Which one of the following nutrients is not available in fertilizers?

Define the terms hybridization and photoperiod.

What type of methods are used before grains are stored for future use?

Find out the correct sentence about manure:
$(i)$ Manure contains large quantities of organic matter and small quantities of nutrients.
$(ii)$ It increases the water holding capacity of sandy soil.
$(iii)$ It helps in draining out of excess of water from clayey soil.
$(iv)$ Its excessive use pollutes environment because it is made of animal excretory waste.

The kind of flowers available determines the taste of honey.

"Crop Protection Management is both a pre-harvesting and a post-harvesting affair". Illustrate the statement with suitable examples.