What’s in News?
- Submerged aquatic weeds have been posing a new threat to the paddy cultivation in various districts of Kerala.
- All India Coordinated Research Project (AICRP) on Weed Management, Thrissur has observed weed shift in the paddy fields of Palakkad district, the rice granary of the State.
- These weeds include aquatic plants like vallisneria, najas as well as utricularia.
- Kannur, Ernakulam, Kottayam and Idukki districts have also recorded cases.
- 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.
- The fertilizers applied to the crop by 60 days become totally ineffective as weeds absorb the nutrients forming a thick mat over the soil.
- In parts of Palakkad, hand weeding is still a common practice and farmers find it very difficult to control it as these new groups of weeds cannot be handpicked easily like grasses, sedges or broad-leaved weeds of rice.
- According to the farmers, these weeds have been seen in paddy fields for the last four or five years.
- Public awareness on safe disposal of these plants is important to avoid them reaching our water bodies and become invasive.
- 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.
- Najas is commonly known as rice field water-nymph, a species of aquatic plant found in freshwater habitats, especially in 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.