Organic Integrated Pest Management in High Tunnel Vegetable, Small Fruit, and Flower Production

Final Report for LNC04-245

Project Type: Research and Education
Funds awarded in 2004: $136,451.00
Projected End Date: 12/31/2006
Region: North Central
State: Missouri
Project Coordinator:
James Quinn
University of Missouri
Expand All

Project Information

Summary:

High tunnels are low tech and inexpensive unheated plastic greenhouse structures that allow for production of extended season, higher quality and greater yielding vegetables, small fruit and flowers. Organic production in this environment benefits from reduced disease pressure, as well as the potential for enhanced prices. Cost effective, safe, and practical methods to control pest pressure in these structures are being researched and evaluated. Field events will be held at on-station and on-farm locations and will allow multi-disciplinary team members to engage with producers. Extension programming is being addressed with a range of educational materials and outreach activities.

Project Objectives:

Research Objectives:

Evaluate three organic integrated pest management (IPM) techniques on selected high tunnel crop production systems in on-station trials at four sites--

Double-cropping annual strawberry and vegetable production systems – Wichita, Kansas

Organic and conventional production systems for green leafy vegetables – Olathe, Kansas

Flower-based production systems – Mead, Nebraska

Extended-season production of warm-season crops – Columbia, Missouri.

[Organic IPM techniques include use of beneficial attractant perimeter crops, release of beneficial insects, and use of Organic Materials Review Institute (OMRI) approved control products for pest problems.]

On-farm Objectives:

Evaluate organic IPM techniques identified through the research, or of current importance. An economic analysis will be preformed on the IPM techniques assessed positively by the grower-collaborators.

Cooperators

Click linked name(s) to expand
  • Melvin Brees
  • Edward Carey
  • Laurie Hodges
  • Lewis Jett
  • Sorkel Kadir
  • James Nechols

Research

Materials and methods:

University of Missouri at Columbia:

Research was conducted from the spring of 2004 until mid-summer of 2005. Research focused on two areas:

- Does the maintenance of beneficial attractant cover crops around a high tunnel reduce pest problems? Can insect attracting food sprays serve the same purpose?

- Can insect screening be effectively used without compromising the high tunnel air temperature?
(Any screening will restrict passive airflow)
Research on the interaction of cover crops, beneficial insects and insect food sprays was successfully implemented in 2004. Review of the samples for beneficial insects and their respective numbers was to be conducted by KSU Entomology/ James Nechols lab.

In April of 2005 two plots each of tomatoes (Fabulous & Sunbrite) and bell peppers (Lafayette) were established in four high tunnels, two with Econet B insect screen (US Global Resources) and two without. One plot of the tomatoes and peppers in each high tunnel was treated with organic insecticides weekly, and one plot of each crop received no treatment. Econet B screen was selected because it only restricted airflow by 5% and would prevent tomato fruitworm and European corn borer moths from entering. Whether the (1000 x 400 mm) mesh would restrict cucumber beetles was in question, and the tunnels also had cantaloupe plantings. Another question was whether the screening material would significantly raise the air temperature in the high tunnel.

Kansas State University-Wichita

A two-year study is under way to compare organic with conventional method to control two-spotted spider mites (TSM) on strawberries grown under high tunnel. Surround WP (60 g/L) is the organic treatment, while Zeal 72 WDG (2-3 oz/A) is used as a conventional control method.

Kansas State University-Olathe

High tunnels provide a relatively low cost protected environment for crop production, and are increasingly being adopted by producers in the USA, many of them organically oriented and serving local markets. During the summers of 2005 and 2006, replicated studies of tomato, cucumber and eggplant were conducted in organically and conventionally managed high tunnels and adjacent open field plots. The objective of these studies were a) to assess the potential effects of high tunnels on crop productivity and the incidence of common diseases and pests which might be present in organic and conventional high tunnel and open field production systems, and b) to compare the efficacy of selected organic and conventional pesticides for control of diseases and pests occurring in these systems.

