OBSERVATIONS MADE IN OTHER VINEYARDS IN 1916. Many vineyards under various exposures and locations were examined during the summer of 1916 and notes of their condition taken. Descriptions of a few of these follow:

Vineyard F. was examined on June 23 and photographs of parts of the area made. The injury in this vineyard probably averaged from 50 to 60 per ct. of dead buds. It is wet over a large part but especially along the main highway where the water is backed up by the road. During spring and late fall it frequently stands over this portion in large ponds. It is over this area that the greatest injury was shown.

Vineyard W. showed very little winter killing of the buds, probably less than 5 per ct. The only injured canes were in a low corner that is very wet. The larger part of the vineyard lies high. A neighboring vineyard, similarly situated, likewise escaped serious injury, but another on the same farm, laying between two woodlots and situated very low, was almost completely killed back. Practically all vineyards in this locality but the two first named were so badly injured that only very small crops were harvested. The greatest injury in all cases was on the low wet areas.

Examined vineyard L. June 27th. All the sections on this farm are severely injured; however the upper end of one section that is situated high, escaped. All other sections are very wet and on most of these the crop will not pay for the handling.

Vineyard G.- Catawba was examined June 29th and this variety was found badly injured. It is low lying and on a heavy soil. At this date it indicates that it has been very wet. The owner estimated his crop at 5 per ct. of the ten-year average.

There were but very few vineyards that escaped some injury, while taking the "Belt " as a whole the crop records show that the yield of 1916 was but 60 per ct. of the 1915 return or 71 per ct. of the seventeen-year average.

VARIETAL (OR SPECIES?) RESISTANCE TO LOW

TEMPERATURES.

Table X shows the extent of winter killing of 146 varieties of grapes during the winter of 1915-1916. These are practically all of the same age, in the same section, under similar soil conditions,

TABLE X.- PERCENTAGE OF WINTER INJURY TO GRAPE BUDS OF DIFFERENT VARIETIES FOR THE WINTER OF 1915-1916.

(100 per ct. indicates that every bud reserved for fruiting was killed.)

Agawam.
America.
Aroma.
Aug. Giant.

Bacchus.

Bailey.

Banner.

Barry.
Beacon.

Dracut Amber.

Dry Hill..

Dutchess

Daisy.

Ohio.
Moore.

Victor.

Jefferson.

Jessica.

Mo. Reisling..

Geant..

65

76

Starks Delicious.

64

46

Marion.

28

99

Emerald..

54

49

88

16

34

70

Bell..

24

26

20

74

35

26

a gravelly loam, with the exposure uniform. All have been subjected to the same cultural practices. The basis for the computations was the same as for the Concord, namely, all buds developed during 1915, which were normally the fruit buds of 1916, were counted.

Of the native varieties it is seen that the injury ranged from 12 per ct. to 100 per ct. or complete killing of the fruit buds. Mission, a variety of the species Rupestris, however, was the least injured with 10 per ct. of its buds killed.

This record is particularly interesting in one respect. It is popular opinion at least, that the carrying of a crop, or a heavy one in particular, delays maturity regardless of other factors. Riparia, Gloire, Rupestris St. George, No. 265, No. 268, Mission and Grand Feuilles are all male plants and consequently set no fruit. In other years they have shown no greater nor less winter killing than has Concord, yet only one, Mission, was less affected than Concord in this vineyard during 1915-1916. Nos. 264 and 265 are female and male plants respectively of the same species, Vitis riparia. Since practically no fruit was borne on No. 265 during 1915 no fair comparison of the degree of injury between the sexes is yet possible. Nos. 267-268 are female and male plants respectively of the same species, Vitis champini. In this instance no crop was matured by 267 in 1915.

However, while it cannot be conclusively stated, yet it is apparent that too much stress has been given to the relation of wood and bud maturity to the size of the crop irrespective of other factors, principally climatic.

