In agricultural practices,higher input gives higher yield. Discuss how?

India is a country where three-fourths of the population is engaged in agriculture. Even though the financial conditions of some farmers allow them to adopt higher-level farming practices and improved agricultural technology,they are hesitant to use $HYV$ seeds with traits such as resistance to diseases and pests,or qualities that would result in higher yields.
$(a)$ What is meant by genetically modified crops?
$(b)$ What are the desired agronomic characters for fodder and cereal crops?
$(c)$ In your opinion,what should be done so that modern agricultural technology is adopted by most farmers?

Sitaram,an educated farmer,convinces his friends to use manure instead of fertilizers in their fields. List any two advantages that the farmers will get if they accept this advice. How does the excessive use of fertilizers affect the environment? Which values of Sitaram are depicted by his efforts?

Pomphret,mackerel,tuna,sardines and Bombay duck are the popular freshwater fish varieties.

Nakul was shooting his arrows towards a target. Every time the arrow fell short of the target. This annoyed him. His brother, Arjun, came to his rescue. He showed his brother the right way to shoot an arrow. When Nakul tried again, he found that the arrows started hitting the target.
$(a)$ What do you think Arjun might have told Nakul?
$(b)$ What are the values imbibed by Arjun?

$(i)$ What are weeds? Give two examples.
$(ii)$ "Removal of weeds from cultivated fields during the early stages of growth of crops is essential for a good harvest." Justify the statement.
$(iii)$ List five preventive methods that help in weed control.