and winter of 1912-1913 much of the season's wood was so immature, as evidenced by the withered canes, that it was impossible to find a sufficient number coming from wood two years old; and so in order to keep the fruiting wood close to the head it was necessary to prune to canes growing from wood older than two years. Buds on canes from the latter are not the best fruit buds, but rather produce wood. Our records show that while 1477 pounds of wood per acre was pruned away in the fall and winter of 1911-1912, but 1098 pounds was pruned in the fall and winter of 1912-1913 and less buds per vine were retained than in 1912.

Thus the probable 1913 crop was largely discernible at the fall and winter pruning of 1912-1913, when the immature canes were cut away, altho many buds that were retained at the time afterward succumbed to low temperatures during the winter. But missing buds were not nearly so apparent at foliation as was the case in the early summer of 1910.

The vineyardist generally ascribes the light yield of 1913 to a lack of wood growth. This is in part true, but as has already been stated the real lack of fruiting wood was essentially a lack of well matured wood that was resistant to low temperatures. With well matured wood in 1912 it is reasonable to believe that the yield of 1913 would not have dropped to the low stage of that year, as the extremes of the winter temperatures that followed were not great nor was a lower minimum than zero reached during the period.

The information for 1912-1913 is brought forward in this bulletin merely to show the relationship of immature wood and buds to the succeeding crop. The data we have taken for the year is not a true indication of the amount of injury that would have occurred were the pruning delayed until late spring, so that the poorly matured canes could have been observed at foliation..

WEATHER AND CROP OF 1915-1916.

RELATION OF CLIMATIC CONDITIONS TO WOOD MATURITY AND SUBSEQUENT INJURY.

The season of 1915-1916 gave abundant opportunity to study bud injury as affected by immaturity and low temperatures. These studies include not only work with the principal variety (Concord) of the Chautauqua area, but a large number of named varieties.

TABLE V.-SUMMARY OF METEOROLOGICAL DATA, WITH SPECIAL PHENOMENA AFFECTING THE GRAPE CROPS OF 1915 AND 1916 AS

COMPARED WITH 1914.

These records were kept at the Vineyard Laboratory, Fredonia, N. Y., cooperating with the U. S. Weather Bureau.

It will be necessary, for an understanding of the effects that followed, that the climatic conditions of the growing and maturing periods. of 1915 be studied, as the unfavorable agencies were operative during those periods.

Table V summarizes the meteorological data, with special phenomena affecting the grape crops of 1915 and 1916 as compared with 1914. The season of 1914 is selected for comparison as the yield of that year was considerably above the average, and the fruit ripened well, as is shown by the sugar content in Table IV.

The wood also matured well, for not enough injured buds were noted in the spring of 1915 to warrant taking any data.

The records given in Table V show that for the growing months of May, June and July there was a total deficiency of 277 degrees, or in other words for each day of this period the temperature was 3 degrees below that of 1914. For the maturing months of August, September, and October the total deficiency was but 87 degrees. But September gave a daily excess of 3.2 degrees or a total of 96 degrees for the month. During August, a critical month in the ripening of the fruit, the daily deficiency was 4.6 degrees or a total for the month of 142 degrees.

The total precipitation for the growing months of May, June and July was 5.52 inches above that of 1914, while for the maturing period it was 2.8 inches above that of 1914, August showing an excess of .23 inches, September 1.10 inches, and October about one-half an inch. The total rainfall, however, does not tell the whole story, for the frequency must also be considered in a correlation of weather with the growing and maturing crop. Table VI, on the page opposite, illustrates the distribution of the rainfall and the condition of the sky for the season of 1915.

From this table it will be seen that some rain fell on approximately one-half of the days of the summer and that of the 183 days included from May to October, 65 were classed as cloudy, while 59 were partly cloudy. These figures are essentially correct, there being very little variation in either direction.

The cloudy days were about equally distributed thru the two periods, the growing and maturing, altho the greatest excess precipitation, 6.11 inches, of any month, occurred during July. The cloudy condition of the sky as well as the large number of rainy days during August, September and October retarded evaporation

so that the soil was kept wet. This condition, coupled with the temperatures of September that were above normal, kept wood growth active late, and retarded the ripening of the fruit. In fact, strictly speaking, the fruit did not mature, as is indicated by the sugar analysis of 1915 shown in Table IV.

TABLE VI.— DISTRIBUTION OF RAINFALL AND THE CONDITION OF THE SKY DURING 1915.

The immaturity of wood during the fall and winter of 1915–1916 was not apparent as in 1912-1913. In the vineyards under consideration practically the same number of canes per acre were put up in 1916 as in 1915, while the amount of wood pruned away was not much less than that removed in pruning for the 1915 crop. In short, enough fruiting buds were retained for the 1916 crop, that normally would produce a tonnage equal to that of 1915. There was no indication whatever during either fall or winter of poorly matured wood. In fact not until early spring, before foliation, was it determined that a large percentage of canes and buds were injured or dead.

What were the weather conditions of the winter season of 19151916 that brought about the extensive injury and killing? Table V summarizes these.

According to our weather records the November temperatures were above normal as well as those of 1914. There was no snow the first half of the month, and then only a trace till the latter part. During the last two days about four inches fell. The maximum reading for the month was 71 degrees while the minimum reached 24 degrees.

During December the temperatures were fairly uniform, with the greatest range on any day reaching 26 degrees. The ground was covered with snow thruout the month, while a total of 27.3 inches fell. A glaze storm occurred on the 13th. The maximum for the month was 50 degrees with a minimum of 13 degrees.

January was remarkable for sudden temperature changes, many days of rain and very high winds, gales occurring on the 10th, 13th, 16th and 18th. The ground was bare nearly the whole month, there being only two days when there was 5 inches or less of snow. During the week January 22–29 for 96 consecutive hours the average hourly temperature was 52.6 degrees. The maximum for the month was 69 degrees while the minimum was 1 degree.

February was somewhat below the average in temperature, when for several days the readings were below zero. A range of 47 degrees was recorded in one day. Some snow fell on 19 days during the month, but by the middle there was 5 inches or less on the ground. At the end of the month 10 inches of snow covered the ground. The maximum temperature recorded was 47 degrees, the minimum -13 degrees.

March was a month of great temperature extremes with the mean temperature of the month below normal. Snow covered the ground till near the end. A severe glaze storm occurred on the 6th and 7th. The maximum for the month was 58 degrees while the lowest minimum of the winter -16 degrees was recorded.

The monthly mean temperature for April was slightly below the normal. The maximum reading for the month was 75 degrees while the minimum was 25 degrees, the last below freezing temperature of the year. The total precipitation for April was 2.19 inches above normal, this largely in the form of rain. However April or subsequent climatic conditions were not factors in a determination of the injury of this season, for as has already been stated, it was noted during the latter part of March that a large percentage of buds were entirely dead, while others showed only partial injury. Many buds at foliation, apparently uninjured, partially or entirely expanded only to die back later. Still others expanded as leaf buds only, the flower parts being killed. Some of the vegetative shoots grew several inches and then withered.