56 
a large number of seedlings failed to survive and results from both 
these experiments must be considered inconclusive. 
These various treatments influenced the percentage of infection 
in susceptible varieties, but had no effect whatever in bringing 
about the infection of resistant varieties, such as Dwarf Yellow 
Milo, 
Field Assistants——Miss Eleanor Shasken, who had completed 
her Jumor year in Brooklyn College, and Mr. Benjamin Wein- 
stock, who had completed his Junior year in Cornell University, 
spent part of their time in July and August in assisting in various 
phases of the experimental work. 
THe Irts 
By Grorce M. REED 
Studies on the hybridization of the iris which have been found 
in Florida and Louisiana have been continued. Several first gen- 
eration plants of crosses have flowered, and their characteristics 
have been recorded. These plants have been self-pollinated in 
order to obtain a second generation series. A few second genera- 
tion plants of certain crosses have flowered and shown various 
combinations of the characters of the two parental varieties. Many 
more may be expected to bloom during the coming year, thus 
~—t 
giving a much larger number of plants for the study of range of 
variation. Miss Louise Mansfield made watercolors of the flowers 
of a few of the first and second generation plants, as well as the 
parental types. 
Tris Thrips and Aphids 
In cooperation with the Division of Truck Crop and Garden 
Insect Investigations, Bureau of Entomology and Plant Quaran- 
tine, Washington, D. C., further tests for the control of iris thrips 
were carried out by Dr. L. Gordon Utter and Dr. Floyd F. Smith. 
Derris powder (.02 per cent. rotenone) with sulphonated castor 
oil (1-400) as spreader, and 40 per cent. nicotine sulphate (1-450) 
with Grasselli-spreader-sticker, gave approximately 99 ee cent. 
control when applied 8 times at weekly intervals during Ma y and 
June, thus confirming previous results. Bi-weekly applications of 
