Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 2/19/2008
Publication Date: 4/8/2008
Citation: Gowda, P., Baumhardt, R.L., Howell, T.A., Marek, T.H. 2008. Planting date forecast for cotton using minimum and maximum air temperature [abstract]. 38th Biological Systems Simulation Conference, April 8-10, 2008, Temple,Texas. p. 50-51.
Technical Abstract: Early planting of cotton can lengthen the growing season and enable growers to avoid inclement weather and late-season pests. However, warm soil conditions are required for seed germination and seedling emergence. Cotton seedlings are adversely affected when soil temperature falls below 15.6 deg C. If cotton is planted when soils are cooler than 12.8 deg C, the crop may suffer stand loss, seedling disease problems, and cold temperature stress, all which reduce yield. The main objective of this paper was to develop a set of linear statistical relationships between minimum soil temperature and minimum and maximum air temperature for forecasting cotton planting dates in the Ogallala Aquifer region. This study focused on counties located south of 40 deg N latitude because northern counties probably have a limited thermal environment for cotton. This region consists of all of the Southern High Plains, the Central High Plains, and a part of the Northern High Plains of the Ogallala Aquifer region. The long term daily soil and air temperature database from 14 weather stations in the region maintained by the National Weather Service was used in this study. Soil temperature data were measured at a depth of 102 mm. Two sets of linear regression models were developed to predict daily minimum soil temperature using maximum or minimum air temperature for each station. Annual cotton planting dates for each county were identified when its estimated daily minimum soil temperature during the planting season was equal to or above a threshold value of 15.6 deg C for both models. The coefficient of determination, (r**2) for those models with daily maximum air temperature as an independent variable (0.42 to 0.73) were consistently lower than that with daily minimum air temperatures (0.53 to 0.84) for all stations. Planting date estimates from those models ranged between 1 April and 30 April in the Southern High Plains i.e., within the typical planting date range (1 April – 10 May) observed in that region. In general, earlier planting dates were identified for counties located in the eastern half of the study area possibly due to their lower elevation and associated increase in daily minimum temperature and higher soil water contents. The later planting dates were commonly found in counties located in the Northern High Plains and the western half of the Central High Plains.