FEASIBILITY OF IMPROVING CUCUMBER YIELD WITHOUT CHEMICAL CONTROL IN SOILS SUSCEPTIBLE TO NEMATODE BUILDUP

Studies were conducted for 2 years in root-knot-nematode-infested soil s to determine growth and yield response of 'Dasher II' cucumbers (Cuc umis sativus L.) to double-cropping with nematode-resistant tomatoes ( Lycopersicon esciilentum Mill.). using hematode-free cucumber transpla nts and preplant treatment with ethoprop nematicide. Cucumbers grown f ollowing the nematode-resistant 'Celebrity' tomato during the same sea son produced significantly more plant dry weight, more fruit per plant , and higher premium and total yields than did cucumbers double-croppe d with the nematode-susceptible 'Heatwave' tomato in both years. The c ucumber produced longer stems in 1992 and fewer culls in 1993 followin g resistant tomatoes. Cucumber plants raised in nematode-free soilless mix for 3 weeks before transplanting produced significantly longer st ems and more plant dry weight than did direct-seeded cucumbers in 1992 , but not in 1993; however, they produced significantly higher premium yield in both years, and higher total yield, more fruit per plant, an d fewer culls in 1993. Preplant treatment with ethoprop significantly increased cucumber stem length, dry weight, premium and total yield, a nd number of fruit per plant in 1992 but not in 1993. Ethoprop treatme nt had no effect on the percentage of culls in either year. Chemical n ame used: O-ethyl S,S-dipropyl phosphorodithioate (ethoprop).