Yield and Fiber‐Quality Potential for Second‐Generation Cotton Hybrids

Abstract

Due primarily to the difficulty of producing F 1 , seed, use of heterosis in cotton ( Gossypium hirsutum L.) has been limited. The objective of this study was to evaluate the potential of using F 2 hybrids by comparing them with parents and F 1 's for yield, fiber quality, and interaction with environments. The genetic design was a half‐diallel consisting of seven mid‐South parents, 21 F 1 's, and 21 F 2 's. The 49 genotypes were grown in 1987 and 1988 at three sites near Stoneville, MS. At each site, April and May planting was made, resulting in a total of 12 environments. Yield, yield components, and fiber length, strength, and micronaire reading were determined from four replications. Yarn tenacity was determined from two 1987 tests, and short‐fiber content from three 1987 tests. Average first‐harvest yield was 594, 688, and 643 kg ha −1 for the parents, F 1 's and F 2 's, respectively; total yield was 953, 1065, and 1025 kg ha −1 , respectively. Average yarn tenacity was 130, 134, and 132 kN m kg −1 for the parents, F 1 , and F 2 hybrids, respectively. Both F 1 and F 2 hybrids had significantly fewer short fibers than the parents. The highest‐yielding parent was ‘DES 119’, which averaged 1031 kg ha −1 , while ‘Deltapine 50’, the most commonly grown cultivar in the USA, averaged 959 kg ha −1 . The highest‐yielding F 1 hybrids DES 119 ✕ ‘Delcot 344’ and DES 119 ✕ ‘Coker 81–613’ averaged 1145 and 1143 kg ha −1 , respectively, ~15% higher than the average of DES 119 and Deltapine 50; their F 2 hybrids averaged 8% higher. No differences in adaptive ability between parents, F 1 's, and F 2 's were detected. The results indicate that F 2 hybrids have the genetic potential for increasing cotton yields and fiber quality.