A comparison of hydroponic and conventional methods of vegetable transplant production

Traditional float bed culture, common in the production of tobacco transplants, was used to investigate the potential for hydroponic transplant production of peppers and cabbage. Experiments were conducted in the summer and fall, 1998 at The University of Tennessee Agricultural Experiment Station, Knoxville, Tennessee. Two varieties of peppers, 'King Arthur’ bell and 'Grande' Jalapeno, and the cabbage variety 'Charmant' were seeded independently in 128 cell Styrofoam trays in conventional growing media. Pepper trials consisted of a conventional hydroponic treatment, a heated hydroponic treatment and a conventional treatment. Cabbage trials consisted of four treatments; aerated hydroponic, aerated- shaded (30%), and non-aerated hydroponic under both shaded and non-shaded conditions. Transplant growth, vigor, and development were monitored in both experiments and total yield and quality of yield were determined after transplant.

Temperature enhanced the germination rate of pepper with the heated treatment resulting in the fastest germination for the 'Grande' jalapeno variety. Pepper plants in both the heated and conventional hydroponic treatments grew faster and larger than those in the conventional treatment. Total mean fresh and dry weights of both root and shoot material were consistently greater for the hydroponic treatments, with the heated treatment showing the greatest positive trends in plant growth and development.

Pepper transplants from all treatments survived equally well in the field. No differences were observed in days until flowering, first fruit set, early yield, total yield or in fruit quality. A significant difference in yield was observed between varieties with 'Grande' Jalapeno producing the greatest early and total yields.

Cabbage transplants grew faster and were larger when grown in the aerated nutrient solution producing transplants that were taller, heavier and that had wider and longer leaves than in non-aerated treatments. Shading of aerated plants reduced shoot weight, leaf length and leaf width. Total plant stand in the field was less for both aerated treatments with the shade + aeration treatment producing the lowest percentage of surviving plants. There was no difference observed in total percentage of plants producing marketable heads or in marketable head weight. Yields were greatest in the non-aerated treatments with the full sun-aeration plants producing the greatest yield.