Drought Resistance of Cowpea Improved by Selecting for Early Appearance of Mature Pods1
- A. E. Hall and
- D. A. Grantz2
We hypothesized that earlier partitioning of carbohydrate to reproductive parts by cowpeas [Vigna unguiculata L. (Walp.)] would result in improved drought resistance. We selected individual plants from adequately-irrigated fields of the cultivar, California Blackeye No. 5 (CB5), and a land race of California Blackeyes, in southern California. The selection criterion was early appearance of mature pods.
Seeds of the selections and populations were bulked in a greenhouse. Phenology, growth, partitioning, and yield were examined at Riverside, Calif. over three summer growing seasons with both optimal irrigation and a treatment which received no irrigation or rainfall after seedling emergence. No differences were observed among the selections and populations in ability to extract water from the soil.
The selection from CB5 flowered earlier, and had substantially more dry matter in peduncles and pods during early stages of pod development, than CB5, in both irrigated and non-irrigated conditions. At maturity, this selection had a higher harvest index and yielded 53% more seed than CB5, under non-irrigated conditions, and a similar harvest index and seed yield as CB5 under irrigation.
In non-irrigated conditions, the selection from the land race had more dry matter in peduncles and pods during early stages of pod development, a higher harvest index at maturity, and yielded 19% more dry seed than the land race. No significant differences were observed in earliness, partitioning, harvest index, or seed yield between this selection and the land race under irrigation. All strains had similar biomass production and seed yield under irrigation.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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