Document Type : Research Paper - Biotic and Abiotic Stress

Authors

• Hana Aboodeh ¹
• Abdelmehdi Bakhshandeh ²
• Mohammad Reza Moradi Telavat ³
• SeyedAtaollah Siadat ⁴
• Seyed Amir Moosavi ⁵

¹ PhD Student, Department of Plant Production and Genetics- Faculty of Agriculture- Agricultural Sciences and Natural Resources University of Khuzestan, Ahvaz, Iran

² Professor, Department of Plant Production and Genetics, Faculty of Agriculture, Agricultural Sciences and Natural Resources University of Khuzestan, Ahvaz, Iran

³ Associate Professor, Department of Plant Production and Genetics, Faculty of Agriculture, Agricultural Sciences and Natural Resources University of Khouzestan, Ahvaz, Iran

⁴ Professor, Department of Plant Production and Genetics, Faculty Of Agriculture, Agricultural Sciences and Natural Resources University of Khuzestan, Ahvaz, Iran

⁵ Associate Professor, Department of Plant Production and Genetics, Faculty of Agriculture, Agricultural Sciences and Natural Resources University of Khuzestan, Ahvaz, Iran

Abstract

Introduction
Growth analysis has a significant perspective on the function of agricultural plants. In the early stages of plant growth, the growth indicators, including the leaf area index, the growth rate of the product decreases, and then due to suitable vegetation, the absorption of light radiation is better, and the accumulation of plant dry matter also increases, and after that Due to aging and yellowing, the leaves are reduced. The amount of light radiation absorbed by the plant varies during the growth period, which depends on the leaf surface index and the arrangement of the leaves of the plant.
 Material and Methods
The experiment was conducted in the research farm of Khuzestan University of Agricultural Sciences and Natural Resources in 2021-2022. In this research, the effect of three factors of irrigation interruption, cultivars and density was investigated in the form of factorial split with the base design of randomized complete blocks in three replications. The factor (no interruption of irrigation (control), interruption of irrigation at the beginning of flowering until the formation of 50% of the pod and interruption irrigation at the stage of pod formation until harvest the main factor, rapeseed cultivars Hayola 4815 and Aram and plant density per meter square (80, 110 and 140 plants per square meter) were considered as secondary factors.
 Results and Discussion
Irrigation interruption caused a decrease in growth indicators, including the amount of plant dry matter accumulation, leaf surface index, and leaf surface durability. The changes in harvest index and durability of leaf surface and accumulation of dry matter at the beginning of the development of leaves had a slow trend until a little before the appearance of inflorescences, but after that the slope of the mentioned parameters increased. During the experiment, changes in growth parameters including LAI, LAD, RGR, CGR and TDW were evaluated. At the beginning of the plant growth season, the growth rate of the product was low due to the lack of complete vegetation cover and proper light consumption efficiency. In all treatments, with the passage of time, the growth rate of the crop was gradually increasing and it reached the maximum value in the reproductive stages and then went through a decreasing process. The effects of stopping irrigation on dry weight were evident and the accumulation of dry matter was observed during the increasing time. which can be due to the increase in dry weight of stems, leaves and reproductive organs over time. Also The relative growth rate also showed an increasing trend with the increase of the leaf area index at first and then a decreasing trend.
 Conclusion
It seems that the second-stage irrigation interruption treatment at a density of 80 plants per square meter and Haiola 4815 variety, by maintaining more green area through more leaf surface durability and lower light consumption in the condition of irrigation interruption at the end of the growing season, was able to achieve a higher RUE100 compared to other treatments. to dedicate The highest seed yield (1572.61 kg per hectare) was obtained from the density of 110 plants per square meter and Hayola variety 4815.
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Keywords

• Active photosynthetic radiation
• Crop growth rate
• Dry matter accumulation
• Leaf area index

Main Subjects

• A: Biotic and Abiotis Stress