Interspecific and intraspecific hybrids show varying degrees of heterosis for yield and yield components. Yield-component traits have complex genetic relationships with each other. To determine the relationship of yield-component traits and fiber traits with seed cotton yield, six lines (Bt. CIM-599, CIM-573, MNH-786, CIM-554, BH-167, and GIZA-7) and three test lines (MNH-886, V4, and CIM-557) ...

Plant genomes are larger and more complex than other eukaryotic organisms, due to small and large duplication events, recombination and subsequent reorganization of the genetic material. Commercially important cotton is the result of a polyploidization event between Old and New World cottons that occurred over one million years ago. Allotetraploid cotton has properties that are dramatically dif...

The active ingredient of TrimaxTM insecticide is Imidacloprid. This insecticide provides control of the major sucking/piercing insects of cotton. In addition, there have been anecdotal reports of yield and growth enhancement in cotton after multiple foliar applications of Trimax. However, the information on the mode of action of the growth-and-yield enhancement properties imposed by Trimax is l...

Transgenic Bt-cotton expresses insecticidal Cry proteins via Cry genes, introduced from the soil bacterium Bacillus thuringiensis (Bt). Data on levels of Cry proteins expressed in transgenic Bt-crops is important for assessing levels of environmental exposure. During investigations into the rhizosphere impacts of Cry proteins from GM cotton we found that Cry1Ac expression throughout the season ...

The effects of two entomopathogenic fungal endophytes, Beauveria bassiana and Purpureocillium lilacinum (formerly Paecilomyces lilacinus), were assessed on the reproduction of cotton aphid, Aphis gossypii Glover (Homoptera:Aphididae), through in planta feeding trials. In replicate greenhouse and field trials, cotton plants (Gossypium hirsutum) were inoculated as seed treatments with two concent...

Studies of fungi in upland cotton (Gossypium hirsutum) cultivated in the United States have largely focused on monitoring and controlling plant pathogens. Given increasing interest in asymptomatic fungal endophytes as potential biological control agents, surveys are needed to better characterize their diversity, distribution patterns and possible applications in integrated pest management. We s...

Bioactive gibberellins (GAs) comprise an important class of natural plant growth regulators and play essential roles in cotton fiber development. To date, the molecular base of GAs' functions in fiber development is largely unclear. To address this question, the endogenous bioactive GA levels in cotton developing fibers were elevated by specifically up-regulating GA 20-oxidase and suppressing G...

Drought and salinity are two major limiting factors in crop productivity. One way to reduce crop loss caused by drought and salinity is to increase the solute concentration in the vacuoles of plant cells. The accumulation of sodium ions inside the vacuoles provides a 2-fold advantage: (i) reducing the toxic levels of sodium in cytosol; and (ii) increasing the vacuolar osmotic potential with the...

The boll weevil causes serious damage to the cotton crop in South America. Several studies have been published on this pest, but its phenology and behavior under the tropical conditions prevailing in Brazil are not well-known. In this study the feeding behavior and main food sources of adult boll weevils throughout the year in Central Brazil was investigated. The digestive tract contents of ins...

Cotton at three stages of crop phenological development was infested with eggs and third instar larvae of the fall armyworm, Spodoptera frugiperda (J.E. Smith), to determine the effect of larval feeding on fruit damage and yield. Regression analyses indicated that numbers of damaged squares and bolls were significantly (P @ 0.05) influenced by the number of egg masses and third instars placed o...