Long term ratooning of sugarcane on sandy soils in KwaZulu-Natal.

Variety x nematicide trials are planted throughout the South African sugar industry to study the response of varieties to nematode damage. Data from one such trial conducted over nine crops showed that the average ERC yield for the control plots ranged from 3.8 to 8.1 t/ha with NCo376 being the better performing variety. The nematicide treated plots produced ERC yields of 8.8 to 12.4 t/ha, with N16 the better performing variety. Treating each crop with a nematicide increased the yield of each of the varieties. The greater yields were due more to an increase in cane quantity (t sucrose/ha, t ERC/ha, t cane/ha, population, length) than cane quality (ERC, Pol, purity, Brix), although the effect was variety dependent. In the untreated control plots scattering the burnt cane tops or green cane harvesting, and changing the time of harvest from late season to earlier in the season, were associated with increased ERC yields.