Phenology and yield of eight cotton genotypes under irrigation and water stress

Due to the character of the original source materials and the nature of batch digitization, quality control issues may be present in this document. Please report any quality issues you encounter to digital@library.tamu.edu, referencing the URI of the item.Includes bibliographical references.Issued also on microfiche from Lange Micrographics.Management of cotton (Gossypium hirsutum L.) can be improved by implementing strategies that optimize plant growth and development. Mid-season water stress, which commonly occurs in the USA, reduce cotton yield and quality. Eight cotton genotypes were field tested for two years to quantify growth and phenological development under full irrigation and mid-season water stress. Significant differences were obtained among genotypes and between water treatments during the season from first square to maturity. Differences were noted for plant height, number of main stem nodes, plant height to node ratio (HNR), number of main stem nodes above the sympodial branch bearing a white flower in the first position from the main axis (NAWF), number of bolls per plant, percent boll retention and lint yield. Averaged over cultivars and years, the irrigated plants produced 3 to 4 more nodes and were 25 cm taller than the water-stressed plants, 95-130 days after planting (DAP). Plant height to node ratio (HNR) was on the average 0.5 units less in the non-irrigated than the irrigated treatment. Reduction in NAWF was I to 1.8 nodes (76-103 DAP) in the non-irrigated plots. Decline in number of nodes, plant height, HNR, NAWF, and boll retention were positively associated with a 39% reduction in yield in the water stressed treatment. Significant differences were observed among genotypes for most traits. Tamcot Sphinx,CUBQHGRPIS-1-92 and CUBQHGRPIH-1-92 were more tolerant to mid-season water stress than the other genotypes. The results will be useful in developing drought resistant cottons and will provide information for within season and end-of-season crop management strategies