What causes the yellow leaf spots that later develop a brown center on my apple leaves?

This a fungal disease called cedar-apple rust. Cedar-apple rust is a common disease of apple and crabapple. The fungus that causes the disease, Gymnosporangium juniperi-virginianae, is unusual because it must spend a phase of its life cycle as a parasite on Juniperus species, such as red cedar or ornamental junipers. Control: Grow resistant apple or crabapple varieties. Apple varieties that normally show good to excellent resistance to cedar-apple rust include ‘Red Delicious’, ‘McIntosh’, ‘Arkansas Black’, ‘Winesap’, ‘Mollies Delicious’, ‘Spartan’, …

How do I find out what variety my apple tree it is? Can my local Extension office tell me ?

It is difficult to identify apple varieties unless your variety is a very common one. There are more than 10,000 named apple varieties in the world today. Sometimes we may be able to tell what “type” of apple it is (e.g., Jonathan type, Delicious type). When planting fruit in the landscape, it is important to create a plan showing where different varieties are planted. Put the plan in a notebook and a copy in the garage or planting shed.…

When is the proper time to thin fruit on apple, pear, and peach trees?

Apples and pears have three periods when some immature fruit drops naturally from the tree. The June drop (Zones 6 and 7) is the last one, and many growers feel that thinning should follow this drop. However, if a heavy bloom has coincided with good weather so that bees worked the blooms, the chances are that relatively few fruit will drop from the tree. In this instance, heavy thinning is required. The earlier the fruit are thinned, the greater the …

How long can I store fresh apples?

Late-maturing varieties of apples will store for use throughout the winter if the fruit is hard, mature, and in perfect condition. Apples picked too green (unripe) are subject to a number of storage disorders, such as scald and bitter pit; if picked beyond maturity, they quickly become overripe in storage. Cool fruit as quickly as possible after harvest for best results. For most varieties of apples, the optimal storage temperature is 30° to 32°F with a 90% relative humidity. Higher …

How can I control insects and diseases on my apple tree?

Homeowners are often surprised at the damage pests can do to apples. It is not easy to grow apples as pretty as those seen in the grocery store. Several diseases and insects can damage apple trees. Besides spraying pesticides, other things can be done to reduce pest damage, but it is very difficult to grow quality apples without some kind of pesticide application schedule. Rake and destroy leaves in the fall to reduce damage from diseases that overwinter in infected …

What is the best way to tell when apples and pears are ripe?

Harvest time varies with individual tastes and locality. One may consider a fruit ripe, while another individual believes it is immature. However, fruit picked too soon does not store well and does not develop full flavor. Probably the most reliable index is the number of days after bloom: Red Delicious takes 135 to 155 days from full bloom to harvest, whereas Granny Smith takes 170 to 180 days from full bloom to harvest. Other factors to consider include seed maturity; …

What are some suggestions for growing apples successfully in Colorado?

Reliable varieties for this area are ‘Cox Orange’, ‘Red Delicious’, ‘Golden Delicious’, ‘McIntosh’, ‘Jonathan’, ‘Fameuse’, ‘Northwest Greening’, ‘Joyce’, ‘Wealthy’, ‘Lodi’, and ‘Haralson’. Select two different varieties for cross pollination and good fruit production. In most cases, planting semi-dwarf varieties rather than standard size trees will allow enough room for at least two different varieties in the landscape. For additional hints for growing apples successfully, see the Colorado PlantTalk script on Apples.…

What are the disease-resistant apple cultivars recommended for Wisconsin?

The following are some of the cultivars that will grow well in Wisconsin:

• Redfree: This is an early season, medium-sized, attractive red apple. You can store these apples up to 30 days.

• Prima: Prima produces medium to large fruit, red blushed on yellow skin. Mild, juicy, white flesh matures a week before McIntosh. You can store this apple for one to two months.

• Priscilla: This is a medium to large apple if you thin trees adequately after …