24 MASS. EXPERIMENT STATION BULLETIN 149. 



No. 2 has borne the largest apples and tree No. 4 the smallest, with tree 

 No. intermediate each year. The apples on tree No. 4 were much 

 smaller in 1913 than ever before, due possibly to the previous seeding down 

 to grass and clover. 



It seems fair to conclude that individual trees may show a fairly constant 

 tendency from year to year to produce apples larger or smaller than the 

 general average of the orchard. 



The extreme difference in average size between the individual trees 

 amounts to a trifle less than 3 millimeters, while between the different 

 parts of the trees it is 2.38 milhmeters; but from year to year the dif- 

 ferences are more consistent. The apples from the upper south part of the 

 trees have been the largest every year. Those from the upper north part 

 have been second every year except 1911, while the lower north apples 

 have been smallest in four years out of six. This would seem to warrant 

 the conclusion that for the variety the better the exposure of the trees 

 to the sun the larger the growth that may be secured. 



The figures for the Baldwins are too fragmentary to be of much value, 

 but so far as they go, while not quite as consistent as those of the Ben 

 Davis, they show the same general tendency. In 1909 the different parts 

 were in the same order as the average of the Ben Davis, while in 1912 

 the upper north led, followed by the upper south, lower north and lower 

 south. 



Considering the average size of the total apples from the Ben Davis 

 trees in the several years we note that they were largest in 1910 and 

 smallest in 1911, the difference between the extremes being 4.04 milli- 

 meters. The small size in 1911 is undoubtedly due to the heavy crop borne, 

 but it is significant that this is the only year in which the trees have 

 borne enough to affect the size. There is no relation between size of apples 

 and the number borne until the crop reaches what may be fairly termed 

 a full crop. Probably there is more danger of breaking down the tree 

 than of any serious deficiency in size, provided the trees are well cared 

 for. In 1909 the apples average 90 millimeters in diameter, nearly as 

 small as in 1911. The probable explanation of tliis is the low temperature 

 prevaihng, the March-October mean being the lowest of any of the six 

 years under consideration. There are some further indications of a rela- 

 tionship between the warmth of the season and the size of the apples, 

 but all the fluctuations in size cannot be thus accounted for. We have 

 been unable to trace any relationship whatever between precipitation 

 and size. One possible influence of fertilization is in the case of the crop 

 of 1910, the large size of which may be due to a previous application of 

 lime. 



While there is evidence that there has been some relation between mean 

 summer temperature and size it does not appear that the slight variations 

 that have occurred have exercised a controlling influence on the size of 

 the apples. In earlier work along this line a greater effect of temperature 

 was observed, but mostly from stations further north, where seasonal 

 fluctuations of temperature are greater. 



