1048 EXPERIMENT STATION RECORD. 



aiul tbose which are weedy and poorly drained, it l)eing nnieli lower in the 

 latter ease. 



The importance of keeping cranberry grounds as free as possible from weeds 

 and pruning the vines is again brought to the attention of the growers as one 

 method of lessening the danger from frost. The minimum temperatures taken 

 from May 9 to Sept. 30 in the vines 2 in. above the surface of the ground and in 

 the air 3 ft. above the ground are tabulated. From this data it is shown that 

 the low temperatures and formation of frost locally are largely the results of 

 radiation, and that under conditions favorable for this process the tempera- 

 tures in the vines go much below that of the air a short distance above. 



A 3 years' summary is given of 3 plats which were drained to a depth of 14 

 in., of 4 to 8 in., and with water at the surface, respectively. The average yield 

 for the 3 years is slightly in favor of the plat drained to a depth of 14 in., and 

 the results appear to be in favor of thorough drainage, the benefits derived being 

 attributed to the warmer average temperature of the drained soil. 



The observations of 1905 on the relation of the humidity of the atmosphere at 

 7 p. m. to the minimum temperature of the night have been repeated during 

 1906, from May 19 to September 30, and are presented in tabular form, in which 

 it is shown that the temperature of the night frequently went 20° below the 

 dew point of the evening, and in one case 2G.2° below the dew point at 7 p. m. 

 The fall of the temperature below the dew point on clear nights was accompanied 

 by excessive dew. 



Sanding the plats appeared to increase the yield and also made an increase 

 in uprights by covering a multitude of runners and allowing them to root, thus 

 invigorating the whole plant. In the fertilizer tests the application of nitrate 

 and phosphate gave the best results, as in previous experiments. 



An experiment was conducted to determine whether the removal of moss and 

 other forms of vegetation from vines before planting lessens the growth, either 

 by injuring the vine or by removing matter which would otherwise act as a 

 mulch. Thus far the results seem to be in favor of cleaning the vine. 



In an experiment carried on to determine the advantage of covering a portion 

 of the vines with muck as they are planted in comparison with planting in the 

 usual way by tamping, no difference was noted in favor of covering with muck. 

 On the other hand, much additional weed seed was added to the plats by the 

 muck. 



With reference to the value of planting cut and uncut vines, the growth was 

 found to be practically the same in both cases. Comparisons were made of 

 propagation by cuttings and from seed, the former being the usual method. 

 The results of these comparisons are given in a table and show a great uni- 

 formity of parent and seedling in respect to color, size, and shape. 



With respect to the effect of flooding on the fruit, the conclusion has been 

 deduced that while cranberries will stand a long flooding where the water is of 

 a low temperature, the use of water above Oo° must be of shorter duration. 



In a comparison of spraying, flooding, and the use of kerosene for preventing 

 injury by worms, spraying with arsenates has been found an effective means of 

 keeping the insects in check, both as a preventive and as a remedy. Spraying 

 should commence not later than July 1 to obtain the best results and be followed 

 by 1 or 2 further applications at intervals of from 10 to 14 days. Flooding as 

 a remedy for fruit-worm is not to be relied upon under the temperature condi- 

 tions prevailing on the open marshes of Wisconsin during the period when it 

 would be most effective, unless water of a sufficiently low temperature can be 

 obtained, in which case it is stated that there is no remedy that is more effective 

 and more easily api)lied than a submersion of the vines, which should continue 

 at least 2 nights and 1 day. A short flooding, sufficient to bring the worm out 



