تنش های محیطی در علوم زراعی (Sep 2023)
Effect of end-of-season drought and foliar application of Zinc and Manganese sulfate on yield and yield components of safflower (Carthamus tinctorius L.) in Saravan climatic conditions
Abstract
IntroductionSafflower has been cultivated in different parts of Sistan and Baluchestan since ancient times and is relatively tolerant of drought. It has many medicinal and food uses for the people of this region. Saravan is also one of the arid regions of the country, so the cultivation of plants compatible with these regions can be effective to improve agriculture in this region. Several studies have been shown that a small amount of nutrients, particularly Zn and Mn applied by foliar spraying can significantly increase the yield of crops Also, foliar nutrition is an option when nutrient deficiencies cannot be corrected by applications of nutrients to the soil. It is likely therefore, in open-field conditions, where the factors that influence the uptake of the nutrients are very variable, foliar fertilization is a privilege. Among the micronutrients, Zn and Mn nutrition can affect the susceptibility of plants to drought stress. Zinc plays an important role in the production of biomass. Furthermore, zinc may be required for chlorophyll production, pollen function, fertilization and germination. Mn plays essential roles in the metabolism of isoprenoids, chlorophylls, carotenoids and phenolics. External application of Mn2+ increases photosynthesis, net assimilation, and relative growth and yield.Materials and methodsthis experiment was conducted to investigate different levels of irrigation and foliar application of zinc and manganese sulfate in November 2020 in the research farm of Saravan Higher Educational Complex as a split plot in a randomized complete block design with three replications. Experimental treatments include three levels of irrigation, including: full irrigation, cessation of irrigation at the beginning of stem emergence and cessation of irrigation at the stage of flowering, and three levels of foliar application with zinc sulfate (three per thousand), manganese sulfate (three per thousand) and no foliar application. Study traits include speed, plant height, number of branches, number of heads per plant, seed weight per plant, head weight per plant, 100-seed weight, biological yield, grain yield and harvest index (division of grain yield by biological yield by percent). Data analyzed was performed using SAS software (version 9/1) and mean comparisons at the level of 5% probability were performed using LSD test.Results and discussionThe results showed that the interaction effects of irrigation and foliar application in plant height, number of branches, number of heads, 1000-seed weight, seed-per-plant weight, head-per-plant weight, biological yield, grain yield, harvest index and chlorophyll meter (SPAD) were significant (P≤ 1%). foliar application with zinc sulfate increased grain yield more than three times in all irrigation treatments, also grain yield in foliar application with zinc sulfate in non-interruption irrigation treatment (693 kg) Per hectare was seven times higher than the conditions for stopping irrigation at the stage of stemming and lack of foliar application (100 kg ha-1). In all irrigation treatments, foliar application of zinc sulfate Element was relatively superior to manganese sulfate and no foliar application. The highest grain yield was observed in the treatments of non-interruption of irrigation, cessation of irrigation in flowering stage and cessation of irrigation in stem stage, respectively. Was seven times the grain yield. In general, foliar application of zinc sulfate can be used as an agricultural solution to increase yield and reduce the effects of cessation of irrigation at the end of the growing season in safflower in Saravan climate. In general, the results of this study showed that under different conditions of irrigation interruption, foliar application of zinc sulfate and manganese can play an important role in mitigating the effects of drought stress on safflower compared to no foliar application. Discontinuation of irrigation at the end of the growing season in the stem and flowering stages reduced the seed yield of safflower compared to full irrigation conditions. Zinc sulfate foliar application improved yield-related traits in this plant, zinc sulfate foliar application increased grain yield about twice and in manganese sulfate foliar application this increase was about 30% compared to non-foliar conditions. The highest correlation was observed with number of heads per plant, head weight, seed weight per plant and number of branches. Due to the alkalinity of the soil in dry areas and the non-absorption of these elements by the plant and the positive effects of this element in relation to the defense system and photosynthesis of the plant, foliar application of zinc sulfate Element is recommended for safflower in Saravan climate.
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