Title

An Economic Analysis of Foliar Fungicides Used in Northeast Texas Wheat Production

Document Type

Thesis

Degree Name

Master of Science (MS)

Department

Ag Science and Natural Resources

Date of Award

Summer 2013

Abstract

Fungal diseases are the number one biotic reason for crop losses around the world and have a significant impact on yield and quality in wheat (Triticum aestivum L.) production. Up to 42% yield loss caused by fungal diseases can be prevented by applying foliar fungicides to winter wheat. The U.S. is the world's largest wheat producing and exporting country. Texas ranks 8th among the major U.S. wheat producing states and most of its wheat is grown in the High Plains region in Texas. The Texas A&M AgriLife Extension Representative in Commerce, TX conducted a two year study to evaluate the response of four soft red winter wheat varieties (Magnolia, Terral LA 841, Pioneer 25R47, and Coker 9553) to a foliar fungicide application treatment (tebuconazole). The experiments were conducted in Northeast Texas, in Royce City, in the town of Howe, and in the city of Leonard during 2011 and 2012. Each treatment was replicated six times in a randomized complete block design. The main objective of the study was to evaluate the economic impact of tebuconazole in wheat production. Statistical Analysis System (SAS) was used to analyze yield and net return. Additionally, a Tukey�s means separation test was used to performed means comparisons between treatments at 5% significance level. The profitability of obtaining net returns from a single fungicide application was conducted by implementing a Bayesian inference method. A sensitivity analysis was used to evaluate the economic effects of spraying and non�spraying tebuconazole at varying wheat prices and fungicide cost. No fungal diseases were found during the two years that were evaluated. In 2011 low levels of barley yellow dwarf, a viral disease, were detected at the Howe location. In 2011, there was not a significant effect of tebuconazole treatment on the overall yield response compared to the control group. In 2012 there was a significant difference of an 8.6% increase on yield from the tebuconazole treatments over the control group, which may be attributed the higher precipitation level in 2012 than in 2011. Excitingly, during the two years of the study, 66% of the observations resulted in positive net returns from fungicide applications. In addition, it was found that high net yields do not necessarily mean high probabilities of obtaining net returns from fungicide applications. However, the probability of breaking even from fungicide use is positively correlated to the yield magnitude (i.e., the variety�s capacity to produce yield) and the variety�s partial resistance to leaf and stripe rust.

Advisor

Jose Lopez

Subject Categories

Agriculture | Life Sciences

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