ABSTRACT
Okra-leaf (OL) cotton (Gossypium hirsutum L.) offers cotton producers advantages that include pest resistance, increased pesticide penetration into the canopy, and early maturity. Although OL cotton comprises 50% of Australian cotton production, it is not commonly planted in the United States. Perhaps the greatest limitation to OL cotton involves the decreased productivity associated with the lower leaf area. The lower leaf area of OL cotton suggests that more plants per unit area are required to achieve the same leaf area index (LAI) as normal-leaf (NL) cotton. The higher populations achieved by planting in narrow rows may alleviate the yield problems of OL cotton by increasing the amount of leaf tissue per unit area available for light interception. Although higher populations are required in OL cotton to achieve the optimum LAI (LAI=5.0), excessively high populations, which exceed the optimum LAI, are negatively correlated with yield. An LAI above 5.0 results in shading of lower leaves and a subsequent shortage of available carbohydrates for the fruit. Thus, the ultimate challenge to OL cotton production involves determining the population necessary for efficient light interception to maximize yields.
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