Study of quality and yield of rapeseed, Hayola 401 cultivar, with applying iron, zinc and manganese compound fertilizer under irrigation cut stress

One of the oil seeds that has attracted a lot of attention in these years in the country and is also considered as a major contributor to the plan to reduce the import of vegetable oil. This product is among the world's most oil-bearing grains It has the highest production in recent decades, and nowadays it has achieved the third place after the soybean and palm oil in vegetable oil products. Water is a key factor in the production of crops. The yield of crops in many areas is limited by living or non-living environmental stresses, and therefore, there is a significant difference between actual yield and yield potential of crops. Low moisture content in each of the different stages of growth reduces the absorption of water, nutrients, decreases the transfer of elements within the plant, and ultimately reduces the yield of the grain or the final product. Optimal water use is of great importance, especially in areas where dry climatic conditions And semi-arid dominant that covers about two thirds of Iran's territory. In order to increase yield per unit area, farmers use one of the common fertilization methods including soil utilization through irrigation, seed mixing and solubility. Leaf solubility is one of the fastest ways to meet the needs. The fertilizer is also used in this method to save fertilizer and in addition to the positive economic aspect, the environment is protected from chemical pollution, which is very effective in achieving sustainable agriculture.

In order to investigate the effect of micronutrients application on qualitative and quantitative yield of rapeseed plants in condition drought stress, a field experiment was carried out to in Hamidieh city in 2017-18 in a split plot is an experiment in a randomized complete block design with four replications. The experimental treatments included drought stress in two levels (I1: optimal irrigation, I2: Irrigation off in pod stage) as the main plot and spraying of complete fertilizer in four levels (M0: non-spraying (control), Spraying with concentrations M1: 2 in thousand, M2: 4 per thousand, M3: 6 per thousand) was implemented as a subplot in the region.

The results showed that drought stress had a significant effect on leaf area index, grain yield, grain protein, protein yield, iron and zinc percentage. The highest grain yield in optimal irrigation treatment (with an average of 3110.7 kg /ha) and the lowest grain yield (with an average of 2280.22 kg /ha) was attributed to irrigation cut off treatment at slaughtering stage. Also, with increasing micronutrient levels, leaf area index, grain yield, protein content, protein yield, percentage of iron and zinc increase. The most of these traits were obtained from optimal irrigation and spraying of six to a thousand, which did not have significant difference with treatment of four. In explaining the reason for the increase in the protein content of seeds by the application of micronutrients on zinc and iron, it should be noted that these elements directly contribute to both the process of gene expression and protein synthesis. The deficiency of zinc prevents the activation of a number of antioxidant enzymes, which results in oxidative damage to protein molecules, which also reduces protein function in the plant. The highest grain yield (with a mean of 3290.4 kg /ha) was obtained in irrigation treatment and spray application of four per thousand. In this experiment, micronutrient spraying reduced the damage caused by drought stress to grain yield and also increased the percentage of iron and zinc seeds.

The results of this experiment showed that using micronutrients such as iron and zinc can play an important role in improving grain yield, seed protein content and enrichment of zinc and iron in drought stress conditions. Regarding the drought and depletion crisis in Khuzestan province, nutrient poverty in the province's soils, especially in terms of micronutrients such as zinc and iron, is a foliar application of fertilizer to increase the amount of elemental elements in the plant. Therefore, in general, the results of this research can be argued that in order to achieve maximum quality yield and agronomic traits, rapeseed cultivation with micronutrient foliar application of four thousand in moisture conditions is recommended.