312 INTERNATIONAL CONGRESS OF VITICULTURE 



Assuming that the total number of grapes does not vary during the ripening, 

 the average weight of 1,000 raisins of each set should furnish a measure of 

 the increase of crop. 



Table V. Increase of Crop of Raisins with Increase of Ripeness of Grapes. 



(Observed.) 



Muscat Kearney, 1913. Muscat Kearney, 1914. 



Bal. Lbs. per Acre Per Cent Bal. Lbs. per Acre Per Cent 



21.00 2,000 100.00 18.6 2,950 100.00 



23.90 2,365 118.25 20.2 3,050 104.07 



25.50 2,408 120.40 21.8 3,032 102.78 



26.75 2,648 132.40 23.6 3,191 108.17 



28.75 2,732 136.60 24.0 3,414 119.12 



23.8 3,876 131.40 



26.5 4,363 147.80 



Average increase per Bal. 4.7% Average increase per Bal. 6.00% 



Sultanina Kearney, 1914. Muscat Davis, 1914. 



Bal. Lbs. per Acre Per Cent Bal. Lbs. per Acre Per Cent 



21.0 3,800 100.00 21.4 2,000 100.00 



21.8 4,244 111.68 25.8 2,046 102.30 



22.4 4,565 120.13 26.1 2,074 103.70 



23.0 4,565 120.13 26.5 2,174 108.70 



24.0 4,740 124.74 28.7 2,244 112.20 

 23.6 4,686 123.32 

 25.4 5,049 132.63 



Average increase per Bal. 7.4% Average increase per Bal. 1.7% 



These results are as concordant as could be expected, especially with 

 the Muscat from Kearney. The vines in this case are very uniform and 

 there is little variation in the soil. The Sultanina from Kearney show 

 slightly less regularity, which may be accounted for by the fact that the 

 vines are grafted on different varieties of resistant stocks. 



The comparatively low increase in weight of raisins, compared to the 

 increase in Balling degree in the case of the Muscat at Davis, can probably 

 be explained by the gathering of second crop during the later pickings. 

 This would decrease the average size of the raisins. The Balling tests of 

 the grapes before picking were made on only first crop bunches. These 

 tests are more liable to error than the other observations, as it is very 

 difficult to choose a small sample of grapes that will give an exact measure 

 of the ripeness of the whole crop. For this reason, the average increase 

 per Balling degree has been calculated only on the samples at the ends of 

 each series, as the greatest differences are liable to the smallest percentage 

 of error. 



The average increase of crop per Balling degree of sugar in the grapes, 

 therefore, appears to be about 5.35 per cent with Muscat and 7.4 per cent 

 with Sultanina in the San Joaquin Valley. This represents an average in- 

 crease in crop per day of 1.18 per cent for the Muscat and .58 per cent for 

 the Sultanina during the ripening period. 



