PRACTICABILITY OF INCREASING EFFICACY OF FUNGI. 



65 



fragments ^vith the rod-fungus si)()r('s, l)ul ii<> results worth noting 

 were secured. 



Seri<>s A was sprayed 11 tnn<'s ])etw('<>n May 7 and Octohei 19, 

 using from 300 to 600 pustules per gallon of water.' The applications 

 weic made on the following dates: May 7, May 26, June 25, July 24, 

 August 27, September 11, September IS, Se]>tember 25, October 2, 

 October 9, October 19. 



Series B was sprayed only once, May 7. 



Eight examinations, each based upon 300 leaves picked promis- 

 cuously from the tiees of each seiies, gave the records shown in 

 Table XII. 

 Table XII. — Average 7iumber of red-fungus pustules per leaf at successive ecaminatio/is. 



A check lot of leaves picked promiscuously from unsprayed trees 

 witliin three rows of the experimental block showed an average of two 

 red-fungus pustules per leaf on October 26. 



The rainfall and the comparative humidity' foi each week during 

 the six months covered by the sprayings are shown by the data in 

 Table XIII, being based upon the mean of the maximum and minimum 

 relative humidity records for each day by a Friez recording hygro- 

 grapli located at the standard Weather Bureau shelter near the 

 Orlando laboratory. 



Table XIII. — Rainfall atid relative humiditi/ records, Orlando, Fla., Mai/ to October, 1909. 



Week beginning — 



May 3. 

 10. 

 17. 

 24. 

 31. 



Monthly mean. 



June 



Monthly mean. 



July 5. 

 12. 

 1ft. 

 20. 



Monthly mean. 



humidity.' '^^^"• 



Per cent. 

 76 

 82 

 78 

 80 

 77 



Inches. 

 .58 

 .0 



1.83 

 .0 



2.01 



Week beginning- 



August 2. 

 9. 

 10. 

 23. 

 3U. 



Monthly mean . 



September C. 

 13. 

 20. 



Monlhlv mean. 



October 5. 

 12. 



la. 



20. 



Monthly mean. 



Daily 



mean 



humidity. 



Per cent. 

 78 

 84 

 91 

 80 

 83 



Weekly 

 rahifall. 



Inches. 



.9 



3.39 



• 2.76 



.57 



.73 



> -Vs in all experiments, imless otherwise stated, the freshest fungous pustules obtainable, according to the 

 sea.son of the year, were useil. 



2 These humidity nioords are not comparable to U. S. Weather Bureau records, which in Florida are 

 taken at 7 a. m. arid 7 p. m. 



21958°— Bull. 102—12 5 



