IPM Tool for Reducing Thrip Pressure in Onions


Use Of Surround® to Suppress Onion Thrips Can Aid in the Control of Iris Yellow Spot Virus

Onion thrips are the known vector for Iris Yellow Spot Virus, and Surround® can assist in protecting your field from this harmful disease. In studies by researchers and commercial use by onion growers, SURROUND has significantly suppressed thrips. Best results are obtained if SURROUND is applied early before thrips enter the field and followed up with repeat applications to protect new growth.

Hermiston (OR) Agricultural Research and Ext. Center (HAREC) — 2007

SURROUND is OMRI and WSDA-listed for organic pesticide use.

Objective: To evaluate several products for efficacy controlling thrips on dry bulb onions.

Table 1. Thrips Control in Onion, Hermiston, OR — 2007

Treatment Rate No. Apps Post Treatment Count 1 Pre to Post Difference Change (%)
Lannate 2 pt/a 5 18.9 bcd + 0.3 + 1.8
Vydate L 2 qt/a 5 20.3 bcd - 3.7 -15.3
Penncap M 2.0 pt/a 7 14.9 def -12.7 -46.9
Trilogy 2.4 pt/a 18 9.3 fgh -5.3 -36.5
BotaniGard 12 oz/a 9 19.6 bcd - 7.1 -26.6
Warrior 3.0 oz/a 5 12.4 efg - 7.5 -37.1
Radiant 8.0 oz/a 9 6.2 h -5.5 -46.9
SURROUND 20 lb/a 8 7.2 gh -6.9 -48.8
Check     15.5 cde -9.1 -36.9
      *** NS  

1 Thrips/plant; average 5 plants/plot/application.
NS, *** Treatment not significant or significant at P=0.001, respectively.
Means followed by different letters are significantly different at P=0.05 (Duncan’s multiple range test).

Results for Registered Products: 

“The post-treatment counts, averaged across several applications, were similar between the control and all treatments except Radiant, SURROUND and Trilogy, which were significantly lower than the control. When the percent change between pre- and post-application thrips counts is calculated in Table 1, it appears that the best control overall was obtained with SURROUND, Radiant and Penncap M, followed by Warrior, Trilogy and Botanigard. Lannate did not perform well.”

Contact us for a full copy of the HAREC report.


Nine Ways SURROUND May Suppress Insects

  1. Repellency
  2. Impedes egglaying
  3. Reduces feeding 
  4. Impedes grasping
  5. Restricts movement
  6. Camouflages the host — prevents host recognition
  7. Alters behavior
  8. Induces paralysis
  9. Causes mortality


  • SURROUND must be applied prior to thrips entering the field to be effective.
  • Reapply 5–7 days later to ensure thorough coverage and create a “base coating” of protection.
  • Reapply as necessary to maintain coverage of new leaf growth. (In overhead irrigated fields this could require weekly application.)
  • If insect pressure exceeds acceptable thresholds then a knockdown insecticide should be used in combination with SURROUND.
  • Use of SURROUND under high heat conditions also provides protection from heat stress and sunburn.
Pest Pounds / Acre Application Instruction
Thrips 25-50 Suppression only*. Start prior to infestation and apply every 5–7 days throughout infestation. Good coverage down into the plant crown is essential for efficacy.
*If complete control is needed, consider using supplemental controls.


  • Application Tips

    • Apply SURROUND to near-drip. Avoid foliage run-off.
    • Change the direction of travel on alternate applications for best coverage.
    • SURROUND can be tank mixed with most pesticides. When tank-mixing, always add SURROUND to the tank first. A pre-mix tank is suggested for sprayers without mechanical agitation.
  • Aerial Application

    • Use no less than 10 gallons per acre. Best mixing results are achieved when mixing no more than 1 pound per gallon of water.
    • SURROUND may be applied using standard aerial application nozzles.
    • Make applications not more than 10 feet above the top of the largest plant unless a greater height is required for aircraft safety.
    • When spraying at low relative humidity, increase droplet size to compensate for evaporation.