Radiation use efficiency and peanut yield as affected by planting pattern and plant density in different crop systems

Adjusting plant density and planting pattern are strategies to improve the production efficiency of Virginia-type peanut (Arachis hypogaea L.), but little is known about their effects on radiation use efficiency (RUE), pod maturity, and pod yield. The objective of the study was to evaluate the yield components, pod maturity, and RUE of peanut based on planting patterns and plant density in areas with different cropping histories. Four experiments were conducted between 2021 and 2023 in the western state of São Paulo, Brazil. Treatments included planting patterns (single-row and twin-row) and plant densities (88,888; 111,110; 133,332; and 155,554 plants ha⁻¹). The optimal plant density was between 111,110 and 133,332 plants ha⁻¹. In the drier growing season the reduction of each 1000 plants ha⁻¹ in plant densities below 111,110 plants ha⁻¹ caused a pod yield decrease of 60 kg ha⁻¹ in the new field and 65 kg ha⁻¹ in the rotation field. In the wetter growing season, the increase of each 1000 plants ha⁻¹ in the plant density above 111,110 plants ha⁻¹ caused a yield decrease of 41 kg ha⁻¹ in the rotation field. Although the twin-row pattern increased leaf area index (LAI), it did not result in higher RUE or peanut yield compared to the single-row pattern. Under the lowest plant density, there was a delay in pod maturation. Our results indicate that it is possible to achieve adequate LAI, RUE, and pod maturity with plant densities between 111,110 and 133,332 plants ha⁻¹, regardless of the planting pattern.