The document discusses various challenges for growing crops in high tunnels, including weeds, pests, diseases, and labor issues. It provides tips for controlling weeds such as using wire weeders and organic mulches. For pest control, it recommends scouting, identifying pests accurately, and utilizing biological controls when possible, such as releasing ladybugs or lacewings. Fungal diseases are a common problem, so the document suggests practices like ventilating the high tunnel and using soil solarization and biofumigation with mustard cover crops to reduce pathogens in the soil.

1. Challenges to High Tunnel Growing Weeds Pests Disease Management & Labor (But we’re not going to discuss these here!)

2. Yes, that’s Red Root Pigweed, only 3 to 4 inches tall and trying to set seed at the end of November.

3. January 8, and yes, that’s a dandelion in bloom!

4. At this stage, they’re easy to handle

5. Unchecked, they can look like this..

9. Scale appropriate tools

10. Lucko Wire Weeder Round wire doesn’t damage drip tape and does a very effective job against young weeds – available from Johnny’s Selected Seed

11. Weed barriers

12. Organic mulch as a weed barrier

13. Effective weed control measures Never allow any weeds to mature and set seed Keep weeds and grasses from maturing and setting seed around the outside of your high tunnel Use weed barriers (mulches) when practical Utilize strategies that eliminate or reduce the amount of cultivation needed to keep the crop weed free Before weeds become a problem, make the time to cultivate when they are young, or better yet, before they even emerge

14. Insects Pests & Predators

15. Sticky Yellow Trap Early detection through scouting and then accurate identification are 2 key components to an effective program!

16. Resources ATTRA ecological pest management Or, if you don’t know what you’re looking at, how will you ever know what to do about it!?!

17. Cornell Universities Resource Guide for Organic Insect & Disease Management http://web.pppmb.cals.cornell.edu/resourceguide/

18. Striped Cucumber Beetle ( Acalymma vittatum ) Striped cucumber beetles (SCB) are 1/4 inch long with black and yellow longitudinal stripes and black head and abdomen View photo 2.3 . In the Northeast, they pass the winter as adults sheltered under plant debris and become active in the spring as soon as cucurbits appear. The overwintered generation lives until August and feeds on all plant parts. Small seedlings are very susceptible and are often killed. Once the plants attain 4-5 true leaves, they are more tolerant of striped cucumber beetle feeding; however, disease transmission is still important (see below). The beetles lay their eggs at the base of cucurbit plants. These hatch into larvae, which feed below ground on the roots and crowns of the plants. The new generation of adults emerges in July, and can cause feeding damage to pumpkins and other cucurbit fruit. They will overwinter and then feed on next year’s crop.

19. http://www.ces.ncsu.edu/chatham/ag/SustAg/index.html

20. Green Peach Aphid Myzus persicae (Sulzer), Aphididae, HEMIPTERA BIOLOGY Distribution - The green peach aphid is a cosmopolitan species. Host Plants - The green peach aphid infests a wide range of plants. Some important hosts include cabbage and related cole crops, dandelion, endive, mustard greens, parsley, turnip, tomato, tobacco, potato, spinach, pepper, beet, celery, lettuce, and chard. Damage - Green peach aphids extract sap from plants and excrete a sweet sticky substance known as honeydew. Black sooty mold grows on honeydew and, though not directly harming the plants, may block out sufficient light to reduce yield. Weakened plants become susceptible to secondary disease and may be inoculated with viruses carried by aphids. Among the virus diseases transmitted by green peach aphids are potato leaf roll, potato virus Y, beet mosaic, beet yellows, and lettuce mosaic. Life History - Adults pass the winter on greens and wild hosts such as cabbage, collards, turnip, wild mustard, and dock. Winged forms migrate to other hosts in late spring. During these migratory flights, aphids may spread virus diseases from infected volunteer plants and weeds to healthy crop plants. Movement between host plants continues through summer and fall. In southern states, the aphids are nearly all females. Successive generations of females, mainly wingless, are produced throughout the year. Winged migrants develop whenever overcrowding occurs or food becomes scarce. This type of development (all females, no males or eggs) occur as far north as Tennessee and Maryland. Many generations are produced each year.

