374 Report of the Horticultural Department of the 



II. INVESTIGATIOXg OF 1900 BY THE NEW YORK AGRI- 

 CULTURAL EXPERIMENT STATION. 



S. A. Beach. / 



EFFECT OF SPRAY MIXTURES ON POLLEN AND ON BLOSSOMS. 



The effect of spray mixture upon blossoms was studied in the 

 laboratory and also in the orchard. Open blossoms in the 

 orchard were sprayed and then tagged so that they might be 

 kept under observation and the final effect of the treatment be 

 known with certainty. In the laboratory pollen grains were put 

 into cultures which contained neither insecticide nor fungicide 

 and the germination and growth in these cultures were compared 

 with the germination and growth in corresponding cultures con- 

 taining either a fungicide or an insecticide or both. 



Laboratory Study of the Effect of Spray Mixtures upon the 

 Germination of Pollen and the Growth of Pollen Tubes. 



In the laboratory pollen cultures were made in distilled water; 

 in sugar solutions containing various percentages of cane sugar 

 in water; in weak sugar solution combined with various dilutions 

 of Bordeaux mixture made of commercial copper sulphate and 

 lime; with Bordeaux mixture made of chemically pure ingre- 

 dients; with Bordeaux mixture combined with some arsenical 

 compound as commonly used in spraying orchards; with arsenical 

 spray mixtures alone; and with lime alone. 



Method of selecthig pollen for the cultures. — The blossoms which 

 were to furnish pollen for cultures were taken to the laboratory 

 before they opened so as to avoid the possibility of some other 

 kind of pollen being brought to the flower either by wind or 

 insect. The stem which supported the blossom cluster was put 

 into water so that the blossom buds might open. From blossoms 

 thus treated a single anther was selected to furnish pollen for all 

 of the cultures in a series. It is believed that by this method 

 pollen of as uniform vigor as it was possible to obtain was fur- 

 nished for all cultures which were to be compared in a single 

 eeriee. 



