Gardening Articles: Edibles :: Fruit & Nut Trees
The New Easy Apples (page 2 of 3)
by Jack Ruttle
What About Insect Pests?
Codling moth is one of the most common apple pests
Most gardeners (the exceptions are isolated and arid places in the West) will have to spray to control three pests that otherwise ruin apples. In the West and South, the biggest challenge is the codling moth. The apple maggot fly has also become established almost everywhere apples are grown in the northern half of the country. The eastern half of the country sees both of those, plus the plum curculio, which is often devastating.
Here's a simple schedule to eliminate most damage from the major insect pests:
In all regions for plum curculio and codling moth, apply Imidan (a synthetic pesticide especially effective against curculio) at petal fall and again 10 to 14 days later. Rotenone and pyrethrum don't work, even if applied more frequently.
In the West and South, where the codling moth has multiple generations, monitor with pheromone traps set about a month after the petal fall sprays. Five to seven days after the number of moths trapped (all males) begins to rise, apply Imidan again and repeat about 10 days later. Or use Bt for the moth larvae, reapplying it every two days for two weeks.
In northern regions, trap apple maggot flies by hanging red spheres (decoy apples) covered with sticky adhesive every four to six feet in the tree canopies. Refresh the sticky adhesive in midseason.
Good Culture Minimizes Pest Problems
'Liberty' apple on dwarf rootstock
The surest way to keep apple insect and disease problems in hand is to keep the trees small enough to tend without ladders. Insist on trees on the most dwarfing rootstocks -- M9 or M27. By using these rootstocks, plus limb-bending and summer pruning, apples can be kept under seven feet tall, which makes it much easier to produce high-quality fruit. This may mean ordering custom-grafted trees from specialty nurseries but the benefits are well worth the extra trouble.
It is also very important to locate the fruit planting carefully. You'll need to spray for insects early in the season, so keep apple trees well away from the vegetable garden where lettuce, beets and other early crops would be affected.
Finally, consider bagging the fruit when it reaches the size of a golf ball. Fasten small brown paper bags carefully to the stems with twist ties and staple the bottoms closed if necessary. This not only excludes late-season insects but also prevents cosmetic skin diseases like sooty blotch and fly speck. A week or two before harvest, remove the bags to allow the fruit to color in the sun. You will get fruit of the very finest quality that has not received sprays of any kind for at least two months prior to the day you pick it.