I have a couple of matchless determinate variety tomatoes in grow bags. I am from Chennai, India (hot, humid and it's monsoon time now). It's been raining the past week. I applied Monopotassium phosphate (0:52:32) for the first time one day back and it rained out of nowhere in the evening.
Now there are a few black spots beginning to occur in the leaves. I also have these plants that are wilting, and I'm not able to conclusively identify the problem.
- Sprayed with Neem oil 2 weeks ago
- Sprayed with NPK 19:19:19 2 weeks ago
- Rained for 3-4 days this week
- Sprayed with MKP 0:52:32 yesterday
- Rained heavily
Plants started setting fruit last month.
I searched "sudden outbreak of yellow leaves on tomato and other plants" and found a link about septoria leaf spot. I looked at that, will probably follow the tips next time onwards.
Soil Medium and fertilizer I am using: Cocopeat (30%), Red Sand (30%), Cow Dung Manure (20%) & Vermicompost (20%) and some gypsum. Been using balanced NPK once each 3 weeks.