Materials and Methods

The studies were carried out on a Kennebec silt loam soil at the Kansas State University Horticulture Research and Extension Center, Olathe. Six 20’ 32’ high tunnels with 5’ sidewalls (Stuppy, North Kansas City, MO) and six adjacent 20’ x 32’ field plots were used for both experiments. The tunnels were covered with a single layer of 6 mil (0.153mm) K-50 polyethylene film (Klerk’s Plastic Product Manufacturing, Inc., Richburg, SC). At establishment in 2002 the six high tunnels were divided into three groups (blocks) and the two high tunnels in each block were randomly assigned for long-term organic or conventional management treatments. A similar set-up was used in the field plots.

Trials were planted each year in May after all danger of frost had passed so that field and high tunnel crops could be established at the same time and comparisons could be made between the systems. Organic plots were fertilized with Hu-More (Humalfa, LLC, Shattuck, OK) compost, and conventional plots fertilized with commercial fertilizer. Compost and fertilizer rates were adjusted according to soil analyses, assuming a nitrogen availability coefficient of 50% for compost. Fish emulsion (5-1-1) was used to fertigate organic plots and calcium nitrate used to fertigate conventional plots at recommended rates. The tomato cultivar was Florida 91, cucumber was Tasty Jade and eggplant was Orient Express. Five plant plots were used for each crop.

Pest and disease incidence on crops was monitored weekly, and pests controlled using appropriate organic or conventional pesticide. Pyrethrin (PyGanic) (McLaughlin Gormley King Co., Golden Valley, MN.) sprays were used in organic plots, and permethrin (Pounce 3.0 EC) (FMC Corp., Philadelphia, PA.) sprays were used in conventional plots to control cucumber beetles (on cucumbers), flea beetles (on eggplant). Lepidopteran pests were controlled using spinosad, Entrust in organic plots or Spintor in conventional plots. Pesticide applications were made weekly at labeled rates, if required. No effort was made to control foliar fungal diseases of tomato, Septoria leaf blight and early blight, but their incidence was monitored.

Yield results were analysed as a split–split plot design with high tunnel vs open field as whole plot factor, and organic vs conventional as the subplot factor. Analysis of variance was performed using Genstat Release 8.

University of Nebraska at Lincoln (2005)

A project was designed to investigate the effects of mowing on the movement of insects between the high tunnels and the adjacent vegetation. Beneficial predatory or parasitic insects were used for insect control in the high tunnels with one exception. Pyganic, an OMRI approved pesticide, was applied once to the lower two-thirds of sunflower stems to control stem borers. No other pesticides were applied.
The 2005 high tunnel (HT) insect monitoring project started on March 29, 2005 and ended on September 30.

In 2006, sampling and data collection of insects inside and outside the high tunnels before and after mowing with yellow sticky traps continued on a weekly basis. Identification of insects is difficult due to the glue on the traps obscuring key details. Data is entered onto the spreadsheets. Pressure to remove dandelions, bindweeds, and other weeds resulted in the vegetation of the entire area being chemically killed, disked, and replaced with turf grasses. This confounds the data considerably but we are optimistic that some general trends in insect movement into the high tunnels may become evident when the data is analyzed.

Research results and discussion:

Missouri

The anticipated pests of focus were aphids and thrips; neither appeared in sufficient numbers during the year to cause any problems on tomatoes, peppers, zucchini, or potatoes. An unanticipated problem with the cover crops was the favorable habitat they created for voles. Control of voles became time consuming with the need of baits and traps to keep their levels tolerable. The issue of vole control and their habitat was discussed in the March 2005 issue of Growing for Market.

Screening Results

1. Use of Econet B raised the air temperature about 5◦ F. While airflow is not reduced significantly, the screen reduces wind by 45%, thus reducing air movement in this passively vented situation. For crops enjoying warmer temperatures in the summer, like melons and tomatoes, this may be acceptable, but with crops like cucumbers, peppers and (most, if not all) salad crops, this would be problematic.

