DEVELOPMENT OF HARDY FRUITS 43 



matures more quickly than in cultivated grounds. This leads to 

 the conclusion that moisture must play an important part in the 

 coloring of fruit, as the relative amount of moisture and heat will 

 determine to a large extent when the tree stops growing and when 

 the fruit will mature. British Columbia, Oregon, Washington 

 and other places where irrigation is practiced afford the best com- 

 binations of sunlight, heat, dryness, and moisture, hence it is that 

 some of the most highly colored fruit is produced there. What 

 part, then, do soils or plant food in soils play in the production of 

 highly colored fruit? This is a ciuestion in which every fruit 

 grower is interested. From the foregoing statement it can easily 

 be seen that warm, well-drained soils are most likely to produce 

 apples of high color, as on these soils the tree and fruit will mature 

 earlier than on wetter soils. 



Local Climatic Influences. 



Some horticulturists have already made lists of apples showing 

 the number of heat units required during the growing season to 

 bring the different varieties of apples to their full development; 

 these lists being based on the heat units during the growing season 

 where these varieties are succeeding best. These lists are valuable 

 guides to intending planters. In our experience at Ottawa it has 

 been found that the maximum temperatures, at least with the grape, 

 are as important as the mean temperature or the total number of 

 heat units. Unless certain maximum temperatures are reached 

 the variety does not ripen. Some grapes will not ripen if there is a 

 cool September and October, while others will ripen every year. 

 Those which ripen in the coolest seasons with us are Early Daisy, 

 Manito, Champion, Jewel, Moyer, Winchell or Green Mountain, 

 Dracut Amber, and Peabody. As many as 118 varieties of grapes 

 have ripened with us in a warm season and it is interesting to find 

 that the relative time of ripening varies according to the season. 

 In a warm season certain varieties will ripen earlier than others 

 that will in a cool season mature first. The Vergennes, one of the 

 latest sorts to ripen in the best grape districts, does not require 

 high temperatures in which to mature and ripens even in a rela- 



