Browsing Cotton Report 1988 by Authors
Field Evaluation of a Presence-Absence, Sequential Sampling Plan for Pink Bollworm EggsHutchinson, Bill; Stroschein, Debra; Beasley, Bud; Martin, Jeanette; Henneberry, Tom (College of Agriculture, University of Arizona (Tucson, AZ), 1988-03)During 1987, a sequential sampling plan for pink bollworm eggs was field-tested in eight 40-acre fields in the Palo Verde Valley, CA. Final analysis of the sequential procedure, including the time necessary to collect and check all bolls, required an average sampling time of 16 minutes/field, approximately a 70% savings over the fixed sample size of 160 bolls/field. Using the sequential plan, the number of bolls examined averaged 46.75/field. The sequential sampling plan error rate for making no-treat recommendations when a field actually required treatment (i.e., actual egg infestation 6%) averaged only 6.4% throughout the season. A final sequential sampling chart, based on the field validation data, is presented.
Pink Bollworm Egg-Larval Survivorship in Cotton Treated with InsecticidesHutchinson, Bill; Beasley, Bud; Henneberry, Tom (College of Agriculture, University of Arizona (Tucson, AZ), 1988-03)Pink bollworm egg -larval survivorship in insecticide -treated fields averaged (± SE) 19.8% (± 2.3) for the F2 and F3 generations developing during the primary boll producing time of the year (July and August). These observations have been useful in developing a simulation model of pink bollworm population dynamics.