364 EXPERIMENT STATION RECORD. 



of asparagus rust {Puccinia asparagi) is noted. So far as the author's observations 

 go, this disease was first reported in Ontario in 1899. During the season covered by 

 the report it had spread and caused considerable injury. The different phases in the 

 life cycle of the fungus are briefly described, and as possible methods of combating 

 the rust the author suggests the burning of all diseased plants in the fall, besides 

 spraying the beds with Bordeaux mixture several times after the market season is 

 over. A brief account is given of a disease of balsam trees due to Tnmmatostroma 

 abietina. An account of this disease has been previously noted (E. S. R., 13, p. 63). 



Spraying in bloom, S. A. Beach and L. H. Bailey {New York Stafe Sta. Bui. 196, 

 pp. 3'j:i-460, ph. S, figs. 6). — The practice of spraying fruit trees in bloom, as )3egun a 

 few years ago, has led to considerable controversy as to the effect of such treatment 

 upon the yield of fruit, as well as the injury to bees. As a result of the agitation a 

 law was passed by the legislature of the State of New York prohibiting the applica- 

 tion of poisons to fruit trees while in blossom. The effect of such treatments upon 

 the production of fruit has been investigated at both the New York State Station 

 and the New York Cornell Station. During the year 1900 extensive field experi- 

 ments were conducted by the Cornell Station on spraying fruit trees in bloom, which 

 showed no decisive results. The season was one of heavy crop and little disease, 

 and good or fair crops followed all treatments. There was no apparent injury to 

 blossoms on trees sprayed when in full bloom. 



The effect of spray mixtures on pollen and blossoms was studied by the State 

 station both in the laboratory and in the orchard. In the laboratory, pollen grains 

 were put into cultures which contained insecticides or fungicides, and the germina- 

 tion and growth compared with others placed in culture media without any fungi- 

 cide or insecticide. "From these investigations it appears that if before pollination 

 occurs the stigmatic surface of the pistil should be covered either 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 after- 

 wards 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 germination of pollen. Bordeaux mixture 

 was diluted in aqueous sugar 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 germination did occur the growth which followed was 

 decidedly slow and the pollen tubes were dwarfed. AVhen diluted to 100 parts, 200 

 parts, or 500 parts either no germination or practically none was found." 



The effect of spray mixtures on the apple blossoms was examined, trees being 

 sprayed in bloom and observations made at different times until the fruit had become 

 as large as cherries. In the tests where the trees were sprayed repeatedly, so as to 

 hit as many as possible of the new blossoms which opened from day to day, but few 

 blossoms survived the treatment and l)ut little fruit was set, showing that spray mix- 

 tures prevent the setting of fruit when applied to blossoms soon after they 02)en. If 

 the tree should have a scant amount of blossoms, serious loss might follow from such 

 treatments. In some cases the spray mixture had a decided corrosive effect on the 

 tissues of the stamens and pistils. In other cases pistils which showed the presence 

 of spray mixture on the stigmatic surfaces awaited fertilization for several days, 

 but eventually withered and died. It appeared that in these cases the spray mix- 

 ture inhibited the process of fertilization. Blossoms which had been opened several 

 days before being sprayed seemed to have reached a stage where the treatment did 

 not check fertilization, and the fruit was set as abundantly as upon those trees 

 which were not sprayed. The effect of spraying in bloom upon the yield was 

 investigated with a number of varieties of apples. In the case of Hubbardston the 

 loss per tree from spraying in bloom was 0.9 bu. of marketable fruit; with Olden- 



