GRABOW ORCHARD AND BAKERY
6397 S State Road 13, Pendleton, IN 46064

Phone Numbers
Toll Free 1-888-534-3225
Noblesville 765-534-3225
local Anderson, Lapel 534-3225
Email us at appleking@iquest.net
or see this page at www.graboworchard.com

(page updated 12.03.04)

Reduced Spray and Biological Program for Apple Orchard.


2004 UPDATE ON CODLING MOTH PHEROMONES AND INSECT DAMAGE.

The following is a report on the experience of using codling moth pheromones during the past several years. We started using the codling moth pheromones in 1999. The results have varied during the past six years.

The decision to use the pheromones had some risk because of the size of our orchard, 3 acres, and previous heavy moth pressure. However we decided because we were out in the open, no orchards around. No significant wooded areas. The risk was worth the risk. Besides we had a problem of spraying the orchard because of the clearance between the trees later in the season and we needed a control for codling moths because we couldn't sprayer later.

In 1999 we applied 200 pheromone ties in part of the orchard. The eastern side of the orchard has 12 rows of 12 trees per row. The balance of the orchard has 14 rows of 36 trees per row . In 2000 we doubled the number of ties in all of the orchard. The control of the codling moth was almost perfect., less than 1 apple damaged in a 1000.

In 2001 the control was not as good, but acceptable. Much better than before the pheromone control. In 2002 the damaged increased some more. But still better than before. However we had significant damage to the gala's. We started to investigate why the sudden increase in damage to the gala's. We through is was caused by Codling Moths.

In 2003 we had a freeze during king bloom and appeared to have lost the entire apple crop. The codling moth pheromone ties were in place, but because of the freeze we did not spray after bloom. Later we found that there was a small apple crop. We started to pick the Lodi in late June and after pickling 4 boxes, there was not one salable apple in the lot.

We then checked the balance of the orchard saw the same damage to other apples. We sent samples to Purdue University and they found significant codling moth damage in all the apples. They found only one oriental fruit moth in one of the apples. Originally they though that the damage would be caused by the oriental fruit moth. No one had a good answer to our problem.

We then contacted Great Lakes IPM Inc., the source of the pheromones ties to find out if other growers had a similar problem. Surprise, the pheromones will not control the first flight of codling moths. One has to spray for the larva when they emerge at approx. 250 degree days. The pheromones will then control the second and third flights.

With this information we went back to our earlier application and found that in 2000 we sprayed at the proper time for the first hatch, therefore controlled the codling moth for the entire seasons. The timing of the sprays in 2001, 2002 were off target. Of course we did not spray at all in 2003.

With this information in 2004 we established the bio fix and calculate that the spray should be applied about May 15th. It was the last insecticide for the season. The results was not quite as good as 2000 but significant better than 2001 and 2002. Because we missed a scab spray while visiting our son in Seattle, we had more apple scab than before.

Now that we understood the codling moth problem we started to look in a different direction for the gala problem and identified the damage to be caused by the Apple Maggot. This fly like insect is active in June and July, lays it's eggs on the skin of the apple. When it hatches enters the apple and sort of roames thru the apple with very small tracks. This year we also had significant damage to all the sweet apple, red and yellow delicious, gala and some of the winsaps and fuji's.

We had trapped for apple maggot in 2000 and found none. Maybe the traps worked and we didn't realize that we had controlled the apple maggots.

CONCLUSION:

Pheromone control for codling moths will work, we have to trap for apple maggots and we need to control apple scab better.

Our objective is to get the orchard in biological balance, by that we want to establish a good predator balance to control such insects as red spotted mite and other minor insects. We have found many of the beneficial insects in our orchard. On one occasion I saw praying mantis pair mating in the orchard. We find many egg masses for the praying mantis. The other thing we have noticed is that the red delicious leaves no longer show signs from mite damage, the leaves have not bronzed like before we started the pheromone control. The leaves stay green and sometimes are last to fall. We also previously could find mite egg masses on the trunk of the trees.

HISTORY

In 1999 Grabow Orchard implemented a reduced spray program with biological control after petal fall. Petal fall is when the young apples can be seen. It was our objective to grow the best quality apple and the safest possible apple for our customers.
Most commercial orchards will spray the apple trees several times before bloom, during bloom, at petal fall and every 10 days after petal fall, later cover sprays every 2 weeks to control insect and diseases up until the preharvest interval for the specific chemical being used. This spray program could amount to more than 15 sprays per season and spraying within one week of harvest.

Our Spray Program

If we control the secondary insects and diseases before bloom we reduce these problems after petal fall. After petal fall we control Plum Curculio (PC) with 2 timed sprays and we control Codling Moth (CM) with pheromones, no sprays. The primary scab and mildew is controlled with fungicide sprays before bloom, 2 fungicide sprays during bloom and 2 fungicide sprays after petal fall.

Results of the Program

After petal fall the most significant insect damage is caused by the (CM). We now have used (CM) biological controls for two years. The improvement in the overall quality of the apples during the 2000 season was significant, less than 0.5 percent rejects from (CM) damage. Previous years we could have 10 percent rejects. Because we do not spray insecticides for (CM) there is less impact on the beneficial insects (predators). In the insect world 97 percent are good and 3 percent are bad. The trees look better now; in previous years before we used biological controls we had signifiant bronzing of the Red Delicious leaves which indicates damage by spider mites. Last year the Red Delicious leaves were the greenest and were the last to fall off the trees. With reduced sprays, it appears that we now have more biological control in the orchard. This is good for the environment, good for the trees and good for the apples. We use Integrated Pest Management (IPM) in the operation of our orchard and "biological controls" is only part of this management program. If you need more details, read the following information.

