POPULATIONS AND CONTROL OF PINK-BOLLWORM, PECTINOPHORA-GOSSYPIELLA (SAUNDERS) IN SHORT-SEASON AND FULL-SEASON COTTON PRODUCTION SYSTEMS IN IMPERIAL-VALLEY, CA (LEPIDOPTERA, GELECHIIDAE)

Narrow-row cotton spacing (2 rows/bed, 51 cm apart on 1.02 m bed centers, or 1 row/bed, 0.76 m bed centers) did not affect pink bollworm, Pectinophora gossypiella (Saunders), populations, boll infestations or insecticide control efficiency as compared to conventional row spacing (1 row/bed, 1.02 m bed centers). NoMate PBW applications significantly reduced male moth catches in Delta traps, but no evaluation was possible of the effect on boll infestations. Late-season insecticide applications initiated 3 September significantly reduced the numbers of diapause larvae in soil and plant trash compared to numbers found in soil and plant trash of untreated plots in both the narrow and conventional row spacings. Lint yields in 1981 were significantly higher in untreated narrow row (2 rows/bed, 51 cm apart, 1.02-m bed centers) than in conventional ones (1 row/bed, 1.02 m bed centers). Yields did not differ significantly in narrow and conventionally spaced plots when 6 and 12 insecticide applications initiated 12 July were made to narrow and conventional row cotton, respectively. Five to 6 irrigations were applied to narrow-row plots and 12 irrigations were applied to the conventional plots. There were no significant differences in lint yields in 1982 from plots planted 1 row per bed with bed centers 0.76 or 1.02 m apart and treated in late season (initiated 3 September) with insecticides.