Sustainable Organic Apple Production

PROJECT BACKGROUND
Blue Vista Farm 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 a 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.

Our Cortland apple planting has been managed organically for the past two seasons. For two seasons prior, we managed Cortlands ecologically, with up to 80% reduction in conventional pesticide inputs. Our intent is to prepare for a high density apple planting, marketing it as organic pick-you-own. The 1992 apple rootstock trial on “Gala”, planted in cooperation with Dr. Teryl Roper of the UW – Madison Department of Horticulture, is being expanded to include two more rootstocks, bringing the total to seven varieties. The trial is prominently located to benefit other producers in our area, and has generated interest among several who have either stopped in person or called to inquire about further information. As a result of our optimism about the possibilities of high density systems, we have contracted a nursery to custom propagate 1,000 trees which will be ready for planting the spring of 1996. The trees will be planted at a rate of over 600 trees per acre, trained on a modified slender spindle and supported on a single wire trellis.

As part of out involvement with the Chequamegon Organic Growers (COG), a local producers’ network, we have received grant monies in 1991, 1992, and 1993 to host field days demonstrating organic management of our apples, three acres of blueberries as well as sustainable production of one acre of raspberries and one and a half acres of fresh cut fried flowers. These field days were well attended and the public was very interested.

PROJECT DESCRIPTION AND RESULTS
The goal of our project was to define the most sustainable organic apple pest control methods on a scab susceptible variety, while maintaining a high level of pack out. Specifically, we compared sulfur and hydrogen peroxide (H202) as two apple scab treatments, evaluated efficacy of pheromone disruption on codling moth (CM) and trap-out procedures using sticky red spheres on apple maggot (AM).

The apple scab treatments were applied with a tractor driven air blast sprayer, and both began with an initial lime sulfur application at ¼” green tip at the rate of 1.5 gallons lime sulfur/100 gallons H20. Sulfur applications were made at 7-10 day intervals, or after 1 inch of rainfall, whichever came first. We used a flowable form of sulfur called THAT at the rate of 2 pints/100 gallons H20 during the primary phase of the apple scab fungus in early season. During the secondary phase we applied THAT at the rate of 1 ½ pints/100 gallons H20 at 10-14 day intervals.

Technical grade hydrogen peroxide (35% H202) was used as a surface sterilant not a protectant, consequently, it was applied during or shortly after a scab infection period developed. Infection periods were monitored manually using a Mill’s chart, orchard thermometer and visual observation of leaf wetness. Rates were 3 quarts H202/50 gallons H20 during primary phase and 1 quart H202/50 gallons H20 during the secondary stage.

Coding moth control was accomplished in a three phase process: pheromone disruption, degree day calculations and habitat management. Codling moth pheromones were placed in the orchard at petal fall at recommended rates and reapplied 6 weeks later at 1/3 rate. Degree day records were kept and wing trap catches made to pinpoint the insect’s phenology. A single application of ryania at the rate of 3 pounds/100 gallons H20 was made to control second generation moths. The original plan of rouging all unmanaged apple trees within 100 yards of the orchard did not happen until after harvest, and consequently was not a factor in controlling already impregnated females from flying into the orchard.

Apple maggot control was accomplished by placing sticky red spheres around the perimeter of the orchard at a15 foot spacing. Apple esters were not used in combination with the traps, but traps were cleaned once during the season. Traps were initially placed in the orchard at the end of June and removed at harvest.

Several laminated posters describing the grant’s intent were made and displayed in our on-farm retail shop as well as our farmer’s market and Apple Festival stands. People were invited to take the packet of information we assembled on sustainable organic apple production and/or ask questions. The information packet contains the following handouts: the project’s goal, a description of our apple scab treatments and results of pest incidence on fruit, diagrams of tree phenology states, an article on low input apple production, pest fact sheets of several major apple pests, and a list of references and suppliers. Posters will remain in our shop and stands and we will continue to disseminate the information generated by the grant at least through the ’96 season.

We also hosted a field tour September 17, 1995 demonstrating our pest control strategies, in which John Markus, County Ag Extension Agent, served as moderator. The field tour was publicized with two advertisements in local newspapers.

The following is a list of people involved in the grant and how they were involved:
- Tom Cogger, District Soil Conservationist. Advice on the impact of elemental sulfur on the soil environment. Suggestions of design for plantings intended to attract beneficial insects.
- John Markus, County Agriculture Extension Agent. Access and help in obtaining pest fact sheets, in spreading the word about the grant, and as serving as moderator at our field day.
- Mike Mlynarek, Superintendent of UW Ashland Ag Research Station. Assisting in design and layout of scab treatments. Recommendations of data collection and interpretation. Assistance in completion of final report.

