b) Pest:

i) Stem & Bulb Nematode (Ditylenchus dipsaci): It is tiny worm, which damages the tissues of garlic and reduces the yield significantly. Basal portion of the mature plants swell and become spongy, the leaves and stems are rotten. Soil fumigation with Dichloro-Propene-Dichloropropane (D-D) mixture before planting @ 500 Kg per ha is recommende for control of Stem & Bulb Nematode.

ii) Onion Thrips (Thrips tabaci): Thrips is small insect which hides in the leaf axils and feeds on leaves turning it to white or silvery in colour. Spray of 0.1% solution of Malathion or 0.075% solution of Methyle Demeton is effective in controlling thrips. Spray of Phorate @ 1 Kg a.i. per ha at the time of planting and 30 days after planting is also effective.

iii) Mites (Rhizoglyphus callae & Glycohaqus domesticus): These insects attack bulbs stored for longer periods. Fumigation of dry bulbs with Methyle bromide @ 1Kg per 1000 cubic feet space for two hours at 80 degree F is recommended after harvest and before storage.

c) Diseases:

i) White Rot (Sclerotium cepivorum): Yellowing and wilting of leaves are the major symptoms of attack of this fungus. It caused rotting of bulbs in later stage. It can be controlled by spraying of 0.15% solution of Carbendazim or 0.25 % solution of Dithen M-45 at the time of planting in rows.

ii) Penicillium Rot (Penicillium corymbiferum): Decay caused by penicillium may occur in field and storage both. This fungus generally invades thick fleshy part of the clove in storage and softens it later shrivels & finally blue-green spores are seen. Very young plants are affected by this fungus in the field.

iii) Stemphylium Blight (Stemphylium vesicarium): Small yellow – orange streaks on the leaves. Soon they develop into elongated spots and turn grey at centre, finally it develop conidiophores and conidia of the fungus. These spots coalesce and blighted portion can be seen which gradually covers entire leaf. Spraying of 0.25% solution of Mancozeb at regular interval of 15 days after appearance of first symptoms, can be used for control of the disease.

iv) Purple Blotch (Alternaria porri): Symptoms of this disease appear on leaves. Small whitish sunken lesions/ purple blotch are seen on the leaves, which enlarge rapidly. The leaves fall gradually. Spraying of 0.25% solution of Mancozeb at regular interval of 15 days after appearance of first symptoms, can be used for control of the disease.

v) Cercospora Leaf Blight (Cercospora duddiae): The symptoms of this disease also appear on leaves. Small irregular dark brown spots scattered on lamina are seen in the plant affected by this disease. These spots gradually coalesce and foliage becomes blighted. Spraying of 0.2% solution of Ziram or Captan or 0.3% solution of Copper oxichloride at fortnightly intervals should be done to control this disease.

vi) Powdery Mildew (Leveillula taurica): Distinct pale yellow patches of variable size coupled with powdery mass on the lower side of leaves are main symptoms of this disease. Spraying of 0.2% solution of Sulphur fungicides should be done to control this disease and it should be repeated at regular intervals of 15 days after appearance of the symptoms.

vii) Mosaic: Garlic plants affected with mosaic virus show typical chlorotic mottling & stripes on the first emerging leaf followed by pale yellow broken stripes on matured leaves. As the virus is transmitted by aphids, controlling the vector is useful. Spraying of 0.05% solution of Monocrotophos is recommended to control mosaic.

d) Physiological Disorders:

Some physiological disorders like sprouting of bulbs, etc are observed in some varieties of Garlic. This disorder is not of permanent nature and varies from variety to variety.