56 NATUBAL CONTROL OF WHITE FLIES IN FLORIDA. 
experiments were conducted with the view to showing the effect of 
applying spores brought nearly to the point of germination in this 
medium. In this and other series of experiments the solutions were 
applied under favorable weather conditions, but no difference could 
be observed between the infection secured with nutrient solution 
and ordinary solutions used as checks. In some instances better 
infections were secured where no nutrient was added. Similar 
experiments with glucose as the nutrient have been reported by 
Dr. E. W. Berger * who also obtained negative results. 
Effect of sulphur waters on spores. — Experiments to determine 
what effect sulphur water has upon securing infections with water 
solutions of spores have been conducted only in the grove. Artesian 
water from Manatee County was used. An equal number of red 
Aschersonia pustules (400) were soaked in sulphur water and in lake 
water for one-half hour, shaken thoroughly, and the solutions used for 
dipping on June 25, 1909. By July 10, on the six shoots dipped in 
sulphur-water solution, representing an aggregate of 54 leaves, 180 
pustules had developed, while on the four shoots dipped in lake- 
water solution with a total of 28 leaves, 89 pustules developed. For 
each solution 3.3 and 3.2 pustules per leaf, respectively, were obtained. 
Check shoots developed no fungus. The results obtained gave no 
evidence of any injurious effect of the sulphur water on the spores of 
the fungus. 
LENGTH OF VITALITY OF SPORES. 
Field tests only have been made by the authors in determining 
the length of vitality of spores of white-fly fungi. No definite infec- 
tions resulted from the use of fungi, either the Aschersonias or the 
brown fungus, collected from September to December, 1907, and 
applied in various ways during the following summer months. Infec- 
tions were secured with fungus dropped by the cold in January, 
1906, during the following June, although far better infections at the 
same time followed the use from freshly picked fungus, as a check. 
In all, the authors have used in their experiments about a barrel of 
fungus-infected leaves, collected during the early winter months, with- 
out success. In several instances a very minute infection, one or two 
pustules, was detected, but under such conditions that it was more 
than probable that the infection came from other sources. Special 
attention has been given to these experiments in order to determine 
the value of picking fungus-infected leaves in the fall so that much of 
the fungus that falls from the leaves during the winter months might 
be saved for spring infections. The results above mentioned would 
indicate that such fungus pustules are valueless unless some more 
successful method be devised for preserving the fungus-infected 
» Rept. Fla. Agr. Exp. Sta. for year ending June 30, 1908, p. HI. 
