Fortex Beans

Asked April 2, 2014, 1:21 PM EDT

My fortex beans were planted in a greenhouse on Feb 25. One row, 5' long. Half of the plants are showing signs of some type of stress. Pics attached. Leaves look blistered. Stunted growth. Peas growing 2 feet away are doing great. I've been very careful not to overwater. What is happening?

Polk County Oregon greenhouse vegetables horticulture

1 Response

I think this is it have a look under the leaves

PNW Insect Management Handbook
Printed page URL: pnwhandbooks.org/insect/node/1118
Bean, snap-Spider mite
Photo of insect
Tetranychus unknown
Includes Pacific spider mite (Tetranychus pacificus)
Strawberry spider mite (Tetranychus turkestani)
Twospotted spider mite (Tetranychus urticae)
Pest description, crop damage and life history See: Common Pests of Vegetable Crops Pest monitoring There is no precise survey technique for evaluating spider mite infestations in snap beans. Infestations usually begin on the lower portions of the plants and move upward as mite numbers increase. Evaluating spider mite infestations is most efficient if older, lower leaves are selected at random and inspected for stippling on the upper surface and webbing, mites, and feeding scars on the lower leaf surface. Management-biological control Spider mite populations may be held at very low levels by a number of insect and mite predators, particularly early in the year. Thrips feed on spider mite eggs; they are effective early year predators. Predatory mites are used to control spider mites in strawberries and in greenhouses. The impact of releasing commercially produced predatory mites in snap beans is untested. Spider mites provide an important food source for predators such as minute pirate and bigeyed bugs. Management-cultural control Minimizing early year insecticide applications, which tend to reduce populations of beneficial insects, will reduce spider mite outbreaks. Spider mite problems can be reduced by keeping fields and field margins clean of weed hosts. Spider mite populations increase more rapidly in areas where dust deposits are heavy. Reducing dust may reduce the spider mite problem. Excessive nitrogen fertilization may contribute to population buildup. Management-chemical control: HOME USE
  • azadirachtin (neem oil)-Some formulations are OMRI-listed for organic use.
  • bifenthrin
  • insecticidal soap-Complete coverage of upper and lower leaf surfaces important. More than one application may be required. Some formulations are OMRI-listed for organic use.
  • plant essential oils (such as cottonseed, clove and garlic oils)-Some formulations are OMRI-listed for organic use.
  • sulfur-Some formulations are OMRI-listed for organic use.
Management-chemical control: COMMERCIAL USE
  • bifenthrin (Capture, Sniper) at 0.08 to 0.1 lb ai/a. PHI 3 days. REI 12 hr. Do not exceed 0.2 lb ai/a per year. Do not apply within 25 ft of an aquatic habitat, 150 ft if applied by air. Toxic to fish.
  • borate complex (Prev-Am) applied as a 0.4% to 0.8% solution. Spray to complete coverage. PHI (see label). REI 12 hr. Retreatment interval 4 days. OMRI-listed for organic use.
  • chlorantraniliprole/lambda-cyhalothrin (Besiege) at 9 fl oz product/a. PHI 7 days for edible podded and succulent shelled legumes, 21 days for dried shelled legumes. REI 24 hr. Minimum of 5 days between applications. Do not exceed a total of 31.0 fl oz of Besiege or 0.12 lb ai of lambda-cyhalothrin containing products or 0.2 lb ai of chlorantraniliprole per acre per growing season. Do not graze livestock or harvest vines for forage or hay.
  • dimethoate at 0.5 lb ai/a. PHI 0 days. REI 48 hr. Do not feed vines or hay.
  • disulfoton (Di-Syston) at 1.0 lb ai/a. PHI 60 days. REI 48 to 72 hr. Use at planting time only. Do not feed vines or hay. Washington and Oregon only.
  • naled (Dibrom) at 0.94 lb ai/a. PHI 1 day. REI (see label). Do not apply within 25 ft of an aquatic habitat, 150 ft if applied by air.
  • phorate (Thimet) at 1.5 lb ai/a. PHI 60 days for forage. REI 48 to 72 hr. At planting time only. Do not graze or feed to livestock. Extremely toxic to fish and wildlife.
  • sulfur at 2.25 to 6.75 lb ai/a. REI 25 hr. PHI 0 days. Some formulations are OMRI-listed for organic use.
Hollingsworth, C.S. (Ed.). 2014. Pacific Northwest Insect Management Handbook.
© Oregon State University.

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