52 CRANBEBRY DISEASES. 



Another plat was sprayed but four times, as follows : July 14, July 

 31, August 1, and August 15. Estimates of the amount of diseased 

 fruit on the sprayed and unsprayed plats, made as in the previous 

 cases, showed 18.3 per cent of rotten berries on the sprayed plat and 

 91.53 per cent on the unsprayed plat. This indicated what had 

 already been anticipated, from our knowledge of the time of ma- 

 turity of the parasites causing the diseases, that the earlier applications 

 are exceedingly important, most of the infection apparently occurring 

 before the fruit is half grown, 



A portion consisting of 1,048 square feet of one of the plats which 

 was sprayed five times was carefully hand picked and produced 3 

 bushels of sound fruit, this being at the rate of about 125 bushels 

 per acre. The same area from the adjoining check plat gave a 

 scanty peck of sound fruit, or 10.42 bushels per acre. In other words, 

 there was twelve times as much sound fruit on the sprayed i)lat as on 

 the unsprayed plat, or a saving of over 100 bushels per acre. 



Preparation and application. — The method of preparation, as well 

 as the dates and manner of application, is of exceeding importance 

 in securing satisfactory results. The Bordeaiix mixture should be 

 freshly made. Good stone lime should be used, and from 3 to 5 

 pounds of commercial resin-fishoil soap should be added to it. In 

 our first experiments, in which the plain Bordeaux mixture was used, 

 it was found that the spray either collected in drops upon the surface 

 of the leaves and fruit or ran off entirely, the surface of the cran- 

 berry leaves and fruit being so glossy that the mixture did not spread 

 and adhere properly. It was found that by adding the resin-fishoil 

 ssoap the mixture not only formed a film and spread over the surface 

 of the leaves and fruit, but also adhered for a much longer time than 

 the plain Bordeaux mixture. 



The comparison of sprayed and unsprayed fruit at the time of 

 picking does not show the full amount of profit to be derived from 

 the treatment, as there is usually a considerable loss from the develop- 

 ment of the diseases during the period between the time of picking 

 and the time of marketing the berries. In order to com]iare the 

 keeping qualities of the sprayed and unsprayed fruit, 2,400 perfectly 

 sound berries, so far as could be determined by external appearance, 

 were selected. Twelve hundred berries were from a sprayed j^lat and 

 1.200 from a check j^lat. They were all kept in the laboratory under 

 similar conditions in order to determine the amount of disease which 

 would develop in each case before the time for marketing the fruit. 

 On October 18, the date upon which most of the fruit from the bog 

 was marketed, and exactly one month from the date of picking, a 

 careful examination of the 2,400 berries showed only 9.8 per cent of 



110 



