Berry bulletin #9 June 30, 2016 – 16-9 Berry Bulletin 06-28-16
Crop conditions: Hot dry weather continues to stress crops. Even berry growers who routinely use irrigation to optimize soil moisture may be underestimating how much water is required at this time. See Irrigation Update – June 24, 2016 for a timely article by Rebecca Shortt on determining how much water is needed based on evapotranspiration units.
Berry crops in the green fruit stage use MORE water than they do when fruit is ripening. Another problem is plugged emitters and areas between emitters where soil is not getting enough water. Soils that become very dry are hard to re-wet adequately with drip irrigation.
If growers would like to have an assessment of the performance of their irrigation system see irrigation efficiency videos at http://www.omafra.gov.on.ca/english/engineer/irrigation.htm
Day neutral strawberries: Harvest of overwintered plug plants continues. This year’s plantings have established, and should be blooming again soon. A delay in return bloom or a “gap” between crops can be related to spells of high temperature when the daily average is over 25C. Although it has its pros and cons, evaporative cooling could be a good strategy to reduce crop stress in the heat of the day.
Check often for tarnished plant bug wherever bloom is present. Tarnished plant bug (TPB) populations are variable from farm to farm. Check blossom clusters at least weekly and be ready to apply an insecticide for plant bug when populations are around 25% infested clusters. Beleaf and Rimon are friendly to beneficial insects, but work best when applied to small TPB nymphs ( and not so well on later instars, which have dots and wingpads on their backs).
Check leaves for two spotted spider mite. These will cause plants to appear dry and scorched, and can build up rapidly in this weather.
Disease pressure is fairly low. Where bloom and fruit are present you will need a fungicide for anthracnose control before a rain. This disease is a threat when weather is warm and rainy, especially when heavy splashing rain, occurs. Choose fungicides for botrytis that will also control anthracnose. These include Captan, Maestro, Switch as well as Pristine.
Remove runners every couple of weeks, these are taking energy away from the plant. Removing runners will encourage more runners, but keeping them nipped off when they are soft and easy to remove is a good strategy.
June bearing strawberries: Most people will have berries available for the July 1 weekend, but harvest will wind up pretty quickly after that. Growers are picking large volumes of Valley Sunset now. Berries are quickly becoming over-ripe in the heat. Yields of early and mid-season varieties have been substantially down for some growers, particularly eastern Ontario, where growers are reporting very small fruit size.
Cyclamen mite is building up now, too late for control. It is important to recognize cyclamen mite injury, and to flag areas where damage is occurring in order to follow up at renovation time and in late summer. Without the use of Thiodan, this pest will be a problem.
In new plantings of June strawberries – check for leafhoppers and especially for aphids. Spray whenever you see aphids are building up again, or approximately every 2-3 weeks. Sivanto and Beleaf are products which are good on aphids and not hard on beneficial insects. Cygon, Lagon, Admire and Assail are also good on aphids but hard on bees. Spray at night when bees are not working.
Raspberries: Raspberry crops are setting green fruit and fruit is sizing. Harvest of early varieties (Prelude) has started in southern Ontario. Raspberry crops need plenty of water at this time of year and most growers are under-irrigating. Cane collapse is starting to occur and is expected to continue through the next few weeks as crops are stressed from dry weather, heavy load, and winter injury.
Raspberry crown borer is easy to find at several farms. This cryptic pest is not well recognized as it causes symptoms similar to winter injury and plant stress. Pest management strategies for this pest need to be developed now that traditional products for control are no longer available or registered.
Other pests we have noticed this week on raspberries are raspberry cane borer, two spotted spider mite. rose chafer, Japanese beetles, aphids and potato leafhoppers. Each field or variety has a different set of pests, so scouting will really pay off at this time.
Blueberries: The blueberry crop still looks good…First large crop in 3 years. Growers are installing bird netting. Considerable crop loss is expected from birds due to the dry conditions. Scale insects seem to be an emerging pest in blueberries. We noticed at least three kinds of scale insects last year and reports are coming in from new locations this year. Michigan growers are also seeing more scale insects that usual.
Scout carefully for scale insects by looking at new growth as well as older wood. Plan to prune well next winter, and apply dormant oil in early spring. The third step for lecanium scale control is application of Movento insecticide, after bloom but before harvest (7 day phi). The optimum timing is when scale insects are producing crawlers – scout for crawlers weekly by flipping over the hard scale shell and looking for crawlers underneath.
Spotted wing drosophila update
SWD flies have been trapped in the early regions of southern and Southwestern Ontario, beginning the week of June 6. We are seeing repeated captures in traps in Essex County, where they are moving into crops. In other areas, so far, counts are still very low – just a fly here and there- and mostly in wild hosts.
However, now that fruit is present on wild hosts in these areas (mulberries, wild raspberries, red elderberry, and early honeysuckle) SWD will be building up. We also expect it is building up in overripe strawberries.
Strawberries, sweet cherries, and early ripening raspberries are now at risk, especially in Niagara and southwestern Ontario. Keep strawberries picked as clean as possible and renovate June bearing strawberries as soon as harvest is over.
Emergency use registrations are in place again this year for SWD control.
- 2016 Registrations http://www.omafra.gov.on.ca/english/crops/facts/swd-registrations.htm
- Printable version: https://onfruit.ca/wp-content/uploads/2016/06/registration-for-swd-june-2016.pdf