Context
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Submerged aquatic plants /weeds have been posing a new threat to the paddy cultivation in various districts in the State.
- These weeds include aquatic plants like vallisneria, najas as well as utricularia.
- Recently a weed shift has been observed in the paddy fields of Palakkad district, the rice granary of the State. Kannur, Ernakulam, Kottayam and Idukki districts have also recorded cases, though the incidence is less severe.
Types of Submerged aquatic plants /weeds
- Vallisneria also known as eel grass or tape grass is a common submerged aquatic plant. This has been introduced to the country as an ornamental aquarium plant. The genus is widely distributed in tropical and subtropical regions of Asia, Africa, Europe, and North America. In Malayalam it is known as thalayattippullu, vazhakala and mudipayal.
Source: The Hindu - Another one is Najas commonly known as rice field water-nymph, a species of aquatic plant found in freshwater habitats, especially still or slow-moving waters, like ponds and in rice fields.
- Utricularia, a carnivorous aquatic plant, is now common in rice fields, but the problem is more severe in the second crop season.
Key Details about Submerged aquatic weeds
- These plants may seem harmless at initial stage, but can grow as a major rice weed.
- The problem is severe in transplanted crops where these weeds get the ideal condition of a standing water column and sufficient inter-space and sunlight. Moreover, as other common rice weeds are absent at this stage, these new groups of weeds are at an advantage.
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