Title: Peanut canopy temperature and NDVI response to varying irrigation rates Authors
Submitted to: International Irrigation Show
Publication Type: Proceedings
Publication Acceptance Date: September 26, 2011
Publication Date: November 6, 2011
Citation: Stone, K.C., Bauer, P.J., Busscher, W.J., Millen, J.A., Evans, D.E., Strickland Jr, E.E. 2011. Peanut canopy temperature and NDVI response to varying irrigation rates. In: Proceedings of the Innovations in Irrigation Conference, November 6-8, 2011, San Diego, California. 9 p. Technical Abstract: Variable rate irrigation (VRI) systems have the potential to conserve water by spatially allocating limited water resources. In this study, peanut was grown under a VRI system to evaluate the impact of differential irrigation rates on peanut yield. Additionally, we evaluated the impact of differential irrigation rates on crop canopy temperatures and vegetative indices. Canopy temperatures and vegetative indicies may be potential tools for VRI system management. The study consisted of four experiments with two planting dates (early and late plant). For each planting date, there were two periods of imposed plant stress (early and late stress). Within these four experiments, there were four irrigation treatments (0, 33, 66, and 100% of the calculated crop evapotranspiration). The overall peanut yields for the study averaged approximately 4300 kg/ha with individual treatment means ranging from 3380 to 4958 kg/ha. Peanut yields across irrigation treatments were not significantly different. The peanut NDVI measurements were significant across irrigation treatments in only one experiment. In this experiment (#1) with significant differences across irrigation treatments, the non-irrigated treatment NDVI measurements began to indicate potential water stress. However, water stress based on NDVI measurements occurred several days after both canopy temperatures and soil water potentials began to indicate potential water stress. The crop canopy temperatures in experiments 1 and 3 were significantly different across irrigation treatments and did indicate potential water stress. In contrast to NDVI measurements, the crop temperature measurements were able to quickly differentiate among the irrigation treatments and could provide a tool that could be used for spatial irrigation management using variable rate irrigation systems.