SOME VALUABLE BULLETINS 



EXPERIMENTS in dust spraying have 

 been tried at a number of places m 

 the United States, inchiding the Delaware 

 College Agricultural Experiment Station, 

 from which a bulletin giving the results has 

 just reached The Horticulturist. Two 

 pounds of dry mixture will answer on trees 

 which would require three to four gallons of 

 liquid. Each tree received at each spray- 

 ing one-half as much copper sulphate and 

 one and one-half times as much poison as 

 are contained in four gallons of Bordeaux 

 mixture with poison. The conclusions ar- 

 rived at from the experiments are as fol- 

 lows : 



The codling nioth and apple scab on Xero, 

 July and Red Astrachaii apples, were satis- 

 factorily controlled by dust spraying, using 

 Paris green for poison, in 1904. If the 

 dust spray will produce the same results on 

 other varieties of apples it can certainly be 

 recommended. In liquid spraying opera- 

 tions for large orchards a mixing house and 

 storage tanks are necessary, as is also a sup- 

 ply wagon if the spraying outfit is worked 

 to its fullest capacity. This involves a 

 heavy expense most of which would not be 

 necessary in dust spraying. Should the 

 dusting method continue to give the favor- 

 able results it has given in its first trial it 

 must soon replace in part the liquid method, 

 except w'here such sucking insects as San 

 Jose scale must be fought during the grow- 

 ing season. 



At present it is probably best to rely on 

 some brand of 'h}-drated lime now on the 

 market and pulverized copper sulphate and 

 Paris green for the dusting material, unless 

 a pulverizing mill is available. In this case, 

 and especially if dry slaked lime is used, the 

 materials should be mixed and run through 

 the mill. The formula now suggested is 

 one pound of pulverized copper sulphate, 

 one pound Paris green or green arsenoid. 

 one pound ground sulphur and 50 pounds 

 limoid. or other hydrated lim.e. It will per- 



haps be well to mix the copper sulphate and 

 lime together a day or two before needed for 

 spraying so as to facilitate chemical action 

 between the two. Further testing may 

 prove that a formula with a larger propor- 

 tion of lime will prove efirective. but at pres- 

 ent the stronger one will be used. 



As to cost, according to the bulletin, the 

 dry spray can be applied on a comm.ercial 

 scale at half the expense of liquid spray. 



WINTER KILLING OF PEACH TREES. 



Another bulletin recently issued by the 

 Ohio station gives a report of investigations 

 in the Lake Erie fruit 'belt on the winter kill- 

 ing of peach trees in 1903 and 1904. The 

 conclusions arrived at are as follows : 



General cause of unusual susceptibility to 

 cold of the orchards of the Lake Erie fruit 

 belt : prevailing low vitality of the trees. 



Specific causes of low vitality of the trees : 

 San Jose scale, leaf curl, lack of nourishing- 

 plant food, im.perfect drainage. 



Exceptional causes of susceptibility to 

 cold in rare cases of apparently healthy, 

 vigorous trees : low, moist, rich black soil 

 which favored an extreme growth of soft, 

 poorly ripened or matured wood ; or high 

 culture upon soil rich in plant food which 

 brought about similar results. 



The unusually deep, hard freezing of the 

 earth's crust Avas due, directly, to the con- 

 tinued steady cold, but was intensified, in 

 many instances, by a lack of humus or vege- 

 table matter in the soil, \v)hich constitutes 

 nature's insulation of the surface of the earth 

 from cold and heat. 



Providing that the orchards had been 

 kept free from fungous diseases and the San 

 Jo'se scale, by tin:iely and thorough spray- 

 ing, no injury of trees was found where sta- 

 ble or barnyard manure had been used upon 

 the ground within the last year or two pre- 

 vious to the winter of 1903-4; rarely was an 

 injured tree found standing in sod; no in- 

 jurv was done where the surface of the soil, 

 beneath the trees, had been covered with 



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