Pomology
Akram Heydari; Saeid Daghighi; Farhad Azarmi-Atajan
Abstract
Introduction Pistachio (Pistacia vera L.) is an important crop in Iran our country and has a unique position in export goods. The amount of pistachio production in Iran has decreased by 50% compared to 2017. The low yield of pistachios per unit area is due to the management problems of orchards, ...
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Introduction Pistachio (Pistacia vera L.) is an important crop in Iran our country and has a unique position in export goods. The amount of pistachio production in Iran has decreased by 50% compared to 2017. The low yield of pistachios per unit area is due to the management problems of orchards, and among these, nutrition and fertilizer management is of special importance. Among the nutrients that are important in pistachio nutrition, especially when the brain is full, are nitrogen and potassium. Humic acid can also improve physical, chemical and biological soil properties and stimulate growth via its effects on plant metabolism.The aim of this study was to investigate the effect of application of some nitrogen fertilizers with different levels of potassium sulfate and humic acid on growth, yield and photosynthetic pigments of pistachio Badami Sefid-e-Mahvalat variety. Materials and Methods This research was conducted as a factorial experiment based on a randomized complete block design with three replications at the Mahvalat during 2019-2020. The first factor consisted of nitrogen fertilizers at 4 levels (control, urea, ammonium sulfate and ammonium nitrate). The second factor was potassium sulfate fertilizer at 2 levels of zero and 250 g per tree and the third factor was humic acid fertilizer at 2 levels of zero and 45 g per tree which as a manure pits after the formation of the cluster and at the same time with the growth of the bony shell in the shade of the tree where the capillary roots are active. At the end of the experiment, morphophysiological traits were measured and recorded. In each tree, three branches were selected in different directions and the length of the current branch was measured in meters using centimeters. The diameter of the middle of the branch was measured with a caliper. From the collected clusters, 100 fruits were randomly selected, and the number of indehiscence fruits and the number of blank fruits were counted and finally expressed as a percentage. Measurements of chlorophyll a and b, total chlorophyll and carotenoids were determined using Arnon method. The experimental data was analyzed by SAS software and the significant differences among the treatment were tested by LSD test. Results and DiscussionThe results of analysis of variance of data in two years of experiment showed that experimental treatments had a significant effect on pistachio growth and yield. The results of the first year showed that the combined treatment of urea and 250 g of potassium sulfate and 45 g of humic acid had the highest diameter and branch length, indehiscence percentage, chlorophyll a, b and total and the lowest pistachio blank percentage. The highest yield in the first year was obtained from the combined use of ammonium sulfate, 250 g of potassium sulfate and 45 g of humic acid. Combined application of ammonium nitrate and 250 g of potassium sulfate and 45 g of humic acid resulted in the highest diameter and branch length in the second year of the experiment. The highest indehiscence percentage and carotenoids and the lowest amount of pistachio blank percentage in the second year were obtained from the combined treatment of ammonium sulfate, 250 g of potassium sulfate and 45 g of humic acid. Most chlorophyll a, b and total were obtained from combined consumption of urea, 250 g of potassium sulfate and 45 g of humic acid. The highest yield of the second year was obtained due to urea consumption, 250 g of potassium sulfate and 45 g of humic acid. Nitrogen is a component of amino acids, proteins, nucleic acids and enzymes and plays a major role in plant physiology, vegetative growth, chlorophyll formation and fruit and fruit production. Potassium is also one of the elements required by the plant that plays an important role in photosynthesis and transport of carbohydrates. The organic acids in humic acid cause the chelating of many nutrients and increase their availability to the plant. By using these substances and its positive and stimulating effects on plant growth and increasing root growth and its absorption power, nutrient uptake, yield is increased.