2. Tomato fruitworm damage was virtually eliminated in a screened tunnel where tomatoes were not cultivated the year before. In the tunnel where tomatoes were cultivated, fruitworm damage was just as significant (about 18%, see note below). While not conclusive, this lends credence to the suspicion that a protected environment can aide tomato fruitworm in successfully over wintering further north then they normally would survive. Tomato fruitworm moths were detected in traps set up at 5 points from south to north in Missouri about mid-May. Since fruitworm damage is often not noted until harvest approaches (harvest typically begins about mid-June), it is difficult to know if the caterpillars are from eggs laid by tomato fruitworm moths flying up from the south, or from moths that emerged from pupae in a high tunnel.

3. Presence of European corn borer (larvae) did not occur on the bell pepper fruit in screened or unscreened tunnels by September. The previous year this pest appeared beginning in August, which is typical of the pest moving from corn beginning to dry down.

4. Both striped and spotted cucumber beetles were able to slip through the screen, with the screen providing no reduction in cucumber beetle numbers. Smaller screen would be required. Typical window screen would be a readily available inexpensive source, but this would restrict airflow more significantly, and may not be compatible with summer temperatures and passive ventilation.

* A combination of the OMRI approved insecticides Pyganic 5.0 and Dipel (B.T.) applied weekly provided control of tomato fruitworm damage, taking about 3 weeks to provide good control (3% of marketable fruit damaged by the caterpillar). Without the insecticides 18% of the marketable fruit was damaged. Caterpillar damage was usually substantial enough for the fruit to be culled.

Kansas State University-Wichita

In 2005, small infestation of two spotted spider mites (TSM) and few aphids were detected under high tunnel. Infestation of TSM was first observed in early April on the weeds between strawberry beds under high tunnel. Fortunately, no TSM infestation on strawberry plants was observed. In addition to the TSM under high tunnel, several beneficial insects, such as Ladybug larvae, Tachinid flies and lacewings were seen under high tunnel which might have prevented TSM from attacking strawberry plants. Strawberry harvest of high tunnel plants started early March. Sweet Charlie flowered and produced earlier than Chandler. Plants were harvested every two to three days. The 2005 harvest data show no significant damage from TSM infestation inside the high tunnel or outside (field plots). As expected, preliminary results showed yield was much higher under the high tunnel compared with that of field plots, data are yet to be analyzed.

Kansas State University-Olathe

Cucumber

In 2005, spotted cucumber beetle pressure was high, resulting in the need for weekly insecticide spray during much of the production period. Plots were harvested thrice weekly from mid-July through mid August, resulting in an overall production of 12 lb no. 1 cucumbers/plant (14.5 lb total/plant). There were significant differences between organic and conventional production systems with the organic cucumbers having significantly lower no. 1 yield than conventional (9.2 lb/plant vs. 14.6 lb/plant). There were no significant differences in cucumber yield between the field and high tunnel plots, though there was a tendency to higher no. 1 yield in the high tunnels (11.5 lb/plant in field vs. 12.8 lb/plant in high tunnels). Percentage of no. 1 cucumbers was significantly higher in conventional plots than in organic (90.5% vs 75.2%), and was also higher in high tunnels than in the open field (86.3% vs 79.3%). While differences in yields cannot be attributed solely to pest control, there were noticeable differences in abundance of cucumber beetles between organic and conventional treatments, with the permethrin effecting much greater residual control than the pyrethrin. There was typically an abundance of pests in the organic plots within 24 hours of treatment, while conventional plots remained relatively pest free between weekly sprays.

In 2006, cucumber beetle pressure was lower, and fewer pesticide sprays were required. Plots were harvested through the month of July with an average overall production of 15.7 lb no 1/plant (19 lb total/plant. There were no significant differences effects of organic vs. conventional or high tunnel vs open field treatments on yield of no. 1 cucumbers, though there was a tendency to higher yield in organic plots (16.8 lb/plant vs. 14.7 lb/plant), and in high tunnels (16.3 lb/plant vs. 15.2 lb/plant). Total yield and fruit counts were significantly higher in organic plots than in conventional. Given the absence of pest pressure, greater yield in the organic plot was presumably due go better soil fertility in organic plots.

