Not sure I am following you here. Was this one plant that was overwintered and produced smaller fruit the second year? Or was the second year a new plant from seeds saved from the first year?

Overwintering without pruning and repotting could give you those results. But if it was a new plant the second year, could it have crossed with some other pepper in your garden?

One way to get larger fruit is to pick off some of the blossoms, or better yet, prune back a couple of the main branches so the root stock can keep up with the aerial part of the plant.

The Plant is overwinter without pruning. I did repotting to a bigger container without removing any old soil and cut off old dying branches. The last year was the first time this plant produced fruits. This year it produced fruits two times the red fruit in the picture were first time (not much fruits and small)and those flowers were for the second times it produced a lot of fruits.

This picture is after I removed the fruits and cut off the old branches.

This picture is after I got aphids and dropping flowers with small fruits and leaves.

I have noticed when plants get over a couple years old they tend to produce smaller fruit as well. Not always but typically. There is nothing like the first 3 or 4 harvest from a plant. But that being said sometimes you will get some nice harvests out of older plants when the conditions are perfect. Low humidity,pests, and temps are also a major factor in pod size and production.

The picture is the present condition of the plant, I did repotting again. I felt guilty of overwinter this plant. My mistake was lack of learning of overwinter. I watched some youtube videos of overwinter and applied it without basic knowledge, really I am killing this plant. This plant is my first plant and I got motivation of container gardening from it. I am not sure the future of this plant, may be died soon.

Okay, alarm bells just went off due to that picture.

I've seen this before, and its going to kill your plant if you don't act right now (if it isn't already too late). You need to trim off the dead parts of those stems that are slowly creeping down towards the base. They likely have an infection (mine was fungal) that will spread right down to the base and kill the entire plant.

Trim it off now and put some hydrogen peroxide on the cut ends to sterilize them. Repeat the peroxide sprayings about twice a day for 2-3 days to ensure you got it all.

Sharp eyes there Edymnion! Right on!

It killed my first bonchi. At the time I thought it was just where I had cut below the fork and the plant was just culling back the extra stem it didn't need. By the time I realized something was really wrong, it was too late.

When I preformed the autopsy to see exactly what had been going on, the insides of the black sections were filled with fuzzy white mold.

Save your plant now, while you can. The good news is I see several growth nodes still below the dead section, so it can come back if you act fast.

Thank you for all these valuable information. I followed your instruction. How much should I have to cut off the branches some of the branches have some dark circles/spots it looks not normal. Please have a look the pictures. I have already lost some plants and some of them are still same condition like this one. Is there any alternative of hydrogen peroxide? To buy hydrogen peroxide I may be asked for prescription from concerned officials. Can I use toothpaste?

I have insecticide from Bayer. I just got Super Thrive 50 in 1 and Chili Focus, today. I have chamomile tea (kamille Te local name)too. Can I use some of them instead of hydrogen peroxide? Forgive me for my poor English and silly questions.

You need a prescription for peroxide where you are?
How odd, you can buy it here from any local pharmacy without question.

Oh well, the chamomile has antibacterial properties, so that would be better than nothing. Anything that will kill bacteria, fungus, and generally sterilize the cuts will help. You just want to make sure that whatever infected the ends the first time can't do it again.

This year is some kinds of learning and experimental year for me. I cut off the branches and applied tooth paste:( this plant.

We all start somewhere. =)

And actually that is pretty much exactly how you want to cut back a pepper for overwintering. You even left the Y split where most of the new growth will come from.

Unless the toothpaste had peroxide in it, I don't think it will do much to help, but toothpaste is generally just baking soda and flavorings, so I don't think it will hurt anything either.

Thank you for the quick reply. So many medicine they are allowed to buy without prescription in some countries are not allowed here. I will use the chamomile tea.

This picture is before I applied fungus gnat insecticide and repotting with new mixed soil. It is the same plant in the previous picture.

Should I cut the Y split? I do not have the basic concept of overwinter. I have read overwinter can produce early fruits that is one of the reasons I did.

No, you want to keep the Y split whenever you can.

New branches grow from the split, so you want to keep it whenever you can.

Thank you again. When I did overwinter before I never applied hydrogen peroxide or anything else. I did not use proper tools such as good cutter or gardening scissor too, sometimes the stems broke. In the first picture of overwinter the middle stem was died on a same manner. Now I have learned a good lesson about overwinter, and I will prepare necessary items before I overwinter for the next time.

Don't worry, the first year I overwintered stuff resulted in a couple of dead plants as well. Its just something you have to do for yourself until you figure it out.