Cucumber pollen germination and tube elongation inhibited or reduced by pesticides and adjuvants

Abstract

Commercial formulations of 5 insecticides: diazinon, dicofol, endosulfan, malathion, and Pyrenone* (6% pyrethrins and 60% piperomyl butoxide); 2 fungicides: captan and Manzate* (zinc and manganese ethylene bisdithiocarbamate); and 9 adjuvants: Fomex*, Multi-Film X-77*, NuTrex*, Dupont Spreader Sticker*, Bio-88*, Target-E*, Bio-Film*, Dupont Surfactant F*, and Regutaid* severely reduced germination of cucumber pollen on an artificial medium. A lesser degree of reduction in germination was caused by the insecticides carbaryl and methoxychlor, the' fungicide benomyl, and the adjuvants Regulaid*, Triton B-1956* and Chevron Spreader Sticker*. Carbaryl, methoxychlor and benomyl were used at spray concentrations of active ingredients recommended on the labels in 100 gal (378.5 liters) of water. The remainder of the pesticides was used at concentrations below label recommendations. Diazinon applied under controlled conditions to hand-pollinated pistillate flowers of cucumbers in greenhouse caused parthenocarpy and fruit abortion.