WEEDS (Syllabus: GS Paper 3 – Agriculture)

Context: Agricultural scientists and policymakers have long sought sustainable methods for rice and wheat cultivation, emphasizing water-efficient rice farming without burning straw residues and no-till wheat farming to reduce the ecological impact of these staple crops.

Weeds

• About: These are unwanted and undesired plants that negatively impact human welfare by interfering with the use of land and water resources. They may alternatively be called "plants out of place.
• Competition with Desirable Plants: In agricultural lands, forests, aquatic systems, etc., weeds compete with desirable and beneficial plants.
• Impact: Weeds pose a serious problem in non-cropped areas like industrial sites, road and rail lines, airfields, landscape plantings, water tanks, waterways, etc.

oWeeds generate more losses to agriculture than any other type of agricultural pest.

• Global Presence: Around 3%, or 8000 species, of the approximately 250,000 plant species that exist in the globe act as weeds.
• Weeding Method: It is the process of eliminating weeds from a field. This is an effective pre-harvest method for managing crop yield and ensuring crop protection.

Weed Control Method

• Chemical Control: Herbicides are utilized to suppress weeds by defoliating, desiccating leaves or stems, or altering the plant's growth patterns.
• Mechanical Control: It employs powered equipment and tools to manage weed infestations with minimal manual labor, ensuring minimal soil disturbance.
• Biological Control: It uses infections or insects to damage weeds, with bio-control agents usually sourced from the same region as the weed species.
• Manual Control: It involves removing weeds by hand or with small tools, minimizing soil disturbance and reducing the risk of erosion and weed seed germination.
• Herbicide-Tolerant Solutions: Direct Seeded Rice (DSR) and Zero Tillage (ZT) wheat methods use chemical herbicides, such as Imazethapyr, to manage weeds, replacing the need for water and repeated ploughing. DSR allows for direct sowing of paddy seeds without nursery, puddling, or flooding.