Part 9 (1/2)
”The general plan of the tests was much like that at Fredonia in most of the vineyards, with the additions of plats for stable manure and for leguminous and non-leguminous cover crops with and without lime.
From two to six check plats were left for comparison in each vineyard.
As already stated the results were often inconsistent in duplicate plats in the same vineyard, and if one test appeared to point definitely in a certain direction, the indication would be negatived by results in other vineyards. In these experiments the yield of fruit was the only index to the effect of treatments as it was not possible to weigh leaves or pruned wood, or to count the canes left.
”Nitrogen and pota.s.sium in combination, which gave the largest gains and greatest profit in the Station vineyard at Fredonia, showed a 13 per ct. increase in yield on one plat in the Jennings vineyard and a 9 per ct. decrease on the other; in the Miner vineyard this combination apparently resulted in a 25 per ct. increase; in the Lee vineyard in a 2-1/2 per ct. loss; in the Hamilton vineyard a 17 per ct. gain; and in the Grandin vineyard neither gain nor loss. In only two of the five vineyards in which this combination was tested was the gain great enough to pay the cost of the fertilizer applied. Similar discrepancies, or absence of profitable gain, mark the use of the other fertilizer combinations.
”Even stable manure, the standby of the farmer and fruit-grower, when applied at the rate of five tons per acre each spring, and plowed in, did not, on the average, pay for itself. Indeed, there were few instances among the 60 comparisons possible, in which more than a very moderate profit could be credited to manure. The average increase in yield following the application of manure alone was less than a quarter of a ton of grapes to the acre; while the use of lime with the manure increased the gain to one-third of a ton per acre. The ton of lime to the acre annually would not be paid for by the gain of 175 pounds of grapes. Cover-crops were used in five of the six cooperative experiments and proved even less adapted to increasing crop yields than did the manure. There was no appreciable gain, on the average, from the use of mammoth clover; indeed, a slight loss must be recorded for the clover except upon the plats which were also limed, and even with the lime the average yields on check plats and mammoth clover plats differed by only one one-hundredth of a ton. Wheat or barley with cow-horn turnips made a slightly better showing, as the plats on which these crops were turned under, without lime, averaged about one-twentieth of a ton to the acre better than the checks. With these non-legumes, lime was apparently a detriment, as the plants with the lime yielded a tenth of a ton less, on the average, than those without it.”
_Practical lessons from the Fredonia experiment._
From this experiment it becomes clear that the use of fertilizers in a vineyard is a local problem. General advice is of little value. It is evident also that the fertilization of vineyards is so involved with other factors that only carefully planned and long continued work will give reliable information as to the needs of vines. Indeed, field experiments even in carefully selected vineyards, as the cooperative experiments show, may be so contradictory and misleading as to be worse than useless, if deductions are made from the results of a few seasons. The experiment, however, has brought forth information about fertilizing vineyards that ought to be most helpful to grape-growers.
Thus, the results suggest:
_Only vineyards in good condition respond to fertilizers._
It is usually waste to make applications of fertilizers in poorly drained vineyards, in such as suffer from winter cold or spring frosts, where insect pests are epidemic and uncontrolled or where good care is lacking. The experiments furnish several examples of inertness, ineffectiveness or failure to produce profit when the fertilizers were applied under any of the conditions named. They emphasize the importance of paying attention to all of the factors on which plant growth is dependent. Moisture, soil temperature, aeration, the texture of the soil, freedom from pests, cold and frosts, as well as the supply of food may limit the yield of grapes.
_A vineyard soil may have a one-sided wear._
It is certain in some of the experiments and strongly indicated in others that the soil is having a one-sided wear--that only one or a very few of the elements of fertility are lacking. The element most frequently lacking is nitrogen. Exception will probably be found in very light sands or gravels which are often deficient in potash and the phosphates; or on soils so shallow or of such mechanical texture that the root range of the vine is limited; or in soils so wet or so dry as to limit the root range or prevent biological activities. These exceptions mean, as a rule, that the soils possessing the unfavorable qualities are unfitted for grape-growing. The grape-grower should try to discover which of the fertilizing elements his soil lacks and not waste by using elements not needed.
_Grape soils are often uneven._
The marked unevenness of the soil in the seven vineyards in which these experiments were carried on, as indicated by the crops and the effects of the fertilizers, furnishes food for thought to grape-growers. Maximum profits cannot be approached in vineyards in which the soil is as uneven as in these, which were in every case selected because there was an appearance of uniformity. A problem before grape-growers is to make uniform all conditions in their vineyards, and the vines must be kept free from pests if fertilizers are to be profitably used.
_How a grape-grower may know when his vines need fertilizers._
A grape-grower may a.s.sume that his vines do not need fertilizers if they are vigorous and making a fair annual growth. When the vineyard is found to be failing in vigor, the first step to be taken is to make sure that the drainage is good; the second step, to control insect and fungous pests; the third, to give tillage and good care; and the fourth step is to apply fertilizers if they be found necessary. Few vineyards will be found to require a complete fertilizer. What the special requirements of a vineyard are can be ascertained only by experiment and are probably not ascertainable by a.n.a.lyses of the soil.
This experiment furnishes suggestions as to how the grape-grower may test the value of fertilizers in his own vineyard.
_Applying fertilizers._
When it is certain that vines need fertilization, and what is wanted is known, the fertilizers should be put on in the spring and be worked in by the spring cultivation. Stable manure should be plowed under.
Grape roots forage throughout the whole top layer of soil so that the land should be covered with the fertilizer, whether chemical or barnyard manure. Applications of commercial fertilizers are generally spread broadcast, though it is better to drill them in if the foliage is out on the vines and thus avoid possible injury to tender foliage.
Commercial fertilizers should be mixed thoroughly and in a finely divided state. In leachy soils, nitrate of soda ought not to be applied too early in the season, as it will quickly wash down out of reach of the grape roots.
[Ill.u.s.tration: PLATE VIII.--Brighton (2/3).]
_Over-rich soils._
Some soils are too rich for the grape. On these the growth is over-luxuriant, the wood does not mature in the autumn, fruit-buds do not form and the fruit is poor in quality. Certain varieties can stand a richer soil than others. Over-richness is a trouble that may cure itself as the vines come in full bearing and make greater demands on the soil for food. It is well, however, on a soil that is suspected of being too rich or so proved by the behavior of the vines, to provide an extra wire on the trellis, to prune little and thus take care of the rampant growth. Some soils, however, and this is often the case, are so rich that the grape cannot be made to thrive in them; the vines waste their substance in riotous living, producing luxuriant foliage and l.u.s.ty wood but little or no fruit.
CHAPTER VII
PRUNING THE GRAPE IN EASTERN AMERICA
The inexperienced look on pruning as a difficult operation in grape-growing. But once a few fundamentals are grasped, grape-pruning is not difficult. There is much less perplexity in pruning the grape than in pruning tree-fruits. Pruning follows accepted patterns in every grape region, and when the pattern is learned the difficulties are easily overcome. The inexperienced are confused by the array of ”principles,” ”types,” ”methods,” ”systems” and the many technical terms that enter into discussions of grape-pruning. Some of the technicalities come from European practices, and others originated in the infancy of grape-growing in this country when there was great diversity in pruning. Divested of much that is but jargon, an inexperienced man can easily learn in a few lessons, from word of mouth or printed page, how to prune grapes.