21. www.drmcbug.com

22. Aphids

23. Aphids can devastate a winter greens crop Demogarden.org Yellowing Virus transmitted by Aphids on a spinach crop

24. Aphids on tomatoes

25. So, why do aphids like my high tunnel & why are they such a problem?! Aphids like humidity Dense plantings provide plenty of food & cover They reproduce at lower temperatures than predators Poly covering excludes rainfall, so insects aren’t disturbed. Parasitoids can cause a worse problem on leafy greens

26. Best chance at Aphid control Early detection through scouting Insecticidal soap spray (underside of leaves) Neem based products Trap crops ( they seem to like mustard!) Remove infested vegetation Overhead irrigation (is this a plus or a minus?) Lady Beetle release* Lacewings release* *effective only if done in summer! The worst thing you can do is ignore them!

27. Spider mites on strawberries Insecticidal soap Neem-based products Predatory mites

28. Tomato Fruit Worm

29. Stink bug damage on tomatoes

30. Hornworm, dark phase

33. Braconid wasp

34. Grasshoppers

35. Direct intervention Removing affected crops…great chicken feed!

36. Help from predators Lures and traps

37. Lady Beetle

38. Lady Beetle larva

39. Lacewing

40. Slugs can be a major problem. Iron Phosphate can be effective against them. As always, remember to check with your organic certifier before using any pesticide!

41. Beer traps can also be effective – but the thought of wasting all that good beer on slugs just makes me want to cry!

42. Mouse damage to plasticulture strawberries. Very effective control when baited with a large seed or peanut butter. We put out a lot of these. Rodents – especially mice, can cause a lot of damage.

43. Diseases

44. Fungal diseases seem to be the most prevalent Vent your high tunnel early in the day to remove moist air. Vent even when cold out Use tall roll-up sides to move air over tall plants Have adequate spacing between plants to allow for good air flow Scout for disease & rogue out (remove) sickly plants! Be cautious – it’s easy to transmit disease between plants Keep your soil biologically alive through the use of compost

45. Sclerotinia sclerotiorum

46. White mold on tomatoes Sclerotinia on carrots

50. Sclerotinia sclerotiorum

51. Strategies we use: Biofumigation Solarization

52. Biofumigation Certain Brassica cover crops, as well as mustard seed meal, contain high concentrations of isothiocyanates (ITCs) – derived from the degradation of glucosinolates (what gives them the pungent taste). The seed meal is also a significant source of nitrogen and other nutrients. When incorporated into the soil ITCs act as an effective biofumigant, reducing populations of pathogenic fungal species (Sclerotium, Rhizoctonia, and Phytium), nematodes, weeds, and certain insect species. UT/TSU 2003 In addition, the residues add important organic matter for soil building.

53. Why are GSL's Important? Glucosinolates hydrolize to form biocidal compounds These include: Isothiocyanates Oxazolidine-2-thiones Nitriles Epithionitriles Thiocyanates (Halkier and Gershenzon, 2006) Potential to suppress pathogens www.wikimedia.org Slide by Craig Rothrock, University of Arkansas, Fayetteville, AR

54. Influence of brassica cover crops on soil microbial populations gurosiksberryplantation.com Slide by C. Rothrock, U of A, Fayetteville, AR Table 7. Soil populations of select microbial groups for different preplant strawberry treatments, Hope. 1 Strawberry transplant Treatment Bacteria (x 10 7 ) Fungi (x 10 4 ) Actinomycetes (x 10 6 ) Control 1.9 b 6.5 a 10.0 b Brassica 2.9 b 18.5 a 17.0 a Brassica +Solarization 9.8 a 19.4 a 19.5 a Solarization 2.9 b 12.3 a 10.4 b Mustard seed meal 8.0 a 31.0 a 14.4 ab

55. 1) Brassica cover crops may be a valuable and profitable addition to a high tunnel production system because they can suppress soilborne pathogens. 2) Brassica crop selection is less important than rate of application. About 1/2 pound per 1000 square feet for Pacific Gold. 3) Duration of suppression by brassica cover crops may extend beyond biofumigation effects by changes in the soil microflora. Brassica research summary from U of A, Fayetteville, AR ~ Dr. Craig Rothrock

56. Pacific Gold Mustard Grow in place, mow, turn under and seal.

57. To obtain a sample of Pacific Gold or Ida Gold Mustard Please contact Kim Davidson E-mail: [email_address] Phone: (509) 487-0755

58. Solarization Heat Moisture Time

62. Germinating Slcerotia (of 40) Sclerotial Survival by Soil Depth and Treatment Kentucky State University research 0” 2” 4” 6” Depth

63. Sclerotial Survival 2, 4, and 6 Weeks After Treatment Germinating Slcerotia (of 40)

65. After Solarization Shallow tillage (less than 4 inches) Inoculate soil with excellent compost Spray with molasses to feed soil food web!

66. Questions?