Peach (Prunus persica) belongs to the family Rosaceae. It is a small, willowy, deciduous tree. Seedling trees can reach a height of 7.5 meters while asexuallypropagated trees grow from 2 to 4 meters. Peach is used as table fruit but it can be dried and processed by canning and bottling.
Low chill varieties that are being tried in the highlands of the Cordillera are Flordared, Flordasun, Flordagold, Earliamber, Earligrande, Newbelle and Indigo. A number of unidentified varieties of peaches are growing in Benguet and Mt. Province. The best rootstock for subtropical environments should be virus-free , low-chill and nematode-resistant. Examples of these are Okinawa, Nemassan, Coastal and Chinese peaches. Plum can also be used as rootstocks for peach.
Soil. Peach can be grown on a wide range of soil types but do best on sandy loam soil with pH of 5.5 to 7.5. Soil drainage is one of the most important factors in determining soil suitability. Peaches trees cannot tolerate water-logging in soils with free water for any length of time. Soils must be open and well-drained throughout the soil profile.
Climate. Most peach cultivars require at least 150 hours of chilly condition (below 7oC) to defoliate and bloom normally upon the resumption of normal temperature.
Temperature. Peaches require a period of cold to break dormancy. The number of hours below 7.2oC that is needed to condition the tree to break dormancy and resume normal growth depending on the cultivar. It can be as low as 50 hours for some and as high as 1,000 for others. Once the chilling requirement of a cultivar has been satisfied, the total rest period cannot be completed until sufficient heat units above 10oC have been accumulated. This is to induce vegetative buds to shoot and flower buds to bloom. Thus, a consistent period of cool days during the dormant period, followed by warm days (during the laer part of dormancy) gives rise to an early and uniform bud break of most low-chill peach and cultivars.
Rainfall. It is important to avoid moisture stress in growing high quality peaches. Low rainfall is not a problem provided it is supplemented by irrigation. Disease are more prevalent in areas with high rainfall during the growing season. Rain during the harvest period can result to fruit splitting on some cultivars.
Propagation. Peaches are normally propagated by budding or grafting during the growing season. But when new production systems are being investigated, the cost of grafting and budding peach trees can be prohibitive in very large numbers. One method to overcome this problem is to use cuttings.
Land Preparation. Cultivation should not be deeper than 0.5 m. Deeper tillage may cut many of the feeder roots.
Planting. Plant anytime of the year as long as the water supply is available and the seedlings are dormant. Plant on slopes with good air drainage. Eroded or rocky slopes will not do.
Spacing. A spacing of 6 x 6 m between trees and rows in preferred.
Intercropping. Plant intercrops during the early years of the trees. However, discontinue the practice when these are grown because the crops will compete with the nutrients needed by the trees. Avoid soil erosion in any intercropping scheme.
Weeding. Remove weeds as soon as they appear. Do not allow them to seed and flower. Hoe regularly to prevent weeds from establishing themselves. Weeds are hosts to insect pests and they compete with much-needed nutrients needed by the trees.
Mulching. Covering the soil with mulch materials such as grass, leaves and rice straw prevents the growth of weeds. Aside from controlling the growth of weeds, mulch reduces the loss of soil moisture and enhances the penetration of water into the soil.
Irrigation. It is essential for the trees to have adequate water from 4 weeks before flowering up to 3 weeks after flowering. Stone hardening begins after this period and this lasts for 3 weeks. Fruit growth ceases during this period so water requirement is very low from 2 to 4 weeks before harvest. If moisture deficiency is acute during this period, the fruits will not develop properly.
An improvement in fruit size and quality can take place under good moisture conditions. However, over-watering can lead to fruit splitting.
Fertilization. For newly-planted trees as well as those 4 years of age, apply an annual rate of 250 g of T-14 mixed with 50 g of urea on a per tree basis. This mixture contains a high percentage of nitrogen which is essential to produce good growth during the early years. Bearing trees require a dose of 2 kilos of T-14 per tree per year. Split application is usually done 4 to 5 weeks before flushing and 6 weeks after flushing. However, excessive nitrogen is as detrimental to fruit quality as nitrogen deficiency is to tree growth. Too much nitrogen leads to excessive leaf development and large, soft and late-maturing fruits which are of poor quality; and color which are susceptible to fungal diseases.
Training and Pruning. In the nursery, the stem is cut 0.6 m from the ground. Three to four branches, equally distributed around the main stem, are allowed to develop. The open-type is the most commonly used training system for peaches.
Fruit Thinning. Immediately after the natural fruit drop, the fruits should be thinned out. The ideal distance between fruits along the twig is 10 centimeters. About 75 leaves should be maintained to sustain a fruit.
Harvesting. The best time to harvest peach is just as the green color is beginning to change to yellow (for yellow peaches) or red (for red-blushed peaches).
Storage. Firm-ripe peaches can be held in cold storage for 2 to 4 weeks at a temperature of 0oC with 85% humidity. If peaches are held too long in cold storage, the fruit tends to lose flavor and quality.
Packing. Peaches are highly perishable and require careful handling to prevent cuts and bruises. Usually, peaches are packed in wooden boxes or corrugated and fiberboard cartons.
Insect Pests and Diseases
Good farm management involves the proper implementation of sanitation. Use clean tools and materials and disease-free planting materials. Prune infected parts then burn or bury. Use the proper pesticide if pest of disease infection is severe. Better control measures will be established if insect pests and diseases are well identified.
Peach Twig Borer – Pesticides cannot kill worms on twigs and fruits. To prevent future damage, kill the moths by spraying the infested trees.
Plum Curculio– Pick and properly dispose off all fallen fruits. Spray Malathion when at petal fall.
Peach Tree Borer– Kill egg-laying moths by spraying the trunk and crotches with any insecticide. Kill individual borers by inserting a wire into the holes.
Bacterial Canker/Bacterial Gummosis– Prune and burn diseased branches. Spray copper-based fungicides. Keep tree healthy with proper fertilization and watering.
Shot hole– Spray Daconil, Chlorothalonil, Mancozeb or Dithane immediately after leaves have dropped.