team-6/backend/storage/plants/diseases.strawberry.md

Strawberry (Fragaria × ananassa)

1. Gray Mold (Botrytis cinerea)

   • Integrated Management Strategies:
     • Cultural & Preventive: This is key. Promote good air circulation through proper plant spacing and by managing runner growth. Use straw mulch to keep fruit from touching the soil. Water in the morning via drip irrigation. Harvest fruit frequently and remove any mummified or rotting berries from the field immediately.
     • Biological: Several biofungicides are effective, containing strains of Bacillus subtilis, Bacillus amyloliquefaciens, or Streptomyces lydicus. These should be applied preventively, starting at early bloom.
     • Chemical: Fungicide applications should be timed to protect the flowers, as infection often begins there. Rotate different chemical classes (FRAC groups) to prevent resistance. Effective active ingredients include fenhexamid, boscalid + pyraclostrobin, and cyprodinil + fludioxonil.

2. Powdery Mildew (Podosphaera aphanis)

   • Integrated Management Strategies:
     • Cultural & Preventive: Plant resistant or tolerant cultivars. Provide good air circulation. In tunnels or greenhouses, manage humidity.
     • Biological: Microbial biofungicides (Bacillus spp.) can provide good preventative control.
     • Chemical: Sulfur is a common and effective organic option but can be phytotoxic in high heat. Horticultural oils and potassium bicarbonate are also effective. Conventional systemic fungicides (e.g., quinoxyfen, myclobutanil) provide excellent control.

3. Anthracnose Fruit Rot & Crown Rot (Colletotrichum spp.)

   • Integrated Management Strategies:
     • Cultural & Preventive: Start with certified disease-free transplants. Use resistant cultivars where available. Use straw mulch to reduce spore splashing from soil to fruit. Avoid overhead irrigation. Remove infected plants and fruit immediately.
     • Biological: Biofungicides have shown some suppressive activity but are generally not sufficient for control in high-pressure situations.
     • Chemical: A preventative fungicide program is essential in regions where this disease is common. Strobilurin fungicides (e.g., azoxystrobin, pyraclostrobin) and captan are commonly used. Rotation is critical as resistance to strobilurins is widespread.

4. Common Leaf Spot (Mycosphaerella fragariae)

   • Integrated Management Strategies:
     • Cultural & Preventive: Plant resistant varieties. Remove old, infected leaves after renovation (in matted-row systems) or during the season. Promote air circulation and use drip irrigation.
     • Biological: Limited options.
     • Chemical: Fungicide sprays are effective. Organic options include copper-based products. Conventional options used for other diseases (e.g., captan, strobilurins) will also control leaf spot.

5. Verticillium Wilt (Verticillium dahliae)

   • Integrated Management Strategies:
     • Cultural & Preventive: The most important strategy. Use certified disease-free, resistant cultivars. Do not plant strawberries in soil where susceptible crops (potatoes, tomatoes, raspberries, mint) have been grown for the past 5 years.
     • Biological: Pre-plant soil treatment with biofumigant cover crops (e.g., specific mustard varieties) or soil solarization can reduce soil inoculum.
     • Chemical: No post-planting fungicides are effective. Pre-plant soil fumigation is the only chemical option and is used in commercial production where disease pressure is high.