- Fruits: apples, general tree fruits
- Crop Production: foliar feeding, organic fertilizers, application rate management
- Education and Training: on-farm/ranch research, participatory research
- Pest Management: biological control, chemical control, cultural control, disease vectors, economic threshold, genetic resistance, mating disruption, prevention, sanitation, traps, weather monitoring
- Production Systems: general crop production
Blue Vista Farm, in Bayfield, Wisconsin, is a diversified fruit and flower farm specializing in sustainable production of apples, blueberries, raspberries, fresh cut and everlasting flowers. Our market emphasis is on farm sales as pick your own and retail; consequently, we are highly public farm. it is very important to us that our visitors experience the vitality of the farm and its products; hence, we strive to create as healthy a farm environment as possible. We do this in part by cutting back on insecticide, fungicide and herbicide applications whenever possible.
In 1996 we planted approximately 1000 apple trees on three acres. Six disease resistant apple varieties are trained on a single wire trellis as a modified slender spindle. In 1998 we had our first yield. We also manage a one acre block of Cortland apples on standard rootstock, approximately three acres of blueberries and one half acre of raspberries. In addition, we have approximately two acres of over 250 flower varieties, which we sell as fresh cuts and everlastings.
The Bayfield fruit growing area is not large, but its microclimate is ideal for apple and small fruit production. It is situated on a high hill overlooking Lake Superior and is comprised of roughly ten full and part time farms with total acreage of under 300 acres. The first apple orchards were planted in the early 1900’s and since the 1940’s and 50’s, apple acreage has gradually declined. Due to the region’s small size, relatively long cropping history, and large number of wild and abandoned orchards, apple pest populations tend to be very high.
PROJECT DESCRIPTION AND RESULTS
Our project’s goal was to demonstrate a low chemical apple production system, while maintaining a high level of fancy and extra fancy fruit pack out. Specifically, we wanted to demonstrate a system implementing pheromone disruption on codling moth, trap out procedures using sticky red spheres on apple maggot, selection of disease resistant cultivars and eradicant fungicide sprays for apple scab, maintenance of fire blight without the use of antibiotic bloom sprays, mechanical tillage for weed control and electric fencing for deer.
Apples can have many potential pest problems and specific problems will vary tremendously from site to site and region to region. For instance, apple growers in the West are not troubled with apple maggot fly or fire blight as Midwestern growers are. Pest populations also vary widely locally. It is, of instance, possible, to escape pest pressures by being isolated. Therefore, the first step in identifying ways to reduce chemical inputs is in identifying the specific pest problems of a given orchard. Here at Blue Vista Farm, we have been trying to reduce chemical sprays on apples since 1989, and have monitored and examined pest populations and damage since that time, giving us a good idea of our primary pests. With this in mind, we developed pest control strategies for our location.
In the past, we have not had satisfactory control of codling moth using pheromone disruption alone and that is why we decided to augment its effectiveness using at least two well timed organophosphate sprays of Imidan. The timing of course, is critical, and that is where the degree day management comes into play. In the case of codling moth, if first generation moths are controlled at petal fall, second generation moths will be less of a factor later in the season. Wing type pheromone traps were used to determine a biofix point and degree day calculations made to determine first generation egg hatch. Using this information, we applied two Imidan sprays at petal fall with 16 days in between applications. Ideally, a 10-14 day interval would have followed, but bad weather prevented an earlier spray time. Wing traps were monitored for first generation emergence and pheromone disruption lures placed in the orchard in late July. We were hoping to use the pheromone disruption to control second generation moths, so that an application or two of Imidan could be saved, but moths immigrating in from outside the orchard prevented this strategy from working well. The Bayfield area has a high population of wild apple trees and even though we had an adjacent abandoned orchard remove din 1996, plenty of already impregnated female moths found their way into the orchard.
