Fruit Thinning of Apple Crops
The earlier hand thinning of Apple trees is completed, the better it will be in achieving optimum results. Midsummer thinning helps improve fruit size and aids formation of the subsequent year's flower buds. Most of the flower buds for next year are initiated during a 4-to 6-week period following full bloom this year. Therefore, thinning should be done before this time.
When hand thinning Leave one apple per cluster, and space the clusters about every 6 inches. Start at one end of a branch and systematically remove fruit. To remove the fruit without damaging the spur or other apples on the spur, hold the stem between the thumb and forefinger and push the fruit from the stem with the other fingers. This method removes the apple and leaves the stem attached.
Well maintained Apple trees grown under favorable conditions can generally set more fruit than they are capable of successfully carrying to maturity. Removing excess fruit from Apple trees aids in the satisfactory development of the remaining apples.
Not removing excessive fruit will effect the following years harvest also as excessive fruit decreases formation of flower buds for the following year and can also cause trees to skip a year in crop formation.
Preventing Frost Damage
Temperatures below 28 degrees F during bloom will kill the blossoms and eliminate that years crop. Avoid planting in low-lying areas, a 10-foot increase in elevation can make the difference between a good crop and no crop at all. Cold air is heaver that warm air and flows into low areas much the same way as water flows into low areas.
Large bodies of water, such as ponds, lakes and large rivers, retain heat and help to protect crops during Autumn and early winter. Planting trees close to water can reduce the likelihood of frost injury. Water also cools the surrounding air in the spring and summer months and delays bloom.
Tree coverings are of little benefit unless a heat source is present such as a kerosene or Coleman heater.
Diseases of Apple Trees
Scab is a plant disease caused by a fungus scientifically known as venturia inaequalis. Scab / Venturia inaequalis also attacks pears, peaches and nectarines . Damage to apple trees can be severe, affecting the fruit harvest, as well as the apple tree itself, it is the Worlds most severe threat to Apple harvests . Deformities, cracks and entire tree death are common in apple trees infected with scab.
The infection cycle starts when temperatures and moisture promote the release of V. inaequalis ascospores in the spring The spores are released from leaves of the previous season near the base of previously infected trees. These spores rise into the air and land on the surface of a susceptible tree, where they germinate and renew the cycle.
Trimmings and leaf litter should be removed from the orchard and incinerated. This will reduce the amount of new ascospores in the spring. Scab lesions on the tree itself should also be excised from the tree if possible and destroyed.
Scab infections can be prevented by applying fungicides at regular intervals throughout the season. The objective is to provide a protective coating that will inactivate any spores landing on the fruit and foliage. It is critical to control scab early in the season from bud emergence through the second spray after blossom petals fall . If scab infection can be prevented when all the ascospores are discharged from the fruiting bodies in the fallen leaves, the disease cycle is broken and no further source of infection remains.
Kearneysville - Apple Scab
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Bitter Rot is caused by a fungus which effects both apples and pears. The fungus attacks the fruit as it approaches maturity. Under hot, and humid conditions, it can destroy an entire crop in a short time. It is precelant in Southern States, and occurs infrequently in the North.
Bitter Rot in apples causes light-brown circular spots on the fruit. In more advanced stages, these spots often show concentric rings .Under very moist conditions, masses of pink spores occur on the rings. Often there will be more than one spot, and by growing and joining together, the entire fruit rots.
Some fruit will mummify and if not removed cling to the tree over winter perpetuating the disease into the following season, Other fruits will fall to the ground. All should be removed and destroyed.
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Fire blight is caused by a bacteria rather than a fungus, it makes leaves and twigs appear burnt. Wind blown rain and insects spread fireblight which attacks the leaves and twigs as well as the fruit.
Managing Fireblight in Apple Trees
Cedar-apple rust is a common disease and easily identified. On cedars, the distinctive orange galls (referred to as "cedar-apples") appear in the early spring following rainy weather. Spores produced on these blow to apple trees where they infect young leaves, primarily during wet periods. Within several weeks, most of the leaves are covered with orange fungus . Later in the season, heavily infected leaves defoliate. Defoliation several years in a row leaves trees weak and nonproductive.
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A myriad of Insects voraciously attack Apples , worms and moths being the most common.
Codling Moth, flat headed apple tree borer, Oriental fruit moth are a few of the most common. See Worms and Moths in the Garden
Beetles, Aphids and mites can also be a big pain in the Apple. The wooly apple aphid is the most destructive aphid attacking apple trees. It does a lot damage to the foliage, but the most extensive damage is to the roots. Beneficial Nematodes can reduce this aphid population to a harmless level.
A variety of snout beetle known as Plum Curculio is another regular insect that likes apples. They spend the winter in the adult stage underneath leaves and trash. During the bloom period they become active. Egg-laying punctures by adult beetles and larvae feeding in the fruit can cause extensive damage. Bioneem is effective against this pest.
Several varieties of Spider Mites also attack apples as well as pears. 2-spotted spider mite, and the European red mite are the most common.
The European red mite a/k/a eriophyed mite creates a rust-like symptom on the fruit. These mites will overwinter as eggs on tree trunks. If problems are present at the end of the growing season, apply a Dormant Oil Sprays before bud-break the following spring to help control these pests.
Harvesting & Storage of Apples
Apples mature at various times, depending on the variety and climatic conditions. You should observe your apples as their growth progresses and inspect them for certain changes indicative of maturity. Flesh color loses its greenish tint and turns yellow or white. Depending on the variety the skin color also changes . When you think the apples look ripe, taste one. If it's to your satisfaction - Bon Apple teit !
Apples that are to be stored, should be picked when hard but mature, showing the mature skin color but a hard flesh. Storage apples should be harvested before eating apples.
Proper storage conditions help prolong the shelf-life of your apples. Store apples at 32 oF and maintain a high humidity. Keep the fruit away from vegetables as ripening fruit gives off gases that will spoil some vegetables. Apples can also be stored in plastic bags in the refrigerator to prevent fruit dehydration.
Also See: Home Made Apple Jelly and Preserves