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Location: Bekasi, Jawa Barat, Indonesia

Wednesday, May 5, 2010

Anthurium Diseases and Pests Attack

A large number of diseases and pests attack the plants damaging flower production and quality of the flowers.

A. Diseases
Fungi, bacteria and viruses sometimes attack the plants producing serious diseases.

1. Fungal Diseases in Anthurium
The major fungi attacking plants were colletotrichum, Pythium spp.

a. Anthracnose
Collectotrichum gleosporioides is the causal organism of this disease. It is the most damaging diseases of anthuriums. Also known as spadix rot or black nose, it is a problem in high rainfall areas. Spadices are damaged and flowers become unsuitable for commercial purpose.

Control of Anthracnose

Spray Maneb @ 2lb/l00 gal and Dodine or Dyrene @ 1 Ib/l00 gal gives good control of the disease. It is suggested that application should be made at 2 -week intef'7al and a sticker should be used. Certain cultivars like Marian seefurth, Uniwai and Manoa Mist are reported to be resistant to the pathogen.

b. Root rot
Pythium splendens is the causal organism of this disease. It attacks-the root of Anthurium andreanum, and often causes serious losses, especially during rainy season.
Control of Root rot in anthuriums
The disease can be controlled by a soil application of PCNB (quintozene) @ 80 ounce 150 gal water.

c. Leaf spot in Anthurium
Septaria anthurium and S. minima are the causal organisms for the leaf spot disease. A non-parasitic leaf spotting may occur under unfavourable cultural conditions.

Control of leaf spot in anthurium
The disease can be controlled by sprays of Carbileen (Zineb) @ 30 g 1100 Iitres of water, repeated at interval of 2-3 weeks. Among the several fungicides tested in vitro under different conditions of temperature and humidity, Oxyquinoline sulphate gives best control of S. minima.

2. Bacterial disease
Xanthomonas compestris poses a considerable threat to the commercial anthurium growers because of systemic infection.

Control of bacterial disease
Strict sanitation measures, the removal of affected leaves and spraying with Streptomycin sulphite or Oxytetracycline. are recommended. The bacterium appears to be resistant to copper based preparations, and those can also be phytotoxic to anthuriums.

3. Viral disease in Anthurium
Mosaic and malformation of leaves and spathes are observed in different anthurium cultivars in commercial nurseries. Up to 20% infection can be observed in pink and red cultivars and 94% in white cultivars. The virus could be transmitted by Bemisia tabaci and possibly also by grafting a piece of infected leaf onto the stem.

B. Pests attacking Anthurium
Though pests are not a problem in anthurium cultivation, insects like aphids, scales, thrips and spider mites are found to attack the plants and cause considerable damage.

1. Aphids
These insects suck (Aphids) the plant's sap, causing yellowing and distortion of leaves and poor growth. They secrete a sticky sugary substance called 'honey dew' upon which a black mould often grows. The mould not only looks very unsightly but interferes with the leaves as well.
Control aphids attack
Systemic insecticides containing Dimethioate and malathion (0.2%) effectively controls the aphids. A formulation containing Pyrethrum extract gives complete control of Myzus circumflexus on A. scherzerianum plants in the green house, without phytotoxicity.

2. Scale insects
Scale insects infest stems and leaves, suck the sap and weaken the plants.

Control of scale insects in Anthurium
Wiping the insect off the plants with a cotton-wool swab soaked in methylated spirit or spray with 0.2% malathion work well against these insects.

3. Spider mites
These minute mites cause yellowish mottling of the leaves which may become brown and shrivel. A fine white web spun on the underside of leaves is another sign.

Control of spider mites in Anthurium
Spraying of affected plants with 0.2% malathion or kelthane (8 ml in 10 I of water) is found to be very effective to control the mites.

4. Thrips
Thrips suck the sap from leaves and cause a mottled effect on foliage and flowers.

Control of Thrips in Anthurium
The control measures are similar to those of aphids and scale insects.

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