Correct Option
The correct option is (c) 2 and 3 only.
Explanation
Weeds are undesirable plants that grow naturally alongside cultivated crops. They compete with crop plants for essential resources such as water, nutrients, space, and light, thereby affecting the growth and yield of the main crop. The removal of weeds is known as weeding.
Statement-wise Analysis
- Statement 1 is Incorrect: Weeds are not cultivated plants grown for fodder; rather, they are unwanted plants that grow spontaneously in agricultural fields (e.g., Parthenium, Xanthium). While some weeds may be used as fodder, they are defined by their undesirable presence in a crop field, not by their utility.
- Statement 2 is Correct: Tilling or ploughing the field before sowing seeds is an effective physical method for weed control. This process uproots and kills the weeds, which then dry up and get mixed into the soil, serving as organic matter.
- Statement 3 is Correct: Weedicides (chemicals used to control weeds, such as 2,4-D) are most effective when applied during the vegetative growth phase of the weeds. Spraying is typically done before the weeds reach the flowering and seed-formation stages to prevent further propagation and dispersal.
Key Takeaway
Weed Management: Weeds are unwanted competitors to crops. Effective control involves physical methods like tilling before sowing and chemical methods (weedicides) applied during the vegetative phase prior to flowering.