I also notice that some of your plants leaves have brown spots and are yellowing.
37+ Pepper Plant Leaves Turning Black. Farmer john takes a look at a jalapeno plant and lets you know whether or not it is misbehaving in this short episode. Avoid watering plants from overhead, and ensure plants are properly ventilated by not crowding them.
Reasons And Fixes For Pepper Leaves Turning Yellow from www.gardeningknowhow.com
Remaining leaves turn light green. I also notice that some of your plants leaves have brown spots and are yellowing. Also the smaller peppers are turning black.
Lesions may also develop on stems.
Yellowing leaves on peppers usually denotes a lack of nutrients, such as iron, calcium, sulphur, etc. They appear healthy with flowers and green leaves however the stems are turning black. Fruit turns black and mushy and leaves can look mottled. Avoid planting peppers in places where you've recently grown other members of the nightshade yellow/brown/purple/black spots on leaves;
