New York Agricultural Experiment Station. 397 



stimulates it to growing into a seed, or in other words, which 

 fertilizes it. If fertilization does not take place there is no 

 further development and the entire flower withers and dies. 



The essential organs of the flower are composed of very tender 

 tissues. It is not surprising that injury follows when they are 

 hit by spray mixtures. Neither is it strange that Bordeaux mix- 

 ture should prevent the growth of the pollen. Bordeaux mix- 

 ture eould not hold its position as a leading fungicide if it did 

 not prevent the growth of fungus spores. The germination of 

 a pollen grain is analogous to the germination of a fungus-, 

 spore. Fig. 14 illustrates pollen grains of an Amaryllis and Fig., 

 15 shows their appearance after they have germinated and begun, 

 to send out the pollen tubes; Fig. 16 illustrates spores of a 

 species of fungus which causes the carnation rust and Fig. 17 

 shows the same after they have germinated and sent out the 

 germ tubes. Since Bordeaux mixture is deadly to the one it 

 might reasonably be expected to have a similar effect upon the 

 other. That it does have such an effect is demonstrated by 

 the experiments in the laboratory and in the orchard, an account 

 of which is given on the preceding pages. 



EFFECT OF SPRAYING IN BLOOM UPON THE YIELD. 



In order to get some evidence as to the effect of spraying 

 apple trees in bloom upon the yield of fruit, and' also upon 

 injurious insects and plant diseases, as compared with spraying 

 when the trees are not in bloom, four bearing orchards were 

 sprayed in different parts of Western New York. These 

 orchards were so free from fungous troubles during 1900 that 

 no information was gained as to whether such diseases as the 

 apple scab may be best controlled by spraying in bloom but the 

 experiments did throw some light upon the effect on the yield, 

 of spraying in bloom, although they are not conclusive on this 

 point, as may be seen by the following account of the work. 



Three of the orchards in which these experiments were con 

 ducted are near Lake Ontario and one is on the upland about 

 five miles west of Seneca Lake. This arrangement was planned 



