Wilt:

This is the drooping of the foliage and ultimately death of the plant. It is caused in seedlings when their bases become rotted due to fungus and fall on the 0ground. e.g. shisham. The only control measure that can be applied is selection of a well-drained site.

Canker:

It is a definite, localised deformation (necrotic lesion) formed mainly in the bark. It results in the death of the part of the tree above the canker. Cankers are caused by frost, sun scorch, fire and drought.

Decay:

It is the decomposition of wood by fungi. When they attack living tissues, they may kill the trees. When they attack the dead wood (as the heartwood) they cause rot or heart rot.

Heart rot :

It is caused by a number of fungi. The presence of fruiting bodies of the heart rot fungi, punk knots, swollen knots, dry branch sticking out of bole and swollen boles are indications of heart rot in trees. Injury to trees should be kept to a minimum to prevent heart rot.

Root diseases:

Diseases in roots of trees are caused by root infecting fungi which may be soil-inhabiting or root-inhabiting. The soil-inhabiting fungi causes wilt in trees eg shisham. The root-inhabiting fungi causes root rot in trees eg shisham and khair. The roots of new seedlings receive infection from old infected roots in the soil.

Nursery diseases:

Damping off is one of the most serious of all nursery diseases. Mortality occurs at three stages of growth of seedling - the seedlings may be killed even before they emerge above ground level due to pre-emergence blight; or the seedling may get killed after emergence from the ground as a result of rotting of tissues at the base; or older seeds may die due to root-rot. The disease can be controlled by raising nurseries in good sites (it should be located in a well drained site with light textured soil without overhead shade) and fungicidal treatment of seed and soil before and after sowing.