CRANBERRY SPRAYING EXPERIMENTS IN 1905. 11 



with a solution of copper siili)bate (1 part to 1,000 of water), 3.600 

 berries, perfectly sound so far as could be seen from external appear- 

 ance, were selected from fruit pickcul on Sopti'mber 18, 11>05. Of these, 

 1,200 were from the sprayed plats and the remainder from the unsprayed 

 check plats. These berries were kept in g"lass dishes in the laboratory 

 and counted each week, in order to determine the amount of disease 

 which developed. On October 18, about the time the fruit from the 

 bog was marketed, 9.8 per cent of the sprayed fruit showed diseased 

 berries, while 38.1 per cent of the unsjirayed fruit and 37.4 per cent of 

 the unsprayed fruit which had been treated with the copper-sulphate 

 solution were diseased. In other words, four times as much of the 

 unsprayed fruit decayed between the time of picking- and marketing as 

 of the sprayed fruit. 



Parts of the check plats which were worth picking were picked by 

 hand and the fruit kept separate. This fruit was sorted for shipment 

 on October 15, 1905, when from 85 to 90 per cent of it was rotten. Mr. 

 Holman states that 40 per cent of all the unspraj'ed berries from Bun- 

 ker Hill bog deca3'ed between the time of picking and marketing. No 

 treatment of the berries with fungicides after picking is likely to give 

 satisfactory results, as we have found that the decaj" which occurs in 

 storage does not arise from germs which are on the surface of the fruit 

 at the time it is picked, but apparentl}' from a dormant form of the 

 fungus already within the bei'ries, where it is awaiting favoral)le con- 

 ditions for development. 



As the time for picking approached, so much of the Bordeaux mix- 

 ture adhered to the sprayed fruit that it was feared enough might be 

 present when the berries were marketed to interfere with their sale. 

 This, however, did not prove to be the case, as the greater portion of 

 the mixture was removed from the fruit during the processes of pick- 

 ing, sorting, and preparing the fruit for market. 



As the result of three years' spi-aying experiments, it is safe to say 

 that by the proper use of Bordeaux mixture the loss from fungous dis- 

 eases can be reduced to 10 per cent or less. The loss may be slightly 

 more the first 3^ear a badly diseased bog is treated, as the benetit, as 

 shown in these experiments, is greater the second 3^ear than the first, 

 and is evident not onl}^ in the prevention of scald and rot of the fruit, 

 but in the general improvement, thriftiness, and productiveness of the 

 vines. Bordeaux mixture has also been applied with very beneiicial 

 results to young vines not j^et in bearing, the leaves of which were 

 badly atfected b}^ the scald fungus. 



COST AND RECOMMENDATIONS. 



The cost of the spraying as it was done in these experiments averaged 

 from $15 to $20 an acre, the mixture being applied at the rate of four 



100— I 



