Influence of Row Pattern and Prohexadione Calcium on Peanut (Arachis hypogaea L.) Maturity and Pod Distribution

Many newer peanut cultivars are offering improved yield benefits but have larger canopies and have taken 10 or more days longer to reach maturity levels that were historically desired for optimal profitability of a crop. Prohexadione calcium growth regulator and twin row planting pattern have previously been individually reported to increase the amount of orange, brown or black pods compared to untreated alternatives. Twin row planting (i.e., planting two rows spaced 18-cm apart on 96-cm centers) has additionally been anecdotally associated with increased concentrations of pods nearer the taproot. Objectives of this work were to evaluate maturity development in single versus twin row planted peanuts and to evaluate how prohexadione calcium application would affect maturity development and pod distribution of both single and twin row planted peanut. Four cultivars were selected based on frequency of use in South Carolina then paired into experiments based on maturity requirements. Experiments were conducted at the Edisto Research and Education Center in Blackville, SC and the Pee Dee Research and Education Center in Florence, SC in 2021 and 2022. Peanut planted in twin row planting pattern yielded greater and had a higher percentage of orange, brown or black pods and total sound mature kernels. For FloRun 331 and Georgia-16HO in twin but not single rows, prohexadione calcium treatment increased the percentage of orange, brown or black pods. Although pod distribution effects for twin rows without and single rows with prohexadione calcium varied by maturity group, twin rows with prohexadione calcium exhibited pod distributions closer to the taproot than treated single rows. Twin row plots were associated with cooler ground temperatures than single rows, while the effects of prohexadione calcium on ground temperature varied between cultivars. Increased ground temperature was negatively correlated with pod maturity and main stem heights. Results from this work contribute to our understanding of potential benefits and variability across cultivars of the use of twin row planting pattern and prohexadione calcium treatment.