Submitted to: Journal of Applied Horticulture
Publication Type: Peer reviewed journal
Publication Acceptance Date: 9/14/2009
Publication Date: 3/1/2010
Citation: Tworkoski, T., Scorza, R., Glenn, D.M. 2009. Leaf N and P in different growth habits of peach: effects of root system morphology and transpiration. Journal of Applied Horticulture. 11(2):95-98. Interpretive Summary: Adequate mineral nutrition is critical for high fruit quality and sustained yield of fruit trees. One important role of root systems is to successfully compete for nutrients such as nitrogen (N) and phosphorus (P), which are often present in low quantities in the soil. In this experiment, peach trees with different shoot and root growth habits were evaluated for leaf N & P concentrations after fertilizer applications in the greenhouse and field. The data indicated that Compact peach trees with fibrous roots systems have an advantage to absorb nutrients such as P when it is present in low concentrations in the soil. However, under conditions of high soil fertility, the fibrous root systems of Compact trees did not improve nutrient uptake, and Pillar trees with greater water movement capacity had greater nutrient uptake. Breeding programs have produced different growth habits of peach with diverse root systems and water movement rates that may affect nutrient uptake. Consequently, the selection of tree growth habit should be considered in soil management plans. Growth habits with more fibrous root systems may require reduced inputs of some nutrients such as P. Selection of peach trees with different root systems or with high water movement capacities could increase the efficiency of fertilization and reduce the use of applied fertilizers.
Technical Abstract: Adequate mineral nutrition is critical for high fruit quality and sustained yield of fruit trees. In this experiment, peach [Prunus persica L. (Batch)] trees with different shoot and root growth habits were evaluated for leaf nitrogen (N) and phosphorus (P) concentrations after fertilizer applications in the greenhouse and field. In the field during 2008, Compact trees had higher root length density than Pillar and Standard trees [6.2, 3.8, and 3.7 mm cm(-3), respectively]. Compact trees also had higher foliar P (0.21 percent) but the same N (1.3 percent) as Standard and Pillar trees (P concentrations of 0.14 and 0.11 percent, respectively) when fertilizer was applied once in the greenhouse. Following multiple applications of fertilizer, Compact leaves had the same P (approximately 0.21 and 0.29 percent in the greenhouse and field, respectively) as the other growth habits. After multiple fertilizer applications, Pillar trees had the greatest increase in foliar N and P which was associated with high transpiration rates. Pillar, Compact, and Standard transpiration rates were 3.0, 2.1, and 2.3 mmol H(2)O m(-2) s(-1). The data indicate that peach trees with fibrous root systems may have an advantage to absorb nutrients such as P that move primarily by diffusion when the nutrient is present in low concentrations in the soil. However, under conditions of high soil fertility, fibrous root systems did not improve nutrient uptake, and trees with greater transpiration rates absorbed greater levels of nutrients. Different growth habits of peach have diverse root systems and transpiration rates that affect nutrient uptake and consequently, the selection of tree growth habit should be considered in orchard soil management plans.