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print the page Introduction
Apple varieties fall into two categories: diploids and tripolids. Diploids have plenty of good pollen and are self-fruitful. Triploids are self-unfruitful and become productive only when pollinated by using suitable pollenizer varieties. Even self-fruitful varieties have to be interplanted to get commercial crops through cross-pollination. Varieties selected for interplating should sufficiently overlap in their blossoming periods. Some of the important varieties in various states are listed below: Himachal Pradesh: `Red Delicious’, `Golden Delicious’, `Worester Pearmain’, `Newton Wonder’ (all diploids), `Cox’s Orange Pippin’ (triploid), `King of Pippins’ (No. 13), `Starking (Royal) Delicious’ and `Richard’. Kashmir Valley: `Red Delicious’ (diploid), `Baldwin’ (triploid) `Ambri Kashmiri’, `White Dotted Red’ and `Blood Red’. Simla Hills: `Beauty of Bath’ (triploid), Red Delicious’, `Jonathan’, `Rome Beauty’ (all diploids), `Early Shanburry’, `Red Astrachan’, `Red Sudeley’, `Stayman Winesap’, `Winter Banana’ and `Yellow Newton’. Kumaon Hills: `James Grieve’, `Jonathan’, `Rome Beauty’ (all diploids), `Blenheim Orange Pippin’, `Delicious’, `Early Shanburry’, `Golden Pippin’, `King of Pippins’, `Rymer’ and `Winter Banana’. Kulu Valley: `Ben Davis’, `Red Delicious’, `Golden Delicious’, (all diploids), `Cox’s Orange Tippin’, `Blenheim Orange’, `Baldwin’ (all triploids), `Red Astrachan’, `King of Pippins’ `Yellow Newton’ and `Granny Smith’. Nilgiri: `Rome Beauty’ (diploid) and `Irish Peach’. Systematic introductions from the USA, Russia, the UK, Canada, Germany, Israel, Netherlands, Australia, Bulgaria, Switzerland, Italy and Denmark have been made at different research stations during the past 5 decades. In apple, about 700 accessions of cultivars, species and rootstocks have been made. The hybdridization programmes in apple were initiated during sixties in Himachal Pradesh and Jammu and Kashmir to combine high dessert quality of delicious group and excellent keeping-quality and shape of Ambri, and indigenous cultivar of Kashmir. As a result of this programme, Lal Ambri (Red Delicious and Ambri) and Sunehari (Ambri x Golden Delicious) were released in 1973 in Jammu and Kashmir. In Himachal Pradesh, the hybridization work has resulted in the release of 4 hybrids – Ambred (Red Delicious x Ambri), Ambrich (Richard x Ambri) and Ambstarking and Ambryoyal (Starking Delicious x Ambri). Ambred a late-maturing hybrid has been found most promising. At Chaubattia in Uttar Pradesh the hybridization programme for early maturity has resulted in the release of Chaubattia Anupam and Chaubattia Princess (Early Shanburry x Red Delicious) as promising early maturity cultivars. Propagation and Planting Most of the apple cultivars especially of the delicious group and its spur types and colour strains need adequate cross pollination for optimal yields. Research on the proportion and distribution of pollinizers has indicated that 20-25% pollinizers are adequate for delicious group of varieties. In marginal conditions where fruit set is adversely affected by adverse climatic conditions, the proportion of pollinizers should be increased to 33-50%. Studies show that the apple cultivars grafted on seedling rootstocks by tongue grafting during February-March give more than 90% grafting success. Mound laying has been found convenient for propagation of clonal rootstocks of apple, however, the propagation through hardwood cuttings is also quite successful. In apple, success of 70% has been achieved in rooting of hardwood cuttings of crabs with 2,500 ppm IBA and bottom heat treatment (21° ± 2° C) during dormant season in Chaubattia. Greater stress is now being given for the propagation of healthy plant material for the improved productivity of new orchards. Virus infection is of great concern in apples as most viruses are graft transmissible, latent in expression, significantly reduce productivity and are incurable. Harvesting at the correct time is essential to the production of quality apples. To ensure maximum storage life, apples should be harvested when mature but not yet fully ripe or overripe. If harvested before they have matured, apples will have poor eating quality, will be more susceptible to storage disorders such as scald, cork spot, and bitter pit, and may not ripen properly. Ripe fruit should be avoided because it will continue to ripen in storage, rapidly becoming too soft and mealy for sale. Firmness and the level of soluble solids in the apple are good indicators of maturity to use in determining picking time. Apples are very susceptible to bruising and other forms of mechanical damage and therefore should not be handled any more than necessary. Workers harvesting apples should be cautioned not to drop them or handle them roughly. The effects of bruising and scuffing cannot be reversed. Damage from rough handling will accelerate deterioration, reducing the value of the product. Apples are normally transported and stored in bulk boxes filled in the orchard. Each of these boxes holds about 600 pounds of fruit. Full boxes should not be allowed to sit for extended periods in direct sunlight nor for more than a few hours before cooling is started. They also should not be overfilled. When overfilled boxes are stacked, many apples throughout the box are bruised. Bulk boxes represent a substantial investment for most growers and processors. They should be kept clean and in good repair and should be stored indoors when not in use. Most bulk boxes made from hardwood have enough open space between the individual boards in the bottom and sides to ensure adequate air circulation and water drainage. For some of the newer boxes built from plywood, it may be necessary to drill holes to improve air circulation. Five to 8 percent of the lateral surfaces and 3 to 5 percent of the bottom should be open. Better circulation is provided by many small, well- distributed holes than a few large ones.
