Mango trees respond well to organic manure applications. Organic manures such as vermicompost, panchagavya and vermiwash are used for promoting healthy tree growth and fruit formation.
From the initial planting stages to caring of full-grown trees, Panchagavya and vermicompost can be effectively used to supply essential nutrients to the trees and prevent pest infestations, according to Dr. S. Sundaravadivel, Vermitechnologist and Environmentalist based in Chennai. Vermicompost is prepared by using earthworms. Vermiwash is the liquid collected after the passage of water through a column of activated earthworms. It is very useful as an organic spray for all crops.
Panchagavya is an organic growth promoter, which is prepared by mixing cow dung, cow urine, cow’s milk, curd and ghee in suitable proportions, and is sprayed on the plants. It contains several macro, micronutrients, beneficial bacteria and fungi, which aid in growth promotion and act as effective pest repellents.
It can be prepared by thoroughly mixing five kilos of fresh cow dung and one litre of cow’s ghee in a plastic or cement tank or earthen pot. The mixture is stirred daily for three to four days.”About three litres of cow’s milk, two litres of cow’s curd, three litres of sugarcane juice, three litres of tender coconut water and 10 to12 bananas are mixed well and added to the mixture. The entire concoction is allowed to ferment for fifteen days,” said Dr. S. Sundaravadivel.
The container should be covered with a net (or) cotton cloth to allow aeration of the fermenting unit, according to him. The concoction is stirred two or three times a day for about fifteen days and then used. For mango trees of about 6-7 years age, vermicompost may be applied at the rate of 10 kilograms per tree and one litre ofpanchagavya diluted in 30 litres of water may be sprayed over the foliage (crown) and at the base of the tree. Spraying Panchagavya over the crown and at the base of the tree must be done four to five times, according to Dr. Sundaravadivel. The first spraying must be done before the flowering season (January-March) to increase flower formation.
A second spraying must be done after 15-20 days. The process must be repeated till the flowers turn into small sized buds. Once the buds start forming then the application can be done once a month, according to him. Use of Panchagavya and vermicompost has been found to increase the size, number and enhance the colour of the fruits.
The recommended practice for one hectare of mango trees is about 25 litres of panchagavya (mixed in 750-800 litres of water) and four to five tonnes of vermicompost. Spraying panchagavya has been found effective in the control of fruit fly menace, a common infestation in all fruit bearing trees, according to Dr. Sundaravadivel. According to him, trees treated with organic manures bore large sized leaves and formed a dense canopy with profuse rooting systems. The taste and shelf life of the fruits were also found to be more satisfactory.
“The interaction of the root hairs of these trees with the organic manures also increased the activity of the nitrogen-fixing bacteria in the soil.
“The organic manures also act as a carrier medium for the development of several beneficial micro organisms such as azospirillum, azotobacter, rhizobium and phosphobacteria,” he said. Dr. S. Sundaravadivel can be reached by mobile at 98843-90104 ,and email: firstname.lastname@example.org.
Alphonso, the king of mango varieties, does well under organic farming conditions in Kanchipuram and Thiruvallur districts of Tamil Nadu, and its full potential should be exploited by the small and marginal farmers in the districts, says Mr. S. S. Nagarajan, Vice President (Agricultural Research), TAFE (Tractors and Farm Equipment Limited), Chennai.
An authority on mango cultivation, and a pioneer in establishing the largest `Rumani’ orchard in Kanchipuram district at `J-Farm’, Kelambakkam, Mr. Nagarajan has successfully demonstrated the promises held out by the superior mango variety `Alphonso’. “After working with `Rumani’ variety in the last thirty five years, I shifted my focus to `Alphonso’ variety in 1998, and it has done exceedingly well in the farm. It responded favourably to drip irrigation and organic inputs, and yielded high quality sweet fruits of attractive aroma,” explains Mr. Nagarajan.In about 0.8 hectares in `J-Farm’ he planted 140 Alphonso grafts got from a nursery in Dharmapuri district. This variety is suited for high density planting, and it will make up for the low yields in the initial few years of bearing.
The regular bearing commences from the ninth or tenth year of planting,” he points out. Every young plant was regularly manured in August with liberal quantities of ripe farmyard manure along with 400 g each of Azospirillum and Phosphobacterium. Drip irrigation to provide 25 litres of water per tree per day was established. All other regular orchard practices such as clipping the sprouts below the graft union, weeding and hoeing in the basins, and ploughing the interspaces and plant protection with eco-friendly botanical insecticides were adopted.
“During the first five years Daincha was raised as rainfed crop, and ploughed in situ as an organic nutrient supplement. Groundnut was grown as an irrigated crop in the interspaces, and haulms were incorporated in to the soil as green leaf manure. Of the 140 trees, 112 trees started yielding in the fifth year after planting, and on an average each tree yielded about 70 fruits each weighing about 250 g. In all about 2000 kg fruits were harvested and it fetched Rs. 12 per kg at the farm gate. The gross income in the first year of bearing is Rs. 24,000, and the cost of cultivation in the first five years worked out to Rs. 24,000”, he said.
“The quality of the fruits were of superior quality, and they were sweet and free of spongy tissues. The results were quite encouraging,” says Mr. Nagarajan. The trees would yield as high as 3000 kg from the 0.8 hectares from the sixth year of planting, and it would fetch a handsome profit to the growers. As the tree grows, the yield will go up, and a thirty year-old tree would produce as much as 2500 quality fruits, according to him. `J-Farm’ has perfected the organic farming practices for raising Alphonso mango, and the farmers should benefit from it, according to him. Farmers, however, should avoid using chemical fertilizers and fruiting hormones to get quick returns from the variety, as they may prove harmful in the long run, he says “Alphonso is an excellent variety for export and if grown organically, its value in the export market will go up significantly,” explains Mr. Nagarajan.