GENERAL POINTS CONCERNING FRUIT TREE STOCKS 189 



both in nursery and later growth, are due to differences in con- 

 geniality between the cions and the variable seedling stocks. 



236. Hardy stocks for tender varieties. At the Canadian ex- 

 periment farms 90 varieties of apples were top-grafted on hardy 

 stocks to see if they could thus be made hardy, but practically all 

 were killed back to the stocks. One Wealthy stock grafted to 

 Milwaukee and Martha carried the former through a very severe 

 winter and matured a crop of fruit, while the latter was killed. 

 Hence the conclusion : Trees tender on their own roots are also 

 tender on hardy stocks. 



237. Slow-maturing stocks (Northern Spy), according to Gulley 

 of Connecticut, do not delay the fruiting of quick-maturing 

 varieties (Jonathan and Canada Red). 



238. Quince effect on pear. Two French investigators, G. 

 Reviere and G. Bailhacke, tested the effects of stock upon cion 

 of two pear trees of one variety upon quince and pear stocks 

 respectively. The trees were 15 years old and had grown under 

 apparently identical conditions. For three successive seasons the 

 fruits were collected ; samples were analyzed, etc. Each bore about 

 300 fruits annually. Those on the pear stock were green, those on 

 quince yellow with a rose blush on the sunny side. The average 

 weight, density, acidity and sugar content were in favor of the 

 quince stock. Observations on another variety tallied with these 

 findings. The differences are attributed to greater activity of the 

 chlorophyll in the quince case. 



239. Hardness and softness of wood in apple grafting. E. 

 Leroux, a French investigator, has concluded from experiments with 

 200 varieties of cider apples that (1) varieties with tender wood can 

 be most successfully grafted on tender-wooded varieties and hard- 

 wooded on hard-wooded; (2) success follows only rarely when a 

 tender-wooded one is grafted on a hard-wooded one; (3) success 

 seldom or never follows when a variety with hard wood is grafted 

 on a soft-wooded stock. These principles are believed to apply to 

 other orchard fruits. 



240. Effect of small growing stock on cion. Booth re- 

 ports an instance in which peaches on Mariana plum stocks 

 grew fairly well for two years, though from the start the 

 peaches grew much more rapidly than the plums, so the 

 peach trunks were at two years twice as large at the 

 union as below. During the second season the weather 

 was very hot and dry, and the peach trees after wilting 

 for several days but reviving during the night, finally 

 dried out and died, evidently because sufficient moisture 

 was not furnished by the slow-growing Mariana roots to 

 meet the demand from the peach leaves during a period of 



