Gummy stem blight
Brown V shaped spots start at the leaf edge, and the stem near the base gets long brown lesions that crack and ooze gum.
Crops it strikes
What you see
When to act
From the first runners, check the crown and the base of the vines twice a week for tan, water soaked cankers that ooze amber gum. Start protectant sprays at the first cankers or leaf spots in wet weather, and from the start where it struck last season.
What to spray
Active ingredients only, never brands. The FRAC group tells how it works: switch to a different group next time, so the disease does not learn to survive it. Spray only when the damage is worth the cost, and only with products registered with the Fertilizer and Pesticide Authority for your crop. Follow the label. The Shopee and Lazada links only show who sells something with that active ingredient, not a recommendation of any seller or product.
Resistance: Gummy stem blight has become resistant to the benomyl group (FRAC 1), the strobilurins (FRAC 11) and boscalid (FRAC 7) in several countries. Keep chlorothalonil or mancozeb as the base and turn the systemic groups.
How to prevent it
- Sow clean seed and plant healthy transplants. The fungus rides on seed and spreads from sick seedlings.
- Rotate for at least two years away from all cucurbits, and plow under or remove old vines after harvest.
- Water at the base or by drip, and keep the vines off wet soil with mulch or a trellis.
- Avoid wounding the vines, and keep squash beetles down, since cankers start at wounds.
- Space the plants and drain the field so the crown stays dry.
Where this comes from
Not sure it is this one?
Many diseases look alike. Send a photo to Anee, the smart farm technician in anee.io. She reads it with your crop, its age and the weather, and tells you what it most likely is and what to do first. In Tagalog or English.