EFFECTS OF STARTER FERTILIZER, GRANULAR PHOSPHORUS FERTILIZER, TIME OF FERTILIZATION, AND SEEDLING PHOSPHORUS CONCENTRATION ON FLUE-CURED TOBACCO GROWTH AND NUTRITION

Abstract

The advent of greenhouse seedling production has resulted in the production of transplants with a different type of root system and growth habit at the time of transplant compared to traditional bare-root transplants. These differences may result in a different response to early-season fertilization. In addition, fertilization practices have changed to favor post-transplant application of nutrients. Field studies were conducted from 1994 to 1997 to determine the effects of starter fertilizer, conventional phosphorus (P) fertilizer rate, delayed fertilization, and the P concentration of transplants on early growth, nutrient uptake, date of flowering, yield, quality, and cured leaf nutrient content of flue-cured tobacco grown on high P soils. Starter fertilizer increased early-season growth and nutrient uptake and resulted in slightly accelerated flowering. Yield and visual quality were not affected except for a slight visual quality improvement in one experiment. Phosphorus fertilization rate had little effect on most parameters measured, with only a small yield increase in one experiment. Delayed fertilizer application lengthened the growing season slightly, but did not have detrimental effects on yield or quality index. Lower than normal transplant P tissue concentration did not affect subsequent growth, yield, or quality. These experiments indicate that there is little advantage to using starter fertilizer on flue-cured tobacco grown on high-P sandy soils and that delayed fertilization is not detrimental to final yield and quality. This study also confirms that the use of height-restricting low-P nutrient regimes during greenhouse production of seedlings is not detrimental to field performance.