BLOOMING PERIOD OP TREE FRUITS 



655 



answer to the question suggested above. 

 It is common Ivnowlerige that European 

 or Domestica plums cross with difficulty 

 on other types of this fruit, and that this 

 group should, therefore, be considered 

 separately and apart from other plums 

 when selecting cross pollenizers. On the 

 other hand, all groups of native plums 

 together with the Japanese varieties in- 

 terpollinate rather freely, and thus we 

 may be quite indifferent as to group re- 

 lations when considering varieties falling 

 under these heads. However, we are not 

 prepared to say whether or not there is 

 any difference in the degree of affinity be- 

 tween varieties of the same group, or if 

 such affinity does exist whether it is a 

 constant character or not. Until we are 

 able to answer definitely these questions, 

 the bloom chart is the only safe guide we 

 have in selecting varieties for the purpose 

 of cross-pollination. Waugh has prob- 

 ably given this problem more attention 

 than any other student, and his work has 

 led him to lay very little stress on mu- 

 tual affinity in his latest publications on 

 this subject. In a number of prelimi- 

 nary hand cross-pollinations with apples 

 at this station, the results indicate that 

 the female parent to the cross is quite 

 indifferent to the kind of pollen offered 

 so long as It is of another variety of 

 apple and is in good condition: but our 

 trials have not been sufficiently extensive 

 to draw positive conclusions. 



If these conclusions are correct, then 

 the bloom chart is even more valuable 

 than at first supposed; but in any case 

 it must always be consulted if we are to 

 practice mixed planting with success. 

 Planting together varieties of different 

 blooming periods does not meet the needs 

 in the case, but the kinds that have prac- 

 tically the same blooming period should 

 be selected. Although a number of ex- 

 periment stations have published bloom- 

 ing data for the benefit of the grower, 

 yet none of these apply to the Virginia 

 planter. It is a well known fact that the 

 relative blooming period of a series of 

 varieties will not be the same for differ- 

 ent localities, especially if they be remote 

 from each other. No one chart can be 

 constructed that will apply with equal 



force to all sections of the United States. 

 However, charts that apply to other sec- 

 tions have some value and should be con- 

 sulted in the event that there is lack of 

 more definite information. Though Vir- 

 ginia has a rather variable climate, the 

 territory covered is not so extensive, but 

 that data taken in one locality will apply 

 in a fair degree to the rest of the state. 



The chart on pp. 656-7-8-9 is therefore ex- 

 pected to serve as a safe guide to the 

 Virginia fruit grower. It has been com- 

 piled from a large mass of notes extend- 

 ing over a period of 13 years; the num- 

 ber of observations, each representing a 

 different year, is given in the left-hand 

 column just after the variety name. The 

 number of years covered guarantees a 

 safe norm, whereas norms reached by 

 only three or four observations would 

 hardly appear to be reliable. The apple 

 orchard was planted in the spring of 

 1S89, but all notes on apple collected 

 prior to 1S96 have been disregarded be- 

 cause of the unreliability of bloom notes 

 from trees during their earlier stages of 

 growth. 



The next step in this work should be 

 the collection of blooming data from dif- 

 ferent sections of the state with the view 

 of developing a phenological map for Vir- 

 ginia, and to this end we solicit the co- 

 operation of all those who are interested 

 in this subject. Bloom note forms and 

 instructions will be furnished those de- 

 siring to aid us in these studies. 



Explanation of Chart 



In the charts following the blooming 

 period of each given variety is repre- 

 sented by the starred line following the 

 name. This line begins with the average 

 recorded for first bloom open and extends 

 two days beyond the period of full bloom. 

 While flowers remain receptive for more 

 than two days after full bloom during 

 cloudy weather, this is not the case if 

 conditions are favorable to pollination. 

 The different fruits or groups of same 

 are arranged in order of their blooming, 

 as this arrangement appears best for 

 comparisons. 



For Apples, see Pollination, under 

 Apple. 



