printable pdf 16-6 Berry Bulletin 05-27-16
May 27, 2016
Crop conditions: Most crops have grown rapidly this past week. Soils are alarmingly dry in many areas. New plantings are at high risk of poor establishment unless irrigated.
Be proactive to prevent spray drift – If your neighbour has soybeans or corn next to your valuable horticulture crops, be sure they know, and their custom applicators know, how costly damage from herbicide drift can be. A conversation could help a lot. It’s that time of year, and herbicide combinations are getting quite complicated. What to do if you suspect drift.
Blueberry pest management workshop: Wed June 1, 2016, in Simcoe (not Woodstock). 4:00 pm – 8:00 pm, includes a light supper, so please RSVP to 1-877- 424-1300. Guest speakers include Dr. Rufus Isaacs, from Michigan (by webinar), and several OMAFRA specialists.
Day-neutral strawberries: Overwintering day neutrals have lots of bloom and green fruit and some early harvest is beginning. Continue monitoring for tarnished plant bugs. It is important to include broad-spectrum group M fungicides (captan, Maestro, Thiram, Granuflo -T) in your disease management program for both botrytis and anthracnose. Anthracnose builds up in warm weather and is spread by splashing rain or irrigation. Anthracnose risk and powdery mildew risk is high right now. Be sure to apply a fungicide for these diseases before the next rain.
In new day-neutral plantings, remove flower buds and bloom until the plant is well established – generally 4-6 new leaves present. If you plan to use Apogee on new day-neutral plantings, the timing is shortly after flower bud removal at the first sign of runners. Do not apply Apogee when bloom or buds are present. See Pub #360, page 152 “Use of Apogee for runner suppression in strawberries”.
June bearing strawberries: Clipper weevil has been very active (Figure 1). This pest loves warm nights. Scout for damage near the edges of older fields. Where clipper weevil damage is evident, border sprays (outer 10-12 m of crop) should provide adequate control. The risk of clipper weevil damage is over when all flower buds are open. Because the only insecticides registered for clipper weevil are pyrethroids, and these can cause problems with cyclamen mite, spray for clipper weevil only where you really need it (i.e. field edges, older plantings).
Everyone should be looking for tarnished plant bug by tapping flower clusters once or twice a week and tracking the increase in small green active nymphs. The threshold is about 1 nymph in 4 flower clusters or 25% of clusters infested. Beleaf (use the high rate) used for aphids will also suppress TPB but suppression will not be good enough if populations are high.
Apply an insecticide for aphids in strawberries, if you have not done so already. During bloom, your options are Beleaf, and if necessary, Sivanto Prime. Apply at night when bees are not working. In newly planted fields, control aphids with a soil drench of Admire.
In new strawberry plantings I am starting to get calls about problems with dying plants. The first question is: how much water did they get after planting. Next dig up dying plants and adjacent plants and look for white grubs. White grubs will sometimes move from plant to plant in a row, and will move down quite deep in dry soil. Look for chopped off roots.
Blueberries – Blueberry growers, who suffered significant injury last year, are pleased to see a heavy bloom, which at the moment is buzzing with bees.
If rainy weather occurs during the bloom period, fungicides will be important for anthracnose and botrytis fruit rot control. Otherwise, if it remains dry, plan to spray at petal fall for cranberry and cherry fruitworm. You will need 1-2 well timed insecticides for cranberry fruitworm and cherry fruitworm control. The newer products such as Intrepid, Exirel and Altacor work best on eggs and young larvae. Apply these a bit earlier than you would traditionally apply older organophosphates such as Malathion and Sevin.
Raspberries– Raspberries are growing as well, with no reports of substantial winter damage. However, cane collapse just before harvest is often associated with stress from environmental causes. Make sure raspberries are not subjected to drought stress at this time.
Developing flower buds on summer-fruiting varieties are susceptible to raspberry fruitworm and strawberry clipper weevil (Figure 2). Scout for these pests by tapping bud clusters over a white trap or dish. If you have any diazinon in stock, use it up before first bloom, or take it to a pesticide disposal facility. Diazinon will not be registered in 2017 and should be used before any bloom is open. Malathion is also good choice before bloom. However, if there are no signs of beetles or leaf shredding, an insecticide is not needed until after bloom.
Spotted Wing Drosophila: A regional monitoring program for SWD flies is in place for 2016, thanks to collaboration between the Ontario Berry Growers Association and OMAFRA. Thanks also to the many agribusiness professionals, consultants, scouts and farmers who are volunteering time to pick up traps. Traps will be set up the week of May 30 and we will begin reporting trap captures the week of June 6. We are already trapping at a few local hot spots but no SWD have been captured. The degree day model information (Oregon model) suggests that overwintering SWD flies could be laying eggs in developing fruit. However there is very little fruit around and since populations are EXTREMELY LOW at this time, control is not required anywhere in Ontario right now.
Emergency use registrations are in place again this year for SWD control and we will post this information early next week. There is one significant change to the malathion label-use of this product is now limited to 2 applications per year.
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