IPM Updates in Almonds

Transcription

1 IPM Updates in Almonds Emily J. Symmes, Sacramento Valley Area IPM Advisor University of California Cooperative Extension & Statewide IPM Program (530) sacvalleyorchards.com February 7 th, 2017

2 Webspinning Spider Mites in Almonds Twospotted spider mite Pacific spider mite Strawberry spider mite

3 Other mite pests you might encounter Brown almond mite European red mite Peach silver mite Rarely cause economic damage Low to moderate #s beneficial - Provide predators an alternate food source

4 Webspinning Spider Mites in Almonds Three species very similar in appearance - All have characteristic dark spots on back Same basic biology, control Overwinter as adult females (reddish) Bark, soil, ground litter, weeds Dormant/delayed-dormant treatments ineffective In-season, color ranges from yellow to green to almost entirely black Round eggs

5 Webspinning Spider Mites in Almonds March April migrate from OW sites into lower areas of trees Reproduce quickly in warm weather June September - Can develop in 7 days - Typically 8-10 generations/year - Females lay eggs each

6 Spider mites Risk Factors Tree stress - Water - Nutrient deficiencies/excesses (N) - Heavy crop load Dust Pesticide use - Disrupts natural enemies Healthy trees can tolerate moderate populations without damage

7 Spider mites Keys to an IPM Strategy Management through biological control supplemented by pesticides - Not management through pesticides supplemented by biocontrol Biological control (it s free!) - Don t starve em, don t kill em Cultural controls - Healthy trees - Irrigation management - Dust reduction

8 Spider mites Keys to an IPM Strategy Monitor & treat when thresholds reached to prevent damage Avoid prophylactic treatments save treatments for when you need them! Avoid broad spectrum, other pesticides that disrupt natural enemies - If unavoidable, KNOW potential impacts on mites & plan accordingly Allow subeconomic populations - Food for natural enemies to build up populations

9 Spider mites Natural Enemies Predatory mites - Multiple species - Similar size to spider mites - More oblong, shiny, no spots/hairs - Cream to amber red in color - Move around faster - Oblong eggs

10 Spider mites Natural Enemies Sixspotted thrips Particularly susceptible to pyrethroids, spinosyns, abamectin

11 Spider mites Natural Enemies Minute pirate bug Spider mite destroyer Green lacewing larva

12 Spider mites Monitoring Prior to mid-june, focus on hot spots - Edges, tree crotches - Early warning follow up with whole orchard sample if threshold reached in hot spot Spot treatments may be possible Random leaves around tree inner & outer canopy Sequential sample start with 75 leaves from 5 trees - Max. 300 leaves (20 trees) Presence/absence (+/-) for mites & predators

13 Spider mites Thresholds Based on pests AND natural enemies General rule of thumb if proportion of leaves with spider mites and predators appr. 1:1, let the natural enemies do the work Use monitoring form or decision tree

14 Spider mites Monitoring Form

15 Spider mites Decision Tree

16 Spider mites Treatments Choose materials with least impact on natural enemies Choose materials based on natural enemies present Proper application get your $$ worth! - Calibration - Water rates - 1% 415 oil (2% alone) - Good coverage - Watch speed (2 mph max) - Careful of surfactants - Time of day/temperature Rotate modes of action mitigate resistance development

17 Miticide Impacts on Natural Enemies Common name (example trade name IRAC #) Predatory Mites General Predators abamectin (Agri-Mek) 6 H H Long acequinocyl (Kanemite) 20B L bifenazate (Acramite) 20D L L Short clofentezine (Apollo) 10A L L Short etoxazole (Zeal) 10B H Very long fenbutatin oxide (Vendex) 12B L L Short fenpyroximate (Fujimite) 21A H L Short Duration of impact to natural enemies hexythiazox (Onager) 10A L L Short/Moderate narrow range oil L L Short propargite (Omite) 12C M L Short pyridaben/sulfur (Desperado) 21A/unk H spirodiclofen (Envidor) 23 L

