Vegetables> Tomato> Pests

Tomato Fruit Worm (Heliothis armigera)

After hatching, the caterpillar crawls over the leaves and feeds on vegetative parts. It eventually finds its way to the fruit into which it cuts holes and burrows. The period of activity commences from October and continues up to March.

Control: Spraying of Endosulfan (0.05 %) is effective to control the pest. Judicious use of synthetic pyrethroids viz., Fenvalerate (50g a.i./ha) or Deltamethrin (10g a.i./ha) is effectively used for controlling fruit borer.

Epilachna Beetles (Epilanvhna vigintioctopunctata)

The yellowish coloured grubs and adults feed voraciously on the leaves and tender parts of the plant and often cause serious damage when they appear in numbers. As a result, the leaves are completely skeletonized leaving only a network of veins.

Control: Collection and destruction of infested leaves along with the grubs, adult and eggs reduces the pest incidence. Spraying the crop with Malathion (2ml/litre of water) or Carbaryl (2-4 g/litre of water) effectively controls the pest.

Jassids (Amrasca biguttula biguttula, Cestius (Hishimonus) phycitis)

Both nymphs and adults suck the sap from the lower surface of the leaves. The infested leaf curl upward along the margins, which may turn yellowish and show, burnt up patches. They also transit mycoplasma disease like little leaf and virus disease like mosaic. Fruit setting is adversely affected by the infestation.

Control: Jassids are controlled by 2-3 sprayings with Malathion (0.1%) or Dichlorvos (0.05%) 20 days after transplanting.

Tabacco Caterpiller (Spodoptera littoralis)

The insects are greyish brown and have white marking on upper wings. Young caterpillars feed gregariously on tender leaves, shoots and fruits at night. The pest is confined to
nursery beds and assumes cutworm habits.

Control: Spraying Nuvan-100 (0.5 ml/ 2 litres of water) or Endosulfan (0.05%) is effective in controlling the disease. However, spraying insecticides that are highly toxic should be avoided.

Whitefly (Bemisia tabaci):

Milky white, minute flies; nymphs and adults suck the cell sap from the leaves. The affected leaves curl and dry up. The growth of the plant is stunted. Whiteflies act as a vector, transmitting leaf curt virus causing severe loss in yield.

Control: Soil application of Carbofuran (24 kg/ha) as side dressing before transplanting is recommended for the control of white flies. Alternately, spraying with Monocrotophos (0.02%) or Phosphamidon (0.02%) at fortnightly intervals starting with the appearance if the pest. 2-3 sprayings of the above insecticides effectively control the pest.

Mites (Tetranychus cucurbitae):

Low relative humidity favours mite multiplication. Both the foliage and the flower buds are seriously affected. Different stages of mite are found in colonies covered by white-silky webs on lower surface of leaves. Nymphs and adults suck cell sap and white patches appear on leaves. Affected leaves become mottled, curl, turn brown and fall.

Control: During egg stage and the resting stages, most miticides are ineffective. At high temperatures, it may be necessary to apply these at an interval of two days. Acaricides like Dicofol (0.05%) and Wettable Sulphur (0.3%) gives effective control of mites. Cutting and burning of severely infested plant parts reduces further multiplication of mites. Proper irrigation and clean cultivation is essential to keep the pest population under control.

Root-Knot Nematodes (Meloidogyne spp.):

The root-knot nematodes invade the roots of the tomato plant and stimulate cell proliferation, which results in formation of rather large galls or roots. The root gall is the most characteristic symptom of the root-knot nematode damage. The aerial symptoms of root-knot nematode infection include stunted plant growth, chlorosis and a tendency to wilt under moisture stress during hot, dry weather. When the nematode population is high, plants of a susceptible variety may die before reaching maturity.

Control: as the nematodes cannot be completely eliminated from a given field, the overall goal is to keep the population density as low as possible. The most practical method of controlling nematodes is the use of resistant varieties. Crop rotation with non-host crops such as marigold, maize, onion etc. reduces the nematode population. Application of neem oil cake (1-1.5 t/ha) 15 days after transplanting helps to suppress the nematode population.