Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 4/2/2016
Publication Date: 2/2/2016
Citation: Mahan, J.R., Payton, P.R. 2016. Canopy temperature and maturity in cotton [abstract]. Southern Section of the American Society of Plant Biologists, April 2-4, 2016, Denton, Texas. 1(71):11.
Technical Abstract: Heat units are a widely used indicator of maturity in cotton. It is generally assumed that it takes approximately 2200°F (1222°C) heat units for a cotton plant on the South High Plains of Texas to mature. This value is based on a typical planting date of May 15 with ample irrigation. As water for cotton irrigation declines in the region, production under water deficits is becoming more common. We are interested in the relationships between water deficits and heat unit accumulation in cotton in the Lubbock, TX region. To investigate these relationships, we carried out a field experiment in 2015 in Lubbock, TX. Cotton was planted on 5 different dates (April 2nd to July 2nd), and each planting was exposed to four water regimes (0mm, 1.5mm, 3.0mm, and 6.0mm per day, via sub-surface drip). Canopy temperatures were collected using in-field infrared thermometers (SmartField Inc., Lubbock, TX). Air temperature data was measured at a weather station in the field. Heat units were calculated using a 15.5 °C base using either air temperatures or canopy temperatures. Yield was a function of irrigation treatment. The affect of planting date on yield was less pronounced. The relationship between days-to-maturity and air temperature heat units was a function of planting date and irrigation. The relationship between days-to-maturity and planting date was less pronounced with canopy temperature heat units We propose that since the accumulation of air-temperature heat units is function of water deficits, the accumulation of canopy-temperature heat units may provide a better tool for monitoring cotton development under water stress.