18 Insecticide Impacts on Natural Enemies Common name (example trade name IRAC #) Predatory Mites General Predators Bacilllus thuringiensis ssp. kurstaki 11A L L Short bifenthrin (Brigade) 3A H H Long buprofezin (Centaur) 16 L H Long chlorantraniliprole (Altacor) 28 L L Short chlorpyrifos (Lorsban) 1B M H Moderate cyfluthrin (Baythroid) 3A H H Moderate diflubenzuron (Dimilin) 15 L H esfenvalerate (Asana) 3A H M Moderate fenpropathrin (Danitol) 3A H H lambda-cyhalothrin (Warrior) 3A H H Moderate methidathion (Supracide) 1B H H Moderate/Long methoxyfenozide (Intrepid) 18 L L None/Short permethrin (Pounce) 3A H H Long petroleum oils L L None/Short phosmet (Imidan) 1B H H Moderate/Long pyriproxifen (Seize) L H Long spinetoram (Delegate) 5 L/H M Moderate spinosad (Entrust, Success) 5 L/H M Short/Moderate Duration of impact to natural enemies sulfur L/H L/M Short

19 Honey Bee Safety During Bloom

20 What NEEDS to be sprayed during bloom? Insecticides Alternate and equally effective timing for Lep pests (PTB, leafrollers) Dormant, delayed-dormant, spring, hull split Nutrients Alternate and equally effective timings Fall & spring (post-bloom) Fungicides

21 Communication is the Key

22 General Guidelines Always provide adequate clean water for bees Cover or remove water sources prior to any application Allows bees to spend more time pollinating crop less time searching for water Bees will forage up to 5 miles from hive seeking sources of food and water if not available in the orchard - Increases potential for contacting harmful materials

23 Never spray hives directly General Guidelines Turn off spray rig nozzles near hives Avoid hitting flying bees with any application - Weight of any droplet on wings impacts ability to fly Avoid application or drift onto blooming weeds in or adjacent to orchard Avoid applying systemic pesticides or those with residual toxicities prior to bloom

24 General Guidelines Agree on proper hive removal timing - Remove when 90% of flowers on latest blooming cultivar are at petal fall Continue communicating with neighbors that may still have bees foraging nearby

25 Considering treatments during bloom? Explore alternate timing options Dormant Delayed-dormant Post-bloom Be aware of presence of bees in the areas outside of your orchard Use IPM only apply as needed based on sound monitoring, thresholds, decision support guidelines Know impacts of all materials on pollinators (and other non-target organisms)

26 Insecticide Guidelines Do not spray insecticides at bloom One exception Bacillus thuringiensis (Bt) Remember that most labels only note honey bee cautionary statements based on acute toxicity to adult bees, not impacts on developing brood Newly emerged, wingless bees pulled from the combs by other bees Empty cells of brood that failed in their attempts to emerge as adults

27 Fungicide Guidelines Disease protection during bloom critical is Fungicide applications need to be made at certain times - Apply fungicides in the late afternoon or evening when bees and pollen are not present - Ensure that fungicides have time to dry before new flowers open, anthers shed pollen, and bees begin foraging the following day - Spraying flowers at bloom when pollen is present may limit pollen germination

28 Fungicide Guidelines Addition of adjuvants may be detrimental proceed with caution Avoid tank mixes synergistic impacts not well understood Bee kill resulting from spraying a tank mix of an herbicide, spray oil, and foliar nutrient

29 Excessive numbers of dead or dying adult honey bees in front of hives Dead newly-emerged workers or brood at the hive entrance Lack of foraging bees on a normally attractive blooming crop Adult bees exhibiting stupefaction; paralysis; jerky, wobbly, or rapid movements; spinning on the back Disorientation and reduced efficiency of foraging bees Immobile or lethargic bees unable to leave flowers Bees unable to fly and crawling slowly as if chilled Queenless hives Signs of Bee Injury

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31 Almond Treatment Timing for Key Diseases Table Updated January 2016

32 Fungicide Efficacy for Almond Diseases Table Updated January 2016

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35 ipm.ucanr.edu/beeprecaution

36 ipm.ucanr.edu/beeprecaution

37 sacvalleyorchards.com

38 New this Year! Monthly IPM Breakfast Meetings Meetings will be held the second Tuesday of each month from February through November and will cover a wide range of timely pest management topics. Meeting locations will be rotated throughout the Sacramento Valley. Colusa: February and July Yuba-Sutter: March and August Tehama: April and September Glenn: May and October Butte: June and November Meeting locations and more information will be available at sacvalleyorchards.com or by contacting UC IPM Advisor Emily Symmes at (530) or ejsymmes@ucanr.edu ***Contact me to request topics*** PLEASE RSVP FRIDAY BEFORE (no host breakfast)