The Effects of Agronomic Practices, Seasonality and Agro-Ecological Zones on Suckering, Scarring, and Weight of Dasheen [Colocasia Esculenta (L) Schott Var. Esculenta]

Scarring caused by the removal of suckers attached to the main corm at harvest is a major constraint to dasheen production, marketing and export in Dominica and the other dasheen producing islands of the Caribbean. Scarring makes the corms unpresentable, provides sites for disease infection, and accelerates rotting, which in turn reduces shelf life and marketability. Experiments addressing the above examined the effects of plant depths and spacing on suckering, during the wet and dry seasons, in Grand Bay (average annual rainfall 2400 mm, rainfall pattern - dry season from January to May, moisture regimes Ustic, soil types smectoids, kandoids latosolics, young soils) and Wet Area (average annual rainfall 5300 mm, rainfall pattern - mild or no dry season, moisture regimes Udic, soil types - kandoids latosolics, alophonic latosolics, young soils). Results showed that the average number of suckers per dasheen corm was more in Wet Area, when compared to that of Grand Bay. Correlation and coefficients of the regression between suckering and scarring in Wet Area, were r = 0.8647 (p<0.001) in the wet season and r = 0.4971 (p<0.01) in the dry season. In Grand Bay, r = 0.7128 and r = 0.7351 in the wet and dry season, respectively, were highly significant (p<0.001). These correlations indicate that factors which reduced suckering would also reduce scarring. Suckering and scarring were significantly (p<0.05) reduced in both locations, during the dry season in response to decreasing plant spacing. In Wet Area, increasing plant depth was also found to reduce suckering during the wet and dry seasons (p<0.05). Fewer suckers were obtained at the deeper plantings when compared to those of the closer spacing. Reduction of suckers on the dasheen corm, as a means of improving corm appearance and prolonging shelf-life, without significantly affecting corm weight negatively, is obtainable in the Wet Area, in the wet and dry seasons, at plantings of 25 to 30 cm deep and a spacing of 55 χ 55 cm. In Grand Bay, similar specifications can be obtained only in the wet season at plantings of 65 χ 65 cm deep and a spacing of 25 to 30 cm.