Parasite Weeds and their Control
Parasite Weeds and their Control
I) Cuscuta Spp. (Dodder, Amarvel, Aksashbel):
It is a parasitic leafless herb with golden yellow, shining wiry stems, found on trees, cultivated crops and hedges.
Control Measure:
1. Cuscuta can be pulled out and buried. Cuscuta can be controlled by proper crop rotation.
2. Paraquat 1% spray with a high volume sprayer will kill dodder. (In case of lucerne 0.05 to 0.1 %)
3. The seed of lucerne are to be treated with 5 to 10% solution of common salt for five minutes. The light seeds of Cuscuta will float on the surface of water.
II) Striga Spp. (Striga, Witch Weed):
Striga is an annual parasitic herb with a wide range of the host crop plants in India. In India the common host plants are sorghum, sugarcane, bajara and maize/
Control Measure:
1. The host plants are rotated with cotton, sunflower, cow pea, groundnut, certain beans, and castor to minimize the infestation of Striga.
2. In heavily infested areas, both parasitic weed and the crop should be ploughed down at early stage.
3. Hand weeding can reduce the weed population
4. Soil may be fumigated with methyl bromide.
5. Increase dose of Nitrogen may help good growth of host crop and suppress the parasitic weed.
6. Use of resistant variety.
7. Herbicidal spray of 2,4-D (amine) @ 1.2 kg ai/ha on flowers of Striga or pre-planting application of Dicanba or Fenac @ 2 kg ai/ha are very effective.
III) Orobanche Spp. (Broomrape):
It is a total parasitic weed observed on different host plants according to its different spp. e.g. Cernua on tobacco and sunflower.
Control Measure:
1. Proper rotation with pepper, rice linseed, sunhemp, sorghum, seasamum, etc for tobacco area.
2. Glyphosate @ 0.5 kg ai/ha is found effective.
3. Orobanche growing outside the crop field should be destroyed by frequent tillage before seed setting.
IV) Loranthus Spp. (Loranthusor Bandagul):
It is a phanerogamic parasite found mostly in the tropics rooting beneath the bark of the trees, particularly mango. It derived the whole of its nutrients from juice of host plants.
Control Measure:
1. Affected branches of host plants should be periodically cleaned or cut down before monsoon.
2. High speed diesel will be helpful to kill the foliage of this parasitic weed.
3. Paraquat 1% spray will be helpful to kill the foliage of this parasitic weed
4. Paraquat + 2,4-D @ 3.5 kg each in 160 litre water/ha sprayed with rocker sprayer on the infested area can kill Loranthus by both contact and translocations to be taken to protect the host tree.