CRANBERRY GROWING 23 



flood should not be held on a bog over twenty-four hours unless the weather is 

 definitely clear and cool and should not be held over twenty hours if the bog has 

 a bad record of injury by June flooding. Ten hours is long enough for most 

 insect pests, but the blunt-nosed leafhopper and the spittle insect require 24 hours. 



A partial flood must be put on if frost threatens in May or June. Two or 

 three inches of water under the vines is enough, for heat will pass from the water 

 to the air and keep the vines from freezing. If water must be saved and it remains 

 cold, the water may be held over on the bog from one night to another for several 

 successive days up to about Ma>- 10 and for a day at a time occasionally after 

 that. 



Cranberry winter buds are not hurt by a temperature of 25° F. till they swell 

 to a diameter of more than 2 mm. The>- usually will endure temperatures down 

 to 20° till the end of April. Temperatures above 29° seem never to do much 

 harm. Often 28° is reached in the time of tenderest growth without injury, 

 but the greatest depression in such cases is brief. 



Flooding should not be done during or after the blooming period, for it will blast 

 the blossoms and promote rapid development of the fungi that rot the fruit. 



Frost in September and October often necessitates flowing again, but the 

 berries and vines will endure more frost then, and longer chances may be taken 

 than in the spring. The water may be held over on the bog from one night to 

 another occasionally, as in the spring, if it seems necessary. Cranberries usually 

 will stand 28° F. in the whitish stage before ripening, but 26° often harms such 

 fruit greetly. Freezing begins among ripe Early Black and Howes berries at or 

 slight!}- above 22°, no softening following exposure to 23". Ripe Howes and 

 McFarlin berries are so resistant that under bog conditions often only 10 per- 

 cent are injured at 16° and only 20 percent at 14°. Sometimes, however, 25 

 percent are softened by 18°. The loss of Early Black berries at these tempera- 

 tures is much greater. 



Frost flooding always does some harm: in the spring tending to reduce produc- 

 tion, and in the fall tending to impair the keeping quality of the fruit and inter- 

 fering with harvesting. For this reason and because unnecessary frost flooding 

 wastes limited water supplies, accurate forecasts of frosts are very important. 

 The Weather Bureau sends out special warnings to the cranberry growers, which 

 are supplemented b}- those of the Cranberry Station of the Massachusetts Agri- 

 cultural Experiment Station. 



As soon as the crop is gathered, the bog should be flooded for a week to water 

 the disturbed roots and float off fallen leaves, berries, and other trash. ^^ This 

 controls the cranberry girdler when it is done late in September. No flooding 

 is necessary after this till the water goes on for the winter. 



Some bogs can be flowed only for the winter and some are not flowed at all. 

 They generally are not so profitable as those with plenty of water, but some ot 

 them pay well under good management. 



Sand and mud wash into the ditches and growing weeds and floating materials 

 help to fill them so they must be cleaned out every few years. 



Irrigation 



Bogs are too wet oftener than too dry. The\' do, howe\'er, often suft'er from 

 drouth, especially in August, the berries being reduced in number and size and 

 retarded in ripening and the vines dying in severe cases. Practice varies in bog 



^^ If much of this material lodges on the vines, it is very harmful. There should be catch basins 

 around the bog margin to receive it from the flood. If no catch basins have been made, the trash 

 must be raked from the water where the wind drives it ashore. 