Blue Vista Farm Apple Insecticide Spray Schedule 2000
Date, Chemical, Rate, Target Pest
June 13, Imidan, 0.75lb/acre, Codling moth, plum curculio
June 29, Imidan, 0.75lb/acre. Codling moth, plum curculio
August 7, Imidan, 1.0lb/acre, Codling moth, Apple maggot
A conventional system, adhering strictly to the spray guide, would recommend insecticide sprays on a 10-14 day interval from petal fall to a couple weeks before harvest. Using Cortland as an example, with a late September harvest date, approximately 7 insecticide cover sprays would have been used. That means that we more than cut our insecticide use in half, and additionally, used no miticide prays.
Sticky red spheres baited with an apple ester and hung on the orchard perimeter at approximately 15-30 foot intervals has worked very well for us in the past eight seasons for apple maggot fly control, except on some of the early season varieties (Redfree and Pristine). Fly emergence was monitored using baited Ladd traps and traps were hung in the orchard in mid June. Extra traps were placed in the block of early maturing varieties, since historically this is where we have seen the most damage. Traps were cleaned three times during the season, or roughly at two week intervals. This is a labor intensive process and no one likes to do it, however, trap effectiveness is greatly enhanced when traps are kept clean. Using a citrus based solvent and scrapers, it is an eight hour job for two people to clean, re-bait, and hang approximately 200 traps.
Apple Incest Injury Summary
Apple Variety, % Codling moth, % Apple maggot, % Plum curculio, % total insect
Cortland, 12, 4, 0, 16
Sweet 16, 0, 16, 10, 26
Liberty, 6, 27, 8, 38
Redfree, 0, 63, 0, 63
Apple maggot fly control was not satisfactory on early season varieties like Redfree and Pristine, probably due to their degree of ripeness during fly emergence. For later season varieties, the strategy worked well as can be seen by comparing damage from Cortland vs. Redfree.
Beneficial insect populations such as lacewings and trichogamma wasps were monitored in mid August in our high density orchard and at a conventional orchard nearby. Four wasps were observed and five lacewing eggs were observed at Blue Vista Farm vs. none at the conventional orchard during a 30 minute spot check. This would seem to indicate that beneficial insect populations were benefiting from the reduced spray program. Of course, the bottom line is how much direct insect pest damage was sustained to the fruit by harvest; however, a more complete picture of the situation would be an analysis of the secondary insect pests (i.e. two spotted spider mites, aphids and spotted tentiform leaf miner) since these pests can affect tree vigor and ultimately yield and fruit quality. None of these pests were evident in economically significant thresholds in our orchard during the 2000 season, which again seems to indicate some natural bio control occurring.
Most of our new varieties are resistant to apple scab; however, we did monitor these varieties for summer disease incidence, such as flyspeck, sooty mold and powdery mildew. Additionally, we cooperated with the Wisconsin Ag Trade and Consumer Protection’s program in monitoring apples scab for the Bayfield area. As part of this program, we were provided computer software and an environmental monitoring station so that we could collect environmental data in our orchard such as leaf wetness, temperature, and relative humidity and download this information into a computer, which would then analyze it to determine if an apple scab infection period had occurred. Fungicide sprays were only applied, to our scab susceptible variety (Cortland), if an infection period had occurred and mature ascospores were present. ascospore maturation was determined by Dr. Patti McManus at the UW-Madison using squash mounts and this information was then posted in the website. Data was transmitted weekly from our site, along with 8 other growers throughout the state, via email and posted on their website for all growers to access. Data was taken to determine if primary scab control was good enough to discontinue scab sprays throughout the cover spray season and then again at the end of the season. One row was left as a control treatment.
Apple scab control was excellent using the DATCP program; there was virtually no scab in the Cortlands. The 2000 growing season was not a heavy scab year, with three infection periods happening during primary scab season. Nonetheless, during our field day I mentioned that our last fungicide application for scab was June 13, and noticed some disbelief among the growers, for they had continued to put cover sprays on during the season. One grower in attendance attested to putting on 14 sprays, compared to our 4; this generated a lot of interest.