Eggplant

In 2005, pest pressure on eggplant plots (flea beetle) was relatively high resulting in the need for weekly insecticide spray during the early production period. As the season progressed, plants grew large and pest pressure declined. Plots were harvested twice or weekly from mid-July through early October resulting in a no. 1 yield of 5.8 lb/plant (9.4 lb/plant). There were significant differences between organic and conventional production systems with the organic eggplant having significantly lower no. 1 yield than conventional (2.1 lb/plant vs. 6.1 lb/plant). There were also significant differences in no. 1 cucumber yield between the field and high tunnel plots, (4.7 lb/plant in field vs. 5.54 lb/plant in high tunnels). Percentage of no. 1 eggplant was significantly higher in conventional plots than in organic (73.8% vs 67.9%), and was also higher in high tunnels than in the open field (79.7% vs 61.9%). While differences in yields cannot be attributed solely to pest control, there were noticeable differences in abundance of flea beetles and lace beetles between organic and conventional treatments, with the permethrin effecting much greater residual control than the pyrethrin. As the season progressed, the greater vigor and health of the conventional crops was notable resulting in the higher yields recorded.

In 2006, pest pressure was lower, and fewer pesticide sprays were required. Plots were harvested from mid-July through late-September with an average overall production of 8.0 lb no 1/plant (11.8 lb total/plant). There were no significant differences effects of organic vs. conventional on no. 1 or total yield, but the effect of high tunnel on yield was highly significant, with no. 1 yield of 11.5 lb/plant vs. 4.4 lb/plant in the open field. The percentage of number 1 yield in high tunnel plots was significantly higher (71.1% vs. 58.3%) than in the open field. In the absence of significant pest pressure, high tunnel yield may have benefitted from improved soil fertility in the protected environment.

Tomato

Arthropod pressure on tomatoes in the 2005 trials was low, with fruit worms readily controlled in both organic and conventional plots by spinosad formulations. The incidence of foliar fungal diseases was, however, high, particularly in field plots, and little effort was made to control disease through the use of fungicides. Plots were harvested once or twice weekly from late-July through early October, resulting in an overall production of 12.7 lb no. 1 tomatoes/plant (22.8 lb total/plant). There were not significant differences between organic and conventional production systems though there was a tendency to higher no. 1 yield in conventional (14.4 lb/plant vs. 10.9 lb/plant). There were highly significant differences in no. 1 tomato yield between the field and high tunnel plots (5.8 lb/plant in field vs. 19.5 lb/plant in high tunnels). The differences in yield between high tunnel and open field were almost entirely due to the heavy infection of foliar fungal disease which occurred in the open field, but which did not occur in the rain-sheltered tomato plants within the high tunnel.

In 2006, arthropod pressure was again not significant in the tomato trial. While less severe than in 2005, foliar fungal diseases were again present in the open field plots. Tomato plots were harvested weekly from mid-July through the end of August with an average overall production of 13.4 lb no 1/plant. There were no significant effect of organic vs. conventional management, but high tunnels again resulted in significantly higher no. 1 yield compared to the open field (14.7 lb/plant vs 12.1 lb/plant). In 2006, there was a significantly higher percentage of no. 1 fruit harvested from high tunnels than open field plots (44.1% vs. 36.8%). Percent marketable (no. 1 and no. 2) from high tunnels was also higher than from open field (91.3% vs 86.2%).

Discussion

Trial results varied somewhat from 2005 to 2006 for each of the warm-season crops in this study. In 2005, when insect pressure was high, the organic cucumber and eggplant crops were not protected by weekly spray with pyrethrin, whereas weekly sprays of permethrin provided superior control of the major pests – spotted cucumber beetle on cucumber, and flea beetle and lace bug on eggplant. As a result, yields in organic eggplant and cucumber were significantly lower than from conventional plots. In 2006, pest pressure was lower in cucumber and eggplant plots, so there were no benefits of conventional pest control, and yields were comparable, or superior in the organic plots, probably due to superior soil fertility. In the case of tomato, arthropod pests (tomato fruit worm) were controlled equally by the organic and conventional formulations used, and there were not striking differences between yields of organic and conventional treatments. Tomato and eggplant to a lesser extent benefited significantly from the high tunnel environment. In the case of tomato, this benefit was enormous, particularly when high levels of foliar fungal disease destroyed the crop in the open field.

