Influence of weeding regime on severity of sugarcane mosaic disease in selected improved sugarcane germplasm accessions in the Southern Guinea Savanna agroecology of Nigeria

Experiment was conducted during 2011 to 2012 cropping season using potted plants, to evaluate the influence of weeding regime on sugarcane mosaic disease severity in selected improved sugarcane varieties from the University of Ilorin – Nigeria sugarcane germplasm. The experiment was laid out following a split plot arrangement where the weeding regime constitutes the main plot and the sugarcane varieties were the subplot. Disease parameters such as symptom manifestation, number of diseased leaves, percentage severity were measured. Growth and yield parameters such as stalk length, number of leaves, number of tillers and yield parameters such as fresh and dry shoot weights, percentage dry matter at harvest were also measured. Analysis of variance showed that percentage severity of sugarcane mosaic disease, increased in non-weeded plots compared with weeded plots. Twice weeding (52.1%) and the weed free plots (53.7%) had the significantly lowest severities. Varietal influence significantly influenced severity and variety NCO-270 produced the significantly lowest severity (45.8%).The interaction of weeding regime and variety indicated that variety CB36411 in the weed free plots, produced the lowest severity (33.5%).Yield parameters showed that significantly highest shoot weight was recorded in the weed free plot, while variety NCO-270 gave the highest fresh and dry shoot weights (254.8g and 50.2g respectively). The results indicate that variety NCO-270 was the most tolerant and that weeding at least once in six months is required to mitigate the effect of sugarcane mosaic disease, as witnessed in significantly increased growth and yield attributes of plants in the weeded plots.