Title: The effect of the foliar application of Zn and Fe -glycine amino acid chelates on yield, yield components and grain Zn and Fe of Hashemi rice variety under macronutrient deficiencies
Author: Shahram MahmoudSoltani
Zinc is the most important micronutrient that adversely affects rice growth and development, and more broadly the quantity and quality of grain yield due to its low plant-available forms. Also, Iron has a vital role in chlorophyll and leghemoglobin synthesis and is a constituent of porphyrin and ferredoxin in electron transfer of photosynthesis processes. Chelation of micronutrients with amino acids is one of the important mechanisms in increasing the solubility of trace elements in the soil and also their uptake by plants. Amino acid chelates, in addition to eliminating the deficiency of chelated elements, have a significant effect on increasing plant adaptation to various stress conditions (salinity, drought, and nutrient deficiency). The current study was undertaken to the effect of the foliar application of Zn and Fe -glycine amino acid chelates on yield, yield components, and grain Zn and Fe of Hashemi rice variety under micronutrient deficiencies (nitrogen, phosphorous, and potassium). The three factors factorial experiment was conducted in a completely randomized block design with three replications at the rice research institute of Iran in 2020-2021. The experimental treatments were: Macronutrients (NPK) application at two levels (recommended rate of NPK-control 1; 1/2 of recommended rate of NPK-control 2), foliar application of zinc chelated with glycine amino acid at three levels (0,1 and 1.5 kg ha-1) and foliar application of iron chelated with glycine amino acid at three levels (0,1 and 1.5 kg ha-1). All foliar application of experimental factors was applied at the start of booting and ripening stages (1/2 of experimental rates). Also, the collected observation data were: plant height, total tiller number, panicle length, grain, and straw yield, N, P, K, Zn, and Fe concentration on grain, straw, and white rice, and protein content of grain and white rice. The results revealed that the foliar application of zinc and iron chelated with glycine amino acid and soil application of macronutrients (NPK)(singly) significantly increased grain yield by about 22.6, 16.5, and 20%, respectively. Moreover, the highest increase in the grain yield (5115 kg ha-1) was found by foliar application of 1.5 kgha-1 amino acid chelate of Zn and Fe by about 200 and 49% compared to control 1 (2505 kgha-1) and control 2 (3427 kgha-1), respectively. The maximum increase in rice Zn content of head rice (19.07 mgkg-1) was recorded by foliar application of 1.5 kgha-1 amino acid chelate of Zn and Fe by about 41.57 and 20.77% compared to control 1 (12.47 mgkg-1) and control 2 (15.79), respectively. Also the maximum increase in rice Fe content of head rice (26.97 mgkg-1) was recorded by foliar application of 1.5 kgha-1 amino acid chelate of Zn and Fe by about 2.79 and 2.17 times compared to control 1 (9.68 mgkg-1) and control 2 (12.49), respectively. The highest increase in protein content of head rice was recorded by foliar application of 1.5 kgha-1 amino acid chelate of Zn and Fe by about 19.64 compared to control. It can be concluded that two-time foliar application of both Zn and Fe enhances both rice grain yield and nutritional quality.
Keywords: Macro-nutrient deficiencies, Rice, Plexomin Zn, and Fe, Hashemi cultivar