Fruit and Vegetable Pest Management

Fruit and Vegetable Pest Management Sheriden Hansen Assistant Professor Horticulture USU Extension Davis County INTEGRATED PEST MANAGEMENT What is integrated pest management (IPM)? A philosophy of pest control founded on ecological principles Involves using SEVERAL control tactics based on: Knowledge of the CROP, PESTS, and associated NATURAL ENEMIES Goal is to AVOID CROP LOSS and MINIMIZE harmful effects on the environment. INTEGRATED PEST MANAGEMENT More tolerant approach to pest control than traditional insect-based programs. Conserves natural enemies Does not eliminate all of the pests Some damage (usually to foliage) is tolerated, less tolerance on fruit BENEFITS OF IPM Greater survival of natural enemies Slower development of resistance Less pest resurgence Fewer outbreaks of secondary pests Less negative impact on the environment Safer for gardeners and those eating produce HISTORY OF IPM Synthetic pesticide era launched after WWII HISTORY OF IPM Broad spectrum pesticides were the answer to most pest problems In 1936 there were 30 registered pesticides By 1972 there were more than 900 Sprays were being used on a routine, preventative basis whether they were needed or not Chemicals were EFFECTIVE, EASY TO USE, and INEXPENSIVE 1

RESISTANCE Insects began to develop RESISTANCE to insecticides RESISTANCE is a significant decrease in sensitivity to a pesticide A population is made up of individuals that vary in genetic make-up. Dogs come in many variations such as lab, border collie, husky, pug but all are dogs RESISTANCE Resistance is the ability of one of the variants in the population to survive pesticide exposure All of the dogs are susceptible to the chemical, except the Labrador The Labrador then has puppies that are also resistant Now you can t control the Labradors RESISTANCE RESISTANCE In the population of squash bugs that you have on your squash plant, one or two may be unaffected by the application of chemicals. Surviving members are referred to as RESISTANT to the pesticide Resistance is the NATURAL ABILITY of a variation of the organism to survive exposure to a pesticide that would normally kill an individual of that species. This occurs with INSECTS, WEEDS, FUNGI, and other pests. HOW DOES RESISTANCE OCCUR? The resistant pest survives the repeated exposure and reproduces, creating more resistant pests The population of this organism can become dominated with this resistant variation The pesticide is no longer effective BUT If resistance is MANAGED from the beginning using IPM, pesticides remain effective and useful 2

BACK TO OUR STORY Pests that had been naturally kept in check before the pesticide era were now becoming pests WHY? Natural enemies were being eliminated with the application of chemicals Populations of pests were RESURGING killing natural enemies, leads to an increase in the target population CHEMICAL CONTROL CYCLE Growers then applied MORE TOXIC products to control SECONDARY PEST outbreaks Some pesticides promote pest activity Carbaryl and imidacloprid are known to INCREASE spider mite reproduction Growers were trapped in a cycle of using more and more chemicals to treat a single pest problem CONVENTIONAL PEST MANAGEMENT This reliance solely on chemical control is called Conventional Pest Management Annual sprays are done based on a calendar date only There is no thought about the chemicals being used Lacks a system-wide perspective MITE CONTROL LED TO IPM In the 1950 s and 1960 s mite populations were out of control in apple orchards Quickly developed resistance to miticides If predatory mite populations were allowed to rise at the right time, they controlled the spider mites SUCCESS OF INTEGRATED MITE CONTROL IPM DEFINITION Integrated mite control became so successful that orchardists in the Pacific Northwest have not had to apply miticides since the 1960 s IPM is a SUSTAINABLE APPROACH to managing pests by COMBINING biological, cultural, physical, and chemical tools in a way that MINIMIZES economic, health and environmental risks 3

