SOIL APPLIED COBALT AND COPPER ALTER THE RHIZOBIUM SYMBIOSIS AND GROWTH STATUS OF LABLAB PURPUREUS (L.) SWEET

Abstract

A pot experiment was performed to investigate the effect of cobalt (Co) and copper (Cu) nutrition on nodulation, nodule activity and growth of Lablab purpureus plants growing in sandy clay loam soil collected from Toshka region in south of Egypt. The pots were given nutrient solution only once with addition of increasing levels of cobalt and copper (50, 100, 150 and 200 μg) as cobalt or copper sulfate solution. The present study has provided a new insight into the effect of cobalt and copper on nodulation and nodule physiology of Lablab purpureus (L.) Sweet (kashrangeeg) that has not yet been examined. Thus, the present work suggest that Co and Cu application is essential for the enhancement of nodulation, nodule activity and growth of Lablab purpureus plants growing in sandy clay loam soil deficient for theses microelements.

Keywords:

• soil fertility
• tropical crops
• cobalt
• copper
• nitrogen