Mr. David is a government employee with a difference. He has been working as Assistant Director of Horticulture in Kadayam, Tiruenelveli District in Tamil Nadu helping farmers in following better farming practices. David motivated famers to follow precision farming techniques in cultivation of Brinjal.
But, in that area, brinjal crop was being infested with brinjal fruit borer. With the quality of harvesting being low owing to fruit borer attack, farmers were getting only 50 paise per kilogram. To overcome this problem, farmers started spraying pesticides, once a week.
Not only was the pesticide expensive, farmers had also to incur additional costs for spraying using petrol sprayer. They were using 2.5 litres of petrol per hectare per spray. Consequently, the cost cultivation increased by around Rs. 2625 per hectare.
Under such circumstances, David was exploring alternatives to reduce the cost of cultivation. Initially he tried with electric sprayer. This had to be operated by an electric motor powered by a rechargeable battery. Once charged, the sprayer could be used for only 3 hours in the field. But, as there were frequent power cuts, farmers found it difficult to re-charge. Then he made an improvement to the sprayer by harnessing the solar energy.
A solar panel was attached to a helmet in such a manner that the panel faced the sun. The solar powered sprayer could be used throughout the day without any interruption. However, after a few trials, farmers felt it was difficult to carry the helmet with the panel on the head. Then David fitted the solar panel in the sprayer itself. The entire process took two years.
Around ten farmers are presently using this solar sprayer. This sprayer is used for flowers, rice, maize, wheat, pulses, plantation crops like coffee, tea, cardamom and tree crops like mango, lime, guava and sapota. Pesticides, fertilizers, bio-pesticides and biofertilizers are sprayed using this sprayer. Some of the examples are neem oil and Pongamia oil for controlling crop pests, liquid formulations of Trichoderma viridi and Pseudomonas to control the crop diseases and bio fertilisers like Azospirillum and Phosphobacteria to accelerate plant growth.
The solar sprayer has many advantages. Besides reducing the cost of spraying, there is a saving on fuel/petrol. Also, the transportation cost for buying petrol is saved. The solar sprayer maintenance is simple. There is less vibration as compared to the petrol sprayer. The farmer can do the spraying operation by himself without engaging labour, thus increasing spraying efficiency.
The solar power system in the sprayer facilitates lighting of ‘wireless light traps’ which controls insect pests and reduces the number of insecticide sprays by fifty percent cutting the cost of cultivation. This also reduces pesticide residues in the agriculture, horticulture and animal products, improving the quality of the products. The light traps control effectively the mosquitoes too.
Farmers are also using this sprayer for other purposes. For instance, a solution prepared with 1.5ml of neem oil, 1.5ml of pongamia oil in one litre of water is sprayed to control mosquitoes in residential areas. By doing this, diseases like malaria transmitted by mosquitoes are being controlled with less expenditure, without polluting the environment.
“It is easy for me to carry and spray easily for my Jasmine crop which spreads across one acre” says a woman farmer. Another farmer from Kolli hills says “in a remote area like ours where we face frequent power failure and low voltage problems, this sprayer is a valuable innovation”.
Mr. David can be contacted at