Technical notes. Bag treatment to control pests of hooded sorghum

Abstract

Head hooding with paper bags to prevent cross-pollination is an essential feature of sorghum breeding work. Conditions within these bags are ideal for the development of insects such as Heliothis armigera (Hubn.),
Cryptoblabes sp. and Aphis maidis Fitch, and damage by these pests can be a limiting factor in the seed produced for plant-breeding purposes. Control trials using paper bags fully or partially impregnated with an
insecticide by thorough wetting and then drying were carried out at the Biloela Regional Experiment Station during 1955, 1956 and 1958. The bags, made of brown Kraft paper double crown 37, were prepared during the week prior to hooding. Immediately after harvesting, infestation ratings of 0-5 (severe) were recorded for species on each head in trials where pest numbers were high. For the later trials a similar rating range for fungi was used and samples for germination testing were taken.