Suckers are young shoots in the 'axil' of plants. A plant's axil is where the main stem splits and forms side branches with leaves. You can find suckers in between the main stem and side branches. They get their name because they 'suck' energy from the plant. As such, it is smart to remove them. Your plant then uses all its energy to grow in height.
By pruning suckers, your plant grows in height instead of in width. In a way, this makes it the opposite of topping. Growing in height has a positive effect on the plant's yield. By removing suckers, your plant spends energy on developing new shoots. This causes the stem to grow thicker and firmer. Leaves also develop better. Additionally, you'll see fruits ripen better.
To remove a sucker, grab it between your thumb and index finger. Then carefully twist them from the plant. You can start removing suckers as soon as the first leaf gets buds. Remove all shoots below this specific branch. The plant can then concentrate on producing new leaves. Check weekly if new suckers have formed. You can remove these immediately.
Try putting a sucker in our Seeding and Cutting Soil. Roots may form on the shoot!. This way, a sucker may become a new plant.