Abstract
Abstract Fifty-six plots measuring 6.1 × 9.1 m were established in an alfalfa field 5 km south of Manhattan. Treatments were replicated 4 times in a randomized complete block design. Insecticide applications were made 17 Apr using a COa-pressured backpack sprayer equipped with 70-degree hollow-cone nozzles, which delivered 187 liter/ha. Alfalfa had reached 16 cm high when a late frost killed all projecting top growth. At the time of treatment the alfalfa had regrown to 13 cm; wind conditions were calm. Ten stems, along with associated alfalfa weevil larvae and pea aphids, were collected from undisturbed areas within each plot on each sample date. Samples from each plot were individually bagged and returned to the lab for examination. Sweep nets were not used to collect samples because scattered dead stems from the previous season’s alfalfa projected above the live canopy and would have hindered sampling. Pretreatment counts were taken and then repeated at 1, 3, 5, 7, 10, 13, and 21 days posttreatment. Data were analyzed by analysis of variance (PC-SAS, SAS Institute 1986) with mean separation accomplished using a protected LSD procedure.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
