INTER- RELATIONSHIPS AMONG THE GROWTH AND YIELD PARAMETERS OF IRISH POTATO (SOLANUM TUBEROSUM L.): CORRELATION/REGRESSION ANALYSES.

An agroforestry experiment was conducted to investigate the interplay of the apparent growth parameters of Irish potato (Solanum tuberosum L.) and their relationships with yield. It was a 3 – year study consisting of 5 treatments (and 3 replicates) in a randomized complete block design. Both rainfed and irrigated cropping seasons were involved, sprouted potato tubers were planted in the alleys (space between rows of trees) of Albizia lebbeck (rattled tree) and the green manure of the rattle tree was applied at various levels. Results from the correlation / regression analyses indicated positive correlation between the independent variables (collar girth, number of leaves and plant height) with the dependent variable (yield) while stem count had a negative correlation with yield. Very importantly, leaf count (number of leaves) and collar girth were the two determinants of this Irish potato (bertita variety) yield. These two independent variables accounted for 61.6 – 91.3% variation in yield (R2 = 0.616 – 0.913).