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Irrigation in groundnut

Groundnut is mainly grown under rain fed situation. Only 19% of groundnut area in India is irrigated.
Groundnut crop is exposed to drought conditions very often during its growth and consequently the yields are lower than the potential yield.
So, if the farmers want higher groundnut yields, the answer is irrigation if water is available.
How irrigation helps groundnut crop?

• Allows efficient use of inputs
• Increases yield
• Improves quality of pods and kernels
• Reduces aflatoxin problem
• Improves reliability and reduces risk
• Increases profitability

Allowing seed to remain in dry soil for several days may result in poor germination and seedling vigor.
So, irrigation prior to sowing is recommended.
Excessive irrigation during early plant growth stages (first 50 days after planting) may result in excessive vegetative growth and shallow root development.
Irrigation during early vegetative growth stages is recommended only to limit severe water stress.
Once pegging and pod formation has begun (about 50 days after planting) it is recommended that the pegging zone be kept moist; this facilitates the uptake of calcium by pods - essential for seed development.
Peak water use occurs at about 12 to 16 weeks from emergence during pod fill and maturity and can be as high as 75 mm per week.
During pod fill it is essential to maintain adequate moisture in the pegging zone to achieve maximum kernel quality through calcium absorption.
Water stress during pod formation and early seed filling stages reduce final yield. So, irrigation at pod formation stage is critical.
Excessive irrigation during the maturity of the crop (after 100 days of planting) can increase risk of leaf and pod diseases, peg deterioration and uneven maturity resulting in harvesting problems.
If the field is too dry a light irrigation helps in easy harvesting. However, control in irrigation is important and the crop need to be harvested immediately else the seeds may germinate within pods itself.
Summary

Growth Stages	Irrigation requirements
Germination And Emergence	Good Moisture conditions are required.  Irrigation can ensure you plant on time.
Vegetative	Groundnuts can tolerate mild water  Stress at this stage. Stress at this  stage may be beneficial.
Peg Initiation	No water stress at this stage, very  sensitive. Use Irrigation
Pod Formation And Filling	No water stress. Use Irrigation
Maturity	Decreasing water use as the crop matures