Future research efforts should focus on evaluating the efficacy of alternatives such as screen for cucumber beetle control in organic cucumber crops. The benefits of high tunnels with respect to reduction of foliar fungal disease, while generally recognized, have not been documented well in the scientific literature. This report is a step on that direction. A manuscript from these trials is in preparation for submission to a peer reviewed journal.

University of Nebraska at Lincoln (2005):

The vegetation is largely weedy species such as plaintain, crabgrass, some bromegrass, dandelions, henbit, chickweed, foxtails, and lambsquarters with about 25% bare ground. The statistical design is a split-split plot with four replications. Preliminary analysis of the data is pending. We anticipate continuing the data collection in 2006.

A summary sheet was designed and the weekly totals entered by order under ‘Beneficials” or ‘Pests’.

Some of the problems encountered were:

1. Difficulty in identifying insects on the sticky trap where the adhesive obscures parts needed for identification. (Examples; antennae stuck to head so form not discernable; wings stuck together or to body as in Diptera vs. Hymenoptera).

2. Difficulty in determining whether similar species are beneficial or pests in look-alike groups.

3. Dirty traps (from soil and debris contamination after being put out) that make counting difficult and may enable insects to escape.

4. Un-represented or under-represented categories of insects that either don’t fly (caterpillars or other immatures) or are infrequent filers (stink bugs, ground beetles, grasshoppers, etc.).

5. Most types of insects captured on the sticky traps normally move by flying.

6. Climatic and physical conditions greatly affect the frequency of certain groups of insects. Examples: temperature, humidity, wind conditions, season (certain insects may only occur for a short period of time) and sky conditions (cloudy/sunny).

The 2005 HT project identifications were done on a predominantly insect Order basis with a small number of readily recognizable genera noted. This method has called attention to some potential problems with insect identifications and has provided a basis for determining protocols for future projects.

In 2006, sampling and data collection of insects inside and outside the high tunnels before and after mowing with yellow sticky traps continued on a weekly basis. Identification of insects is difficult due to the glue on the traps obscuring key details. Data is entered onto the spreadsheets. Pressure to remove dandelions, bindweeds, and other weeds resulted in the vegetation of the entire area being chemically killed, disked, and replaced with turf grasses. This confounds the data considerably but we are optimistic that some general trends in insect movement into the high tunnels may become evident when the data is analyzed.

Experiences with biological control of insect pests in the high tunnels through the release of predatory insects continued. On the flower crops, thrips and spidermites were the biggest problems, followed by aphids. Predatory mites, Amblyseius cucumeris, provided adequate control of thrips for the early spring crops in the high tunnels. Thrips damaged the white and yellow snapdragon flowers. No thrips damage was observed on red, orange, or purple snapdragon flowers. Release rates were roughly 1000 per 100 sq ft, considered a heavy release rate, due to the packet size from the supplier. The interior space of each of the six high tunnels is approximately 100 sq. ft.
Spidermites were controlled with the predatory mite, Phytoseiulus persimilis, released when spidermites became evident on the leaves. Phytoseiulus persimilis was released at a rate of roughly 300 per 100 sq. ft. with repeated applications made through the summer. Control varied from excellent to fair, depending on the crop and the specific high tunnel.

Green peach aphids, Myzus persicae, were controlled quite well with releases of the parasitic wasp, Aphidius colemani. Aphidius colemani did not control the milkweed aphid, Aphis nerii, but releases of the convergent ladybeetle, Hippodamia convergens, were very successful against this pest on ornamental Asclepia species in both the high tunnels and the field.

A quandry arises with the use of biocontrol insects when insect pests occur for which there are no biocontrols, e.g. cucumber beetles (Diabrotica spp.), bean leaf beetles, and sunflower stem clipping weevils, which were a major problem in late-season ornamental sunflower crops. Pyganic (pyrethrum) and neem oil were options considered but both are contact control agents that would adversely affect the adults and larvae of beneficial insects, released or native.

