Influence of Nutritional Conditioning on Muskmelon Transplant Quality and Early Yield

Abstract

Abstract Pretransplanting nutritional conditioning (PNC) regimes were evaluated for their effects on improving tolerance to transplant shock and increasing early fruit production. Muskmelon seedlings (Cucumis melo var. reticulatus L. ‘Magnum 45’) were fertilized twice weekly with solutions containing N, P, and K to determine nutrient needs required to produce high-quality transplants. Seedling height, stem diameter, leaf area, shoot and root dry weights, leaf number, and shoot: root ratios of 27-day-old transplants increased as N rates increased from 10 to 250 mg liter−1. These growth variables also increased with P from 5 to 25 mg·liter−1 but decreased as P increased from 25 to 125 mgliter−1. Increasing K rates from 10 to 250 mg·liter−1 increased seedling height, stem diameter, and leaf area. Nine PNC regimes ranging from low to high N-P-K status were tested under field conditions to determine any long-term advantage. Generally, as PNC levels increased, transplant shock (percentage of necrotic leaves) increased as measured 12 days after transplanting. However, vining, female flowering, fruit set, and early yields increased as PNC levels increased. A high level of PNC (250N-125P-250K, mg·liter−1) conditioned transplants to overcome shock and to resume growth sooner and yield earlier than those at lower PNC levels.