Emergence of Phorate-Treated Cotton Seed as Affected by Substrate Moisture and Temperature

Abstract

Deltapine-15 cotton seeds with and without phorate were planted in washed river sand at 2 moisture levels and 4 temperatures. Regardless of treatment, seedling emergence was favored by a moisture level of 50% of field capacity as compared with one of 75%. The final stand counts at 86[degree] and 77[degree]F were comparable for the phorate-treated and untreated seed. Phorate, however, caused a marked reduction in the rate and total emergence at both 72[degree] and 67[degree]. A similar experiment with another lot of seed of the same variety showed that seedling emergence with and without phorate seed treatment were comparable at 80[degree] and 67[degree]. It was concluded that reduction in emergence in phorate-treated seed often found may be due to inferior quality of seed as well as to low temperatures and high levels of soil moisture.