Jan., 1924] PROGRESS OF AGRICULTURAL EXPERIMENTS 9 



Compared with those grown in the complete nutrient solution, those grown 

 in the nutrient solution minus phosphorus are much lower in insoluble nitrogen, 

 higher in soluble nitrogen and slightly higher in lipoid nitrogen. 



The plants grown in the nutrient solution minus nitrogen are feebly vegeta- 

 tive and non-fruitful. Those growing in the nutrient solution minus phos- 

 phorus show a similar effect, but the former are high in total nitrogen and ni- 

 trate nitrogen, while the latter are low in total nitrogen. An examination of 

 the form of the nitrogen present shows that the plants grown with the nutrient 

 solution minus the phosphorus, while high in total nitrogen and nitrate nitro- 

 gen, are low in synthesized or protein nitrogen and that the plants grown with 

 nutrient solution minus nitrogen are also low in protein nitrogen. 



The effects of limiting the supply of phosphorus upon growth and reproduc- 

 tion may be explained in part at least by the effect on protein and carbo- 

 hydrate metabolism. 



The very marked effect of large applications of available phosphorus in 

 increasing fruitfulness and hastening maturity of the tomato has been shown 

 in field experiments a,s related on page 27. 



Fruit Bud Formation. 



Work on this project has been carried on in the Woodman Orchard as in 

 previous years by G. F. Potter and S. W. Wentworth (Horticulture), and 

 additional data are now being obtained from the Renovated Orchard at the 

 Horticultural Farm. 



In the Woodman Orchard Baldwin trees under sod mulch without addi- 

 tional fertilizer, trees under cultivation where no cover crop is planted, trees 

 which receive good culture including cover crop but no fertilizers, and trees 

 which are under the cultivation cover crop system supplemented with complete 

 chemical fertilizer, are under comparison. The experiment is now in its six- 

 teenth season. It has previously been reported that the addition of fertilizers 

 produced no significant increase in the crop during the first ten years of the 

 experiment. Some differences in growth were recorded and these differences 

 are still apparent. The trunk diameter, which is a fair index of the total 

 development of the tree, averages 15.1 inches on those plots receiving fertilizer 

 in addition to cultivation and cover crop; 14.4 on the plot which is cultivated 

 and receives a cover crop each season; 13.5 inches on the plot cultivated with- 

 out a cover crop; and 12.1 inches on the sod plot. 



In recent years, increases in yield on the fertilizer plots have been reported 

 approximating 50 per cent more than those-not fertilized, and a very significant 

 difference is apparent in the state of the trees. The mifertilized trees are 

 declining in vigor very rapidly. It has been customary to drop out of each 

 plot any tree which becomes weak and no longer able to produce normal 

 crops of fruit. During the season of 1922, nine trees were dropped, because 

 of their weakened condition, from the plots which receive no fertiUzer. Only 

 one tree was dropped from those plots which receive fertilizer. The yield 

 data for the season of 1922 are of Uttle significance as there was practically no 

 crop. The highest average production was on Plot 4, which averaged 82 

 pounds per tree. A good yield for Baldwin trees comparable in size to those 



