Cabbage Looper and Beet Armyworm Control on Lettuce, 1978

Cabbage looper and beet armyworm control on Iceberg lettuce 'Climax' from plant emergence to plant thinning was investigated in Imperial Volley, California. Two types of lettuce planting practices are used in the Imperial Valley. They are the following: Precision-where seeds are planted in pairs, two inches apart from each other and pairs were planted at ten inch intervals; Standard-one seed every two inches apart. Each planting practice was treated as an independent plot until thinning. After thinning, the two plantings were combined in the counting of the larvae because the plant spacings were now identical. The plots were 2 beds (40 inch double planting), 50 ft long with 4 replicates in a randomized block design. Treatments were applied using a hand sprayer equipped with a CO2 cylinder fitted with 4 nozzles (#8004) per bed, operated at 60 gals/acre and 30 psi. The treatments were made on Oct 2 at plant emergence and on Oct 17 when plants were in the 4-5 leaf stage.