The Effect of Soil Texture and Irrigation on Rotylenchulus reniformis and Cotton

Scott R. Moore, Kathy S. Lawrence

Abstract


The reniform nematode, Rotylenchulus reniformis, is the most damaging nematode pathogen of cotton in Alabama. Soiltexture is currently being explored as a basis for the development of economic thresholds and management zones within a field.Trials to determine the reproductive potential of R. reniformis as influenced by soil type were conducted in microplot and greenhousesettings during 2008 to 2010. Population density of R. reniformis was significantly influenced by soil texture and exhibited a generaldecrease with increasing median soil particle size (MSPS). As the MSPS of a soil increased from 0.04 mm in clay soil to > 0.30 mm invery fine sandy loam and sandy loam soils, R. reniformis numbers decreased. The R. reniformis population densities on all soil typeswere also greater with irrigation. Early season cotton development was significantly affected by increasing R. reniformis Pi, with plantshoot-weight-to-root-weight ratios increasing at low R. reniformis Pi and declining with increasing R. reniformis Pi. Plant height wasincreased by irrigation throughout the growing season. The results suggests that R. reniformis will reach higher population densities insoils with smaller MSPS; however, the reduction in yield or plant growth very well may be no greater than in a soil that is lesspreferential to the nematode.

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