Explain various effects of weeds on crop plants.

Given below are statements about the harmful effects of weeds on crop plants. (i) They interfere in harvesting. (ii) They help crop plants to grow healthily. (iii) They compete with crop plants for water, nutrients, space and light. (iv) They affect plant growth. Choose the correct combination of statements.

Answer the following questions in detail: Explain the various effects of the disaster of railway accident.

Explain the various methods of crop improvement. Name one improved variety of Rice, Maize, Soyabean, Sunflower and Mustard.

Explain various types of simple tissues in a plant.

Explain various types of simple tissues in a plant.

Why do weeds threaten crop plants?