Influence of cultivar and amendment of soil with calcium silicate slag on foliar disease development and yield of sugar-cane

Abstract

Puccinia melanocephala H. Syd. & P. Syd., the causal agent of sugar-cane rust, was significantly influenced by cultivar selection but was not affected by soil amendment with calcium silicate slag at a rate of 6.7 t ha −1. However, severity of ringspot ( Leptosphaeria sacchari Breda de Hann) was reduced with slag application. Across five cultivars, slag application reduced ringspot severities by an average of 67%. A significant cultivar effect and slag × cultivar interaction also were observed with respect to ringspot severity. Sugar-cane (interspecific hybrids of Saccharum spp.) yields were increased with addition of slag by averages of 17.2 and 21.8% across five cultivars during 1989 and 1990, respectively. Similar increases were observed for total sugar yields. Enhanced resistance to foliar diseases such as ringspot may partially explain yield increases obtained with application of calcium silicate slag to soils low in plant-available silicon.