THE BLACKHEAD FIREWORM OF CRANBERRY. 33 



number of gallons used for a thorough application. Approximately 

 12 trips were necessary across an acre with this outfit. In point of 

 time and material the spray gun was the most economical, requiring 

 only 35 or 40 minutes to spray an acre, with an average of 375 gallons 

 for an application. It was necessary to make only 6 to 8 trips with one 

 spray gun across an acre. 



Effect of the Nicotine-Sulphate-and-Soap Solution on the Cranbeeet Plant. 



Although 40 per cent nicotine sulphate in the proportion of 1 part 

 to 800 parts of water with fish-oil soap at the rate of 2 pounds to 

 each 50 gallons of solution was applied to the vines when they were 

 almost in full bloom, no decided decrease in the setting and maturity 

 of the berries seemed to occur on those plats on which the spray 

 was not applied forcefully or on a nearly horiz(^ntal plane. It will 

 be noted, however, in Table 4 that the percentage of unfertilized and 

 immature berries, i. e., the very small, dried, and undeveloped ones, 

 but which were free from fire worm injury, was slightly, and in some 

 cases considerably, increased in all the sprayed plats except F as 

 compared with the respective untreated ones, the three plats with the 

 highest percentage of berries of this kind being plats B, C, and G. 

 Some explanation of this may possibly be found in the fact that in 

 two of these plats, namely, B and G, the spray was applied forcefully 

 with the Bordeaux nozzle on a nearly horizontal plane, which prob- 

 ably could have seriously affected the fertility of the blossoms, as in 

 some cases they were almost blown from the uprights. Plat C re- 

 ceived four rather forceful applications with the spray gun, and this 

 also may in a measure account for the high percentage of unfertilized 

 berries picked from this plat. 



It is generally recognized among cranberry growers and others 

 familiar with cranberry culture that the presence of a large amount 

 of wet weather during the blooming period sometimes results in a 

 small crop of berries. Whether or not the wet weather causes a de- 

 creased crop by preventing the ordinary poUenization by insects or 

 by destroying the fertility of some blossoms still seems to be a matter 

 of conjecture. Since all the plats were affected by the same set of 

 natural conditions, however, it would seem logical to suppose that 

 the spraying of the vines while the blossoms were open with a type 

 of nozzle which delivered a forceful spray on a more or less hori- 

 zontal plane, and which thus thoroughly wet the floral organs, might 

 have caused the comparatively small crop on the plats thus treated, 

 by the sterilization and mechanical destruction of the blossoms. 



On the other hand, a certain rather beneficial effect in addition to 

 the control of the fireworm was observed from the use of the nicotine- 

 sulphate-and-soap solution, especially on the McFarlin variety. On 



