High Tunnels For Vegetable Production

High Tunnels For Vegetable Production- Updates for 2013

The NRCS EQIP Grant Program • Environmental Quality Incentives Program (EQIP) • Seasonal High Tunnel Initiative 2013 – In 2012 NRCS approved 227 applications around KY. – Have 1 year to implement the practice – Only paid when the tunnel is completed

Seasonal High Tunnel Initiative 2013 • Three application deadlines – Early Winter (Jan) and Early Spring (March/April) • Rolling application deadline

• Cannot start purchasing until approved and paperwork signed

Seasonal High Tunnel Initiative 2013 • The maximum size is 5% of 1 acre or 2178 ft2 – Realistically this means a 30 x 72 (2160 ft2) tunnel

• Do not pay for materials and supplies just installation of equipment BUT you can install yourself – $2.37/ft2 so $5,162 for a 30 x 72 tunnel – $2.84/ft2 for historically underserved ($6,286) – Must be a kit from a manufacturer

Seasonal High Tunnel Initiative 2013 • Can be fixed or movable, but have different payment schedule scenarios for each • Supposed to have a 4 year life-span – 4 year plastic not structure – Within the 4 years you are responsible for repairs to tunnel – http://www.nrcs.usda.gov/wps/portal/nrcs/detailf ull/national/programs/?&cid=stelprdb1046250 – Google “Eqip nrcs high tunnel”

Traditional Tunnels

Locating Tunnels • For maximum and most uniform sunlight interception locate tunnels in a N-S orientation if at 40 oN or further south • If above 40oN orient E-W • If multiple bay tunnels then orient N-S • In winter E-W orientation tends to capture more light as sun is low in the horizon, but in spring it is distributed poorly in E-W orientation Hightunnels.org

Locating Tunnels • Wind is also an issue – High winds can destroy tunnels – UPLIFT is important – anchoring tunnels – Consider wind breaks

• Single bay high tunnels oriented perpendicular to prevailing if structure has roll-up sides * • Multi-bay high tunnels should be oriented parallel to prevailing winds

Tunnels and uplift • Proper anchoring of tunnels is essential – Tunnels are basically a giant wing

• An 80 mph wind blowing perpendicular to a 28’ x 100’ tunnel can create an uplift force of 22,000 pounds or 220 lbs per foot • Estimated a 30 x 72 tunnel would then be 15,840 lbs of uplift

Anchoring tunnels • Assuming a maximum of 16,000 lbs of uplift – Subtract tunnel weight (2846 lbs without baseboards, endwalls, etc) – We need to account for about 13,000 lbs of anchoring – 18 bows with 2 anchor points is 36 total contact points – 360 lbs per contact point of resistance or 720 lbs per bow

Anchoring tunnels • Should you concrete bows in? – yes for many cases • “Earth Anchors”- 30” anchor 4” helix rated at 1500 to 2500 lbs vertical pull out • “Telephone pole anchors”- rated at 14,000 lbs uplift

Wind Damage to greenhouses- bows anchored in concrete 70-80 mph

Wind Damage January 2013 ~ 35 mph wind

Wind Damage January 2013

High Tunnel Structural Supports

Lack of additional support

Plastic • 4 mil is considered 1 year plastic • 6 mil is considered 4 year plastic– If it gets too hot >120 for a long period of time that cuts life of the plastic

• Super Strong Woven Poly- 11mil – Can outlast hail even and can be walked on – Costs 30-50% more

• Shade cloth – Is it worth it? Wouldn’t go more than 40%.

Infrared films • IR films have a coating that block long-wave radiation back into tunnel – Typically this long-wave radiation goes right through plastic unless a barrier is present – One side of the plastic is coated with a film that keeps long-wave radiation in • Often coated with a wetting agent to reduce condensation

Infrared films • Bill Roberts (Rutgers Univ.) found that IR films showed a heat savings of up to 35% on clear cold days – Realistically this will be 15-20% over the course of a season (assuming a tightly sealed tunnel) – Only use on the inside layer of plastic

• IR Cost 32’ x 100’ $304 vs. $256 for non IR

Tunnel temperatures • Air-gap between twin walled (2 layer plastic) reduces energy loss by 35-40% • Energy loss due to condensation will be less on a 2 layer tunnel

High Tunnel Temp. • When there is a lot of condensation present, which may evaporate, temperatures in the early morning may be several degrees cooler ambient outdoor temps • Latent heat of vaporization • OVER IRRIGATING

www.ocw.usu.edu

Fog/Condensation in a tunnel

End walls • Double layer polycarbonate has about the same R value as double layer plastic – Single layer plastic has a very poor R value

End Walls

High Tunnel Venting • Should have reasonable side walls for venting • Ridge vents are not a great option – Some complete ridge vents are good, but expensive

• Taller tunnels tend to keep heat up away from plants – HAF-Horizontal air flow fans

HAF Fans

HAF Fans • Help bring hot air down to plant level

Note this piece of plastic

No Crop

3 feet tall tomato

100% 73% 100% 100%

71% 85%

6 foot tall tomato 45% 48% 81%

Wind coefficients higher is more air flow

Tomatoes

Indeterminate or Determinate • The most critical decision – Spacing will impact everything • Disease, yield, working conditions, etc.

