The Effect of Weed Management Practices and Planting Patterns on Dry Matter Accumulation and Individual Plant Growth Indicators in Peanut Cultivars (Arachis hypogaea L.)

Introduction: Peanuts (Arachis hypogaea L.) have significant nutritional value due to their high content of protein (۲۰-۲۵%), oil (۴۵-۵۵%), carbohydrates (۱۶-۱۸%), minerals (۵%), fatty acids, and various vitamins. They also hold considerable commercial value (Güllüoğlu et al., ۲۰۱۶). Peanut cultivars are significantly influenced by soil type and the length of the growing season. Given the limited area under peanut cultivation in Iran, it is essential to implement various agricultural practices, such as optimizing plant density and planting pattern, to increase yield (Koochaki and Khalghani, ۱۹۹۷). Dry matter allocation is also affected by planting pattern; studies have shown that square planting rows result in maximum dry matter allocation during the podding period compared to the rectangular planting rows commonly used in the region (Jaaffar and Gardner, ۱۹۸۸). In one experiment, the leaf area index and dry matter production increased with higher plant density (Minh et al., ۲۰۲۱). Weed control is the most critical production factor in peanut cultivation, with the choice of method depending on both effectiveness and cost-efficiency (Mathew et al., ۲۰۲۱). In light of these factors and the importance of planting pattern and weed control in peanut cultivation, this experiment aims to investigate the effects of planting pattern and weed management on dry matter accumulation and one-plant growth indicators in peanut cultivars under the weather conditions of Kermanshah. Materials and Methods: This experiment was conducted as a factorial based on a randomized complete block design with three replications at the research farm of Razi University in Kermanshah, Iran, in ۱۴۰۰. The experimental factors included: (۱) peanut cultivars NC۲ (North Carolina ۲) and NC۷ (North Carolina ۷); (۲) planting patterns—P۱ (row spacing of ۵۰ cm × plant spacing of ۲۵ cm) and P۲ (row spacing of ۷۵ cm × plant spacing of ۱۸ cm); and (۳) various combined weed control methods, as follows: M۱: two rounds of hand weeding along with the application of the herbicides Treflan (۷۹۶ g/ha, active ingredient), Bentazon (۹۶۰ g/ha, active ingredient), and Haloxyfop (۷۵ g/ha active ingredient), M۲: two rounds of hand weeding with Treflan (۱۲۳۳ g/ha, active ingredient), M۳: two rounds of hand weeding with Haloxyfop and Bentazon, M۴: complete hand weeding throughout the growing season (every two weeks), and M۵: a weed-infested control treatment throughout the growing season. To analyze growth indicators, including total dry matter accumulation (TDM), crop growth rate (CGR), and relative growth rate (RGR), sampling was conducted every ۱۵ days after greening. The pattern of dry matter accumulation was analyzed according to Equation ۱, the crop growth rate (CGR) was calculated using Equation ۲, and the relative crop growth rate (RGR) was calculated using Equation ۳. To calculate and fit the curves related to TDM, CGR, and RGR, SigmaPlot v.۱۴ and Excel ۲۰۱۶ software were used. Results and Discussion: At the beginning of the growing season, there was no significant difference in dry matter accumulation between the two planting patterns. However, as the season progressed, dry matter accumulation increased, and by the end of the season, it was higher in P۱ than in P۲. The allocation of dry matter was also influenced by planting arrangement, with maximum dry matter allocation during the podding period observed in square planting rows compared to the commonly used row patterns in the region (Jaaffar and Gardner, ۱۹۸۸). An examination of dry matter accumulation in NC۲ and NC۷ cultivars showed that it increased with the length of the growth period, up to ۱۲۰ days after emergence. The NC۷ cultivar produced more dry matter than NC۲ in both planting patterns, with P۱ (row spacing of ۵۰ cm × plant spacing of ۲۵ cm) being more effective than P۲. This difference was attributed to the NC۷ cultivar’s better utilization of space and resources in the P۱ patterns, which led to greater dry matter production. Additionally, under weed management conditions, NC۷ produced more dry matter, demonstrating better competitive ability and higher grain yield. At the beginning of the growth period, changes in crop growth rate (CGR) for both planting patterns were minimal. As the plants grew

کلیدواژه ها:

Weed Management ، Planting Patterns ، Dry Matter Accumulation ، Peanut Cultivars ، Plant Growth Indicators