Response of cowpea (Vigna unguiculata (L) Walp) varieties to leaf harvesting in Botswana.

Abstract

In Botswana, cowpea (Vigna unguiculata (L) Walp) is not only grown for grain but also the leaves are harvested and used as vegetable. The effect of leaf harvesting on grain yield under Botswana conditions is not known. This study was, therefore, undertaken to assess the response of four cowpea varieties namely Tswana, Blackeye, ER 7 and TVx 3236 to leaf harvesting. Under field experiments carried out over two growing seasons, effects of four levels of leaf harvesting (0, 25, 50 and 75%) on growth and grain yield were determined. While harvesting of up to 50% of leaves increased grain yields of Tswana and Blackeye, these were depressed when up to 75% of leaves were harvested. Also, all leaf harvesting treatments had significant negative impact on ER 7 and TVX 3236 grain yields. The results suggest that Tswana and Blackeye cowpeas could be developed for the dual purpose of leaf and grain production in Botswana and other areas where cowpea leaves are relished as a vegetable.

UNISWA Jnl of Agric Vol 8 1999: pp 5-11