Symptoms: the rust disease of Begonia is very common, which is mainly harmful to the branches and leaves. It is also very infectious. At the beginning, it grows small round orange spots. At the later stage, it will produce some small black particles on the surface, and then the back of the leaves will protrude, which will eventually lead to the black spots, leading to dry and falling.
Prevention and control: in winter, cut off the diseased branches. The best way is to eliminate the pathogens from the source, completely remove the source of the disease, and apply a little more phosphorus and potassium fertilizer to enhance the resistance. In order to have a good control effect, it is necessary to spray Triadimefon 2-3 times continuously, so as to have a good effect.
Symptoms: aphid is a common pest of Begonia sessile. It often occurs in wet weather. It will lie on the stem and suck the juice inside, causing water shortage and drying up inside, and may eventually make the leaves fall down.
Prevention and control: when the number is small, the first consideration is to remove it artificially. If there is a large number of chemicals, you can spray them. There are many optional chemicals. You can spray them with either a 1000 fold solution of 40% Omethoate or a 2500 fold solution of 20% pyrethroid emulsion. The effect is also good.
