Determination of the effect of different planting densities on leaf area index and yield in main crop and second crop peanut (Arachis hypogaea L.) farming

Peanut (Arachis hypogea L.) is a warm climate and oilseed plant of economical importance from the Fabaceae family. In this study, the response of a total of three peanut cultivars, one from different market types, to row spacing adjustments in terms of yield and quality under main and second crop conditions in Osmaniye, one of the main peanut producing provinces in Turkey, was investigated. In this study, which was carried out at the Oilseeds Research Institute Directorate (Osmaniye) research and trial area in 2022 and 2023 under main crop and second crop conditions, NC-7 (semi-upright/semi-recumbent form, Virginia type), Florispan (upright form, Spanish type), Georgia-Green (recumbent form, Runner type) peanut cultivars were used. The row spacing was 70 cm in plantings at five different row spacings (5 cm, 10 cm, 15 cm, 20 cm and 25 cm). In the main product, as the distance between rows increased with different planting densities, the main stem length, side branch length, and fruit yield decreased. However, the number of fruits per plant, fruit yield per plant, 1st quality fruit ratio, 100 fruit weight, and 100 seed weight values increased. In the second product, at different planting densities, the number of days to 50% flowering, the number of days to gynophore formation, main stem length, side branch length, the number of fruits per plant, fruit yield per plant, 1st quality fruit ratio, 2nd quality fruit ratio, interior ratio, and fruit yield decreased as the distance between rows increased. As a result, the highest fruit yield (397.3 kg.da-) was obtained in 5 cm, 10 cm, and 15 cm row applications of the NC-7 variety in Osmaniye in 2022 and 2023 under main crop conditions. Leaf area index (LAI) values at different planting densities were between 1.84-2.97 in main crop conditions and 1.98-2.40 in second crop conditions, according to two-year average values, with values in a wider band in the main crop compared to the second crop. As the row distance increased in main and second crop conditions, the LAI and fruit yield decreased. In this study, the response of a total of three peanut varieties, one from different market types, to row spacing adjustments under main and second crop conditions was investigated in terms of yield and quality in Osmaniye, one of the main peanut producer provinces in Turkey. Since all fatty acid types decreased as the distance between the rows increased in the main and second crop conditions, all fatty acids were found to be higher on the narrow row.