KNOWLEDGE Of the pest The pest biology The host plant COMPONENTS OF IPM The pest? Mite The pest biology? Overwinter under leaf bud scales Emerge in the spring Many generations over the summer Will reduce apple size and decrease photosynthesis The plant? Apple KNOWLEDGE What to do? Encourage predatory mites Application of dormant oil before leaf bud break Can combine with carbaryl Application of sulfur (not with dormant oil) KNOWLEDGE The Pest? Coryneum Blight The pest biology? Fungus Overwinters in infected buds and cankers Wet springs moisture on leaves and fruit The plant? Stone fruits What to do? Prune out infections Application of a fungicide at shuck fall (one time!) KNOWLEDGE HOW DO I KNOW WHAT I AM DEALING WITH? Unsure? Every state has a plant pest diagnostic laboratory In Utah: Utah Plant Pest Diagnostic Lab (UPPDL) on campus in Logan www.utahpests.usu.edu/uppdl Call your county extension office and ask for help Davis 435-919-1336 (Diagnostic clinic: Thursdays 9-noon, Mid-April to Oct.) Email: usudavishotline@gmail.com Weber 801-399-8200 Box Elder 435-695-2542 Salt Lake 385-468-4828 (Diagnostic clinic hotline) COMPONENTS OF IPM KNOWLEDGE Of the pest The pest biology The host plant Monitoring for insect or disease occurrence Visual observation Trapping Determining a Biofix Degree day model for estimating insect activity and treatment 4

WHY MONITOR? Provides early warning of potential pest problems Determines which life stage is active for both pathogens and insects Helps determine if you should treat Determine if your management strategies are working SPRING TO SUMMER Once per week LATE SUMMER Every other week WHEN TO MONITOR? WHAT DO I NEED TO MONITOR? HOW DO I MONITOR? Hand lens is helpful Helps see tiny insects (like mites) Helps see signs of disease 10x 30x Search online for Jeweler s Loupe or Hand Lens Visual observations Check under leaves, at the base of plants, look for small clusters of eggs or insects Look for signs of disease, fuzzy growth, wilting plant parts, discolorations, oozing, etc. Can remove eggs and insects as you see them Brown Marmorated Stink Bugs Hatching HOW DO I MONITOR? Traps Sticky traps (many colors) Many contain attractants or pheromones TRAPPING 5

Sticky Traps Can be used in orchards, gardens, greenhouses Monitor for first arrival of certain insects Helps you know the severity of the problem TRAPPING Pheromone Baited Traps Pheromones are sex-hormones Secreted by one sex (usually the female) to attract to other Insects fly in a zig-zag pattern following pheromones TRAPPING Western Cherry Fruit Fly Apple Maggot Walnut Husk Fly PHEROMONE TRAPS Why use them? To monitor the population over time To get BIOFIX (biological fix) Biofix is the FIRST DATE at which moths consistently fly, or when more than two moths have been caught in a trap over two consecutive nights. DEGREE DAY MODEL What are degree days? Measurement of heat units over time Insect life cycles are dependent on temperature Specific range for specific insects Helps you pinpoint right stage/time to treat Codling Moth Greater Peach Tree Borer Peach Twig Borer USU Monitors degree days for a number of insects You can get alerts on when to spray and treat based on this model: DEGREE DAY MODEL KNOWING AT WHAT LEVEL TO TREAT Threshold Levels How much damage are you willing to tolerate? Determines when you treat Utah TRAPs app for android or ios Website for pest advisories: https://pestadvisories.usu.edu/ 6

KNOWING AT WHAT LEVEL TO TREAT USING AN INTEGRATED APPROACH Threshold for spider mites is 10 mites per leaf. Cultural control Sanitation Encourage natural biological control Select least-toxic pesticide option first TIME TO TREAT! Proper water management Mulches or groundcovers Optimal fertilization Using resistant varieties Good soil management CULTURAL CONTROL Clean field equipment Sanitize pruners between cuts (fireblight) Removing diseased/damaged tissue SANITATION Quick removal of infested trees and plants Early blight Tobacco mosaic virus Tomato spotted wilt virus (TSWV) BIOLOGICAL CONTROL BIOLOGICAL CONTROL Predators: seek out and eat multiple prey specimens Parasitoids: specialized insects that deposit egg(s) inside a host, eggs hatch and larva(e) develop, eventually killing the host 7

