Effect of dates of sowing on dry matter production and partitioning in yam bean (Pachyrrhizus erosus (L) Urban)

Abstract

Climatic factors like temperature, relative humidity, rainfall, day length, and soil edaphic factors influence the growth and yield of a crop. The rate of dry matter accumulation remains faster at higher than lower temperature. However, high temperatures decrease the proportion of dry matter translocated to the tuber. Hence a field experiment was conducted in 1995 to 1996 at the Regional Centre of Central Tuber Crops Research Institute, Bhubaneswar to study the effect of climatic factors on dry matter production and partitioning in yam bean (Pachyrritizits erosus (L) Urban). The results revealed no genotypic differences in dry matter production and yield, indicating that all genotypes used were equally efficient in dry matter production and partitioning, However, date of sowing has marked influence on dry mater production and yield. Sowing on the 17th of August led to the production of higher dry matter with the highest tuber yield comparable with those sown on the 1st of September because of their higher partitioning efficiency. Although the partitioning efficiencies of the October 1st and September 16th sowings were higher, these resulted in lower yield due to lack of sufficient dry matter. These findings clearly indicated that early sowing between the 17th of August and the 1st of September is essential for higher tuber yield in fertile acid laterite soil.