Abstract Pyrethroid insecticides were compared with a standard treatment (Lannate) at the Yuma Valley Experiment Station in Oct. Seed was planted on 40 inch beds Aug 20. Each plot consisted of single-row 50-ft long with 4 replicates in a randomized block design. The test area was treated Sept 11 with Diazinon (1 lb ai/acre) to control the lesser cornstalk borer. Scheduled treatments for the corn earworm were started Oct 11 (25% of the plants silking) for both the 2 and 4-day intervals. All sprays were applied at a rate of 14 gpa with a CO2 pressurized backpack sprayer operated at 40 psi. Evaluations were made on Oct 31 by harvesting 25 ears from each replicate. Categories selected for evaluation were: 1) clean - no damage; 2) slight -tip injury only; 3) unmarketable - extensive injury. Some fall armyworms were present with entrance and damage near the middle of the ears.
Abstract Eleven acaricidal compounds were evaluated for the control of the carmine spider mite at the Yuma Experiment Station during Sept and Oct. The population increase of mites followed a scheduled control program for lepidoptera larvae (particularly the pink bollworm). The test was a block design with 4 replications per treatment. Plots within the blocks were 2-row, skip 2 with 6 ft alleys in row between plots. Sprays were applied Sept 10 with a pressurized CO2 backpack sprayer (40 psi) at the rate of 40 gpa. Post treatment counts were made from 25 leaves/ plot picked at random and processed in the laboratory with a mite washer and separator technique.
Abstract Four numbered compounds were evaluated for control efficacy in November and December: PP067 and PP199 50DG; and PGP-102 and PGP-103 40EC. Plots were treated November 18 at the rate of 25 gallons of spray per acre with a ground sprayer to replicated plots (4X) of .25 acre each. Mite counts were recorded on November 21, 26, and December 1. Figures represent the number of mites per head based on 5 heads per plot. These grain heads were rapped or beaten on a seed sieve over a plastic funnel. The grain heads were used in preference to leaves since they were heavily infested to the extent of considerable webbing.
Abstract Fourteen insecticides were evaluated in this test on alfalfa for control and effect on the insect fauna. Plots measuring 10 × 10 ft were utilized on the Yuma mesa. Each treatment as shown in table was replicated three times. Applications were made with a hand sprayer at 20 psi May 7 covering the treated area as uniformly as possible by using 20 seconds/plot. The amount of spray per acre was approximately 25 gal/acre.
Abstract Several chemical sprays were evaluated during Feb at the Valley Experiment Station. Population levels were lower than 1978 due to lower temperatures during Jan but were increasing throughout the valley. Treatments were applied Feb 7 with a C02-backpack sprayer at the rate of 25 gpa using 40 psi. Each treatment was replicated 4 times to plot of 10 × 10 ft. During Feb the aphid population in this field was 60% blue alfalfa aphid and 40% pea aphid.