BIOLOGICAL CONTROL Pathogens: nematodes, viruses, bacteria, fungi, protozoans BIOLOGICAL CONTROL DEVELOP HABITAT Develop a habitat to promote beneficial insects Make it native, lowmaintenance, and drought tolerant USE AN INTEGRATED APPROACH - PESTICIDES Reduced Risk pesticides Materials that the EPA has determined to be safer for humans and the environment Some are made from plants and plant derivatives Others are just considered softer https://www.epa.gov/pesticide-registration/reduced-risk-and-organophosphatealternative-decisions-conventional Biopesticides Made from micro-organisms or from their metabolites Avoid broad-spectrum pesticides USE AN INTEGRATED APPROACH - PESTICIDES Application times: Dormant Delayed dormant (starting at bud swell) Spring to summer cover sprays Keep a record of what you applied When you applied it Rate that it was applied RECORD-KEEPING 8

INSECT EXAMPLES - APPLE & PEAR Primary pest of apple and pear Damage occurs when larvae burrow into fruit to feed on seeds Can potentially infest 100% of the fruit on a tree or in an orchard CODLING MOTH CODLING MOTH CODLING MOTH CODLING MOTH Overwinter in silken cocoons under loose tree bark 7 to 30 day development period depending on temperature Three generations per year in Utah MONITOR!!! Moths fly at night CODLING MOTH MANAGEMENT Cultural controls: Thin fruit to one apple/cluster Remove unmanaged trees Clean and remove all unharvested or dropped fruit all season (sanitation) Monitor with traps (alerts from app) Insecticides (horticultural oils, Bt, spinosad, see fact sheet) https://digitalcommons.usu.edu/cgi/viewcontent.cgi?referer=https://www.bing.com/&httpsredir= 1&article=1879&context=extension_curall 9

SAN JOSE SCALE Fruit tree pest Severe infestations can kill limbs, deform fruit, reduce yields, and kill trees Can be difficult to control, timing is key Delayed dormant period is when you would apply chemical control SAN JOSE SCALE SAN JOSE SCALE Armored scale hard bodies Phase called crawler phase where they are soft bodied Crawlers resemble spider mites but have antennae Crawlers congregate at new growth SAN JOSE SCALE MANAGEMENT Scout for infestations during dormancy (pruning is ideal time) Males can be monitored with pheromone traps (females don t fly) Traps should be placed at PINK stage of apple bloom OR wrap double sided sticky tape around trunk to detect crawlers Traps app for biofix dates and alerts for crawler emergence and spray dates SAN JOSE SCALE MANAGEMENT Chemical control at crawler stage Horticultural oil combined with an insecticide (delayed dormant) For list of chemicals see fact sheet: http://extension.usu.edu/files/publications/publi cation/san-jose-scale'97.pdf Biological control Keep populations of natural enemies high Lady beetles and parasitoids Supplement with chemical control SAN JOSE SCALE MANAGEMENT Pruning Good pruning practices reduce scale problems Prune out infested limbs and watersprouts Open canopy to allow for good spray coverage in the top of canopy 10

INSECT EXAMPLES - VEGETABLES APHIDS Many different species (over 500 in Utah) Attack multiple vegetables and fruits (some host specific) Soft bodied, pear-shaped Multiple colors (green, red, purple, yellow, black) Can be winged or wingless APHIDS Suck the phloem out of plants Mouthpiece called a proboscis (like a straw) Can reduce crop yields Can cause leaf twisting, rolling, galls or unsightly cottony masses Exude honeydew which can encourage fungal growth APHIDS Do NOT need to mate to reproduce Give birth to live young in the summer Lay eggs in the fall that overwinter APHID MANAGEMENT SQUASH BUGS Tolerate certain levels of insects Encourage beneficial insects Wash off with a strong stream of water Apply insecticidal soaps to nymphs and adults Apply systemic insecticide (neonicitinoid) in the spring Apply a cover spray (pyrethroids) when aphids are present https://utahpests.usu.edu/ipm /ornamental-pestguide/arthropods/aphidsadelgids/other-aphids Pest of squash and pumpkin Plant damage includes: Necrosis (tissue death) Scarred fruits, sunken areas Sudden Wilt Piercing, sucking mouthparts Can transmit diseases (vector) Curcurbit Yellow Vine Disease (CYVD) 11

