the cost, there are several objections to growing grapes under
irrigation. The vines are subject to more diseases and physiological
troubles; the fruit is said to lack aroma and flavor; grapes grown on
irrigated land do not stand shipment well, the unduly inflated grapes
often bursting; wine-makers do not like irrigated grapes as well as
those from non-irrigated lands; and watery grapes from irrigated lands
make inferior raisins. It is maintained, however, with a show of
reason, that grapes suffer in irrigated vineyards in the ways set
forth only when the vines are over-or improperly irrigated.

[Illustration: PLATE VII.--Barry (x2/5). Delaware (x2/5).]

CHAPTER VI

FERTILIZERS FOR GRAPES

As regards fertilizers, the grape-grower has much to learn and in
learning he must approach the problem with humility of mind. For in
his experimenting, which is the best way to learn, he will no sooner
arrive at what seems to be a certain conclusion, than another season's
results or the yields in an adjoining vineyard will upset the findings
of past seasons and those obtained in other places. Unfortunately,
there is little real knowledge to be obtained on the subject, for
grape-growers have not yet broken away from time-worn dictums in
regard to fertilizers and still follow recommendations drawn from work
with truck and field crops. This is excused by the fact that there
have been almost no comprehensive experiments in the country with
fertilizers for grapes.

No fallacies die harder than the pronouncements of chemists a
generation ago that fertilizing consists in putting in the soil
approximately that which the plants take out; and that the chemical
composition of the crop affords the necessary guide to fertilizing.
These two theories are the basis of nearly every recommendation that
can be found for the use of fertilizers in growing crops. The facts
applied to the grape, however, are that the average tillable soil
contains a hundred or a thousand times more of the chemical
constituents of plants than the grape can possibly take from the soil;
and many experiments in supplying food to plants show that the
chemical composition of the plant is not a safe guide to their
fertilizer requirements. Later teachings in regard to the use of
fertilizers are: That the quantity of mineral food in a soil may be of
far less importance than the quantity of water, and that the
cultivator should make certain that there is sufficient mo