PEST MANAGEMENT IN NAGPUR MANDARIN

PEST MANAGEMENT IN NAGPUR MANDARIN

Citrus is the most important fruit crop of Central India. It suffers heavily on account of the serious damage caused by insect pests. About a dozen of them attack this crop regularly right from nursery stage to the harvest with cognizable damage. But only a few are quiet serious of which effective control at appropriate time is must to ensure the quantity and quality of the produce.

Citrus leaf miner

Newly emerged larva mines the undersurface of the leaf in a zigzag way. This results in curling and drying of leaves, stunted plant growth and die-back in case of nursery plants.

Occurrence:

The pest attacks the crop through out the year except during severe cold and hot summer having peaks in March and September.

Control:

Spray monocrotophos @ 1.5 ml or quinalphos @ 2 ml or phosalone @ 1.5 ml/L of water at the bud burst stage and/or as soon as infestation is noticed.

Second spray should be given 10 days after the first with any of the above insecticides or neem oil @ 10 ml/L of water

Pruning of infested branches during rainy season is suggested in case of severe infestation and spray should be aimed at young flush only.

Citrus Blackfly

It is a very serious pest. Both nymphs and adults cause excessive desapping and secrete honey dew on which sooty mould grows that leads to "KOLSHI" manifestation. General plant health, its productivity and quality of the produce is severely hampered.

Occurrence:

The pest attacks the crop during all the three flushing periods viz., Ambia (Jan. - Feb.) , Mrig (Jub. - July)and Hasta (Oct. - Nov.) bahar and completes three generations in a year.

Control:

Spray monocrotophos @ 1.5 ml or phosalone @ 1.5 ml or phosphamidon @ 0.7 ml/L of water on the lower side of leaves covering the entire tree canopy.

After 15 days second spray should be given with any of the above insecticides or neem oil @ 10 ml/L of water.

Time of application:

Timing of spray is very vital, as only first nymphal instar of the pest is vulnerable to insecticides. The stage of 50% eggs hatching is the most ideal timing for spray application. This needs regular watch on the pest population in the field. Following timings were found most suitable to initiate control measures.

Flushing periods		Period of 50% egg hatching
I	Ambia	First fortnight of April
II	Mrig	Second fortnight of July
III	Hasta	First fortnight of December

Citrus psylla

Nymphs and adults suck the cell sap that causes heavy drop of flush and drying of twigs. It secretes honey on which sooty mould grows. The pest also acts as the vector for the deadly disease known as "Greening''.

Control :

Foliar spray of monocrotophos @ 0.7 ml/L or phosphamidon @ 0.3 ml/L or quinalphos @ 1 ml/L of water should be given as and when sprouts appear in June-July and January-February or when infestation is noticed.

If necessary, second spray of any of the above insecticides should be given after 15 days.

Citrus mites

Mottling of leaves, chlorotic appearance due to multitude of grey spots and leaf drop are the major maladies caused by this pest.

Occurrence:

The pest attacks the crop from November to May having peaks in February and March.

Control:

Foliar spray of dicofol @ l.5 ml or wettable sulphur @ 3g or monocrotophos @ 1.5 ml/L of water should be given when pest incidence is noticed. Second spray, if required, may be given after a week.

Precautions:

Insecticides used in the first spray should not be repeated in the second spray as far as possible.

In case of citrus blackfly spray coverage should also be extended to collateral hosts of the pest.

Spray application should not be given on rainy days.