The chart on Page 6 was part of the information packet which we put together for the grant.

[Editor’s Note: The chart could not be posted on the website. If you would like to see this chart please email us at [email protected] or call us at 800-529-1342. Thanks]

Data was collected by examining a total of 110 fruit at time of harvest. Then fruit were collected randomly from eleven randomly spaced trees.

We can see form the results that scab control for both the sulfur and hydrogen peroxide was satisfactory. Actually, control was so good in the sulfur treatment that very few fruit were afflicted. The hydrogen peroxide treatment, however, not only had noticeably more scab, but sever russetting from phytotoxicity as well. Consequently, the overall appearance of the H202 fruit were at least as bad as the control group.

It should be pointed out that there was very light disease pressure during the 1995 season, due to excessively dry conditions. In fact, only two infection periods were recorded in June, none in July and August and two late in September shortly before harvest. For this reason, our scab control in the sulfur treatment was comparable in effectiveness to a conventional system. In previous years when conditions were more favorable for scab development we saw a much higher disease incidence using the same sulfur spray schedule.

Apple maggot control was acceptable in treatments 1 and 2. We usually shoot for under 2-5% injury and I think we achieved this goal. There was no statistically significant difference between apple maggot control treatments 1 and 2. Our system was comparable to a conventional system with 0-2% injury.

Codling moth control using pheromone disruption was unsatisfactory. Again, we saw a lot of our damage from second generation moths and probably already impregnated females flying into the orchard. The single ryania spray aimed at controlling second generation moths seemingly had no effect.

Plum Curculio control continues to be unnecessary at our site. Frequent examinations were made of developing fruit for egg laying scars and adult feeding damage through the season. Our strategy for control was to use rotenone at 5 pounds/acre, but due to low populations none was applied.

Damage from the “other” category was due to a combination of tarnished plant bug and various lepidopterist species.

The two most important points learned from the grant had to do with hydrogen peroxide use, and codling moth control.

The rates we used for hydrogen peroxide (3 quart H202/50 gallons) during primary phase were too high. Even though only two applications were made at the high rate, an excessive amount of phytotoxicity was evident. Symptoms included leaf russetting and curling as well as intensive fruit russetting, however, even at this high application rate, some scab developed. It is possible that other apple varieties would be more tolerant than Cortland; however, I would not recommend its use unless trailing was conducted first.

Codling moth control continues to be a problem for us. We saw essentially no difference between the control treatment and the pheromone disruption treatment. This was mildly surprising since in the previous years we noticed some control from pheromones and we weren’t making a second application in those years. It is possible 1995 was just a good year for moths which would account for our high rates of damage. Even so, we would expect to see a difference from the control. The only possible explanation for this is that moth pressure is extremely localized.

A case in point is a grower down the road from our farm who has been growing apples organically the past several seasons. Due to his isolated location and young orchard age he has few insect pest problems. In fact, codling moth damage is absent even without a control strategy being implemented.

For our site, I do not consider pheromone disruption by itself, a viable control option. We are being forced to consider other control strategies, and since there is a lack of effective sustainable organic options, we will resort to a few will-timed applications of Imidan, a short-lived organo-phosphate, for codling moth control.

With the grant’s help, I have been enable to evolve more sustainable farming practices. Since farming is a complex interaction of humans and nature, it is our duty to be as responsible as possible when manipulating if for our benefit. Viewed in this light, a farming system should constantly be evolving until it reaches the highest sustainable level. This process is facilitated by the exchange of ideas and the sharing of experience and knowledge among growers. Without it, progress is impeded. For this reason I am always willing to share any information I may possess.

The economic, environmental and social impacts of our system can be viewed two ways; both small and large scale. Alone, as an independent unit, our system has negligible influence. However, when viewed as part of a farming revolution, then its effects could e larger than most people realize, for farmers are the producers of our nation’s food and proper nutrition is the foundation of health. It is true that conventional systems have increased production but it is hollow production with little integrity to the grain or fruit. They deal with systems filled with artificial aspects of creation and they lack the overriding positive energy infused in the natural growing cycle. A sustainable system, on the other hand, is more in harmony with nature and therefore creates a healthier environment socially, economically, and environmentally. Good health of ourselves and environment would mean fewer health care costs, pollution clean-up costs and hard-to-measure commodities such as the quality of life.

OUTREACH
The main avenue of outreach was direct contact of individuals through out farm’s retail shop and at our farmer’s market and Bayfield Apple Festival stands. We had several laminated posters stating the purpose of the grant and that an information packet was available.

We also hosted a field day which we advertised in local papers with a 3x3 ad.