Weed Interference Periods in Ratoon Sugarcane

The present Work aimed to determine the period prior to interference and the total prevent ion period to interference of weeds in sugarcane (ratoon) cultivar SP 80-3280. The experiment was carried out on a Dark Red Oxisol. The treatments consisted of increasing periods of presence or absence of weeds: 0, 0 15, 0-34, 0-59. 0-90, 0-124, 0 157, 0-269 days (sugarcane harvest). The most common weeds found in the experimental area were Panicum maximum, Acanthospermum hispidum and Altemanthera tenella. The results obtained. admitting 2% and 5% reduction in sugarcane productivity, showed that the period prior to interference ice tolerated by the culture was 9 and 18 clays after ratoon sprout (DAS) and the total prevention period to interference was 200 and 137 DAS, respectively, resulting in a critical period of prevention to interference from 9 days at 200 DAS of 296 reduction, to 18 days at 137 DAS, of 5% reduction.