Cultivation of Aonla
Botanical Name: Emblica orficinalis
Aonlais in cultivation in India since time immemorial; It is an important minor fruit crop having commercial significance. It belongs to the family Euphorbiaceae. The crop is quite hardy, prolific bearer and highly remunerative even without much: care. The fruit is capsular (drupaceous) with a flashy exocarp.
Origin and Distribution:
Aonla is said to be indigenous to tropical Soutti-Eastern Asia. It is also reported to be the native of India, Ceylon, Jalaysia and China. The data on area under aonla cultivation are not available. Although, it. is found growing in different states throughout tropical India even up to elevation of 1500 m in South India. It thrives well through tropical India, however, commercial orcharding can be seen in U.P; and-Gujrat The main aonla growing areas are the eastern;:-districts of U.P; like Faizabadr Pratagarh, Allahabad and Yaranasi.
This is a fruit of sub – tropical region but its cultivation in topical climate is quite successful. The treed is not much affected either by hot wind or frost. The mature trees can tolerate freezing temperature as well as a temperature as high as 460 C. Soon after the fruit set in spring, the fruits remain dormant through summer without any growth, makes it highly suitable fruit crop for arid region.
Aonla is not very exacting in its soil requirement and grows well in sandy loam to clay soils in India. It has a great tolerance to salinity and sodicity and cultivted in pH range of 6.0 to 8.0 very successful. However, production shall be highly benefited in deep and fertile soils.
Grafts or buddings of Aonla are best planted in the beginning of rnonsoon in the months of June to July. Since the free grows to a huge size a distancepf-8 to 10 in bothways is recommended. In areas with irrigation facilities planting can also be done in spring (February to March). Prior to plantings the field should be deeply ploughed, harrowed, leveled and marked appropriately. The pits 13 m size are made well in summer, kept open for about a fortnight fit each pit 10-15kg FYM are mixed with surface soil and filled. After first shower the plants are planted in the center of these pits and staked properly.
In dry are as where mortality after transplanting is usually high the seedling root stock can be raised ‘in situ’ at appropriate distance for budding with superior cloned
Training and Pruning:
As the branches of Aonla trees often break off carrying heavy crop.lead due to brittle nature of, wood the plant should be tained to Avelep a strong-frame for which the tree should be trained to single stem up to the height of 0.75 m from the ground. The plant should trained to modified leader system. The frame work should be developed by encouraging the growth of 4 to 6 well spaced branches all around the trunk.
The pruning of the bearing plants can be done after the termination of the crop each year. While pruning, dead, diseased, broken, weak, crossing branches and suckers appearing, from root stock should be removed.
Aonla tree is quite fast growing type. However, in initial 3 to 4 years sufficient space is available which could be, advantageously used for raising intercrops. Since this crop does not require any irrigation in summer due to dormancy of fruit, only scope of raising inter crope is in rainy season or in post monsoon period provided irrigation facilities are available. For this legumes and vegetables crops can be taken as an intercrop.
It refers to management of soil in such a way that productivity is maintained and soil losses are minimum. The techniques should be compatible to crop behaviour. In aonla flowering takes place in February and after fruit set the fruits remain dormant through summer until monsoon when fruits begin to grow and ready to harvest in December / January depending on the climate of the place. Therefore, in summer soil should not be disturbed and natural cover can be allowed. In the beginning of monsoon the basin can be cleared, fertilizer and manurial application can be done and the place between rows could be brought under green manure could be ploughed at flowering stage and left as such.
Manuring and Fertilization:
Regular orcharding of Aonla is a rare phenomenon, therefore, nutritionist hardly practiced. However, beneficial effect of nitrogen, phosphorus potash, zinc, copper, manganese and boron have been recorded. Nitrogen increased vegetative growth and female flowers, while P205 increased sex ratio, initial set, fruit retention and yield, TSS and vitamin C content of the fruit. Potassic fertilizer increased the fruit retention and quality. The young plant should be given 15-20 kg FYM and the matured tree 30 to 40 kg per year during Sept-Oct In addition, application of .30. gm N for each year age of the plant upto 10 years and afterwards-1 kg N, 1 kg P2Q5:and 1 to. 1,5= kg K2Q per plant per year should be provided, in two equal doses .to mature bearing free tree once during and again during April-May after setting of fruit. The plants need to be irrigated after fertilizer application. Spray of 0.6 per cent borax thrice in the month of September and October at about 10-15 days interval to control fruit necrosis which develops due to deficiency of boron.
Aonla trees are hardy; and stand very well against drought.Therefore, hardly any irrigation is practiced. The young plants require watering during summer, months at fortnightly intervals till they have fully established. The crop shall be benefited by giving 2-3 irrigations at the time of Ml bloom and set. Irrigation during Oct. to Dec,, at 20 days interval helps, in better development of fruits. During summer, when the fruit is dormant, there may not be any benefit to irrigate trees.
Flowering takes place on determinate shoots appearing in spring season. There is no self incompatibility in Aonla and the cause of poor fruit set (12 – 18%) may be due to a high percentage of staminate flowers. Flower and fruit drop in Aonla is divided in three stages.
i) The ‘first drop’ is the highest as 70% of the flowers drop off within three weeks of flowering due to unfertilized ovaries and degenerated ovules.
ii) The ‘second drop’ occurs from June to September, consists of drop of young fruit lets at the time of dormancy break may be due to lack of pollination and fertilization.
iii) The ‘third drop’ is spread over a period of rapid growth from August to October may be due to lack of auxins i.e. embryological and physiological factors.
A vegetatively propagated tree starts fruiting commercial crop after 6 – 8 years of planting, while seedling trees may take 10 to 12 years to begin bearing. Productive life of trees is estimated to be 50 to 60 years under good management.
Generally Aonla fruits are ready for harvest in November / December. Their maturity can be judged either by the change of seed colour from creamy white to black or by the development of translucence exocarp. The fruits are light green at first when they mature the colour becomes dull, greenish yellow or rarely brick red. Maximum Vitamin C content is observed in mature fruits while immature fruits are acrid and low in Vitamin ‘C’ content and minerals.
The mature fruits are hard and unyielding to the touch and so are well suited for bulk harvesting as well as distant transportation and marketing. For getting attractive price, fruits after harvest should be made in to different grades depending on the size.
The production varies from cultivar to cultivar. A full grown grafted Aonla with good bearing habit yields from 187 to 299 kg fruits per tree.