New York Agricultural Experiment Station. 385 



with Bordeaux mixture alone or with arsenical poison alone of the 

 strength commonly used in spraying orchards there would be no 

 germination of any pollen which might afterwards reach the 

 stigmatic surface and so fertilization would be prevented and no 

 fruit would be formed. Even the presence of lime alone, of the 

 strength commonly used in spray mixtures, prevented the germi- 

 nation of po'llen. Bordeaux mixture was diluted in aqueous 

 «ugar solution to 500 parts, 200 parts, 100 parts, 50 parts, 2 parts 

 and 1 part in 10,000 of culture media into which various kinds 

 of pollen were introduced. Even when diluted to 50 parts in 

 10,000 it prevented germination to large extent and where germi- 

 nation did occur the growth which followed was decidedly slow 

 and the pollen tubes were dwarfed. When diluted to 100 parts, 

 200 parts or 500 parts either no germination or practically none 

 was found. 



Effect of Spray Mixtures on Apple Blossoms. 



In order to test the practical effect of the spray upon op«n 

 apple blossoms the following tests were made. 



Individual Uosso^is known to have been hit hy sprat/ mixtures. — 

 Blossoms of Hurlbut and Jefferies were sprayed soon after they 

 opened. On the other hand Baldwin and K. I. Greening were 

 sprayed several days after the trees commenced to bloom. It is 

 instructive to note the different results obtained. On a Hurlbut 

 tree which was chosen for one of the tests the blossoms com- 

 menced to open May 13. Open blossoms on one side of the tree 

 were sprayed the next day with Bordeaux mixture, 1-to-ll form- 

 ula, combined with green arsenite of copper, 1 lb. to 150 gallons. 

 At that time one could rarely find an anther which had begun 

 to discharge its pollen ^. Some of the sprayed blossoms were 

 examined and those which plainly showed the spray mixture in 

 the center were tagged. In ease the spray could be clearly seen 

 on the stigmatic surface the tag was given a special mark to dis- 



'The structure of the apple blossom is explained and its parts are 

 Darned on p. 395. 



25 



