Search Results

You are looking at 1 - 1 of 1 items for

  • Author or Editor: W.M. Colt x
  • All content x
Clear All Modify Search
Free access

Esmaeil Fallahi, Brenda R. Simons, John K. Fellman, and W.M. Colt

Influence of different quantity and timing of nitrogen application on various physiological aspects of `Redspur Delicious' apple, including nutritional partitioning, bud initiation, fruit set, yield, fruit quality and nitrate movement in the soil were studied over several growing seasons. Urea at the rates of: 40.2 Kg/ha; 160.8 Kg/ha; 281.3 g/ha; 401.9 Kg/ha; 522.4 K /ha were applied. Each rate of urea was applied: all at full bloom; half at full bloom and half at late spring; or all in fall. In 1993, time of application did not influence yield, fruit weight, color or soluble solids at harvest. Trees that received 401.9 and with 522.4 Kg/ha had higher yield than those with other quantities. Trees with 160.8 and 281.3 Kg/ha had higher yield than trees with 40.2 Kg/ha. Fruit weight in all quantities, except that of 522.4 Kg/ha, were similar. Fruit weight of trees with 522.4 K /ha was reduced. Fruit color was reduced as N quantities increased. Trees with 40.2 Kg/ha N had lower soluble solids than all other quantities. A high level of N increased ethylene and respiration in the fruit. Thus, if the poor color of fruit is due to high nitrogen, a long delay in harvest to improve the color could lead to an over ripe fruit. A preliminary test did not indicate harmful levels of nitrates movement in the soil.