26 MASS. EXPERIMENT STATION BULLETIN 371 



Pruning 



Vines often grow too thick and tall, especially on new bogs with a rich 

 bottom and a thin sand covering. The runners that float over the tops 

 of the vines after harvesting must be cut of¥ carefully with a knife rake 

 or pruner (Fig. 20 A and B). Experienced men should do this work, for 

 it is often very harmful when done carelessly. No other cranberry pruning 

 is advisable. The vines should be mowed with a machine if they are so 

 heavy that fruit production is much reduced. They will be even and 

 usually less rank when they grow again. Some burn oflf heavily vined 

 bogs, but the burning may harm the roots, the vines are slow to come to 

 bearing again, and the bog is more exposed to weed growth. 



Fertilizers 



No advantage is gained by fertilizing peat-bottom bogs. Nitrate of soda 

 and acid phosphate often greatly increase the yield on "hard bottom" 

 areas (sand or clay underneath instead of peat), and 150 pounds of the 

 former and 300 pounds of the latter to an acre is a reasonable application 

 Potash has little value on any bog. Mid-June, when the spring frost- 

 flooding is past and the vines are beginning to bloom, is probably the best 

 time to apply fertilizer. 



Nitrate is likely to promote too much vine growth on peat bottom, 

 especially if the bog is new. It is generally better to get more vines, 

 where they are desired, by holding the winter flood late than to fertilize 

 for them. Continued use of nitrate impairs the keeping quality of the 

 fruit and encourages weeds. 



Fertilizer helps greatly to repair old bogs out of condition from grub 

 injury. Reground nitrate of soda scattered broadcast early in April, 250 

 pounds to an acre, reduces haircap moss well and helps the vines compete 

 with it. 



Diseasesi2 



Many fungous diseases attack cranberries. Some seriously affect the 

 vitality of the vines or cause the leaves to drop and some reduce the crop 

 by blasting the blossoms and young berries or by rotting the berries on 

 the vines and in storage. Late holding of the winter flood (to May 23) 

 and good drainage during the growing season curtail such troubles. 

 Bordeaux mixture reduces rot of the berries on the vines and improves 

 their keeping quality; it has been very helpful in some cases, but whether 

 its use generally pays in this State is doubtful. Lead arsenate also has 

 this effect, but its frequent use weakens the vines on sanded areas. Care 

 in handling the fruit in harvesting, separating, sorting, and packing does 

 much to reduce decay in shipment. 



The rot diseases of cranberries caused by different fungi vary greatly 

 in their prevalence in the different cranberry-growing regions of the 

 country. Early rot, which blasts the flowers and young berries and rots 

 the fruit on the vines and in storage, is the most serious of these troubles 

 in New Jersey. As this disease is more completely controlled by spraying 



" Technical bulletin No. 258 of the United States Department of Agriculture is the 

 l)est general account of cranberry fungous diseases. E.xtension I.eatiet No. 154 of the 

 Massachusetts State College discusses false blossom. 



