Slurry Treatments on Grain Seeds, 1982

Abstract

Abstract The primary objective of these tests was to evaluate the effectiveness of Lorsban and Reldan in comparison to methoxychlor and malathion treatments for protection of seeds when treated seeds were exposed to insects in (1) single treatment exposures (STE) and in (2) multiple treatment exposures (MTE), with all containers of treated grain seed stored together. Gustafson Captan 30 DD was applied to 10-lb lots of corn, grain sorghum, and wheat seed in a Batch Lab Treater. Insecticides were added to the slurry treatment mixture as needed for calculated rates. Duplicate 10-lb lots of seed were prepared and stored at ambient room temp for 2 wk before use in STE tests. Each 10-lb lot of treated seed was divided into five 2-lb samples, and each of these was put into a plain paper bag. Five 2-lb bags of the same kind of seed and treatment were placed upright in a 10-qt aluminum pail, which served as an infestatiogn chamber for exposure to insects. Twenty-five laboratory-reared adults of each species of beetles and 25 mature moth larvae were placed in the center of the test chamber and allowed to move freely about the chamber to infest seed as they desired. Each aluminum pail was covered with black cloth held in place with two large rubber bands. All prepared test chambers were kept in a room maintained at 80°F and 50 to 60% RH for 2 weeks before seeds were sieved gently to remove insects. Although all live insects present in each bag of seed were counted and the number recorded, infestation data are shown as the average number of insects in 10-lb duplicate lots of seed. After removing insects, five 2-lb samples were put together in large paper bags to reconstitute each duplicate lot of treated seed. The bags of seed were held at ambient room temp to age 3 months before use in MTE tests. In the latter, 10-lb treatment lots of each kind of seed were placed at random in a 128 ft3 wooden storage chamber held outdoors without benefit of temperature or humidity control. Each chamber was infested initially with 50 insects of each test species per duplicate 10-lb lot of seed; the same number of insects were used to reinfest chambers after 30- and 60-day exposures. Seeds were sieved after exposure to insects for 90 days, and the number of live insects in each 10-lb lot of seed were recorded.