Crop architecture effects on elephant foot yam (Amorphophallus paeoniifolius) productivity and economics under rainfed conditions

A field experiment was conducted during 2008–09 and 2009–10 under rainfed conditions in Alfisols, to investigate the effect of broad bed and furrow, crop geometry and spacing on elephant foot yam [Amorphophallus paeoniifolius (Dennst.) Nicolson]. The experiment was conducted in a randomized block design with 5 replications. The treatment consisted of 90 cm × 90 cm, 75 cm × 75 cm and 60 cm × 60 cm spacing in square and triangle planting on broad bed and furrow (BBF) along with 90 cm × 90 cm square planting on pits followed by mounds (normal). The broad bed and furrow method of planting performed better than pits followed by mound. Triangle planting under all spacings gave higher yield owing to better growth, leaf-area index (LAI) and dry-matter production. Decreasing the plant spacing significantly increased the corm yield. The highest corm yield (28.4 t/ha) was observed at the closest spacing of 60 cm × 60 cm, though per plant yield was lesser. The corm yield at 60 cm × 60 cm spacing was statistically on a par with 75 cm × 75 cm spacing both under square and triangle planting. Higher net returns of 1,18,800/ha were noticed with 75 cm × 75 cm spacing in broad bed and furrow (BBF) triangle planting. But higher benefit: cost ratio (1.96) was noticed in 90 cm × 90 cm spacing BBF triangle planting.