May Berry Maintenance

Adapted from Cornell ENYCHP’s Berry News

Inspect irrigation equipment and row cover. Make sure you have an adequate temperature detection system at the field level, especially for frost protection.
Red stele, the common name for root and crown rot of strawberry, is caused by the fungus Phytophthora fragariae. Leather rot of the fruit is caused by Phytophthora cactorum. Earlier in the season, Ridomil and phosphorus acid products (such as ProPhyt) are recommended as soil drenches in fields where flooding was a problem last fall. Those same products can be added to bloom sprays if extended wet fields or overhead iirrigation because of frost were problems, or if leather rot has been a problem in past years. Add these products at first bloom. Straw mulch helps minimize the water splashing that spreads leather rot.
Spray early for best leaf spot control, if leaf spot incidence has been increasing in your area.
Consider strawberry pre‐plant herbicide options. Prowl H20 or Chateau are both great. Depending on your weed pests, you may want to try Dual magnum or Goal 2XL. Both of them have timing limitations, so read the label carefully.

Green tip sprays for mummyberry and Botrytis should be applied now. Abound and Indar are labelled for both diseases, but there are other choices as well. Check the guidelines on the label.
Prepare for nutrient applications in May and again in early June. Review foliar tests. Apply sulfur if soil pH is higher than 5.2 – 200#/A is the maintenance rate that should be applied 1‐2 times annually to prevent soil pH from creeping up. Remember that the target pH is 4.5. Make sure soil boron or foliar boron tests show that those levels are appropriate.
To improve pollination of blueberries, plan on adding bumblebee hives into the planting. Stocking density of hives varies greatly depending on the variety of berry you are growing. Ask your local extension agent for details.

Brambles are breaking dormancy in all but most northern locations.
Complete the necessary pruning, to keep cane density at no more than 4 canes per square foot. There may be some winter injury, so look for that and prune it out.
Bud break is the trigger for sprays to control anthracnose, spur blight, and cane blight.
Apply early season herbicides. Casoron 4G (granular) can be used in caneberries. The same caveats listed above for blueberry apply. Casoron CS can be applied a bit later, but still needs to be incorporated by rainfall, before weed germination; it is labeled for blackberry and raspberries if applied before new shoot emergence. Don’t delay: you are running out of time, and the southernmost counties are likely too far along to use Casoron safely and effectively.
Watch for raspberry fruitworm feeding on new leaves.

Now is the time to spray for apple curculio and/or saskatoon sawfly if you’ve had damage in past years. The larval stages of these insects feed inside the developing berries, resulting in fruit losses or the presence of insects inside fruits at harvest. Treat if damage to berries exceeded 10% last season. Products include Molt‐X (10 fl oz/A) or SuffOil‐X (1 – 2 gal/100 gal) or PyGanic 1.4 ECII (16‐64 fl oz/A).
There are relatively few pesticides registered for use on this crop. Even for products that are registered, there is limited information on the efficacy of the active ingredients against specific saskatoon pests. Therefore, the recommendations are based largely on how well the pesticides are known to work on related pest species on other fruit crops.

Powdery mildew sprays (many organic options including oil, Kailgreen, sulfur and Actinovate, but also Rally, Cabrio, and Rampart) should begin now if this has been a problem in the past.