Production management of white potato in the lowland tropics

The results of the study indicated that higher weight of tubers, number of marketable tubers, marketable tuber yield and least number of non-marketable tubers were recorded on white potato fertilized with 100% inorganic fertilizer and fertilizer with 50% of the recommended rate from sagana 100 + 50% of inorganic fertilizer. The effect of different input levels on the marketable tuber yield of white potato was also significant. The marketable tuber yield obtained from different cultural input levels when applied singly regardless of fertilizer used were: 18.29, 17.88 and 11.39 t/ha for mulching, insect control and weed control (cultivation) respectively. However, the yield of white potato was improved by the combination of two or three of the different cultural input levels. Plants that received mulch + insect control recorded a high marketable yield of 21.88 t/ha comparable to plants that received mulch, insect and weed control with a yield of 20.47 t/ha. The combinations of insect control + weed control and mulching + weed control have marketable tuber yield of 17.60 and 15.63 t/ha respectively. The interaction effect of the different fertilizer levels and cultural inputs showed that higher yield of marketable tubers were attained with the application of 100% inorganic fertilizer and 50% of the recommended rate from Sagana 100 + 50% of inorganic fertilizer and received mulching + insect control. The yield are 26.30 and 25.14 t/ha respectively. There was no significant difference observed on the plant height, number of tubers and incidence of weeds on the different fertilizer levels. The economic analysis indicated that white potato applied with 100% inorganic fertilizer contributed higher net return over variable cost with an average of P111,570.00 compared to plants fertilized with Sagana 100 combinations. Among the cultural input levels employed mulching alone obtained the highest net return over variable cost P151,465.00, benefit cost ratio 6.92 returns per unit labor 101.58, and 8.49 for return per unit cash applied with 100% inorganic fertilizer.