1913.] PUBLIC DOCUMENT — No. 31. 225 



L means 1 ton of lime (slaked) per acre, 

 KCl means 200 pounds muriate of potash per acre. 

 Ni 1/2 means 150 pounds nitrate of soda per acre. 

 N2 means 200 pounds nitrate of soda per acre. 



In combinations they mean, for example, as follows : N2PK 

 = 200 pounds of nitrate of soda + 400 pounds of acid phos- 

 phate + 200 pounds of high-grade sulfate of potash per acre. 



The nitrate of soda evidently had a marked effect in increas- 

 ing the quantity of fruit. As is shown by the figures in column 

 four of Table XL (the average sizes of the berries were inversely 

 proportional to these figures), the variation in size between the 

 berries from the different plots was not very great. The in- 

 creases in quantity were evidently due for the most part to an 

 increase in the number of the berries, the increase in their size 

 being a minor factor. The potash caused no increase in fruit 

 and the phosphate but very little. If the lime had any effect, it 

 was detrimental. The boxes used in measuring this fruit were 

 bushel boxes. The area of each of these plots is 8 square rods. 



While the vines showed more growth on the plots to which 

 the nitrate was applied than on the rest of the bog, this growth 

 was not more than is desirable. There seem to be indications 

 that the degree of drainage during the growing season has an 

 influence on the action of nitrogenous fertilizers in their effects 

 on fruit production and vine growth. 



7. Insects. 

 The total cranberry insect injury of 1912 was greater than 

 is usual on Cape Cod. The damage done by the fruit worm 

 was more than in any season for four or five years before. The 

 blackhead cranberry worm (fireworm) did greater and more 

 general injury than in any season before for many years. The 

 span worm caused serious injury for the first time in several 

 years, destroying the crop and all the foliage on the greater 

 part of the Old Colony bog at Yarmouth. The scale insect 

 (Aspidioius oxy coccus Woglum), discussed in last year's report 

 as having done serious injury on a bog in Yarmouth, disap- 

 peared almost entirely, having been destroyed, appannitly, by 

 the winter flowage. It now seems evident that winter flowage 



