Jan., 1924] PROGRESS OF AGRICULTURAL EXPERIMENTS 27 



The increases are especially noticeable in Plots 2, 2a, and 3, 3a, where no 

 manure was used. In the other two treatments where twenty loads of manure 

 were used per acre the increases were much smaller. 



The tomato experiment was continued by J. R. Hepler and H. R. Kraybill 

 along the same line as the previous years. Four separate plots of 32 plants 

 each were used for each fertilizer treatment. 



Eight plants of each plot were measured every week during the growing 

 season, by getting the length of the main shoot of the plant and the number and 

 average length of the axillaries. 



The effect of phosphoric acid in hastening the maturity of the tomatoes was 

 again clearly shown. In plots where applications of 1000, 500, and 1500 

 pounds of acid phosphate were applied in addition to 20 tons of manure, in- 

 creases amounted to 141.8 per cent, 77.9 per cent, and 163.8 per cent respec- 

 tively over the check where 20 tons of manure alone were used. An increase 

 to 40 tons of manure brought only lfi.5 per cent. 



Potash used in connection with phosphoric acid delayed maturity and 

 decreased the yields, bringing an increase of only 9.4 per cent over the check 

 as compared with 141.8 per cent where acid phosphate was used alone. A 

 bulletin on the results of this experiment is planned for the coming year. 



Tomato Selection Experiment. 



The strain of tomatoes used at the University has been grown and re-selected 

 in the greenhouse every year since 1914. In 1920, seed from the best plant was 

 again selected by Mr. Hepler, and a whole greenhouse planted with it. Seed 

 from these plants was used in the 1921 fertilizer experiment. It showed con- 

 siderable variation in yield but very little in size and shape. Selections were 

 made from the highest yielding and from the lowest yielding plants of each 

 plot, in all thirty-two separate sub-strains. Analysis of the data shows the 

 same range of variation in each sub-strain that was found in the parents. As 

 to yield in 1922, the average yield per plant from the low-yielding plants was 

 68.7 ounces, from the high-yielding plants 67.0 ounces. In 1923 the low- 

 yielding plants averaged 66.8 ounces and the high-yielding plants 65.3 ounces. 



Tomato Variety Experiment. 



In the variety test twenty-five different varieties of tomatoes were grown. 

 Most of these are main season varieties and did not ripen much fruit. In this 

 list may be found Hummer, Enormous, Golden Ponderosa, New Globe, Gulf 

 State Market, Dwarf Champion, Dwai-f.^tone, Model, Early Detroit, McCul- 

 lough's Special, Greater Baltimore, Wilt Resistant Marvel, Matchless, Nittany, 

 and Matchum. The highest yielding variety was Avon, which is probably an 

 early strain of Earliana, and ripened all its fruit amounting to about 2^ pounds 

 per plant, June Pink also ripened about 2| pounds per plant, but the fruit 

 cracked so badly and was of such poor color that the variety seems hardly 

 worth growing. John Bear and Penn State Earliana are very promising 

 varieties. Hudson Valley Maid and Burbank followed the above varieties 

 in amount of fruit ripening before September 20, also Chalk's Jewell, Ponderosa, 

 and Acme. 



