Flowering and Fruiting :-
The whole period of bud development is divided into eight stages. It takes 21 days to 22 days for passing through various stages of bud development. The flowering period lasts for about two and a half months from September to November. The peak of flower anthesis is at 6 A. M. in Sanaur-2, Sanaur-5 and Chhuhara ultivers and 2 P.M. in Thornless, Khaithli and Umran cultivars. The dehiscence of anthers starts just after anthesis and completes within 4 hours. Pollen grains are highly viable - the viability ranging between 87 to 91 percent in different cultivers. Pollen grain germinability is also quite high to 36 - 48 per cent. The peak receptivity in stigma is found on the day of anthesis. It does not set any fruit by self-pollination, thereby shows self-incompatibility.
Fruit-setting starts in second week of October and continues upto first fortnight of November. The ber fruit reaches to ripe stage in about 180 days after fruit-setting. The fruit growth in terms of lenght and diameter shows three distinct phases and follows a pattern of 'Double Sigmoid' curve.
Orchard Cultural Practices :-
Training and Pruning :
Training : The ber plants start bearing within 2-3 year of their planting in the orchard. In the fourth year, the trees bear commercial crop. Hence, the ber plants should be properly trained during the first 2-3 years, to build up a strong framework. The young budlings should be given support with a bamboo stake to avoid the breakage of the bud-union and to support the main stem. The commercial varieties are spreading in nature, therefore, staking is absolutely essential during the first two years to train the tree properly. The plant will make vigorous growth during the first year. Many secondary branches will emerge from the main stem. All the branches upto 75 cm from the ground level should be removed. Four or five laterals which are most favourably located around the main stem should be selected to make the proper framework. At the end of the year, the main stem should be headed back to some outgrowing laterals.
Pruning : The pruning of ber trees is highly desirable to maintain their vigour and productivity as well as to improve fruit size and quality. Pruning also saves the fruit from being affected by the powdery mildew disease and strong winds. The ber tree remains young upto 30 years, if proper pruning is done regularly. Ber fruit is borne in the axils of leaves on the younge growing shoots of the current year. Hence, a regular annual pruning is essential to induce a good and healthy growth which will provide a maximum fruit bearing area on the trees as well as to improve the fruit size and quality. In unpruned ber tree, the canopies of the trees get un-necessarily enlarged, the growth and branchlets become weak and both fruit size and quality gets impaired. Ultimately, such trees become economically unproductive besides occupying large orchard space. Some thinning out of the branches of ber trees is also necessary to avoid too much crowding so as to admit adequate sunlight and facilitate proper aeration. Ber pruning experiments have shown that the light pruning, i.e. heading back of 25 per cent of the previous year's growth (branchlets, shoots, etc) is desirable to obtain heavy yield, good fruit size and better quality. The lower branches should be pruned suitably to prevent them from spreading on the ground. The diseased, broken and intercrossing branches should also be thinned out. Severe pruning after every four-five years, is recommended.
The ber trees shed their leaves and enter into dormancy by the end of May. The best time for taking up pruning would, therefore, be end-May or beginning of June.
Irrigation :-
Irrigation is essential during the development of fruit, i.e. from October to February at intervals of 3 or 4 weeks depending upon the weather. Trees will continue to bear even if no irrigation is applied during this period but the yield is substantially reduced because of heavy fruit drops and smaller size of the remaining fruit. The quality of fruit is also very poor. It has been observed that the fruit become large and their quality is improved the fruit shedding is very much minimised if irrigation is applied during fruit development period. Irrigation should be stopped in March as fruits on the branches lying on the ground get damaged and their ripening is delayed. The harvesting of fruit is over in April and they become dormant in May-June and shed their leaves. They need little or no irrigation during this period. If irrigation is applied during the dormant period, the trees would continue to put fourth growth haphazardly which is not desirable. Under Panjab conditions there are sufficient rains during July to September when the tree produce the maximum fresh growth. During the second half of September and in October the trees come into flowering. At this time, light irrigation should be given.
Manuring and Fertilization :
Proper nutrition of ber tree is necessary to get good crop over the years. The fruit becomes large and attractive and get decent price in the market. 20 kg farmyard manure and 100 g nitrogen (400 g CAN) is recommended for one year old ber tree. Similar amount of farmyard manure and nitrogen should be increased every year up to the age of five years. The quantity of farmyard manure and nitrogen should be stabilized at 100 kg and 500 g (2 kg CAN), respectively, after the age of five years.
Farmyard manure should be supplied in May-June. Half of the CAN may be applied during rainy season (July-August) and the other half at the time of fruit-set (October-November). The fertilizer should be evenly spread in the basins of trees upto the periphery. After adding the fertilizer, light hoeing with spade or khurpa should be given to the basins to mix it thoroughly with the soil.
Intercropping :
The ber tree begins to bear after one year of its planting in the field. To develop the tree properly, it is advisable that no fruit should be taken at least for the first two-three years. Intercropping can be successfully practised on the vacant land in the young orchard during the first four years. Only leguminous crops of short stature like gram, moong and mash can be grown to get some income from the land in these initial years. These crops also enrich the soil by fixing nitrogen. The other exhaustive and tall-growing crops should not be grown in the ber orchard as they deplete the soil of its nutrients to a greater extent and compete for light with the trees.
