Bacterial Diseases in Mango

Pseudomonas wilt Symptoms: There are two bacterial diseases in banana: Erwinia Rot Pseudomonas wilt Symptoms: This disease occurs in scattered plants or groups of plants. The initial symptom is wilting of terminal leaves, followed in 2-3 days by a sudden and permanent wilt. Adventitious roots may develop on the main stems. Additional symptoms include vascular browning, water soaking of pith followed by browning, and in later stages browning of cortex near the soil line.

Bacteria streaming can be seen when a freshly cut stem is suspended in water. Mode of spread: The pathogen survives in soil for extended periods without a host plant. It enters roots through wounds, which may be caused by insects, nematodes, and cultivation. High temperature and high soil moisture favor disease development.

Management practices: Disease can be minimized by exposing soil to sunlight. Selection of healthy planting material, eradication of infected plants. Disinfecting cutting knives and providing better drainage. Flower visiting insects are main agents for transmitting the disease and this is good reason for following the practice of removing the bud from the male axis before the bunch matures. Herbicides, e.g., 2, 4-D and 2, 4, 5-T, can be used to kill infected plants in situ and dieldrin sprayed onto a chopped down mat will prevent insects transmitting the disease to the unaffected plants.

Disease affected plants Infected fruit Infected stem

B.) Erwinia rot or soft rot of Rhizome- Erwinia spp This is a minor bacterial disease, but causing concern in West Bengal. Symptoms It is characterized by a massive soft odorous rot of the centre or a portion of the rhizome. The rot progresses up the pseudostem destroying the growing point and causing internal decay often with vascular discoloration. Externally, the symptoms sometimes resemble those of Fusarium wilt. Yellowing and wilting of the leaves are the characteristic symptoms.

Management practices: Banana should not be grown along with onion and other vegetables. The soft rot pathogen load increases in such cropping system. Soil drenching with bleaching powder was found beneficial. Soil and plant drenching with bleaching powder at 2 g/l water at an interval of 10-15 days was found effective in controlling the disease. Avoid planting during rainy season and in soils, which do not have good drainage. Select infection free suckers for planting and should be trimmed to remove dead tissues.

To sum up Pseudomonas wilt and Erwinia rot commonly noticed bacterial disease in banana. This disease diversely infest the growth of the plant. Pseudomonas wilt – wilting of terminal leaves resulted permanent wilt of plant – exposing to sun light (control). Erwinia rot: massive soft odorous of the centre or a portion of the rhizome – yellowing wilting of leaves – soil drenching with bleaching powder (control).