Research findings says that majority of the soils of Tamil Nadu are deficient in zinc, boron, iron (micronutrients).

Apart from the basal application of major nutrients especially, nitrogen, phosphorus and potassium the groundnut crop also needs some micronutrients at minimum dose.

A technology has been formulated by the Oilseeds Research Station, Tindivanam (TNAU) to supply micronutrient mixture as foliar application during the flowering stage to boost the yield.

Foliar spray

The main objective of this spray is to increase the number of flowers, speed up photosynthesis, arrest flower drop and supplement the required micronutrients at a faster rate compared to soil application.

The components of the micronutrient mixture are one kg of diammonium phosphate, about 400 gm of ammonium sulphate, 200 gms of borax and ferrous sulphate each, 175 ml planofix, and 500 gm of zinc sulphate.

All the above nutrients are readily available in the local market and are cost effective. The nutrient mixture should be mixed thoroughly in 10 lit of water and filtered. The clear solution is then diluted in 190 litres of water and sprayed for an acre.

Spraying must be done during evening especially at 25 and 35 days after sowing. The cost of entire spraying cost comes to around Rs.750 per spray.

Increased yield

The increased yield ranges from three to four bags (40kgs/bag) of dry pods per acre coupled with high shelling percentage. Many farmers in and around Villupuram district are practicing this technology and call it “Tindivanam tonic.”

Recently Department of Physiology, TNAU, Coimbatore has come out with instant nutrient mix spray named “Groundnut rich” which consists of all required micro nutrients for the plant growth. The cost of the groundnut rich tonic is Rs. 120/kg.

Recommended dosage

The recommended dose is 2.3 kg/spray. This groundnut rich instant mix can be obtained from the Department of Crop Physiology, TNAU, Coimbatore (phone: 0422-6611243). Otherwise farmers can make their own tonic by mixing the above ingredients in the correct proportion.

(Dr.R.Vaidyanathan is Professor & Head, Oilseeds Research Station, Tindivanam, TNAU, Phone: 04147-250293, mobile: 9442472103.)