Growth and yield responses of commercial sugarcane cultivars to mulching in the coastal rainfed region of South Africa

Abstract

The perceived negative cultivar responses to mulching has limited the adoption of this practice in the South African sugarcane industry. This study was aimed at evaluating cane yield and quality responses and population dynamics of popular cultivars to mulching in the rainfed region of South Africa. A four-replicate field trial was established using a strip-plot design. Cane and tonnes estimated recoverable crystal yields (TERC) yields, and yield components were determined in three summer ratoons and one winter ratoon. In-season soil water and temperature were monitored. Mulching significantly improved cane and TERC of all cultivars across ratoons. The highest improvements in cane and TERC were 85% (N45) and 92% (N39), respectively. The improvements were attributed to the higher soil water content under the mulch blanket. Stalk height, mass and population (winter ratoon) were improved at harvest for most cultivars across ratoons with mulching. Mulching reduced emergence and tillering presumably due to lower soil temperatures under the mulch blanket. The highest mulch-yielding cultivars were N47 and N42, for which yield increased by 15 and 13 t ha−1, respectively. Mulching was beneficial for sugarcane production, regardless of the cultivar and ratooning season, and can be recommended for all current cultivars in the coastal rainfed region.