Phosphorus nutrition of tobacco seedlings grown in greenhouse float culture¹

Technical Contribution No. 4299 of the South Carolina Agricultural Experiment Station.

Abstract

Little work has been done investigating phosphorus (P) nutrition in tobacco seedling production. Three greenhouse experiments were conducted in 1993 and 1994 to determine the influence of P on seedling growth. Treatments consisted of fertilizers containing from 0 to 10% phosphorus. Growth parameters measured in all experiments included seedling dry weight, stem length, and tissue P concentration. Reducing P rate did not affect any growth parameters until the solution nitrogen (N): P ratio became less than 20: 1. The 0 P treatment did not produce any transplantable seedlings in two of three experiments. Final seedling usability was not affected as long as at least a 20: 1: 20 ratio fertilizer was used. Seedling growth in the field, as well as final leaf yield, was not affected by reducing P from 10% to 1%. Data suggest that previous greenhouse fertility recommendations contained excess phosphorus and should be reduced to at least a 20: 5: 20 ratio fertilizer.

Notes

Technical Contribution No. 4299 of the South Carolina Agricultural Experiment Station.