MEDICINAL AND AROMATIC CROPS (2+1)

Pests and diseases

Pests
Rose plantations are attacked by a number of pests, among which the following are the important ones.
Aphids (Macrosiphum rosae): Aphids attack the plants during the flowering period. They can be controlled effectively by prophylactic sprays at 15 days’ interval with Methyl Demeton or Metasystox (0.1%) or Dimethoate (0.25%) or Phosphomedon (0.1%).
Caterpillars: The caterpillars of Operophtera frumata, Malacosoma Neustria, Orgyia antique and Archips podana attack the foliage during the summer and the reainy seasons. The caterpillars can be controlled by spraying Endosulphon (0.2%) or Quinalphos (0.15%) or Fenthion (0.12%).
Red Spider Mites (Tetranychus spp.): Heavy infestation results in the leaves becoming bronzed and falling prematurely. Wettable sulphur (0.4%) can be sprayed to control the mites.
Rose Thrips (Thrips fuscipennts): Thrips attack is common during the flowering period. Heavy infestation causes a significant loss to the flower-yield. Sprays of Malathion (0.2%) or Sumithion (0.1%) at an interval of 10 days control the attack of thrips.
Caspid Bugs (Lygocoris pubulinus): These pale-green insects suck the sap from the shoot-tips mainly from young flower-buds, causing the flower petals to develop small holes. The application of Carbofuron or Phorate @ 10 kg/ha to the soil after pruning, at the time of bud-formation, is recommended for the control of this insect.
Brown and Scurfy Rose Scale (Aulacapis rosae): The scales occur on the stems and suck the sap from the stems, resulting in the drying up of the shoot. The incidence is more during the rainy/autumn season. For control of this insect, foliar sprays of Monocrotophos (0.15%) or Carbaryl (0.3%) is recommended.

Diseases
Black Spot (Diplocarpon rosae): The fungus causes black spots on the leaves, due to which the leaves will abscise. Fungicidal sprays with Captan (0.2%) or Mancozeb (0.3%) have been recommended for the control of rust.
Powdery Mildew (Sphaerotheca pannosa): Small, white, powdery pustules of fungus appear on the leaves, stems and occasionally on the flowers. Dinocap (0.1 to 0.15%) or wettable sulphur (0.4%) should be sprayed at 15 days interval for the control of this disease.
Downy Mildew (Peronospora sparsa): Small reddish-purple areas appear on the youngest leaves resulting in leaf distortion. Repeated sprays of Mancozeb (0.2%) or Captafal (0.3%) or Copper Oxychloride (0.3%) should be employed for effective control.
Viral Diseases: Rose mosaic is the most common virus disease. Control measure should be followed to kill the various virus vectors.
Rose Rust (Phragmidium subcorticium): The disease attacks the leaves, flowers and shoots and causes leaf-fall and abscission of buds. The most important control is to bury the fallen leaves under heaps of soil around the rose bush. The winter rust spores perish due to the development of antagonistic micro-organisms. The disease is chemically controlled by the spraying of Bavistin @ 0.1% twice during the flowering period (March and May). After the harvest, Benlate @ 0.1% is sprayed periodically in order to check the disease.