IMPACT OF SUCKERING AND LODGING ON PRODUCTIVITY OF CULTIVARS IN THE WET TROPICS

Lodging and sucker content in the cane supplied to mills have been linked to declining CCS in the wet tropics. This research aimed to separate the impact of nitrogen and cultivars on these phenomena and identify their effects on CCS and cane yield on three different soil types. Nitrogen applications of 0, 70, 140 and 210 kg N/ha had no influence on CCS, cane yield, lodging, and suckering in plant crops of Q117, Q120 and Q138. All cultivars were susceptible to lodging irrespective of soil type with Q138 being the most susceptible. Lodging reduced CCS by 1.2 units, on average, with the reduction being less pronounced for Q117. Lodging caused cane yield to plateau, although negative effects on yield of up to 8% were obtained with Q138. Lodging was not a pre-requisite for sucker development as suckering occurred under a closed canopy. All three cultivars exhibited a high propensity to sucker, with Q138 being the most prolific. Suckers increased crop yields by up to 26.3%. Mature-stalk CCS was reduced by 1.0 for each 10% increase in sucker content in the crop, which had a negative impact on profitability. Results are discussed in terms of management strategies to negate the effects of lodging and suckering on profitability.