934 Summary of Agricultural Experiments, [feb., 



the leaves took place in dry weather and at the same time of day, 

 those selected being uninjured, of average size, and formed in the 

 spring. The leaves were weighed before and after drying, and were 

 then reduced to powder, the weight of the various substances in the 

 powder being determined. 



In 1907 the leaves were removed at the end of May, and the amount 

 of nitrogen, potash, lime, phosphoric acid, and ash in the dry matter 

 of the leaves was shown to be the greatest in the case of plum trees. 



During 1908 removal of the leaves took place at four periods of 

 the year, namely, (1) just after the appearance of the leaves (beginning 

 of May), (2) middle of June, (3) end of August, (4) shortly before the 

 fall of the leaves, i.e., after they had begun to lose colour. 





Water. 



Dry 

 matter. 



Nitrogen. 



Percentage of Dr 

 Potash. Lime. 



/ Matter. 



Phos- 

 phoric 

 Acid. 



Ash. 







Per 



Per 



Per 



Per 



Per 



Pet- 



Per 







cent. 



cent. 



cent. 



cent. 



cent. 



cent. 



cent. 





r 9 May 



75-90 



24*10 



4-087 



2460 



0754 



1 357 



6*908 



Pear 1 



22 June 



62-53 



37 '47 



2*282 



1 690 



1-977 



0-414 



7-157 



29 August 



59-90 



40-10 



2*041 



1-770 



3-147 



0-406 



9 '454 





2 October ... 



52-99 



47-01 



0917 



1-321 



3-473 



0-158 



9*552 





' 9 May 



78-18 



21-82 



4-152 



3-160 



i*i86 



1-299 



8-304 



Apple - 



22 June 



69-60 



30-40 



2-628 



1-886 



2*166 



0-562 



8-017 





29 August 



64-24 



35': 6 



2*015 



1-927 



2*762 



o'475 



9-166 





.15 October ... 



56-85 



43-I5 



1-198 



1 601 



3-723 



0-288 



10-889 





'14 May 



78-81 



21-19 



4-867 



3-006 



1-511 



1-386 



9*006 



Cherry - 



22 June 



68-82 



31-18 



2-639 



2*782 



2*699 



0-692 



10*510 





29 August 



62*97 



37-03 



2* l60 



2-637 



3^7 



o-7S2 



12-319 





v 2 October ... 



67*31 



32-69 



I -022 



3-080 



4-558 



0625 



14*446 





'18 May 



79-09 



20-91 



4-9I7 



2-774 



1 -026 



1-171 



7-369 



Plum - 



22 June 



73-51 



26-49 



3*208 



4-887 



3-512 



0*699 



15*031 





29 August 



68-31 



31-69 



2-398 



5'22i 



4-591 



0*662 



17-757 





^30 September 



72-12 



27-88 



1-152 



5*825 



5*696 



Q'45 1 



20*987 



The results of the experiments in 1908 are shown above. It will 

 be seen that the water-content of the leaves decreases with their age, 

 until autumn is reached, when, in the case of cherries and plums, the 

 water content increases again. This was also found to hold good for 

 pears and apples in the next year of the experiment, when the leaves 

 were not removed until three weeks later in the year. The proportion 

 of lime and ash in the leaves increased, that of nitrogen and phosphoric 

 acid decreased as the leaves became older. In the case of nitrogen 

 and phosphoric acid the decreases were most marked in the period 

 from the beginning of May until the end of June, i.e., at the time when 

 these materials are most required in the- formation of the fruit. The 

 amount of potash decreased in the case of pears and apples, increased 

 in plums, and remained fairly constant in cherries. The high content 

 in potash of the leaves of the plum tree in autumn (5*825 per cent.) 

 would make them valuable as a manure. 



Analyses were made in 1909 in the same way of the mineral content 

 of the leaf buds and fruit blossoms of cherry and plum trees, with the 

 result that the fruit blossoms showed a larger content of water than 



