Calcium is one of the most important but less mobile nutrients in plants. In groundnuts, it is responsible for pod formation. Its deficiency is therefore reflected in poor pod formation resulting in a fewer number of and small ill-developed pods per plant. For vegetative growth, it is manifested as localized pitted lesions on the lower surface of the leaves which eventually develop into brown necrotic spots. Severe deficiency of calcium in groundnuts can result in the death of the root tips and terminal buds.
Calcium is a yield limiting nutrient in groundnuts. It is needed for both vegetative growth and pod development. Its deficiency is most often seen in the pods. At the vegetative growth stage, the deficiency manifests as pitted lesions, which result into brown necrotic spots.
Calcium deficiency can be managed by applying the following:
- Apply gypsum at the rate of 600 kg/Ha using band application or 900 kg/Ha using the broadcasting method at the time of planting or at the early flowering stage
- Apply calcitic lime at the rate of 2 t/Ha by banding or using the broadcasting method two months before planting groundnuts