Effect of irrigation level, insecticide and variety on root rot and yield of sweet corn

Summary Irrigation effects on root rot and yield Reducing irrigation during the first 6 weeks after planting reduced root rot of sweet corn at midseason and at harvest, consistent with findings of the past two years. Reducing the early season irrigation level increased yield of Jubilee by 20% because of an increase in the number and size of ears produced. Insecticide effects Vapam reduced midseason radicle root rot slightly. The number of insect bites declined as the number of insecticides applied increased. Insecticides had no effect on root rot at the Vegetable Research Farm, the site with greatest root rot levels. Insecticides may have increased root rot ratings at the Botany farm. There was a positive but weak correlation (R=0.57) between insect damage to Jubilee roots and nodal root rot at the Vegetable Research Farm. Insecticides may have increased yield of Coho (at both irrigation levels) and Jubilee (at the Low irrigation level) at the Vegetable Research Farm. Insecticides increased yield of all varieties in the Botany Farm experiment. Varietal effects Yield of Coho was greater than Jubilee, Kokanee, and Chase at both sites. Coho yields were consistently High under stresses of root rot and insect damage.