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INJURIES AND PROTECTION
The tree is wind-firm; the branches are seldom broken even in storms. Seedlings are very frost tender.
In an experiment at the Forest Research Institute, Dehra Dun, neem seedlings were killed by frost to
ground level in spite of the thatched shelters provided. They have little power of recovery. Seedlings
die in the dry season. They are also killed by Waterlogging.
In an experiment at the Forest Research Institute, Dehra Dun, neem seedlings were killed by frost to
ground level in spite of the thatched shelters provided. They have little power of recovery. Seedlings
die in the dry season. They are also killed by Waterlogging.
Biotic
The most serious problem about growing neem is biotic. The neem leaves are considered good
fodder for camels and goats. Heavy damage is caused by repeated lopping of trees for this purposes.
In parts of Rajasthan, the trees do not produce seeds due to repeated cutting of branches. The cutting
of young twigs for use as toothbrushes is also responsible for severe retardation in growth of trees.
Planting of neem had to be totally stopped in Etwah district of Uttar Pradesh due to extensive damage
caused by owners of camels and goats.
The most serious problem about growing neem is biotic. The neem leaves are considered good
fodder for camels and goats. Heavy damage is caused by repeated lopping of trees for this purposes.
In parts of Rajasthan, the trees do not produce seeds due to repeated cutting of branches. The cutting
of young twigs for use as toothbrushes is also responsible for severe retardation in growth of trees.
Planting of neem had to be totally stopped in Etwah district of Uttar Pradesh due to extensive damage
caused by owners of camels and goats.
Insects
Tewari16 has reported that young neem plants are frequented by no less than about sixty insect
species all over the world primarily in the African and Asian countries as follows: India (38 species
including two species of mites and one species of snail), Japan (2 species), Pakistan (3 species),
Africa (6 species), Middle East (4 species), USA (5 species) and Australia (2 species). The important
insects affecting the growth of neem trees in India are briefly discussed as follows:
The neem scale (Palvinaria maxima) is a serious pest in Central and South India. It feeds on sap,
covers the tender shoots and stem in numbers and sometimes does considerable damage of young
trees. A tree in an advanced stage of infestation is recognized by the thick coating of white mealy
patches formed on the foliage, shoots and bark. Another scale insect (Aspidiotus orientalis) thickly
covers the shoots and stems of about 0.6-2.5 cm diameter, appearing on the new shoots and
spreading to the leaves in severe infestation. The growth of the plant is retarded, leaves are shed, the
stems die and young trees may be killed. Some Coccids also feed on sap but the damage is
insignificant. The nymphs of Helopeltis antonii feed on sap by puncturing the soft plant tissue. Certain
larvae attack the leaves, while others feed on rolled or super imposed leaves and when young bore
into the tender top shoots. A larva bores into neem seeds and certain thrips attack the flowers. Neem
is usually avoided by the desert locust.
Tewari16 has reported that young neem plants are frequented by no less than about sixty insect
species all over the world primarily in the African and Asian countries as follows: India (38 species
including two species of mites and one species of snail), Japan (2 species), Pakistan (3 species),
Africa (6 species), Middle East (4 species), USA (5 species) and Australia (2 species). The important
insects affecting the growth of neem trees in India are briefly discussed as follows:
The neem scale (Palvinaria maxima) is a serious pest in Central and South India. It feeds on sap,
covers the tender shoots and stem in numbers and sometimes does considerable damage of young
trees. A tree in an advanced stage of infestation is recognized by the thick coating of white mealy
patches formed on the foliage, shoots and bark. Another scale insect (Aspidiotus orientalis) thickly
covers the shoots and stems of about 0.6-2.5 cm diameter, appearing on the new shoots and
spreading to the leaves in severe infestation. The growth of the plant is retarded, leaves are shed, the
stems die and young trees may be killed. Some Coccids also feed on sap but the damage is
insignificant. The nymphs of Helopeltis antonii feed on sap by puncturing the soft plant tissue. Certain
larvae attack the leaves, while others feed on rolled or super imposed leaves and when young bore
into the tender top shoots. A larva bores into neem seeds and certain thrips attack the flowers. Neem
is usually avoided by the desert locust.
Fungi
Certain fungi cause white sap, heart rot, white spongy rot and leaf spot. A new species of bacteria
Pseudomonas azedarachtae has been reported for the first time of cause leaf spot and blight
disease in neem. Repeated dieback by an unidentified fungus in young plantation of neem was
controlled by drenching the plants in 0.2% Bavistin. ISTF News reports that a soil-borne root infecting
fungus appears to be infecting numerous neem trees over substantial portions of Niger. In the
Maggia valley 100% of mature pollarded trees, 15% of younger trees in windbreaks, and nearly all
1991 private plantings are affected. A number of international agencies are becoming involved in
attempts to identify and counter the disorder.
Certain fungi cause white sap, heart rot, white spongy rot and leaf spot. A new species of bacteria
Pseudomonas azedarachtae has been reported for the first time of cause leaf spot and blight
disease in neem. Repeated dieback by an unidentified fungus in young plantation of neem was
controlled by drenching the plants in 0.2% Bavistin. ISTF News reports that a soil-borne root infecting
fungus appears to be infecting numerous neem trees over substantial portions of Niger. In the
Maggia valley 100% of mature pollarded trees, 15% of younger trees in windbreaks, and nearly all
1991 private plantings are affected. A number of international agencies are becoming involved in
attempts to identify and counter the disorder.