GROWTH OF POTATO (SOLANUM TUBEROSUM L.) OF GRANOLA VARIETY UNDER APPLICATION OF EARTHWORM CASTING AND INOCULANT OF ARBUSCULAR MYCORRHIZAE

Abstract

This study was intended to identify effect of earthworm casting application and arbuscular mycorrhizae (AM) inoculant on growth of potato (Solanum tuberosum L.). Experiment was conducted at Kanreapia-Tombolopao in Malino-Gowa from April to June 2002. It was arranged in 2-factor randomized complete block design. First factor was four levels of earthworm casting application, which were 0, 100, 200 and 300 g casting plant-1 respectively. Second one was four levels of arbuscular mycorrhizae inoculant, which were 0, 2.5, 5.0 and 7.5 g plant-1. Thus, there were sixteen treatment combinations, each one was repeated three times giving 48 experimental units. Potato growth rate increased with increasing age from 38–68 days after planting (dap) and then declined on 78–88 dap. Highest rate (0.0055 g cm-2 day-1) occurred at treatment combination of 300 g casting plant-1 and AM inoculant of 7.5 g plant-1 on 67 dap. S/R ratio declined with age increment from 28–88 dap. Highest S/R ratio (3.5) was obtained by treatment without casting and AM inoculant of 7.5 g plant-1 on 28 dap.