Inhibitory effects of phorate, disulfoton and carbofuran on the germination of wheat, lucerne and turnip seeds : A dissertation submitted in partial fulfilment of the requirements for the degree of Bachelor of Horticultural Science (Honours) in the University of Canterbury

Abstract

These four experiments investigated the effects of the insecticides carbofuran, disulfoton and phorate on the germination of wheat, lucerne and turnip seeds. They all used the roll towel germination technique.

The first experiment was a determination of germination percentage for a check on the accuracy and uniformity of the technique. The second was the germination of the seeds between paper strips treated with from 0.0001% to1.0% active ingredient. The third was the germination of seed imbibed by soaking for 12 hours in 1.0% active ingredient. The fourth was a combination of soaking seeds for 3, 6, or 12 hours in 0.0001% to 1.0% active ingredient of an insecticide, then germinating them.

The first experiment showed the roll towel technique to be uniform and the seeds to have high germination percentage - 100% for wheat and 95% for lucerne and turnip. The second showed treating a paper surface prior to germination gave no effect at any concentration. The third showed a decrease in germination percentage with seeds imbibed in an insecticidal solution, reducing it in the first 42 hours by 90% in wheat, 50% in lucerne and 75% in turnip. All the insecticides affected the same seeds similarly. The final experiment showed increasing duration of seed soaking decreased germination regardless of treatment and the 1.0% active ingredient soak was significantly more toxic to wheat seed for all insecticides. Phorate was possibly less toxic to lucerne, and carbofuran more toxic to turnip.