IDENTIFICATION OF NUTRITIONAL AND ENVIRONMENTAL-FACTORS AFFECTING SUGARCANE BARBADOS

Sugarcane production in Barbados has declined since the 1950s. Plant n utrition and fertilization deficiencies are generally believed to nega tively influence yields in Barbados. The objective of this study was t o identify nutritional and environmental factors related to sugarcane yields. Leaf analyses, respective crop yields, and other data were col lected from the Barbados Sugar Industry Ltd. during the period 1985-19 90. The database was constructed from 2,853 site observations, consist ing of crop cane yield (Mt/ha), soil grouping, ecological grouping, gr owing elevation, and leaf tissue analysis [nitrogen (N), phosphorus (P ), potassium (K)]. Simple mean separation and tree-based regression we re used to identify nutritional and environmental factors associated w ith sugarcane yields. Twenty-three environments were delineated by tre e-based regression, in which plant nutrient deficiencies (i.e., yield limiting) were identified. One environment described N-deficient condi tions, four environments described P-deficient conditions, and five en vironments described K-deficient conditions.:Different critical leaf n utrient concentrations were related to yields. A single nutrient norm under different environments may be misleading. If current fertilizer recommendations are adhered to by growers in Barbados, attention to ad ditional fertilization should be given only under these environments.