– Indeterminate – 4 square feet per plant for trellised plants in a greenhouse* • Based on lack of air movement and disease risk in tunnels move to 5.2 - 6 square feet per plant • 4 foot centers and 15-18 inch spacing

– Determinate –6.75 square feet per plant • 4.5 ft centers with 18” in-row spacing • This will give you 6-7 rows in a 30’ wide tunnel

5.5-6.0 feet

4.5 ft

Note- Indeterminate plants pruned to a central leader with leaves removedfacilitates closer spacing

Determinate tomatoes on 5’ centers

Pruning, training, etc. • Typically prune determinate plants as you would in the field – If you prune them to a central leader you will ruin your yields

• Indeterminate plants prune

Keep leaves/vines off the ground

Cluster Pruning • Cluster pruning – Leave 4 fruit per cluster early and then move to 5 fruit. – Prune off when pea size – Typically do not want more than 18-20 fruit on a plant

• Truss hooks on tomatoes

Leaf Pruning • Keep 18-21 leaves on a plant • Remove leaves up to cluster being harvested • Remove any senescing leaves • If too aggressive can rob fruit of essential nutrients – Depends on aggressiveness of variety too

‘Cobra’

Varieties • Indeterminate – – – –

Big Beef Trust (hydro) Geronimo (hydro) Heirlooms benefit from the tunnel, but results variable

• Determinate – – – – –

Rocky Top Empire BHN 589 (fall) Primo Red Red Deuce

Parthenocarpic Tomatoes • Have done well in Mississippi • Do not need pollinators – Varieties (Territorial Seed) • • • •

Legend Santiam Siletz Oregon Spring

Insect Management with High Tunnel Tomatoes

High-Tunnel Insect Pests Pests with Short-life cycles Fosters the rapid development of resistance to some pesticides Rapid recovery from sprays

Need to manage pests/pesticides For safety For resistance management

Opportunity for biological control Controlled environment Some of our best examples come from enclosed areas

Limited insecticides/miticides Without GH restriction • • • • • • • • • •

Sevin Malathion Orthene Mustang max Pounce Baythroid Asana XL Proaxis Danitol Warrior

Without GH restriction • Admire • Belay • Venom • AgriMek • Distance/Knack • Fulfill • Dipel • Courier • Acramite

Limited insecticides/miticides With GH prohibition • Diazinon • Endosulfan • Assail • Platinum/Actara • Radiant • Proclaim • Beleaf • Rimon • Intrepid

With GH prohibition • Avaunt • Oberon • Movento • Coragen • Portal • Belt/Synapse

2012 Tomato Russet Mite

2012 Tomato Russet Mite

Tomato Russet Mite • • • •

Mistaken for other problems Start at bottom of plant and work upward Leaves dried out- ‘burned up’ Mite move quickly to green leaves – develops fast

1/2013 Jessamine Co.

Tomato Russet Mite • Life cycle of 5 to 6 days • Feed on Solanaceous plants/weeds • Can be moved by people or equipment • Scout for damage and confirm with 20x lens • Treat with Agri-Mek or insecticidal soap (low populations)

2012 Broad Mite

2012 Broad Mites (aka Tropical Mite) Eggs Agri-Mek 0.15 EC for broad and tomato russet mites when they first appear

Broad mites: wide host range found in and around the buds complete life cycle in a week Insecticidal soap inject toxic saliva as they feed hardened, twisted growth, leaves curl downward peppers most susceptible

Spider Mites • Two spotted spider mite • Stippling of leaves and gold flecking of fruit • Produce fine webbing • Favored by hot dry conditions • Tomatoes, beans, melons, cucumbers

Casey Co - 2012

Spider Mites • • • • •

Complete life cycle in 8+ days Females lay 100+ eggs Under leaves, around buds Prefer tender leaves Scouting: – Look for stippling – Look for webbing

Spider Mites • Management – Control weeds in/outside of GH/HT – Monitor weekly with hands lens or tap leaves over white paper – Use horticultural oils or insecticidal soap for light populations – Use Agri-Mek or Acramite for ↑ numbers

Whiteflies • Two types, greenhouse and silverleaf

Whiteflies • • • • •

Undersides of leaves Complete life cycle in less than a month Produce honeydew, stunt plants Can transmit Yellow Leaf Curl Virus Silverleaf can cause plant distortions

Whitefly Management • Monitor weekly – tap plants • Check undersides of leaves with hand lens • Use biocontrol – Encarsia formosa (GHWF)or Eretmocerus eremicus (SLWF) wasps

Whiteflies • Insecticides (IGRs) for nymphs: Knack Courier

• Insecticides for adults and nymphs Admire (foliar or systemic) Portal Venom (foliar or systemic)

Thrips in the High Tunnel • Direct damage to tomato fruit – ‘gold fleck’ • Vectors of Tomato Spotted Wilt Virus

Thrips Life Cycle Two protected stages eggs pupa

Thrips in the High Tunnel • Pierce plant cells • Mainly females – 150 to 300 eggs each – eggs inserted into leaves

• Resting stage in media

• Life cycle complete in 7 to 14 days

Thrips and Virus • Vectors of TSWV – Acquire when immature and transmit primarily as adults – Transmit for life – Acquire from infects crop plants or weeds

• Monitoring – Yellow or blue sticky cards – Tapping buds/flowers over white paper – Avoid bright colored clothing

Thrips Management • Limited insecticides to control thrips for the high tunnel – Baythroid (foliar) – Brigade (foliar) – Agri-Mek (foliar) – Venom

• Second treatment?