Cuke problem - Ask Extension
Hello,
I grow cucumbers in my greenhouse/hoophouse in summer and grow Lettuce, Cabbage in fall/winter. I don't use any pesticide (soap water only), h...
Knowledgebase
Cuke problem #876147
Asked July 06, 2024, 7:50 PM EDT
Hello,
I grow cucumbers in my greenhouse/hoophouse in summer and grow Lettuce, Cabbage in fall/winter. I don't use any pesticide (soap water only), herbicide and fertilizers. Usually I have to fight with Aphids on cucumbers but this year I have other problems, see attached. I already lost 4 plants. Please let me know what can I do.
Thanks.
Montgomery County Maryland
Expert Response
Your main problem is a serious case of spider mites. You can see the fine webbing and if you looked closely or with magnification you may be able to see them sliding within the webs. You could also do a 'tap test' where you firmly shake plant stems over a white piece of paper and look for tiny dots walking.)
Spider mite populations tend to explode when conditions are hot and dry. Are you able to vent the greenhouse setup (roll up the sides?) to allow some more air circulation?
Your second set of photos may show an infection, but it is difficult to tell that close-up and without seeing the top side of the leaf. (We don't think it's the bacterial infection called angular leafspot, downy mildew has not been confirmed yet in MD in 2024.)
These pages will guide you on these issues:
https://extension.umd.edu/resources/yard-garden/vegetables/cucumbers/
Christine
Spider mite populations tend to explode when conditions are hot and dry. Are you able to vent the greenhouse setup (roll up the sides?) to allow some more air circulation?
Your second set of photos may show an infection, but it is difficult to tell that close-up and without seeing the top side of the leaf. (We don't think it's the bacterial infection called angular leafspot, downy mildew has not been confirmed yet in MD in 2024.)
These pages will guide you on these issues:
https://extension.umd.edu/resources/yard-garden/vegetables/cucumbers/
Christine
