92 EEPOET OF OFFICE OF EXPERIMENT STATIONS. 



strictly limited to citrus trees. Work on other citrus diseases demon- 

 strated that the scab of grapefruit, Satsuma oranges, and lemons is 

 due to CladospoTium citri. 



The chemist continued the study of soils and fertilizers in relation 

 to the development and the growth of the orange tree begim near 

 Tavares on Lake Harris. This field work comprises 48 plats with 

 10 trees per j^lat. Careful notes were taken as to the gi^owth of the 

 trees, the results of diseases affecting them, the fertilizer require- 

 ments, with special reference to the nitrates, forms of phosphates for 

 citrus trees, etc. These field experiments on Lake Harris are supple- 

 mented by a study of trees grown under more perfect control in tanks 

 at the station. 



The studies on the white fly were continued, and life-history work 

 on a second species was pursued. As a result of this research work, 

 progress was made in the general management of white-fly infected 

 orchards. It was observed that no one single method of combating 

 the white fly will prove uniformly successful, but that the most eco- 

 nomical and satisfactory method of handling the pest will be to com- 

 bine the spray with insecticides with the spraying of fungus spores, 

 and under certain conditions to fumigate the orchards. It was found 

 that cultures of the fungi can be kept for at least seven months in cold 

 storage, and in connection with this fact practical methods of grow- 

 ing the cultures were worked out, making it possible to have spore- 

 bearing material for spraying at any time. Private parties in the 

 State have taken up the spraying with fungus spores for white-fly 

 control, and one concern sprayed 750,000 trees in 1910. 



In the investigation on plant nutrition in relation to physiological 

 diseases, important advances were made, special attention being given 

 to the effect of different soils, methods of watering, and the character 

 of fertilizers on melanose and die-back of citrus trees. In connection 

 with this work, it was found that phosphorus is a means of correcting 

 overfeeding with nitrogenous compounds, and that acid phosphate 

 corrects the injurious effect of excessive applications of nitrate of soda. 



In plant-breeding work attention was principally given to velvet 

 beans and corn. An acre of the first generation of hybrid velvet and 

 Lyon beans was under observation, together with an acre each of pure 

 lines of these two plants. Careful records were made of color of 

 flowers, dwarfing tendency, vigor, and other vegetative characters. 

 Studies were pursued of the F^ generation of com hybrids, and line 

 breeding was conducted with a number of varieties of corn introduced 

 from Mexico, Central America, and elsewhere. 



The Hatch fund work of the station in animal husbandry included 

 feeding experiments with pigs, cattle-breeding experiments, determi- 

 nations of the cost of milk production, and trials of various crops, 

 Japanese cane and velvet beans were used in the feeding tests with 



