Diseases and Pests of Gerbera
Diseases :
Root Rot:
It is a soil borne disease caused by Pythium irregularac and Rhizoctonia solani. Soil sterilization gives good control of the disease.
Foot Rot:
This disease is also caused by soil borne pathogens. This can be controlled by soil sterilization with vapam at 100 ml/m2.
Blight:
This disease, also known as gray mould, is coused by Botrytis cinerea which kills young growing tissues.
Spraying of 0.7% Captan, 1% TMTD or 0.7% Cuparen at 8 to 10 day interval was also suggested to control the disease.
Powdery Mildew:
Tow fungi Erysiphc cichoracearum and Oidium crysiphodesf. Sp. Gerbera producing a white powdery coating on the foliage, have been reported on gerbera.
Good control was obtained before flowering with the contact fungicides, elemental sulphor or Dinecap.
Pests of Gerbera:
White Fly:
In greenhouse, gerbera is a subject to heavy infestation of whitefly, a sucking insect. Control measures includes biological control with Encarsia Formosa and the use of BHC sprays, aerosols, smokes and parathion and malathion sprays.
Lepf Miner:
The leaf mining fly, Liriomyza trifolii, is a serious pest of gerbera. The larvcac born into the leaf and make irregularly shaped tunnels or blotches which are generally light yellowish tan to brown in colour.
Dimothoate at 0.1 % gave good control.
Mites:
Greenhouse-grown gerberas are often attacked by hemitarsonemus latus and Steneotarsonemus pallidus. The development of leaves and flower buds was adversely affected and the flowers were malformed and unsaleable.
Good control was obtained by spraying the plants with 20% Endrin at 200 ml per 100 l, a further application was made after 4 week.
Aphids:
This insoct infests young leaves and buds and causes injury by sucking the sap which results in distortion of tissues.
For the control spraying or fumigation are recommended.
Nematodes:
Root-knot nematode is occasionally serious in gerbera. The use of dasanit at 800 or 1000 ppm or mocap at 400 or 800 ppm is the later being more effective.