276 Missouri Agr. Exp. Sta. Research Bulletin No. 8 



had set as much so the activities of the curculio would not have been 

 concentrated on so small an area. 



It may be said also that trees on another plot fertilized with 

 sixty-three pounds of sodium nitrate to thirty-six trees in March, 

 1909, had a smaller percentage of buds killed during the winter of 

 1909-10 and set a heavier crop in 1910. From these results it is 

 evident that where there are a large number of warm periods in the 

 early part of the winter before the rest period is entirely ended, any- 

 thing that prolongs the growth in the fall greatly reduces the per- 

 centage of buds killed. In fact from the southern tier of counties 

 in Missouri, south, even where the freezes follow warm days as late 

 in the season as February, it will still be a benefit to have the trees 

 grow late in the fall, as witness later blooming of the more vigorous 

 trees mentioned above. 



It should be said with reference to the ending of the rest period, 

 that so far as we can tell, this does not occur at a definite time, but 

 buds that will push very rapidly when taken into a warm greenhouse 

 in March can be pushed in January or early February, but not nearly 

 so rapidly; so that whatever the ending of the rest period is, it is cer- 

 tainly a gradual process. While the differences between the rate 

 of pushing on vigorous and weak trees would be smaller following 

 warm days late in the season, say in February, than as early as De- 

 cember and January, yet with trees in extreme southern Missouri, 

 there are some differences to be observed as late as February or March 

 as mentioned above. This was certainly true in the case of blooming 

 of peaches in February, 1911, when the more vigorous trees did not 

 bloom until more than a month later than weak trees bloomed. How- 

 ever, in years when the bloom is rather late there will be little or no 

 difTerence between the blooming of vigorously growing and weakly 

 growing trees. Thus in the spring of 1913 the full bloom on Elberta 

 trees that were fertilized with sodium nitrate in the spring of 1912 

 and those that were not, came at practically the same time, which 

 was approximately April 5. Carman, though, was at least four 

 days later in coming into full bloom than Elberta, and Carman from 

 our experience has a longer rest period than Elberta, 



As far north as Columbia, Missouri, where the peach bloom 

 is never earlier than March 20, and is usually in April, weak trees 

 have never bloomed earlier than vigorous trees, and varieties like 

 Carman, Chinese Cling, etc., have never bloomed during our observa- 

 tions later than trees with a shorter rest period. Thus neither by 

 forcing late growth to prolong the rest period nor by choosing varie- 

 ties, such as those of the Chinese Cling group, with long rest periods, 



