Massachusetts IPM Berry Blast
April 26, 2016
In this Blast
CROP CONDITIONS SUMMARY
- Crop Conditions Summary
- Mummy Berry ID & Mgt
- mulch has been removed and plants are greening up and growing new foliage. Flower trusses are visible in the crowns but have not expanded except where row covers have been used to accelerate growth. Matted row fields are reported to be looking better than plasticulture fields and June bearing varieties are reported to be looking better than day neutral varieties. Blueberries
- buds are expanding and some are reaching the early pink stage. The extent of cold damage from the early April freeze has been variable with variety and location. There are some reports of nearly 100% damage and other reports of 0% damage. Once bushes reach bloom it will become more clear how much injury there is in any specific field. Brambles
- new shoot growth is expanding with 3-5 leaves showing in raspberries and some blackberries showing flower cluster expansion. There is variable damage to both flower tissue and vascular tissue and sublethal damage may still lead to collapse as canes continue to grow. Ribes
- plants are in or nearing bloom showing little damage from cold. Grapes
- buds are expanding slowly and showing some damage from cold temps in February. Damage is highly variable by variety and location. Once temperatures warm up, growth will accelerate and growers should be prepared for early season disease management. See latest issue of New England Grape Notes
for more on this topic.
Images: strawberry field, blueberry twigs of several varieties, blueberry bud damage, damaged blackberry shoot growth. S. Schloemann
Mummy Berry ID and Management
Sonia Schloemann, UMass Extension
: The first symptom of this disease is browning along the major leaf veins on newly emerging leaf clusters. The leaves wilt quickly and bend to resemble a shepherd's crook. A light gray powdery layer of spores develops at the leaf base. These spores go on to infect flowers and fruit. Infected green berries appear healthy but cutting them open reveals a white fungal growth inside. When berries start to ripen, infected berries appear pinkish tan and slightly ridged. They feel rubbery and contain a gray to black fungal mass inside. Infected berries eventually become faded, shrivel up, and fall to the ground. After the fruit skin has weathered off, the berries look like tiny black pumpkins.
The fungus overwinters in the mummified fruit on the ground. In early spring, trumpet-shaped mushroom cups produced on the mummies eject windborne spore that infect young shoots. Frost may increase susceptibility of blueberry shoots to infection. Spores are produced on blighted shoots and are carried to flowers by wind, rain, and insects (bees), resulting in fruit infections. Mummies that fall to the ground provide inoculum for the disease in the following year.
photo credits: 1) MSU Blueberry Facts 2) eXtension fact sheet 3) NC State Fruit Consortium
: The fungus infects and invades the developing fruit rendering it unmarketable.
: Consult scouting records from previous years to determine if build-up of this disease is indicated. Monitor weather conditions to identify likely infection periods. Scout fields beginning at budbreak for symptomatic tissue. This timing often coincides with Fortsythia bloom.
- Plant resistant varieties whenever possible. Those that are most resistant to the shoot blighting phase of the disease include Bluejay, Darrow, Duke, Elliot, and Toro. Cultivars that are consistently resistant to the fruit infection phase include Northsky, Reka, Northblue, Bluegold, Bluejay, Weymouth, and Patriot. Resistance to fruit infection appears to be unrelated to resistance to shoot blight, and weather factors can also affect cultivar response to the disease.
- Prune bushes to open the canopy to light, air, and spray penetration.
- Cultivate beneath plants in fall and again in early spring to disrupt overwintering inoculum.
- Apply a 3-4” layer of mulch material over the soil surface in early spring before mushroom cups emerge to create a physical barrier to spore release.
Summary Management Table:
- Apply recommended fungicides at budbreak if scouting and weather monitoring indicate risk of infection.
- Time fungicide applications closely to frost/freeze events that predispose tissue to infection.
- Repeat fungicide applications at recommended intervals if weather conditions are conducive to infection.
- Rotate fungicide materials from different FRAC groups to avoid promoting the development of resistant strains of this disease.
||Organic (OMRI Listed)
|Abound F, 6.2-15.4 oz (0 day phi; Note caution regarding spray near or with equipment also used in apples)
Captec 4L, 0.75-1 qt (0 day phi)
Indar 2F, 6 oz (30 day phi)
PropiMax EC, 6 oz (30 day phi)
Quash, 2.5 oz (7 day phi)
Quilt Xcel, 14-21 oz (30 day phi)
Switch, 11-14 oz (0 day phi)
|⊗ Actinovate AG, 3-12 oz (0)
⊗ Double Nickel 55, 0.25-3 lb (0)
⊗ Serenade Max, 1-3 lb (0)
|Use resistant varieties
Prune for open canopy
Cultivate beneath plants after harvest to disrupt inoculum
Mulch in early spring to cover inoculum
|Read labels thoroughly for application rates and restrictions (REI, PHI, etc.)
* restricted use material
⊗ OMRI listed
Archived IPM Berry Blasts are available at the UMass Extension Fruitadvisor website.
We thank Nourse Farms for their underwriting of this newsletter which allows us to keep subscription rates low.
Our newsletter is presented in Adobe PDF format. To read the newsletter you'll need to download a free utility from Adobe called "Acrobat Reader"
It is available from www.adobe.com.