Introduction
The world population is growing at a rate of 1.6 to 1.7 percent, adding about 90 million people to the world's consumer base every year. To feed the growing world population, the need for agricultural production will increase significantly in a relatively short period. Arachis hypogaea L., a legume in the Fabaceae family, is recognized as a dual-purpose crop. It serves as both an oilseed and a nutritional source for humans and animals. Peanut yield is significantly influenced by various factors, including agronomic and cultural practices, as well as pest management strategies. Planting patterns play a crucial role in shaping crop canopy structure and influencing physiological characteristics like radiation use efficiency and light interception. Both plant density and row spacing are key determinants of planting patterns. Square planting patterns, in particular, can enhance canopy structure, increase light availability, and improve ventilation, ultimately benefiting crop growth. Maximal crop density amplifies "size-asymmetric competition," favoring the larger crop plants, which typically possess an early growth advantage over annual weeds. A more evenly distributed crop pattern diminishes early-season interspecific competition, enabling crops to suppress weeds more efficiently through increased collective shading. Unlike traditional methods such as mechanical weed control and herbicide, this approach is entirely harmless to the environment. This study evaluated the effect of planting patterns combined with weeding, herbicide, and cover crops on weed control and peanut yield.
Materials and Methods
This experiment was a split plot based on a randomized complete block design with three replications in the cropping years of 2021 - 2022 and 2022-2023 in the Agricultural and Natural Resources Research Center of Moghan. The main plot includes a planting pattern in three levels (single row, two parallel rows, and two zigzag rows), and the subplot includes 7 levels of weed management including (planting cover crops 1- crimson clover, and 2- Vetch, chemical control: 3- application of bentazone + supergalant herbicide combination, 4- mechanical control: 4- Weeding once (20 days after planting) and 5- Weeding twice (20 and 40 days after planting), 6- Weeding the total season of weeds and 7- The control without the use of cover crop and the use of herbicides. Sampling of weed density and biomass by species was carried out 50 days after planting peanut plants using a random quadrat of 0.25 m2 (0.5 × 0.5). To obtain the weight of one hundred seeds, one hundred seeds were randomly selected from each experimental treatment from an area of one m2 in each plot and after drying at 75 °C, their weight was measured with a sensitive balance with an accuracy of 0.001 g. To determine the oil percentage, peanut kernels were ground after peeling. Peanut kernel powder was extracted using the Soxhlet method (temperature 45 °C and dry diethyl ether solvent).
Results and Discussion
The results of the experiment showed that the number of single seed pods, the number of two seed pods, the total number of pods, pod yield, biological yield, seed protein percentage, weight of 100 seeds, seed yield, density of weeds, and biomass of weeds were influenced by weed control methods and planting patterns. The highest measured traits were obtained in the two-row zigzag planting pattern and at different levels of weeding, and then in the treatments of vetch, clover, and herbicide application, and the lowest values of the mentioned traits were found in the single planting pattern and in without control. The comparison effects of planting patterns × weed management showed that the highest density and biomass of weeds was in the single-row planting pattern and without control and the lowest weed biomass was in the two-row zigzag planting pattern and in weeding twice or planting cover crops of vetch. The results of the two-way interaction indicated that the highest weight of 100 peanut seeds was obtained in the two-row zigzag planting pattern and the weeding treatments and then in the vetch and clover cover crop treatments, and the lowest weight of 100 peanut seeds was obtained in the single-row planting pattern and the control condition without weed control. It seems that the use of the two-row zigzag pattern has increased the plants' utilization of light due to the better distribution of the plants on the soil surface, and has caused a greater distribution of photosynthetic materials in the reproductive tanks and an increase in the weight of 100 seeds. The highest amount of grain protein was also obtained for the two-row zigzag planting pattern and the lowest amount was obtained in the single-row planting pattern.
Conclusions
According to the conditions of the Moghan region, planting two zigzag rows and weeding twice (will be the best option to control weeds in increase the yield of peanuts. Also, due to the lack of manpower for weddings, it is recommended to use a mixture of bentazon and super gallant herbicides in the climatic conditions of the Moghan region. |
