Production - IPM Pest Advisories

Pest and Production Update, Utah State University Extension, May 31, 2016ProductionAlso included in the guide are numerous tables with specificplanting and pest management recommendations and colorimages of pests, monitoring methods, and common naturalenemies.2016 Utah Vegetable Production andPest Management GuideThe 2016 Utah Vegetable Production and Pest ManagementGuide is now available online at T-veg-guide-2016.pdf or as a printedbound book (for commercial producers, limited in number).Funding for this publication was provided by the USUExtension Grants Program and Utah Specialty Crop BlockGrant Program administered by the Utah Department ofAgriculture and Food (UDAF). Authors of this guide include ateam of USU Extension agents and specialists.Farm Field Day Coming Up!The guide contains helpful information on: general vegetable production practices; soils, nutrition, and water management; integrated pest management (IPM) practices; pesticide information; and in-depth crop chapters on: brassicas (broccoli, Brussels sprouts, cabbage,cauliflower, kale, kohlrabi), cucurbits (cucumber, pumpkin, squash), melons, onions, potatoes, tomatoes, pepper, and eggplant, and sweet corn.On June 28th 2016, commercial growers are invited to joinUSU fruit and vegetable specialists to learn about the latestresearch results for commercial orchards and vegetable cropsin northern Utah.The tour will begin at 9:30 am at the Kaysville EducationCenter building on Sego Lily Dr. just off of 50 West inKaysville. Pre-registration is required (and more informationcan be found) at http://usukaysvillefieldday2016.eventbrite.com/?s 66625520.Tree Fruit ResearchHighlights:Irrigation; apple and peachrootstocks; high density tartcherries; fire blight and cherryfruit fly control; codling mothbiofix-setting; invasive pests; andorganic peach systems.

p. 2Production / DiseasesVegetable IPM Advisory 05-31-2016Identification and Damage:Organic asparagus; organicvegetable cover crop rotations;mulches, staking, and shadingfor tomato and pepper; onionnitrogen and crop rotationmanagement; introduction of theupdated 2016 Utah VegetableProduction and Pest ManagementGuide; and biochar application toenhance production and diseasesuppression.Many weeds, landscape plants, and native plants can beinfected with TSWV. Symptoms vary among different hostsbut commonly occur as stunted growth, which is generallymore severe in young infected plants. Other symptomsinclude: chlorotic or necrotic rings on leaves, and fruits;necrosis of plant foliage; discolored seeds; and reducedquantity and quality of plant products.Don Ferrin, Louisiana State UniversityAgricultural Center, Bugwood.orgVegetable Research Highlights:DiseasesTomato Spotted Wilt Virus (TSWV)Transmission:A healthy tomato plant (left and right) next to a tomato plant infected withTSWV (middle); note the stunted growth and necrotic/chlorotic (brown/yellow) leaves of the infected plant.Western flower thrips larva (top) and onion thrips larva (bottom) can carryTSWV and transmit the virus to susceptible plant hosts as adults.Edward Sikora, AuburnUniversity, Bugwood.orgDavid B. Langston, University ofGeorgia, Bugwood.orgWilliam M. Brown Jr., Bugwood.orgTSWV leaf necrosis on tomato leaves (left and right); note both the necrotic(brown) and chlorotic (yellow) rings and spots (left).Chlorotic/yellow (left) and necrotic/brown (right) rings and spots on tomatofruit infected with TSWV.Gerald Holmes, California PolytechnicState University at San Luis Obispo,Bugwood.orgWhitney Cranshaw, ColoradoState University, Bugwood.orgWhitney Cranshaw, Colorado StateUniversity, Bugwood.orgIn Utah, TSWV is transmitted by western flower thripsand onion thrips. Thrips must acquire the virus when theyare young (larvae) in order to transmit the virus as adults.Because adults do not transfer the virus to their progeny andthrips nymphs cannot fly, adults need to lay eggs on infectedplants for the virus to be transferred to the young thrips.Paul Bachi, University of KentuckyResearch and Education Center,Bugwood.orgThis month, cases of tomato spotted wilt virus (TSWV) havebeen reported in Emery and Sevier counties. TSWV is a majorpathogen of tomatoes, peppers, peanuts, and tobacco.Necrotic symptoms of TSWV on the stemtissue of a tomato host.

