REDUCTION OF INSECT INFESTATION AND FUNGAL INFECTION BY CULTURAL-PRACTICE IN DATE GARDENS

'Deglet Noor' date gardens were subjected to various degrees of sanitation of damaged dates to observe effects on infestation of a carob moth, Ectomyelois ceratoniae (Zeller), raisin moth, Cadra figulilella (Gregson), four species of nitidulid beetles, and fungal infection. In a year of above average rainfall, 1984, infestation by carob math, raisin moth, and nitidulid beetles was significantly reduced at harvest (P < 0.05) in areas sanitized by the weekly removal of damaged dates from the ground. Fallen dates consisted of "Junedrop" and khalal stage dates, many of which had been infected by fungi (chiefly Aspergillus and Alternaria spp.) as a result of rain. These provided a substrate conducive for the buildup of insect populations in July and August. However, in a year of no summer rainfall and above-average summer temperatures (1985), June-drop dates became completely desiccated in the palms and on the ground, and fungal infection of khalal stage dates was inhibited. Consequently, populations of E. Ceratoniae, raisin moth, and nitidulid beetle were greatly suppressed by the lack of suitable substrates and no benefit by sanitation was indicated. © 1990 Entomological Society of America.