Harvest
Biology and Monitoring
Insects |
Diseases |
• Black Vine Weevil • Dryberry Mite • Orange Tortrix Leafroller • Redberry Mite * • Spotted Wing Drosophila • Strawberry Crown Moth |
• Cane & Fruit Rot Botrytis ** • Dry Cell Syndrome *** |
*More damaging to late-maturing cultivars.
**More commonly found on ‘Evergreen’ cultivar.
***More commonly found on ‘Marion’, ‘Kotata’, and ‘Boysenberry’ cultivars.
Biology
Insects
Black Vine Weevil
By this time most black vine weevil adults have emerged from the soil. Adults feed on foliage, removing large scallops (notching) from leaves. Notching is a good indication weevils are present in your field, however it is not economically damaging. Adults can be a contaminant in machine harvested fields. Egg laying will continue throughout harvest which will lead to an increase in population the following season. Eggs hatch within 2-3 weeks and larvae burrow into the soil to feed on roots and crowns.
Dryberry Mite
Mites can be found feeding on leaves and fruit. Symptoms are easily confused with various fungal diseases and poor pollination. Affected berries turn red before becoming brown and dry resembling sun scald. Leaves develop yellow blotches and may be reduced in size. There are several overlapping generations each year and all developmental stages are present during summer and fall months.
Orange Tortrix Leafroller (OT)
Overlapping generations and successive egg hatches can complicate control strategies. Repeat applications may be required. Scouting for larvae and monitoring adult traps should continue through the end of harvest. Overuse of broad-spectrum insecticides can intensify problems by eliminating natural control agents.
Redberry Mite
The redberry mite feeds at the core, stem, and base of drupelets and injects a toxin that prevents proper drupelet development. Affected drupelets usually remain hard, green, or bright red and result in unmarketable fruit. Some fruits may be partially affected resulting in only part of the berry ripening.
Spotted Wing Drosophila
At higher temperatures (above 86ºF), fly activity, egg laying and longevity may decrease. This may result in fewer generations per year, but damage may still occur. Infestation of fruit reveals small scar, indented soft spots, and bruises on the fruit surface. Eggs hatch and the larvae develop and feed inside the fruit, causing the flesh to collapse around the feeding site within as few as two days. Fungal and bacterial infections and secondary pests may contribute to further fruit deterioration. Larvae are small (less than 1/8 inch), cylindrical and white to cream colored. More than one larva may be found feeding within a single fruit.
Strawberry Crown Moth
Adults are still emerging throughout the month of July. They lay eggs on dead or green leaves around the base of the plant. Eggs hatch in about two weeks and the young larvae begin feeding on the outside of the crown and at the base of small roots. As larvae mature, they bore deeper into crown and are found in the center of the crown after about one month of feeding. Larvae can cause economic damage by girdling the canes causing the plants to become stunted and have poor vigor. Mature larvae are about ¾ inch long, white, with a dark brown head.
Diseases
Cane & Fruit Rot Botrytis
When conditions are favorable for disease development, new infections appear as pale brown lesions on primocane leaves in mid to late summer. The infection moves into the cane through the petiole and will first appear as brown lesions on primocanes, often encompassing more than one node. The lesion becomes tan as the infected cane matures eventually causing the cane to wilt and die.
Fruit infections generally remain dormant until fruit is nearly ripe or after harvest. Infections can recur throughout the season by sporulation of the fungus on unpicked, overripe fruit left on the vine. Fruit infections usually appear as soft, light brown, rapidly enlarging areas on the fruit. Berries become shriveled and covered with grey tufts when the fruit matures.
Dry Cell Syndrome
The cause of dry cell syndrome is unknown. Several fungi have been associated with this disease. Individual drupelets become shriveled, dry and hard. Some fruit may also have small dry, scabby lesions on green, red and black drupelets. Affected drupelets may be scattered or found in clustered patches on the berry.
Monitoring
Follow general guidelines in the “Introduction” section. For each pest below, record pest numbers or symptoms on record sheet.
Insects
Black Vine Weevil
- The best way to evaluate the effectiveness of your clean up spray is to ride the harvester to see what insect contaminants are coming across the belt.
- If weevils are detected on the belt, it usually means pre-harvest sprays were not effective or adult weevils are continuing to emerge.
- Control measures should be taken if adults are still emerging during harvest in order to prevent egg laying and the onset of a larger weevil population the following year. Chose an insecticide with a short PHI.
Dryberry Mite
- Due to the sporadic and infrequent occurrence of economic damage by dryberry mites, consider field and cultivar history problems to determine if it is economic to monitor for this pest.
- Watch for affected drupelets that become red, dry and die. Symptoms are similar to sun scalded damage. The entire berry may be affected or only individual drupelets. Search within the fruit or at the base of drupelets where they are feeding. Record the percentage of infested hills.
- Examine the underside of leaves showing signs of mite feeding for adults and/or eggs.
- These mites are microscopic; use either a 20X hand lens or a dissecting scope to see them.
Orange Tortrix Leafroller (OT)
- Continue to inspect hills as described in previous sections to determine the percent leafroller infested hills. Greater than 10% infestation may warrant control.
- Continue to monitor pheromone traps weekly to determine if adult trap numbers increase, indicating the onset of an additional larval hatch. Larvae tend to appear about ten to fourteen days after peak trap catch occurs.
- Ride harvester and check belt for leafroller larvae. Train harvest crew to find and collect larvae.
Redberry Mite
- Watch for fruit that never ripens and remains hard.
- Inspect susceptible fruit at the base of drupelets with a 10 to 20x hand lens or dissecting microscope to verify mite presence.
- Record the percentage of infested hills.
- Threshold will vary according to the end product usage and processor. Check with your buyer for their suggested threshold.
Spotted Wing Drosophila
- Monitor traps twice per week and record number of adults found. Also monitor for small puncture (oviposition scar) wounds on fruit and soft fruit. Adults are attracted to ripe or ripening fruit.
- Record the number of adults found per trap and the percentage of contaminated fruit.
- Check soft fruit on the cane as well as on the harvester/processing belt for the presence of larvae.
Strawberry Crown Moth
- Throughout July, continue checking pheromone traps weekly and record number of adults trapped to determine emergence.
Diseases
Cane & Fruit Rot Botrytis
- Inspect leaves and canes in mid to late summer for new infections, which first appear as brown lesions on primocanes. Scout for symptoms at each site and record level of damage on a scale of 0 to 3.
- Scout each site checking fruit for over ripeness, which may show beginning stages of infection. Record level of damage on a scale of 0 to 3.
- Inspect harvested fruit for signs of fruit rot.
- Monitoring is particularly important during wet conditions and/or in fields containing heavy foliage.
Dry Cell Syndrome
- Examine hills for dry, hard and shriveled berries and record level of damage on a scale of 0 to 3.
- Inspect harvested fruit for affected drupelets.
- Threshold will vary according to the end product usage and processor. Check with your buyer for their suggested threshold.
Secondary content using h2 tag.
Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.
Heading using the h3 tag
Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.