
%0 Journal Article
%A Walker, S. R. 
%A Barnes, J. E. 
%A Osten, V. A. 
%A Churchett, J. D. 
%A McCosker, M. 
%T Crop responses to sulfonylurea residues in soils of the subtropical grain region of Australia
%J Australian Journal of Agricultural Research
%D 2000/06/07
%V 51
%N 5
%P 587-596
%K sorghum, sunflower, chickpea, chlorsulfuron, metsulfuron-methyl, triasulfuron.
%R https://doi.org/10.1071/AR99040
%U https://www.publish.csiro.au/paper/AR99040 
%X Crop response following applications of sulfonylurea herbicides can vary considerably across the grain region of subtropical Australia. The aim of the study was to develop recommendations for safe re-cropping following chlorsulfuron, triasulfuron, and metsulfuron-methyl specific for the different soils and climates of this region. Seedling dry matter (SDM) and grain yield were measured at 17 sites over 4 seasons. Soils were ferrosols (pH 5.5&#8211;6.8), sodosols (pH 6.6&#8211;7.1), and vertosols (pH 7.8&#8211;9.0). Sorghum and sunflower were sown at plant-backs between 2 and 20 months, and chickpea at 10&#8211;13 months, after applications of sulfonylurea herbicides. Seedling response of the summer crops to these herbicides was substantially different for the 3 soils. Crop response in theferrosols was largely unaffected by plant-back, soil, or climatic factors after a minimum of 2&#8211;3 months. In contrast, response of summer crops in the vertosols and sodosols was strongly affected by plant-backs for up to 10 months, and SDM was more affected in sodosols than in vertosols. Predictive relationships between SDM and plant-back, cumulative temperature, and measured chlorsulfuron residues were developed for sowing summer crops in these soils. In ferrosols and vertosols, chickpea was unaffected by any treatment following plant-back of 10&#8211;12 months. These findings indicate that shorter re-cropping is possible in this region than currently recommended. However, the decision should be based not only on plant-back, but on soil type, cumulative temperature, and possibly even residue level in soil. These more specific recommendations will improve the safety and flexibility of re-cropping following applications of sulfonylurea herbicides in this region. 