Overall, use of predatory insects has been encouraging for control of spidermites, thrips, and aphids. In the future, predatory insects will be released earlier in the season with sequential releases as thrips pressure builds from March through June. Use of beneficial insects will continue as the high tunnel crop production system transitions toward certified organic status.

Research conclusions:

Five collaborators were identified to evaluate organic techniques or tactics for pest control in 2006. They were asked to record the following:

- Crop treated, it’s growth stage, and amount, if any, damage from the pest;
- The pest or pests, how numerous, and stage of development (e.g. nymph vs adult);
- Date and time of application;
- Product applied, the rate used, the amount of mixed material applied, and the approximate area to which it was applied;
- Finally, a follow-up evaluation on the effectiveness of the material, which will depend on the situation, and may be from the next day up to up to several weeks later.

Collaborator with cut flower production:

1. Use of two different biofungicides to control root rot on high tunnel cut flowers. You have Companion and Plant Shield to test on Delphiniums. Since Companion is applied as a liquid drench, you also have two injectors (Young Mixer Proportioner; Add It Proportioning Fertilizer Injector) with which to try and compare for functionality.

2. Evaluation of several insecticides for control of insect pests. The following pests (and products for testing) are anticipated and could be tested:
- thrips (Conserve; Pyganic & Neemix);
- sunflower head weevil (Pyganic & Neemix);
- Various caterpillars (BT; Conserve).
We understand that sometimes the pest does not show up on a given year, or that a sufficient amount of crop area may be available for effective testing. However, to aide you in testing quickly and effectively, a Rocket Electric Sprayer is being provided, and your feedback on its usefulness is expected.

3. Use of insect screening for reducing grasshopper damage. The insect screen Econet B has been purchased for this purpose. It would screen out new populations of grasshoppers from entering the high tunnel. To control any nymphs that may hatch out in the high tunnel, Pyganic with and without Neemix could be evaluated for their control.

Result (summary)

1. The producer felt both biofungicides provided some benefit, as it seemed they had less disease problems. Rootshield was easy to work with as a preplant incorporated product. Companion mixed up easily, and of the two injectors, they had more confidence in Add It, but both were easy to work with and acceptable. The Young Mixer was probably more well suited to smaller application.

2. The producer loved the Rocket Electric Sprayer and noted that due to the ease of application they got to their pest control duties more timely and had better control. They noted that not having to carry around a backpack sprayer on a post 50 year old back probably makes the price cheap compared to back problems. Lastly the long hose made negotiating into difficult areas easier. Pyganic, Neemix and B.T. were all used and seemed to work for the pests they treated for, blister beetles & leaf scraper, aphids, and tiny (sunflower?) headworm, respectively. They did not have enough pest pressure to do comparative treatments.

3. Econet B continued to work well in screening out large grasshoppers and cucumber beetles. Any small grasshoppers or cucumber beetles that got inside were controlled with Pyganic. The crops they grow in tunnels with Econet B can accept the higher temperatures it creates, by reducing wind through the tunnel. It has a secondary benefit in that the cut flowers do not lodge.

Collaborator producing roses (with minimal pesticide use):

1. Use of one biofungicide (Sonata) to control powdery mildew on high tunnel roses. I anticipate you will compare its performance to baking soda.

2. Use of predator mites for control of spider mites on high tunnel roses. You will receive five shipments of Phytoseiulus persimilis (2,000 each) from Hydrogardens in the following schedule: two for March, then one each in April, May & June. I strongly suggest you to use a hand lens to view the predator mites prior to their release. These will aide you in recognizing them on your plants. Please follow the beneficial insect release instructions included with the shipment. You will also receive Floramite, a new insect growth regulator that is effective against two-spotted (and similar) spider mites while not harming predator mites. This is a back-up in case the predator mites do you provide you with adequate control, and should allow you to bring your pest and predator mites into balance.

Result (summary)-

1. Compared Sonata to baking soda to control powdery mildew. Sonata worked better and left no residue. Sonata also seemed to cure as well as prevent.

