Which of the following did not help farmers? reaper
crop-rotation
better fertilizers
boll weevil

The Boll weevils effect

boll weevil did not help farmers in fact it did quite the contrary here "Boll weevils entered the U.S. from Mexico in the late 1800s, when they were first spotted in Texas. ... Cotton production moved in advance of the weevil, creating a boom in cotton plantings in areas that were weevil-free. But as the cotton spread, so did the boll weevil – costing cotton growers billions in revenue." (fwi boll weevil is a type of beetle looking bug)    

Wth is a boll weevil

The boll weevil is a beetle that feeds on cotton buds and flowers. Thought to be native to Central Mexico, it migrated into the United States from Mexico in the late 19th century and had infested all U.S. cotton-growing areas by the 1920s, devastating the industry and the people working in the American South.

this statement is true.

forests are public goods, available for everybody. when usage of such a good becomes interesting for consumers and its usage increases, there can be a risk of overexploitation. it is a non rival good therefore, if one person consumes the good it does not reduce the availability for subsequent consumers.

these caracteristics require the establishment of measures in order to prevent the destruction of a commonly owned space, for example, to restrict the amount of people that have access to the same time.