Manures and fertilizers, irrigation and plant protection measures should be given seperately to the fruit trees and intercrops according to their needs.
Weed Control :
Pre-emergence application of Hexuron 80 WP (diuron) at 1.2 kg/acre can be made during the first fortnight of August when field is free from growing weeds and stubbles. Glycel 41 Sl (glyphosate) at 1.2 litres/acre or gramoxone 24 WSC (paraquat ) at 1.2 litres/acre as post-emergence should be sprayed when the weeds are growing actively preferably before weeds flower and attain a height of 15-20 cm. Dissolve the herbicide in 200 litres of water per acre to give complete coverage of weeds/field. Spray Glycel and Gramoxone during the calm day to avoid spray drift to the foilage of the fruit trees.
Control of Fruit Drop :
Spray application of 20-30 ppm Naphthalene acetic acid once in the second week of October and again in the second week of November, check 11 per cent fruit drop in Sanaur-5 snd 10 per cent in Kaithli cultivers of ber.
Harvesting and Fruit Handling :-
Harvesting : The ber tree grows quickly and and the first crop can be harvested within 2-3 years of planting. The fruit itself requires about 22-26 weeks to mature after fruit-setting. The peak season of harvesting in north India is in mid-March to mid-April but some early varieties may ripen by end-February. This period being a slack season for other kinds of fruits, ber sells readily at remunrative prices.
The fruit should always be picked at the right stage of maturity, i.e. when it is neither under-ripe nor over-ripe. It should be picked when it has acquired normal size and characteristic colour of the variety, e.g. golden yellow colour in Umran. Normally four to five pickings have to be made as all the fruits on the tree do not ripen at the same time. In no case, the fruit should be allowed to become over-ripe on the trees, as they deteriorate in taste and quality and thus fetch lower price in the market.
Insect-pests :-
Fruit-fly (Carpomyia vasuviana costa) : It causes great damage to ber fruits. The larvae feed inside the fruits and render them unfit for human consumption. To control the pest, pick and destroy the infested fruits and spray 500 ml of Roger 30 EC (Dimethoate) in 300 litres of water during February-March, care being taken that sprayings are stopped atleast 15 days before fruit harvest.
Leaf-eating caterpiller (Porthmologa paraclina Meyrick) and ber beetle (Adoretus pallens Harold) : The plantation should be watched carefully during rainy season regarding the attack of these insect-pests. Leaf-eating caterpillars feed on leaves and cause huge damage. To control these, spray with 750 g Sevin 50 per cent (Carbaryl) in 250 litres of water as soon as the damage is noticed.
Lac insect (Laccifer lacca): This insect also causes serious damage by sucking the sap from the twigs which usually dry up. To control this insects, remove and destroy the infested dry twigs. Spray the trees with 250 ml of Rogor 30 EC (Dimethoate) or 100 ml of Dimecron 85 WC (Phosphamidon) in 250 litres of water in April and again in September.
Diseases :-
Powdery mildew : The disease is caused by Microsphaera alphitoides f.sp. Zizyphi and appears from September to December. It has become a big meance to ber orchards in north India. If not checked in time, the disease can wipe out the entire crop. Young developing leaves and fruits are covered with withish powdery mass of the causal fungus. The disease cause premature defoliation and heavy fruit-drop. Affected fruits remain small and become cankered and disfigured. Sometimes the attack is so sereve that the entire crop is lost either through drop or rendered unmarketable, thus causing heavy economic losses to the growers. The disease can be controlled by 3-4 spray of 0.05 per cent Karathane 40 EC (50-80 ml in 100 litres of water) or 0.25 per cent wettable sulpher (250 g in 100 litres of water). First spray must be given before flowering (first fortnight of September), second spray after fruit-set in early October and the third in the end of October. Another spray can be given if need arises.
Leaf spots : Two leaf spots of ber are very common in ber growing regions, i.e. 'Phoma Leaf Spot' caused by Phoma macrostoma Mont. and 'Black Mould of Leaf' caused by Isariopsis indica. Both diseases are caused by different fungi, while the Phoma leaf spot appears on the upper surface, the black mould make its appearence only on the lower surface of leaves. In case of Phoma leaf spot symptoms appear when the leaves have fully expanded, in the Black mould case the sysmptoms can appear even on young leaves. Phoma leaf spot appears with grey centre, yellow margin and dark fungal growth on the mid-rib, main vein, petiols and the leaves. Black mould spot appears as small circular, small finger-like projections like softy tufts. Both the leaf spots of ber can be controlled by spraying the following fungicides as given below :
First spray : Bordeaux mixture 2 : 2 : 250 or with 0.3% copper oxychloride 50% (300 g in 100 litres of water) should be sprayed both on upper and lower surface of leaves with the appearance of disease in August or when the leaves have expanded.
Second spray : This spray should be given after 14 days of the first spray with 0.2 per cent Dithane M-45 WP 75% (200 g per litres of water) both on upper and lower surface of leaves.
First and second spray should be repeated alternatively at 14 days interval till the fruits are fit for marketiing. Thereafter sprayings are stopped a week before harvesting.