2. They released the spider mites and did not have any problems with spider mites that season. Could see the spider mite predators, they were orange, and moved fast. They could never find 2 spotted spider mites on the roses the entire season. Grower would release on their own next year. Whether that was a ‘this year fluke’ or the result of the predator release, they could not be sure, but given past problems, felt there must be some credit. Due to no spider mite problems, they were not able to use the Floramite. However, they also work with an adjoining nursery and the report is it has worked well when used there.

Collaborator with tomato and greens production using beneficial insect releases:

1. Use of organic insecticides to control harlequin bugs on high tunnel kale. I anticipate you will compare Pyganic, Neemix and Pyganic & Neemix in combination.

2. Use of predator mites for control of spider mites on high tunnel tomatoes. You will receive nine shipments from Hydrogardens in the following schedule: two each for April & May, then one each from June through October. I strongly suggest you to use a hand lens to view the predator mites prior to their release. These will aide you in recognizing them on your plants. Please follow the beneficial insect release instructions included with the shipment.

3. Use of Trichogramma to reduce the incidence of Cole crop caterpillars and tomato fruitworm. Since adequate control of these pests are not likely, you will probably have to supplement with BT applications. You may find use of Neemix and/or Pyganic worth considering as well

Result (summary)-

1. Did not end up trying to control harlequin bugs in high tunnel because they had a planting right behind in the field that did not have any problem. Harlequin bugs did show up, and did kill off the kale, but when they waited long enough the swiss chard recovered as the harlequin bug population fizzled.

2. Released spider mite predators as scheduled through the season, but had a problem in July. Corrective action was Mite-X (OMRI approved) twice a week for 2 weeks and then they did a double release. Then the mite pressure seemed to decline and the plants resumed fast enough growth to be OK. Looked for spider mite predators at release and could find, but once were on the plants they had a difficult time telling the difference. May try next year to see if they work again. Otherwise they would probably just plant and spray Mite-X if they had trouble. [Growth was very thick and may have been too hot, so (next year) they will put less plants & spray instead.]

3. Trichogramma were easy to release but they did not feel like there was any reduction in caterpillar population. They had plenty of tomato fruitworm in the fall high tunnels.

4. Installed Home Depot insect screen in the greenhouse ‘as a tent’ which did keep the cucumber beetles off the cucumbers, but they had troubles with aphids on the cucumbers. The aphids were controlled with ladybugs and Aphidius, but yields were low (fruits kept aborting). Field cucumbers planted in white plastic and with floating row cover worked quite well.

Collaborator with tomato and greens production using a high pressure sprayer:

1. Use of organic insecticides to control harlequin bugs on high tunnel kale. I anticipate you will compare Pyganic, Neemix and Pyganic & Neemix in combination.

2. Use of BT to control tomato fruitworm in high tunnels, with the aide of a high pressure sprayer. You may find use of Neemix and/or Pyganic worth considering as well. Since the principle question here is whether the use of the high pressure sprayer makes a significant impact of pest control (and labor needed for application) everything you can do to more fulle document this would be helpful. Three things to consider are 1) leaving a couple of tomatoes untreated in each high tunnel, 2) applying BT with the same sprayer you have in the past and use of the high pressure sprayer for some field applications as well.

Result (summary)-

1. On harlequin bugs tried row cover, Pyganic, and Pyganic & Neemix- nothing worked.

2. Insect screening worked well for tomato fruitworm and tomato hornworm. Had almost no incidence. But the aphids quite bad April into July. But the tomato crop followed some salad greens & herbs.

3. For the unscreened greenhouse they did get control with BT and the high pressure sprayer and did observe the caterpillars with blackened guts. Sprayed about every 2 weeks with copper, fish emulsion and BT. The sprayer was much faster. Compared to the tractor sprayer the droplets were much smaller and gave better coverage. More spray may have been used, but it wasn’t anything that substantial.

Collaborator with salad green production and flea beetle problems:

1. Use of insect screening for reducing flea beetle damage on salad greens. The insect screen Econet M has been purchased for this purpose. It would screen out new populations of flea beetles from entering the high tunnel. To control any larvae or adults that may already be in the high tunnel, you have four products to work with- Entrust, Pyganic, Neemix and Diatect V. All but Diatect V could be tried in combinations to enhance the pest control.

