The Topping of Sugarcane

Abstract

Experiments were undertaken to determine the influence of the height of topping of sugarcane at harvest on profits. Six cane varieties, P.R. 975, P.R. 980, B. 4362, P.R. 1013, P.R. 1016, and P.R. 1028, growing in both humid and irrigated areas of Puerto Rico were topped at harvested ages of 12, 18, 20, and 22 months. Two heights of topping were used: High, at a point near the spindle, and low, at a point approximately below the tenth node. The results were as follows: 1. In general, low topping was more profitable than the high topping now in commercial use in Puerto Rico. 2. Low topping was most profitable for P.R. 975, which ranged from 89 cents per ton of harvested cane at 12 months to $1.68 per ton at 22 months of age for the humid cane area, and from nothing at 12 months to $1.79 per ton at 22 months of age for irrigated cane. 3. B. 4362, P.R. 980, and P.R. 1013 showed profit from low topping vs. high, with a few exceptions at certain ages. 4. P.R. 1016 gave variable results both for age and location, and P.R. 1028 showed only losses. 5. The reasons for profit or losses attributable to low or high topping are discussed, regarding as indicators the percentage increases in sucrose-percent- cane and losses in cane tonnage resulting from the topping methods.