SQUASH BUGS Prone to developing resistance to insecticides Preventative, cultural, and mechanical controls should be the first line of defense One egg cluster per plant is the treatment threshold SQUASH BUG One generation per year Spend the winter as unmated adults in protected sites Under plant debris Compost piles Around building foundations A female can lay up to 250 eggs New, summer generation of adults appears in June/July Eggs are small, long, oval shaped Can be yellow brown to brick red in color Laid in clusters on the underside of leaves Spring to late summer Hatch in 10-14 days SQUASH BUGS SQUASH BUG MANAGEMENT Cultural Practices Maintain healthy plants Appropriate site selection Soil preparation, fertilization Irrigation Sanitation Minimize populations of overwintering adults Resistant Varieties See fact sheet https://extension.usu.edu/files/publica tions/factsheet/ent-120-08.pdf SQUASH BUG MANAGEMENT Trap Crops and Traps Includes squash varieties that are attractive to overwintering squash bugs Treat trap crops Trap insects with wooden boards, shingles, heavy cardboard Turn over and kill bugs in the mornings Crop Rotation Row Covers Floating row covers or fabrics SQUASH BUG MANAGEMENT Mechanical Destruction Hand picking Squashing eggs Promoting beneficial insects Parasitoid wasps Insecticides Should NOT be used as first management Combine with other strategies See fact sheet https://extension.usu.edu/files/publicati ons/factsheet/ent-120-08.pdf 12

DISEASES FIRE BLIGHT Bacterial disease of rosaceous plants Erwinia amylovora Most serious on apples and pears Spread by: Insects Splashing water Contaminated tools Wind Must have an opening in the plant Blossom, fresh pruning cut, open wound FIRE BLIGHT Signs and Symptoms Scorched leaves, blossoms, and shoot tips Wilting shepherd hooking Tissue turns black Cankers Oozing of an amber liquid (infectious) Progresses quickly and can cause whole plant death FIRE BLIGHT MANAGEMENT Practices that promote excessive new growth should be avoided Be careful with fertilization of fruit trees Frequent assessment of trees in the spring (1-2 x/week) Immediate removal of any blighted blossoms or twigs Prune any infections 8-12 inches below the infection FIRE BLIGHT MANAGEMENT Dormant pruning Look for cankers and prune out Remove suckers at base of the tree Sanitize pruners Between cuts 10% bleach solution Remove disease hosts near trees Cotoneaster, hawthorn, crabapple, pyracantha FIRE BLIGHT MANAGEMENT Do not wet tree canopy Adjust sprinklers Avoid excessive watering to reduce humidity Plant less susceptible varieties Geneva rootstocks for apples are resistant See fact sheet for more resistant varieties FIRE BLIGHT MANAGEMENT Delayed dormant Copper-plus-oil sprays Silver tip to green tip Bordeaux mixture See fact sheet: https://digitalcommons.usu.edu/cgi/viewconte nt.cgi?referer=https://www.bing.com/&httpsre dir=1&article=1900&context=extension_curall Agricultural antibiotics For commercial operations Timing of application is critical Get alerts with TRAPS app 13

IN CONCLUSION IPM promotes BEST practices Combines cultural, mechanical, biological, sanitation, and pesticide application practices to provide the best treatment Protects beneficial insects Safer for humans Pesticides are used in combination with other practices or as a last resort A WORD OF CAUTION NEVER USE A CHEMICAL PESTICIDE IN A MANNER THAT IS INCONSISTENT WITH ITS LABELED INSTRUCTIONS, IT IS A VIOLATION OF FEDERAL LAW. THE LABEL IS THE LAW! QUESTIONS? Can bees fly in the rain? NOT WITHOUT THEIR LITTLE YELLOW JACKETS!!! 14