Fertilizer and Nutrient
Management Results of studies that have
been carried out in Himachal Pradesh to find out nutritional requirements
of apples have revealed fairly widespread deficiencies of N, P, K, Ca,
Zn, Mn and B. The optimal nutrient ranges established through orchards
surveys are: 2.43-2.65% N, 0.17-0.2% P, 1.34-1.74% K, 1.29-1.47% Ca, 0.41-0.62%
Mg, 28.5-44.9 ppm Zn, 73.1-94.1 ppm Mn, 350-482 ppm Fe and 17.2-24.3 ppm
Cu. A significant positive correlation has been observed in available
N, P, Ca and Mn in soil and fruit yield. Nutrient interaction studies
have shown that P is a strong antagonist of Zn. The studies have indicated
that leaf nutrient contents and available nutrients in soil are responsible
for variability in fruit yields to the tune of 20.2 and 31.4% respectively.
Recent studies in Himachal Pradesh have shown that foliar application
of urea (0.5%) in combination with Triton X –100, given after 5 hr pre-treatment
of foliage with 2% ethyl oleate further increased N-absorption. The soils
of Himachal Pradesh and other parts of north-western Himalayan regions
are rich in phosphorus and with various micronutrients, which usually
remain unavailable to apple plants. A new dimension to the nutritional
research in apple has been added recently by undertaking studies on the
role of biofertilizers, in particular mcorrhizal fungi. Symbiotic association
of vesicular arbuscular mycorrhizae (VAM) in apple roots is well established
which influences plant growth through improved availability of limiting
soil nutrients. In general, VAM fungi increase phosphorus uptake by apple
roots besides the possibilities of increased uptake of micronutrients
like Zn and Cu by certain selected strains of VAM. Four strains of VAM
fungi Glomus mosseae, G. fasciculatum, G. macrocarpum and G.
versiforme have been tested on apple seedlings with and without addition
of Zn in soil in Himachal Pradesh. The preliminary information has indicated
that G fasciculatum has highest potential of mycorrhizal infection
and colonization, seedling growth and biomass of apple seedling. The incorporation
of Zn to soil up to 5ppm level was helpful in further improving colonization
of VAM and seedling growth, indicating the more availability of Zn from
soil, which is otherwise given as foliar spray only in deficiency. However,
the high levels of Zn in soil, ranging from 7.5 to 10 ppm, have shown
adverse effect on VAM fungi infection as well as subsequent seedling growth.
Apple orchards in India are situated in rainfed sloppy lands where irrigation facilities are inadequate. However, success of apple culture depends mainly on uniform distribution of rain during the year or where supplemental irrigation during the critical periods is available. The most critical periods of water requirement are April to August, and peak water requirement is after fruit set. In areas where irrigation is not a limiting factor, 114 cm water during whole year through 19 irrigation has been recommended. It includes 1 irrigation during December-January after manuring, 1 before flowering in April, followed by irrigation at 7-10-day interval during critical summer and later on at 3-4 weeks interval till the onset of dormancy. In general, 8 irrigation is recommended for Starking Delicious apple during critical period. Experts also recommend drip irrigation in areas with scarce irrigation sources. Results of extensive studies that have been carried out on mulching, herbicides and clean basin management in apple in Himachal Pradesh as well as Uttar Pradesh have indicated that mulching followed by herbicidal application has been most effective for floor vegetation management and soil-moisture conservation. Oak leaves as mulch material have been found effective for growth and fruiting at Chaubattia whereas, hay mulch has been found beneficial in Himachal Pradesh. Black alkathene mulch in cooler climatic conditions has been most effective in weed control, moisture conservation, reduction in fruit drop and improvement in fruit size, colour and quality. In warmer climatic conditions, the black alkathene mulch has adverse effect on root growth due to rise in soil temperature. Some of the effective floor management methods in apple are given below:
Significant achievements have been made in crop regulation through flower
and fruit thinning, control of pre-harvest fruit drop, improvement in photosynthetic
efficiency, fruit set, colouration and fruit quality with the use of plant
growth regulators and agrochemicals. Most of the commercial varieties of apple have been noticed to have the following three waves of fruit drop:
The application of 10 ppm NAA before the expected fruit drop or 20-25 days
before harvest can check the fruit drop effectively. In Delicious varieties of apple, colour development is generally poor
in marginal areas below 1828.8 m elevation above mean sea level which fetch
poor market price. Application of 1,000 ppm 2-chloroethyl phosphonic acid
(Ethrel, CEPA or Ethephon) about 10 days before harvest improves colour
of fruit substantially in Himachal Pradesh conditions but impairs shelf-life.
In Jammu and Kashmir, ethephon 250 ppm along with 15 ppm NAA sprayed 20
days before expected harvest has been beneficial in improving colouration
of Red Delicious apples. In very high elevations above 1828.8 m, fruits
develop intense red colour even before they are mature, which also do not
fetch optimal prices. An application of 500 ppm ethephon can enhance maturity
by 7-10 days when applied 3 weeks before harvesting along with 10 ppm NAA.
Productivity and fruit quality Extension of shelf-life of fruits | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
