Feb., 1926] 



PROGRESS OF AGRICULTURAL EXPERIMENTS 



19 



manure is used on the potato ground, the supplementary fertihzer need 

 not contain more than 4 per cent of potash. 



Certified versus Uncertified Seed 



Two one-tenth acre plots side by side were planted by F. W. Taylor 

 to certified seed of 1924 and to seed grown from certified seed in 1924, 

 but uncertified. 



The comparative yields in bushels per acre of ones, twos, and threes are 

 given below ; 



The differences in yields are not material. This is in accordance with 

 previous tests here when the season is favorable and disease attacks are 

 shght. On the other hand, in unfavorable seasons when yields are com- 

 paratively low, the certified seed proves its merits. 



FORESTRY 



Forest Plots (Hatch Fund) 



Measurements are now being made by K. W. Woodward on the follow- 

 ing experiments: 



(1) Response of white pine when released from shade — 15 plots. 



(2) Response of white pine to periodic thinning — 12 plots. 



(3) Growth of exotic species — 6 plots. 



Some of the plots in the first group have served their usefulness and 

 will be discontinued, but others will be taken on in their place so as 

 to check the results already obtained and get data on species not originally 

 included. 



B}' expansion of the plots on thinning we now have a series running 

 from 20 to 40 years at ten-year intervals so that we will have results for 

 the critical period in pure stands of white pine. 



No striking results can be reported for the plantations of exotics, but 

 thej^ are now 12 years old and will be increasingly valuable. New species 

 are to be tried out in the spring. 



HORTICULTURE 

 Fruit Bud Formation (Adams Fund) 



The usual records of yield and growth have been made in the Woodman 

 Orchard by G. F. Potter and S. W. Wentworth. 



In addition, it has been noticed that there are differences in regularity 

 of bearing and that the trees in the different plots are now showing 

 significant differences in vitality. This is indicated, in addition to growth 

 differences, by their ability to resist winter injury and the inroads of 

 parasites such as the European apple canker. It now appears that some 

 of the more important differences between the several plots are in the 



