Relative Annual Broomweed Abundance as Related to Selected Climatic Factors

Abstract

Regression models were developed to predict relative abundance of annual broomweeds on a Texas rangeland as a function of selected climatic factors. Based on 16 years' data, above-average precipitation in May and below-average daily maximum temperatures in April were the principal climatic factors most closely associated with heavy infestations of annual broomweeds for any given year (R2 = 0.902). Similar models developed from bimonthly and trimonthly averages were less precise than monthly averages for predicting relative abundance of annual broomweed.