Arturo Diaz, Field Manager, is key to making sure best practices are put into place on the farm.
Twin Springs Fruit Farm
The farm is owned by four individuals; two growers and two marketers. The growers working with Penn State on this project are Michael and Jesse King along with field manager, Arturo Diaz. Twin Springs produces a variety of tree fruits, berries, field crops, and greenhouse crops on 95 acres. Twin Springs makes an effort to employ sustainable and environmentally conscious practices, including IPM and the use of organic fertilizers.
What Twin Springs Fruit Farm hopes to learn from this project
Twin Springs Fruit Farm is interested in learning more about integrating new IPM techniques and practices successfully. They currently are in the process of acquiring more land that needs improvements in soil health. They hope to come out of this project with a recipe for success, including the use of cover crops to provide a more sustainable way of farming.
What Twin Springs Fruit Farm hopes to share by participating in this project
They are eager to share all of the practices of this study, whether stories of success or failure. With the ever-changing ways of farming, it is important for all growers to stay on top of new, innovative practices to support food security. They plan to share their experiences through hosting study circles and having their model plots serve as 'on farm' demonstrations.
Twin Springs Fruit Farm, Model Plot Case Study - Vegetable Rotation
Twin Springs Fruit Farm is located in Orrtanna, which is in the heart of the Adams Country Fruit Belt. The 95 acre farm is home to a variety of tree fruits, berries, field crops, and greenhouse crops. The growers involved in the model plot project include Field Manager Arturo Dias and Michael and Jesse King, who are next generation owners.
Twin Springs has been marketing their produce primarily at markets in Bethesda, Maryland and Washington, DC since the early 1980s. Consumers' growing demands for organic products have motivated Michael, Jesse, and Arturo to use sustainable and environmentally conscious farming practices. IPM is currently used in all three production greenhouses as well as in the field. The growers manage weeds with biodegradable plastic and cover crop rotations that also improve soil health.
Twin Springs Fruit Farm soils are primarily silt loams. The tomato plot in Year 1 of the 3-Year Model Plot Project was a Highfield Channery silt loam, which is well drained with no frequency of flooding. Mean annual precipitation is between 35-50 inches, and the water table is reached at greater than 80 inches. The farm is located in plant hardiness zone 6b, with a frost free date of May 10. This site is on a western facing slope of approximately 3-8%. The farm is irrigated from a well on the property. Deer pressure has been low.
Soil survey map for Twin Springs Fruit Farm at 936 Orchard Rd., Orrtanna PA. (Source: United States Department of Agriculture)
|Winter cover 2014||crop 2014||Winter cover 2013||crop 2013||Winter cover 2012|
Twin Springs Fruit Farm leased this site from Adams County Winery beginning in spring of 2012, harvesting cash crops of onions and carrots in 2013 and 2014 respectively.
The Models for the Future vegetable rotation plot is located in field 'Orange.'
Survey soil map for Twin Springs Fruit Farm vegetable plot. Location near 253 Peach Tree Rd, Orrtanna, PA. Approximately half mile away from Twin Springs address.
The primary goals of the vegetable rotation are to improve soil health and reduce overall disease pressure. The plot will alternate between cash and cover crops on almost a half year basis to build up the soil and ensure that a profitable crop is being produced each season. No crop family will be planted in the same area during the course of the six rotations in order to reduce both disease and pest pressure.
Tomato Transplant Production
Michael and Jesse seeded their tomatoes into new flats in their greenhouse in early March 2015. Mt Merit tomato variety was selected to provide late blight resistance. BHN589 was included as Twin Spring's standard beefsteak variety in the model plot so that we could make fruit quality and yield comparisons. Prior to planting, the Mountain Merit seeds were hot water treated to reduce the risk of seed borne bacterial diseases such as spot and speck. The seeds were treated for 25 minutes at 122 degrees F.