Integrated Pest Management (IPM) of Insects and Diseases

"IPM" is the identification of important pests, using appropriate preventive cultural practices, monitoring and selective use of control strategies.
The tools of (IPM) are; orchard scouting, use of pheromone traps to identify when insects are present, good sanitation of the orchard and perimeter, selective chemical controls, biological controls and weather monitoring.

Orchard Scouting....Orchard scouting is the random inspection of the orchard looking for insect eggs, insect larve, insect damage to the leaves, insects, disease tissue(fire blight or scab). The scouting starts early in spring and continues thru the season.

Pheromone Traps....Female insects use a scent to attract their male counterpart for the purpose of reproduction. This scent is called a pheromone. When the female insects are flying they release their pheromone so the males can fly to them for mating. Science has synthesized insect scents (pheromones) and placed them in a dispenser (lure). The pheromone lures are placed in a trap which has sticky paper to catch the insects after they fly into the trap. By counting the number of insects captured we can determine when to take corrective action.

Orchard Sanitation....The proper pruning of the trees is probably the most important operation in the orchard. When the trees are open for good air circulation and light penatration, several things happen, reduction of summer diseases (sooty blotch and flyspeck, mildew, scab), improved bud set(next year's apples), better quality apples (apples need sunlight to develop the color and sugars). The removal of the dead and diseased wood from the trees, from the orchard floor and the perimeter around the outside of the orchard is also very important.

Chemical Controls....The choice of which chemical to use can be very important to the population of beneficial insects in the orchard, because some chemicals are more toxic to benefical insects. We can actually obtain better results, because we save more of the beneficial insects (biologic control). Proper application of chemicals is also important, the materials have to be applied at label rate, otherwise resistance can develop. This has happened in many orchards around the county. Resistance also develops sometimes with overuse of a particular chemisty. The way to avoid resistances, is to rotate with different materials which have different modes of action.

Biological Controls....The use of natural enemies that attack pests, use of pheromones for mating disruption (see details below), and cover crops to attract beneficial insects.

Weather Monitoring....Temperature and moisture are important tools for controlling insects and diseases. Insects development depends on the accumulation of degree days (DD). We can predict when insects will hatch, pupate, and emerge as adults by the accumulation of (DD). The (DD) are calcultated by summing the high temperature and the low temperature for 24 hours, dividing by 2, then subtracting the base temperature. Some of the base temperatures used are 32 deg, 42 deg and 50 deg. Tree development is also dependent on (DD). Scab infections also are dependent on temperature and the time moisture is present on the leaves.

Diseases

The primary disease is Scab, it has to be controlled before and after petal fall. Using weather data (temperature and how long leaves stay wet) we can determine when scab infection is possible. The fruit rots, sooty blotch and flyspeck are the secondary diseases that occur during the summer. We have found that if the trees are properly pruned one can minimize the amount of sooty blotch and flyspeck. We don't spray for fruit rots because we have not experienced them as a significant problem.

Insects

The primary insects are Codling Moth (CM) and Plum Curculio (PC), secondary insects are Redbanded Leaf Roller,Aphids and Spotted Tentiform Leaf Miner. We control the secondary insects before bloom. We time the sprays by using pheromone traps to determine when the specific insects are flying, and scouting the orchard to determine when the insect larvae are present.

Primary Insects Details

Plum Curculio (PC) emerges just after petal fall and continues for several weeks in May. Depending on the scouting for (PC), two sprays may be required, one just after petal fall and the second 10 days later. This year as we picked the apples we found more (PC) damage on some apples then we would like. This indicates maybe our timing was off slightly. There is no bio control for (PC) therefore we have to spray for this insect. However when we spray, the apples are the size of large peas, the spray material will be degraded by the time the apples are picked and the surface area of the apple increases significantly further reducing, if any, the amount on the surface. All the apples are washed when we sort them, this further removes any remaining pesticide and dirt.

Codling Moth (CM) is another story, this insect is present for the entire growing seasons, starting just after petal fall and requires several sprays to control its damage. However using the (CM) pheromones for (mating disruption), insecticide spraying can be eliminated. The (CM) pheromone dispensor is like a large bread tie about 4 inches long, and will last for the entire growing season. These ties are placed high in all of the apple trees before petal fall. This creates a saturated female pheromone over the entire orchard which prevents the male moth from finding the female to mate. Mating has to take place before a female can lay her eggs. When mating is disrupted there is no egghatching so no apple damage.

Actual Spray Program 2000

In 2000 we applied 1 insecticide spray before bloom and 3 insecticide sprays after petal fall. The last insecticide was for Japanese Beetles.
We sprayed 1 fungicide before bloom, 2 fungicides during bloom and 3 fungicide sprays after petal fall. When possible we combined both the insecticide and the fungicide in the same spray.
As far as we know, we are the only orchard in central Indiana using this biological control program, because of this fact, and we feel we have the safest apples available.

Apple Tree Development Stages

There are 9 stages of development for apple trees; Dormant, Silver Tip, Green tip, 1/2 Green, Tight Cluster, Pink, Bloom, Petal Fall and Fruit Set.

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