NITROGEN SUPPLY DURING GREENHOUSE TRANSPLANT PRODUCTION AFFECTS SUBSEQUENT TOMATO ROOT-GROWTH IN THE FIELD

Tomato transplant (Lycopersicon esculentum Mill.) root growth in the field was directly related to N level supplied to the transplants as seedlings in the greenhouse. Root growth in the field increased exponentially when N was applied at 50 to 350 mg-liter-1. Transplant growth in multicelled trays increased in a sigmoidal fashion with N, up to 200 mg-liter-1. The optimal N range for maximum survival, growth, and early yield in the field was from 100 to 200 mg-liter-1. Strength of the seedling stem increased with N level curvilinearly. Seedling survival in the field was highly correlated with seedling stem strength.