Tomato Soil Fertility
The soil was sampled on April 21, 2015. Fertility analysis was conducted by the Penn State Ag Analytical Lab. Each sample was analyzed for pH, Mehlich buffer lime requirement, and for phosphorus, potassium, magnesium, and calcium by the Mehlich 3 (ICP) test
Penn State Ag Analytical results:
|Plant Nutrient Needs|
|50 lb/A||110 lb/A||NONE|
In order to meet the nutrient needs of their tomato crop the growers first considered the history of the field to see if they could get any nitrogen credits from manure, legumes, compost or organic matter. Because nitrogen availability goes up and down based on microbes mineralizing it, most nitrogen recommendations are based on plant needs, not what is in the soil. To get a better estimate we accounted for what nitrogen might be available based on organic matter content.
|Adjusted Fertility Recommendations|
|Field Orange: Tomato||Acre(s)|
|2014 Fertility Levels||OM||pH||N||P205||K20|
|OM (20 lb per % over 2%)||20|
|Prior Legume Cover Crop|
|Subtract above from recommendations||0||20||0||0|
|Amendments||Applied nutrients 2015|
Twin Springs was credited 20 lb/A of N due to their OM percentage being at 3.0%. See conversion on table. Nutritional status, based on plant tissue tests, was further adjusted by seasonal fertigation.
A soil health analysis was conducted by the Cornell Soil Health Lab including organic matter, soil texture, active carbon, wet aggregate stability, available water capacity, surface and sub-surface hardness interpretation, and root health.
Results from the soil health test showed that the surface hardness, aggregate stability, and active carbon were possible limiting factors for plant growth. The test also showed a Root Pathogen Pressure value of 7.0. This result indicated a constraint and suggests that special management attention will be necessary to control disease incidence and spread. Overall the soil was scored at a 61, which is a medium soil health level.
Tomato Soil Preparation
In order to prepare the soil for tomato production, residue from the fall carrot crop was disked in during the first week of May and allowed about two weeks to break down. On May 15 the field was chisel plowed, and the recommended phosphate and nitrogen were applied. On that same day, the plot was disked again, and a biodegradable black mulch was applied to the rows. The tension was loosened in order to not stretch the biodegradable mulch too tight, which can cause the mulch to rip. Using mulch reduces weeding, and improves water efficiency among other benefits. A biodegradable mulch also helps reduce or eliminate future removal and disposal costs.
Black mulch applied May 15, 2015.
Weed suppression by mulch through the 2015 season
July 12, 2015
July 19, 2015
August 2, 2015
August 9, 2015
The Kings transplanted their tomatoes on May 15 into the biodegradable mulch. Beds were on 5 ft centers with 24-inch spacing between plants. Row cover was not used due to warmer May temperatures with no risk of frost. Tomatoes were staked every 2 plants, alternating between new 6 foot untreated oak stakes and 6 foot metal stakes. Plants were trellised using the Florida weave technique.
A closer look at the tomatoes right after being planted in the black mulch.
Irrigation was supplied by a single line of drip tape per bed at. 45 GPM per 100 ft. In order to provide the tomato crop with sufficient water (one inch per acre per week) the crop was irrigated daily for one-half hour when rainfall was not sufficient. The drip line also allowed for timely application of fungicides to protect roots from soil-borne diseases in addition to fertigation based on plant nutrient analyses.
Oats were seeded between beds as a method of reducing weed pressure in the plot. The between- row cover crop was maintained by one mowing early in the season.
Oats growing in between rows prior to mow down in early season.
Tomato Disease Management
Many pathogens can be carried over to the next year by seed. Tomato seed was not saved. All seed was purchased from reputable sources. All tomato seed was hot water treated at 122° F for 25 minutes to reduce the possibility of the seed being contaminated by bacterial disease.
Bacterial pathogens can overwinter on stakes and cause disease the next year. Wooden stakes in the plot were new. In an effort to reduce costs, Twin Springs reused metal stakes, although this is not advisable, as they may harbor disease from years past.
Rotation is key. Crop groups (both cash and cover crops) should not return to the same field for a minimum of three years to break up disease cycles. Many pathogens cannot survive in the soil on their own once the crop residue is thoroughly decomposed. Weeds in the same crop groups can host a number of pathogens so weed management is also essential.
The model plot rotation planned for Twin Springs will ensure that no crop family comes back to the same area for six years. The crop rotation used in model plots was also designed to improve soil health and to promote diverse microorganisms that compete with plant pathogens.
Creating an Unfavorable Environment
As most bacteria and fungi require wet conditions (or high relative humidity) to infect and cause disease, it is important to space plants well, maintain good air circulation, and drip irrigate to the root zone while keeping the plant foliage dry. At Twin Springs, all tomatoes were on drip irrigation, well-spaced, and trellised to allow for maximum air flow.
