Yes, and several scab-resistant cultivars already are scab-susceptible at some locations. Most scab-resistant apples trace their origins to a collaboration between Purdue University, Rutgers University, and the University of Illinois. The PRI apple breeding program began in 1926 when crosses made from the crab apple, Malus floribunda 821, were found to show some resistance to apple scab. The PRI group then bred the resistant Vf gene from Malus floribunda 821 into commercial apple cultivars. Decades of subsequent hybridization and selection …
Apple Yield Efficiency
Pomological researchers have assessed other approaches to determining potential yield. Since planting density works together with per-tree yield to determine productivity per acre, researchers have used canopy dimensions to estimate planting density and then estimated potential yield per acre. This approach is perfect if the trees used to measure yield and canopy size are not contained by any pruning. Once the canopy is manipulated, and particularly if it is manipulated differently for trees of different sizes, potential yield per acre …
Does an apple cultivar ripen at the same time every year?
Not necessarily. Time of apple ripening is affected most by bloom date and growing season weather. For example, McIntosh typically ripens 125 Days After Full Bloom (DAFB), but can range from 115 to 135 DAFB. There are formula(s) for determining harvest timing, for example, this one for McIntosh from Cornell University. In any year the best indicator of maturity and harvest timing is a combination of flavor and fruit background and over-color, but the starch-iodine index test is also …
Do apples need to be harvested with stems?
Harvesting apples with their stems intact will prevent fruit loss. Detached stems provide a point of entry for microorganisms and can result in decayed fruit. …
How many fruit should my apple tree bear each year?
Apple trees often set more fruit then they can adequately support. When a tree has too many fruit, the fruit tend to be small, poorly colored, and may have low sugar levels. Limb breakage may also result from over-cropping. In general, large trees can support more fruit then small trees, therefore the ideal number of fruit per tree varies with tree size. The number of fruit per tree can be based on the circumference of the trunk. To determine trunk
What makes apples healthy to eat?
USDA nutrient data base lists all compounds found in a medium size apple (100 grams or 4 ounces) at http://www.nal.usda.gov/fnic/foodcomp/cgi-bin/list_nut_edit.pl . But what within the array of compounds in an apple fruit makes it good for human health? First, apples are a great source of fiber. If you ate a 100-g apple, 2.4 g would be fiber. According to the Mayo clinic’s web site (http://www.mayoclinic.com/health/fiber/NU00033) apples provide soluble fiber which dissolves in water to form a gel-like material. …
What is sunburn damage to apple fruit and how can it be prevented?
Sunburn damage is a skin discoloration of the exposed side of the fruit, and can be caused by several conditions. Sunburn can be prevented by cultural and chemical means. See this article on Sunburn of Apple for detailed information on symptoms and prevention.
… What are fruiting spurs on apple trees and why do some cultivars have more than others?
The term fruiting spurs does not have a universally agreed upon definition. Most fruit scientists consider fruiting spurs to be short shoots, usually less than 6 inches long, with a rosette of leaves just behind a fairly large bud at the tip of the shoot. the large bud (the terminal bud) is usually a flower bud, from which a cluster of five flowers will emerge the following spring. Spurs arise from portions of a branch that are at least two …
What is apple cork spot and can it be prevented with calcium sprays?
Apple cork spot is a physiological disorder that can affect apple quality and reduce visual appeal. Cork spot generally appears in the outer portion of the fruit flesh as small green dimples or depressions. This disorder may begin developing in June and continue throughout the initial stages of growth and enlargement. The green spots eventually enlarge to corky, discolored areas 1/4 to 1/2 inch into the flesh of the apple. The corky spots may occur anywhere on the fruit flesh.…
Can kaolin clay sprays reduce insect damage to apple fruit?
Yes. Kaolin clay (formulated commercially as Surround WP®) has been shown to be effective against several orchard pests, including apple maggot, white apple leafhopper, and pear psylla. It generally gives at least fair control of plum curculio and several species of fruit pest caterpillars (codling moth, oriental fruit moth, tufted apple bud moth, lesser appleworm). However, university trials also show that heavy use is harmful to beneficial species, and can lead to a flare up of European red mites or …