Vegetable IPM Advisory 05-31-2016Management:Infected plants need to be removed. Control thrips (ifpresent) and weeds to prevent TSWV from spreading within atomato field or garden.Diseases / Insectsp. 3 seedcorn maggot host plants asparagus, cabbage,turnip, radish, onion, beet, spinach, potato, sproutingcorn seeds, beans, peas, and alfalfaFor more information on managing Western FlowerThrips and Onion Thrips, search the internet for (orclick the text below):USU Western Flower ThripsUSU Onion Flower ThripsFor a more extensive list of ornamental and weedhosts of TSWV, search the internet for (or click thetext below):Cabbage maggot damage on a young cabbage plant; note the chlorotic(yellowing) leaves.Cornell Vegetable MD Tomato Spotted Wilt VirusFor more information on TSWV,search the internet for:Utah Pests Tomato Diseases to Watch for in 2012APS Net Tomato Spotted Wilt VirusUC Davis IPM Tomato Spotted Wilt VirusInsectsOnion maggot levels of injury on green onion hosts.Watch for Root and Seed MaggotsWith the recent cool, wet weather in many areas of Utah,conditions are favorable for root and seed maggots, namelycabbage maggots, onion maggots, and seedcorn maggots.Damage:Maggots cause damage by burrowing into the seeds and rootsof many vegetable crops. They can destroy the seed germ andcause rot in plant tissues. Seeds attacked by maggots may notemerge, causing reduced plant stands. Maggot damaged rootscause wilting, reduced growth, lighter green plant parts, andpotentially plant death. Later maggot larvae that feed on hostplants can provide openings for other diseases, reducing cropquality and storability.Susceptible plants: cabbage maggot host plants cauliflower, Brusselssprouts, radish, cabbage, broccoli, collards, kohlrabi,turnip, cress, beet, and celery onion maggot host plants onion, beans, alfalfa,strawberry, wheatCorn seed damage from a seedcorn maggot; note that the maggot is stillpresent inside of the seed.Management:Any practice that speeds up germination, plant emergence,and overall plant health will help reduce crop losses frommaggots. When possible, wait to plant susceptible plants untilsoils warm up to 70 F (see link below for "estimating soiltemperature"). Use row covers early in the season to preventflies from laying their eggs on the soil near the base of theplants.

Insectsp. 4For more information on the description, life history,damage, monitoring, and management of root andseed maggots, see the new 2016 Vegetable ProductionGuide here: T-veg-guide-2016.pdfRoot and Seed Maggot References in the 2016Vegetable Guide:Brassica Chapter Cabbage maggot, pg. 40Vegetable IPM Advisory 05-31-2016Life History:Flea beetles overwinter as adults and typically emerge to feedon weeds and other available plants in mid-to late spring. Afterseveral weeks of feeding, adults will lay eggs in the soil at thebase of host plants. Larvae hatch from the eggs and beginfeeding on the roots of the host plant. The larval stage lastsfor about a month, after which, larvae pupate and emerge asthe second generation of adults in late spring to mid-summer.Depending on the species of flea beetle, a third generationmay occur before winter. Seedcorn maggot, pg. 41 Pesticide tables on pg. 43-46Onion Chapter Onion maggot, pg. 99 Seedcorn maggot, pg. 99-100 Pesticide tables on pg. 106, 109Sweet Corn Chapter Seedcorn maggot, pg. 177-178 Pesticide tables pg. 192-194For more information, search the internet for:MSJ Estimating Soil TemperatureVirginia Tech Cabbage and Seedcorn MaggotPurdue University Seedcorn MaggotFlea beetle damage occurs as shallow pits and small, rounded, irregular holesin the foliage, cotyledons, and stems of host plants.What can you do before resorting to chemical control? Usemonitoring, cultural, physical, and biological control practices.Monitoring:Flea BeatlesDescription:Flea beetles are active leaf-feeders that populate many Utahgardens and crop fields. Their leaf-feeding habits can quicklydefoliate and kill plants when high populations are present.Susceptible plants include: eggplant, cole crops (e.g. broccoli,cauliflower, cabbage, kale), and seedlings of tomatoes, potatoes,peppers, turnips, radishes, and corn. Check seedlings, especially in the spring, at least two timesa week until 4 to 5 true leaves have formed. For seedlings,consider treatment if 1-5 flea beetles per plant arefound. For mature plants, consider treatment whenpopulations are high on more susceptible plants such asleafy greens and ornamentals. Use yellow or white sticky traps to detect the presenceand quantity of flea beetles. Place sticky traps aroundsusceptible host plants just after planting but beforeseedlings emerge. Use these until plants are wellestablished or until harvest. Replace traps whenadhesive is covered with insects or is no longer sticky.Cultural/Physical Controls:Flea beetles have metallic bodies and enlarged hind legs (left) that allow themto jump when disturbed. Some flea beetles are striped (right). Avoid peak activity by planting early or late. Promoteearly maturity (to avoid flea beetle flight peaks) andincrease plant tolerance by planting under protectivecovers and/or into soil-warming mulches. –or– Plantin late May to avoid early-season larval injury andheavy feeding by overwintering adults. Late springplantings also allow soil temperatures to warm andprovide better conditions for plants to outgrow andcompensate for flea beetle injury.