Choosing Less Susceptible Varieties
Mt Merit late blight resistant tomatoes were included in order to have a variety with some known disease resistance.
Using the Tomcast and Simcast models provided by NEWA, as well as USABlight mapping and regular scouting, disease pressure was tracked so that growers could spray accordingly. Adams County reached threshold values for Early Blight and Septoria in late June. Twin Springs began their spray schedule on June 17th, rotating materials of similar chemical classes.
Disease symptoms of Bacterial Speck/Spot were first noted in early July while disease scouting. The Kings began preventative sprays every 7 to 14 days in mid- June.
Tomato Leaf Tissue Testing
Tomato tissue samples were taken on May 18, at first flower, and sent to the Penn State Ag Analytical lab for analysis to track plant nutritional status and make any necessary fertility adjustments. Results from the tissue test indicated that all nutrients but nitrogen were in a sufficient range. Copper levels were excessive, which was likely due to contamination from protective spray applications.
Recommendations were based on the following nutrient levels for optimum tomato production.
A second tissue test was taken on July 22, at fruit set.
The second tissue test indicated that Nitrogen was continuing to fall while most other nutrients seemed to be maintaining. It was recommended that Nitrogen be applied at at least the. 5lb/A/day rate. Again, the high copper levels are attributed to spray application.
Twin Springs started their regular fertigation regimen on July 20 with Magnesium Sulfate (20lb), Potassium Nitrate (15lb) and Iron (1lb) at a 2% dilution through drip. After receiving the tissue analysis, they switched to straight Calcium Nitrate (50lb) at 2% dilution through the drip, and the crop responded well.
Tomato Disease Pressure
Disease scouting was conducted once a week for six weeks from July 13 to August 26. Particular attention was paid to detecting early blight, late blight, septoria leaf spot, and bacterial speck and spot on both the Mountain Merit and BHN-589 varieties.
On each scouting date, the entire plot was walked for a presence/absence assessment using standardized methods and data sheets. Scouting included selecting 10 plants per variety that were evenly distributed within the plot. Penn State scouts paid close attention to areas where disease generally starts to appear (i.e., wet and low spots). Three leaflets were examined throughout each plant (one low on the plant, one at mid-level, and one in the upper canopy) for disease symptoms. The percent of affected tissue for each of the 3 leaves per plant was recorded, as well as the diseases observed. A separate data sheet was used for each variety. Bacterial speck and spot developed in both varieties in early season on the lower leaves. By mid-August lower leaves had as much as 70 percent coverage, while the upper canopy had small patches of disease.
Tomato yield was monitored for a period of 5 weeks during peak harvest, from August 6 to September 1, 2015. For each variety (Mt Merit and BHN 589), 4 blocks of 5 plants were flagged to be skipped over by the farm's harvest staff. Plants were harvested once a week for marketable and unmarketable yield, determined by weight. Below are the results given in pounds and averaged according to the 4 blocks per plot. Note: The yield and fruit quality of Mt. Merit was more severely stressed by a late summer heat wave than that of BHN-589.
|Mountain Merit Variety|
|Date||Mean weight||Mean weight marketable||Mean weight unmarketable|
6.34lb fruit x (43,560 sq ft)/(1 Acre) x (Mt. Merit model plot)/(40 sq ft*)=6,904.26 lbs marketable fruit/A
|Date||Mean weight||Mean weight marketable||Mean weight unmarketable|
8.78 lb fruit x (43,560 sq ft)/(1 Acre) x (BHN-589 model plot)/(40 sq ft*)=9,561.42 lbs marketable fruit/A
*40 square feet calculated from 5 repetitions of 4 plants spaced 2 feet apart, with 5 feet between centered rows.
Sample unmarketable harvest based upon whether the fruit were over-mature, highly discolored, or had disorders such as blossom end rot.
The Interactive budget from " Models for the Future" tomato plots allow growers to assess the costs and benefits of cover crops and other sustainable practices in their own operations.
This material is based upon work that is supported by the National Institute of Food and Agriculture, U.S. Department of Agriculture, under award number 2015-70017-22852.