A moderate powdery mildew infection was a problem in the Sweet 16’s as a consequence of reducing scab sprays. 10% of the fruit were reduced in a grade as a result of this disease. A relatively heavy infection of Brooks fruit spot occurred on Pristine and Jonafree, also as a result of no fungicide application. In the Pristine, almost 75% of the fruit were affected and reduced in grade. In the Jonafree, 30% of the fruit were affected. This was the first time Brooks fruit spot was observed in the Jonafree, however, it has been observed in Pristine in the past. Some early season fungicide sprays may be necessary to control this disease in the future.
Fire blight management started during the dormant season by pruning out any disease inoculum in the orchard. A Bordeaux spray was applied at silver tip as a further precaution and nitrogen fertilizers were used very sparingly (15lbs of actual N/A). Environment was not conducive to fire blight development in 2000 and no strikes were evident in any of the varieties.
All weed control was accomplished with a Weed Badger in our high density orchard. A Weed Badger is a rotary in row mechanical tiller with a 3 point hitch attachment for a tractor. Five “weedings” with the Weed Badger were used in lieu of herbicide applications and each weeding took approximately five hours on 38, two hundred foot rows with 1000 trees in total. We have used this system since planting the orchard in 1995 and 1996 and have gotten very good control. Some of the problems with the system include a difficulty in controlling grasses immediately next to the trunk of the tree, throwing stones into the grass alley and an inability to weed close to harvest. However, the control of weeds is good and the system has the added benefit of destroying rodent habitat in late summer and post harvest. Tiller maintenance is low and depends largely on soil type. Our soils are coarse and sandy making it extremely hard on the metal tines. Even so, tine life is approximately 1.5 years.
Our electric fencing system consists of a six foot fence with nine strands of high tensile strength 12 gauge wire. All corner posts and in line posts are fiberglass and the charger was regularly emitting 8400 volts measured at the fence. Deer pressure is extremely high in late winter and early spring. Snow levels in the winter vary, but average 2-3 feet on the ground with drifting significantly higher. In the five years we have had the fence; we have had virtually no damage from deer. Occasionally, deer will get inside the fence, but do so only when pushed and are not in the feeding mode. Heavy snow years are hard on fencing but the strength of the wires and flexibility of the posts really help. The Achilles heal of the system is in early spring where drifting snow grounds out the lower wires and in other fence sections there is no snow. Deer seem to have an ability to detect which wires are “hot” and will go underneath the bottom strands if they detect an opportunity to do so. The only solution is to walk the fence perimeter and make sure the system is not grounding out.
Having our apple customer’s fill out the following voluntary survey monitored social impacts of our system: (results are in parenthesis and were tallied from 70 survey questionnaires).
1) From a consumer’s point of view, how important is reducing chemical sprays in commercial apple production?
a. Very important (84%)
b. Mildly important (12%)
c. Doesn’t matter as long as the apple looks and tastes good (4%)
d. No opinion (0%)
2) Assuming price is the same, which would you rather buy?
a. An apple produced with a standard spay program (1%)
b. An apple produced with a 50% reduction of sprays (low spray) (25%)
c. An apple produced with no man made spray (organic) (71%)
d. Does not matter, any (3%)
3) How much more would you be willing to spend on your apples if you knew they were produced with 50% fewer sprays?
a. 0% (6%)
b. 10% (29%)
c. 20% (41%)
d. 30% (16%)
e. More (3%)
4) How much more (than conventional) would you be willing to spend on your apples if you knew they were produced organically?
a. 0% (6%)
b. 10% (12%)
c. 20% (46%)
d. 30% (16%)
e. More (20%)
From this survey we can conclude that the majority of our customers are willing to spend at least 10% more for apples produced using at least a 50% reduction in chemical use. Ideally, it seems, most people would prefer to buy organically grown fruit.
Our primary method of outreach was hosting a field day. Results of our project are also being shared with John Markus, Bayfield County Agriculture Agent, Mike Mlynarek, Superintendent of the Ashland Ag Research Station, and Dick Weidman, Superintendent of the Peninsular Ag Research Station. Information about our project is also being shared with customers and visitors to the farm.
Twelve people attended our field day, four of which represented four different commercial apple orchards in the Bayfield area. Display advertisements were put in two area newspapers advertising the event and personal invitations were sent to all commercial orchards.