Which crop provides the highest net primary productivity of $2-4 \ kg/m^2$ from solar energy?

In $C_4$ plants,the primary $CO_2$ acceptor is .........

As compared to a ${C_3}$ plant,how many additional molecules of $ATP$ are needed for the net production of one molecule of hexose sugar by ${C_4}$ plants?

In $C_4$ plants,mesophyll cells and bundle sheath cells are specialised to perform respectively:

In a $CAM$-plant,the concentration of organic acid

Sorghum and sugarcane plants show saturation at about