The nitrogen nutrition of the peach tree. 5. Influence of rate of application of calcium ammonium nitrate fertilizer on yield, tree growth and nitrogen content of fruit

Abstract

A field experiment was done on mature peach trees (Cv. Golden Queen) growing under an irrigation/cultivation management system to test tree response during two consecutive growing seasons to a wide range of application rates of calcium ammonium nitrate fertilizer. Results presented in this and a previous paper show that, over the range 0 to 18 lb calcium ammonium nitrate per tree per year, gross yield, shoot extension growth, annual increase in butt circumference, and leaf and fruit nitrogen content were usually in proportion to rate of fertilizer applied. In contrast, application of nitrogenous fertilizer delayed the rate of fruit ripening compared with nil nitrogen treatment and did not influence weight of prunings per tree, butt circumference per tree at any given date, flowering performance, fruit set, leaf size (dry weight) during the growing season, fruit size at harvest (dry weight), or the concentration and amount of total nitrogen in the seed at harvest. Since records were made on 20 trees only over two growing seasons and the trees were not thinned, it is suggested that the practical significance of the gross yield response should be further assessed in a conventional, long-term experiment.