Plant Production Department, Faculty of Agriculture, Saba Basha, Alexandria University, Alexandria, 21531, Egypt.
Botany and Microbiology Department, College of Science, King Saud University, P.O. Box 2455, Riyadh, 11451, Saudi Arabia.
Environ Sci Pollut Res Int. 2021 Jan;28(2):1983-1991. doi: 10.1007/s11356-020-10658-7. Epub 2020 Aug 30.
Our experiment was conducted during the seasons of 2018 and 2019 on 10-year-old "Anna" apple trees (Malus domestica L. Borkh) planted at 4 × 4 m apart in a clay soil under drench irrigation. Sixty uniform trees were selected and subjected to the same cultural practices during both seasons. Apple trees were sprayed three times as follows: before flowering, during full bloom, and 1 month later with the following treatments: control (water only); tryptophan at 25, 50, and 100 ppm; glycine at 25, 50, and 100 ppm; and their combinations, 25 ppm tryptophan + 25 ppm glycine, 50 ppm tryptophan + 50 ppm glycine, and 100 ppm tryptophan + 100 ppm glycine. The results demonstrated that the foliar spraying of "Anna" apple trees with glycine and tryptophan at 25, 50, and 100 ppm and their combinations significantly increased shoot length and diameter, leaf area, total chlorophyll, percentages of fruit set and yield, fruit physical and chemical characteristics, and leaf mineral composition of N, P, K, Ca, Fe, Zn, Mn, and B, whereas it reduced the fruit drop percentage in both seasons in comparison with control. Better results were obtained from the concentrations of 50 and 100 ppm which were more effective in both seasons in comparison with the concentration of 25 ppm. Moreover, the combination of 50 ppm glycine 50 ppm tryptophan was the best treatment and provided the highest results in both experimental seasons in comparison with the other applied treatments and control.
我们的实验于 2018 年和 2019 年在灌溉充足的黏土土壤中进行，实验对象为每 4×4 米种植一棵、树龄为 10 年的“安娜”苹果树（Malus domestica L. Borkh）。选择了 60 棵均匀的苹果树，在两个季节中都进行相同的栽培。苹果树在以下三个阶段进行了三次喷雾处理：开花前、盛花期和开花后一个月，处理方法如下：对照（仅水）；色氨酸 25、50 和 100ppm；甘氨酸 25、50 和 100ppm；以及它们的组合，25ppm 色氨酸+25ppm 甘氨酸、50ppm 色氨酸+50ppm 甘氨酸和 100ppm 色氨酸+100ppm 甘氨酸。结果表明，叶面喷施 25、50 和 100ppm 的甘氨酸和色氨酸及其组合显著增加了新梢长度和直径、叶面积、总叶绿素、坐果率和产量、果实物理和化学特性以及叶片中氮、磷、钾、钙、铁、锌、锰和硼的矿质元素组成，而与对照相比，两个季节的果实脱落率都有所降低。50ppm 和 100ppm 的浓度比 25ppm 的浓度效果更好，在两个季节中都更有效。此外，50ppm 甘氨酸+50ppm 色氨酸的组合是最佳处理方法，与其他处理方法和对照相比，在两个实验季节都提供了最高的效果。
