response of 1,3-dichloropropene for nematode control in spring squashin deep sand soils

The solid fumigant 1,3-dichloropropene (1,3-D) formulated with chloropicrin is viewed as a likely alternative for replacing methyl bromide in Florida when the latter is phased out in 2005. Therefore, it behooves us to learn m ore about using 1,3-D in deep, sand soils. Two trials were conducted on spr ing squash to determine the most effective rate of 1,3-D for the control of Meloidogyne spp. Rates tested included 0, 56, 84, 112, and 168 liters/ha o f 1,3-D applied broadcast with conventional chisels 30 cm deep. The chisel traces were sealed by disking immediately after fumigant application. Cucur bita pepo cv. Sunex 9602 was sown 7 days after fumigation. The population d ensity of plant-parasitic nematodes in soil and root-knot nematode galling severity was determined. The number of fruit and yield were higher in all p lots that received 1,3-D than in untreated controls. The number of Meloidog yne spp. second-stage juveniles was lower in all fumigated plots in trial 1 at both 34 and 65 DAP, and in trial 2 at 65 DAP, than in the untreated con trol. The severity of root galling was decreased with all treatments in bot h trials, with broadcast rates of 84, 112, and 168 liters/ha providing the best control of root-knot nematodes in spring squash grown in sandy solid. Satisfactory management of root knot on squash grown in early spring months in north Florida can be achieved with low rates of 1,3-D.