Submitted to: National Cotton Council Beltwide Cotton Conference
Publication Type: Proceedings
Publication Acceptance Date: January 30, 2000
Publication Date: N/A
Interpretive Summary: As pressure to reduce water use from non-agricultural sectors increases, exploring alternative approaches to improve cotton plant water efficiency becomes even more important. Active leaf transpiration is necessary for normal physiological plant processes and is necessary for adequate yields. In this study, we considered two approaches to improving cotton plant water rstatus, and thus sustaining transpiration rates. The first approach was t reduce leaf heat load by reducing the total solar incident irradiation on the leaf by application of a particle film to the upper leaf surface. A particle film has the advantage over an anti-tanspirant by not interfering with stomatal closure and the regulation of internal leaf temperature. The second approach was to stimulate the occurrence of mycorrhizal association with cotton roots by treating the seed before planting. Cultural practices that stimulate mycorrhizal association with cotton have been known to improve seed establishment and subsequent yields. Mycorrhizae can also improve plant water potential when plants are subjected to drought stress. Results indicate that particle film, mycorrhizal seed treatment, or a combination of both, significantly reduce plant canopy temperatures and improve lint yields when compared to untreated plants.
Cotton was planted in Weslaco, TX, into a Raymondville clay loam soil on 26 March 1999 to evaluate the potential use of a particle film and of VA mycorrhizal (Gomes intaradices, L.) inoculation in reducing abiotic plant stress. Four treatments consisting of control, "Surround"-sprayed plants, mycorrhizal-treated seed and the combination of the later two treatments were evaluated for their effect on plant water status, phenology and lint yield. "Surround" applications reduced canopy temperatures and increased leaf transpiration rates compared to control plants. Plants grown from mycorrhizal-treated seed had higher transpiration rates than control plants, improved plant stand and higher levels of mycorrhizae associated with their root system when compared to untreated seed. "Surround, mycorrhizae, or in combination, significantly reduced whole plot canopy temperatures and improved lint yields, when compared to the control treatment. Plant phenology, soil water profile, leaf chlorophyll and leaf blade nutrient content were not affected by any of the treatments.