Reproductive efficiency of 14 Virginia-type peanut cultivars

The reproductive efficiency (RE) of most peanut (L.) cultivars has not been studied and methods for estimating RE have not been consistent. The objective of this study was to determine the changes in RE of 14 Virginia-type peanut cultivars due to breeding efforts since 1944. The cultivars varied in release date, maturity, growth habit, and development breeding method. Field experiments were conducted at the Tidewater Agricultural Experiment Station, Suffolk, VA on two-row plots 0.9 m wide by 6.1 m long. Plantings were made on 16 May 1983 on an Eunola loamy fine sand (fine-loamy, siliceous, thermic Aquic Hapludult) and on 10 May 1984 on a Nansemond fine sandy loam (coarse-loamy, siliceous, thermic Aquic Hapludult). Two randomly chosen plants were selected from each cultivar from each of four replicates for evaluation. Five methods of estimating reproductive efficiency (REM) were used: REM 1 = harvest index or (mature pod dry weight) (plant dry weight); REM 2 = (mature pod total) (flower total); REM 3 = (pod total) (flower total); REM 4 = (peg total + pod total) (flower total); and REM 5 = (mature seed total) (flower total ✕ 2)✕. Results indicated that earlier maturing cultivars had a greater RE than later maturing cultivars, erect cultivars had a greater RE than spreading cultivars, and RE was not affected by breeding method. Newer cultivars had a higher RE as estimated by REM 1 than older cultivars, but not as estimated by REM 2, 3, 4, and 5. The higher yield of most newer cultivars appeared to be related more to total flower production than to RE. Future increases for yield might best be accomplished by developing cultivars with combinations of high RE, harvest index, and total flower count.