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.
Associate Professor. Present address: Coastal Research and Education Center, Clemson Univ., 2865 Savannah Hwy., Charleston, SC 29407.
Received for publication 9 Dec. 1985. Journal Article no. TA 21206 of the Texas Agriculture Experiment Station. Mention of a trade name or proprietary product does not constitute a guarantee or a warranty of the product by Texas A&M Univ. and does not imply its approval to the exclusion of other products that may be suitable. The cost of publishing this paper was defrayed in part by the payment of page charges. Under postal regulations, this paper therefore must be hereby marked advertisement solely to indicate this fact.