Insect-pests in rose crop

INDIA WITH varied agro climatic and soil types offers abundant opportunities for cultivation of all kinds of ornamental plants practically all year round at one or other places. Besides the various factors responsible for low production of quality flowers, insect-pest is an important one. Various insect-pests - thrips, aphid, leaf minor caterpillar mites and snails lead to extensive loss of flowers. A brief account of nature of damage and their management practices in rose are given below.

Red Scale Aonidiella auranti Both adult and young scales suck the sap. Infested mature shoots bear reddish brown encrustations, lose vigor and finally dry up. Scales appear in severe forms in pre and post monsoon period. It can be managed by * Use of healthy planting material free from scale infestation. * Cutting and burning of infested parts reduces further spread. Various natural enemies Chilocorus nigritus, Aphytis spp, and Pharasymnus horni are effective biological control agents. * Soil application of phorate or carbofuran at 1.0 kg a.i/ ha after pruning. * Use of malathion 50 EC or dimethoate or monocrotophos 36 WSC or chlorpyriphos at 0.1 per cent.

Thrips Rhipiphorothrips cruentatus The attack of thrips starts with the appearance of new flush after pruning. Both blackish brown adult and reddish nymph suck cell sap from tender leaves buds and flowers. The symptoms of the damage appear in the form of mottled and deformed leaves with brown patches and deformed buds with burnt margin. Severe attack by thrips adversely affects production of flowers.

Biological control agents like predatory wasp, Polistes herbraeus Preys on R. cruentatus * Soil application of phorate 10 G or carbofuran 3G at 1 kg a.i./ha. also helps. * Use of oxydemeton methyl or dimethoate or monocrotophos at 0.05 per cent manage the thrips.

Aphids Macrosiphum rosae: Both blackish green coloured nymph and adult suck cell sap from growing shoots and buds and devitalised plants. Natural enemies - grubs and adults of coccinellides and maggots of syrphids preys aphids. Application of extract of Solamum indicum and Erythrina indica in alcohol (four per cent) provides effective control. Soil application of aldicarb 3G or phorate 10G at 1.0 kg a.i./ha. controls the aphids.

Use of monocrotophos 36 WSC at 0.05 per cent or phosphamidan at 0.02 per cent or dimethoate at 0.03 per cent or oxydemeton methyl at 0.05 per cent or malathion 50 EC at 0.1 per cent at 10-15 days interval, prevents aphid attack.

Digger wasp (Crabro) damage the plants after pruning. They dig hole through cut end and the organism of die back often gain entry into the stem through it. * After pruning, painting the cut with fungicidal paint to prevent entry of die back fungus. * Pouring of few drops of rogor or dimecron in the hole and plugging with mud or small piece of cotton, controls the pest.

Termites (Microtermus obesi): Termites mainly feed on roots. In case of severe infestation they spread to stem portion and feed on the bark. Under dry soil conditions, damaged plant wilt, dry and finally die if infestation is very high.

Deep ploughing, proper irrigation and avoiding dry soil prevents its spread. Drenching soil with chlorpyriphos at 0.05 per cent or endosulphan at 0.07 per cent or malathion at 0.1 per cent before planting, protects plant against termites.

Besides, above mentioned pests, infestation with caterpillars, chaffer beetles, ash weevil, Red spider mites etc., occur causing damage to rose plant at different stages of growth.

Sunil Kumar CCS Haryana Agricultural University Hisar 125 004

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