Growing Potatoes - Moisture & Light
There is no farm crop more affected by the supply of moisture than the potato. It has been found by experiment that it takes about 425 tons of water to grow a ton of dry matter of potatoes. A crop of 200 bushels per acre would therefore require 650 tons of water, equivalent to a rainfall of nearly six inches.
Because of its need for a good water supply, and its susceptibility to the weather, the average potato yield is more affected by water supply than by a lack of plant food.
The application of fertilisers or the presence of large amounts of plant food will be of little value if the moisture supply is deficient.
It is also true that too much water will check the growth as much as too little.
summarised from Grubb & Guilford, 1912.
ND / Diversity website