2. Use of insect screening for keeping cucumber beetles from cucumbers, with a further goal to keep bacterial wilt from being transmitted. The insect screen Econet M has been purchased for this purpose. Any cucumber beetles that may already be in the high tunnel or slip in could be controlled with Pyganic, Neemix or Diatect V. Pyganic and Neemix could be tried in combinations to enhance the pest control.

3. Use of insect screening used in the open field for reducing flea beetle damage.It would be supported in the field with materials and design similar to high tunnel support. The insect screen Econet M has been purchased for this purpose. It would screen out new populations of flea beetles from entering the area. To control any larvae or adults that may already be in the area, you have four products to work with- Entrust, Pyganic, Neemix and Diatect V. All but Diatect V could be tried in combinations to enhance the pest control. Use of insect screening in the open field was developed to enhance the quality you obtain with salad greens produced subject to full sum and wind, that results in them being more toughened up. You also desire to move the material frequently and easily.

Result (summary)-

1. Did not get to insect screen but will try next year.

2. Tried Pyganic and Neemix combined and gradually increased rate until the results were noticeable but not adequate. The biggest problem was that it just doesn’t kill the beetles. Customers did accept the product, but they did need to stop with wholesale accounts when damage was bad. Farmer’s Market sales continued. But the control does not give the grower any confidence, especially compared to rotenone. And they had to treat more often. Neemix did not burn the salad greens.

3. Did not use Diatect. Just did not get to it.

Economic Analysis

None performed.

Farmer Adoption

A critical component of the project is the on-farm testing by the collaborators and their subsequent participation in educational activities. One collaborator used Econet B insect screening to successfully keep grasshoppers out of a high tunnel in 2005. Warm weather cut flowers were grown in the tunnel during the late spring/summer, so slightly elevated temperatures were not a problem. The screening had an unforeseen benefit; during periods of high winds, the plants in the high tunnel with screening were protected sufficiently to prevent lodging. Five collaborators were identified to evaluate organic techniques or tactics for pest control in 2006. (Note Impact of Results/Outcomes Section)

Participation Summary

Educational & Outreach Activities

Participation Summary:

Education/outreach description:

A series of field days were held in the fall of 2004 to promote university research and demonstrate producer practices with high tunnels. This provided an ideal format to educate producers about this project and receive input from them on the issues being investigated by the researchers. The field days, three at research stations and three at farms, were held at the following locations during the noted month, and had a combined attendance of 80 growers:
Wichita, Kansas -- October 5th
Lincoln, NE -- October 6th
Kansas City, KS -- October 13th
Westphalia, MO -- October 21st
Columbia, MO -- October 28th
Olathe, KS -- November 8th

The Great Plains Vegetable Growers Conference held in early January of 2005 had a high tunnel workshop with 120 attendees. The featured speaker extensively addressed organic IPM issues in high tunnel production.

A field day in late July of 2006 at Olathe, KS featured an IPM discussion on some of the research and collaborator work during a high tunnel tour held after the classroom presentations. More than 25 individuals were present during this tour stop.

The Great Plains Vegetable Growers Conference, held in early January of 2007, had a high tunnel workshop with over 100 attendees. The five collaborators (mentioned above) comprised the ‘farmer panel’ that was been the late afternoon session of the high tunnel workshop (as in prior years this closing has been popular). They each described their results at that time. (Details are in the Impact of Results/Outcomes Section)

Project Outcomes

Recommendations:

Areas needing additional study

The research was frequently shortchanged when the 'anticipated pest problems' did not develop. Yet growers would seem to predictably have their pest problems. The growers would often 'get busy' and not have the time or skill set needed to follow up with the required monitoring or diagnostic work. More time and travel $$ for an individual with IPM skills to visit growers on a frequent basis through the production season would help remedy both of these limitations. Some of the most valuable results were developed through the interaction between the grower and an 'IPM technician'. These results could have easily been expanded upon by adding other growers or pest problems into the model.

Information Products

Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.