-3- 



There are other factors besides temperature that affect the length of the 

 incubation period for apple scab. Observations in Massachusetts indicate that 

 2 to 3 applications of Yrettable sulfur during the incubation period v.dll lengthen 

 it from 1 to 3 days over the incubation period for the corresponding infections in 

 unsprayed orchards. W. D. Mills states that lime-sulfur applied too late for 

 after-rain (kick-back) control may delay the appearance of scab spots as much as 

 5 days. Phenyl mercury spray has been knovm to permanently inactivate the scab 

 fungus midway in a l^'-day incubation period. Under some conditions, however, like 

 ILme-sulfur it may only lengthen the incubation period. The reason v;-hy the scab 

 fungus in incubation may be slovred up or otherwise hindered by spray applications 

 is its close proximity to the surface of the leaf, i.e., just beneath the cuticle. 



~ C. C. Boyd 



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NOTES ON ORGMIC GARDENING ; 



In a recent issue of Agricultural Chemicals the opinions of tvro eminent soil 

 scientists on this controversial subject are expressed. Dr. Truog of "..isconsin 

 is reported as saying, "Soil organic matter is of tremendous importance: it 

 facilitates the intake of water and thus reduces runoff and erosion. It also 

 favors workability or ease of cultivation, aeration and drainage. Fresh organic 

 matter contains all of the elements needed for plant grovrth, vj-hich as decomposition 

 proceeds, are released in forms suitable for nevf plant grovfth ... Hc;vever, to say 

 (as the organic school does) that checmical fertilizers, such as super-phosphate 

 and muriate of potash should not be used to make up inevitable deficiencies of 

 nutritive elements that cannot be supplied through the use of organic matter is 

 just pure bunkum. 



This same authority is also quoted in part as follows: "Fertilizer elements 

 in commercial fertilizers are fully as available to crops as those in organic 

 materials, and in some cases even more so. There is absolutely no difference in 

 the nature of the nitric and sua.pha2:*L(r'-'acfd3' -forBed in, theuSoil. from organic matter 

 through the action of bacteria, as the nature of these same acids as used in a 

 fertilizer factory. The form in vfhich plants take up their nutrients is the same 

 whether they are originally supplied as organic material, such as compost or 

 commercial fertilizer. It is true that the use cf composts adds to tiie supply of 

 organic matter in soils, and in this vvay promotes a better physical condition of 

 soils ... .This use maybe important especially with the city gardener. .. .The farmer 

 in general, however, cannot cover his large acreages v.'ith compost. Sufficient 

 amounts of leaves and other organic materials just do not exist on his farm for 

 this." 



Dr. Bear cf New Jersey refers to the organic group as an "international cult — 

 cluttering up our soils literature with a mixture cf facts and fancies that are so 

 cleverly interwoven that it is very difficult to knov; vihere one leaves off and 

 the other begins. .. .Such teachings link the farmer inseparably vdth the manure pile 

 and peasantry. They set aside some of the most important findings of a century of 

 agricultural science." 



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