To what is the difference of susceptibility between two varieties due? Is it an inherent specific character? Assigning the varieties included in Table X to the species from which they have been derived, it is apparent that there are wide differences of susceptibility, even among varieties derived from the same species. Of the pure Labrusca varieties, the range of killing is from Cottage with 13 per ct. of injury to Wyoming with 78 per ct. The varieties containing Riparia blood along with that of other species, vary in degree of injury from the minimum of 12 per cent with Noah, to 88 per ct. with Secretary. Varieties derived in part from Aestivalis range from 22 per ct. injury with Wine King, to 94 per ct. for Dutchess. This group as a whole however shows a percentage of injury slightly greater than the Riparia varieties, and considerably greater than

616 REPORT of the DepARTMENT OF HORTICULTURE OF THE

the Labruscas. Injury with the Labrusca-Vinifera hybrids varies from 15 per ct. for Woodruff, to 100 per ct. with Mills and Rebecca. The percentage of injury for all varieties of this group is but slightly less than for the Aestavalis. However the varieties of the LabruscaVinifera group in which the Vinifera fruit characters are more prominent, as a rule show a higher percentage of injury than those in which the Labrusca characters predominate, and also a greater percentage than those with Aestavalis blood. It has been thoroly proven that pure Vinifera varieties practically kill back to the ground in New York during winter if left uncovered.

Pure Riparia represented by Gloire and Grand Feuilles with 29 per ct. and 21 per ct. injury respectively show a consistent, fairly high resistance. With the pure Rupestris varieties, St. George and Mission, the variation between the two is greater than with the two pure Riparia. Mission, of all the varieties recorded, was the least injured with 10 per ct. of buds killed.

The resistance to injury for varieties derived from the same two or more species as the Labrusca-Vinifera hybrids is probably due to the degree of dilution of the hardier Labrusca in certain sorts than others. The extent of dilution not always being apparent in the fruit, the variety is assumed to have inherited other characters of both parents in equal degree.

However, some, as Barry for example, show more clearly the lack of Vinifera fruit characters than others from the same cross, as for example Goethe and Gaertner.

It would seem in view of these data that certain species are more resistant to low winter temperatures than others, or that wood and bud maturity is reached earlier and more completely in some species than in others.

Beach and Allen 37 found that the hardness of the wood of certain apple varieties was quite closely correlated with hardiness or resistance to low temperatures.

It is well known that the texture of wood among grape species varies considerably. However there have been no investigations, to our knowledge, that have considered the possible correlation of wood hardness with hardiness to cold.

These data indicate that there is no complete immunity from low temperatures among species or varieties if immaturity is not 87 L. c. Beach and Allen, p. 12.

complete at the beginning of winter. The nearest approach was Mission with a 10 per ct. killing.

CONCLUSIONS.

The question now arises, Is it possible to influence the maturity of grape tissues? If so to what extent and how? With the unfavorable season of 1915 little could have been done that would have entirely eliminated the injury, yet we are convinced that the injury could have been considerably lessened in many instances. The experiences of some growers in severely cutting, in the spring, frostinjured vineyards, thus inducing a rank growth of wood, indicates that this is a doubtful practice, but rather it is better that all uninjured growth no matter where located on the vine, be allowed to develop. Excess water in the tissues being correlated with immaturity during late summer and early fall, it is obvious that practices tending to reduce the available supply are desirable. It is the opinion of the writer based on many observations during the past few years, that poor drainage has determined the injury in the majority of cases. Many vineyards are growing on soils that should never have been planted to grapes, at least until underdrainage had been installed. Such as these will never be immune to low temperature influences. It is possibly true that many such soils will return as much profit per acre in vineyards as could be obtained from general farm crops, yet there is always the prospect of heavy losses from low temperatures.

It is the customary practice to discontinue all vineyard cultivation in late July or early August. The time however should be conditioned upon the character of the weather, especially as to the rainfall. After discontinuance, all weeds should be allowed to grow, and it is a doubtful practice to mow these just before the beginning of harvesting, as is quite generally done. The mulch provided by the mown weeds at this period conserves soil moisture, a thing that should be avoided. Green manure crops operate in converse ways in regulating water in the soil. While the plants are but partially grown, all kinds no doubt produce a drying effect upon the soil, but those possessing broad leaves as rape and in lesser degree cow-horn-turnips later exert a shading, and especially where rainfall is abundant, results in a retention of more moisture than is withdrawn thru the tissues. This in a large measure may be corrected