What is benefit of high-yield crops?

The benefits of a high-yield crops are:

-The improved varieties of crops give us more yields per hectare.

-The high yielding varieties of crops are dwarf. Due to short height, their plants are stronger and hence can withstand strong winds. The problem of lodging is less in these improved varieties.

-The high yield varieties of crops give better response to fertilizers. This means that when fertilizers are supplied to high yielding varieties their yield increases substantially. This is not so in case of traditional varieties.  

-The high yielding varieties of crops take less time for maturing. As a result, some additional crop can be raised in the spare time thus saved.

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explanation:

since there isn't any suggested answers i will give you the reason and hopefully you can figure it

south africa, or rather all of africa, has not been in the location in which it is nowadays throughout the geological past. after the super-continent pangaea started to break apart, gondwanaland, in which was africa, moved further south, and parts of it came to be very close to the south pole. because the climate in this part of the world is very cold due to the very dispersed sun rays in there, what is now south africa, started to freeze, and the conditions were right for the formation of glaciers. the glaciers existed up until the period when gondwanaland started to break apart and what is now africa started to move towards north, sp it warmed up and the glaciers melted.