October, 1923
INDUSTRIAL A N D ENGINEERING CHEMISTRY BIOLOGICAL PROPERTIES
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PHYSICAL EFFECTS-Bordeaux mixtures are, as a simple inspection of the dried washes would show, unequally transparent, the opacity increasing as the ratio of cupric sulfate to calcium oxide approaches unity. One would therefore expect that a plant sprayed with a neutral wash would respond somewhat differently than a plant sprayed with an alkaline mixture, and, effectively, as the data in Table IV show, we find that the sprayed plant develops normally on the one hand and slightly abnormally on the other. TABLEIV-EFFECT OF SPRAYING WITH BORDEAUX MIXTUREAND MILE LIMEON DRY MATTERFORMED AND TRANSPIRATION PER GRAMDRY MATTER’S Transpiration per Gram Dry Matter ---Dry Weight-Sprayed with Sprayed with BorBordeaux Mixture N o t deaux Mixture Not 1: Alkaline Sprayed 1: 1 1 : Alkaline Sprayed 1 : 1 VARIETY USED G. G. G. G. G. G. 27.80 25.20 24.20 0.95 0.66 Radish Early 0.74 37.50 27.60 30.60 2.33 2.74 Scarlet Globe 1 . 9 7 32.39 34.84 3.10 2.92 40.73 2.67 2.10 35.34 28.39 29.88 AVERAGE...^.^^ 2.12 19.70 9.77 9.95 3.18 2.95 TomatoBonny 2 . 4 2 23.82 21.83 22.06 8.47 8.43 Best 7.59 AVERAGE . . . 5 . 0 0 5 . 8 2 5 . 6 9 21.76 1 5 . 8 0 16.00 20.20 18.20 18.70 3.41 3.68 BeanDwarf 3.28 4.78 6.52 4.97 4.76 5.38 Horticultural 3 . 6 0 4 . 5 3 13.66 11.58 11.74 3 . 4 4 4 . 0 8 AVERAGE ...
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The literature is not in agreement in regard to the effect of Bordeaux mixtures on the rate of transpiration of sprayed plants, though the weight of the evidence indicates increased’ transpiration.16 It has been observed by Daggar and Bonns16 that spraying with Bordeaux mixture increases transpiration especially a t night. The writer has observed that increased transpiration is noticeable especially under conditions favorable for radiation and that Bordeaux mixtures are opaque to the infra-red. We would therefore expect, other things being equal, sprayed plants to transpire more actively a t night than nonsprayed plants. However, it should be noted that increased transpiration of sprayed plants a t night does not of itself account for the effect of Bordeaux mixtures, because all Bordeaux mixtures cause increased transpiration to some degree but they do not all affect plants in a similar manner. The response of sprayed plants is to be attributed to difference in translucency of the mixtures to the solar spectrum. Schrander” was the first to advance the view that the action of Bordehux mixture on p1ani.s was one of shade. Bordeaux mixtures, however, while not equally opaque to luminous radiations, do not show inter se quite so marked differences as the behavior of the sprayed plants indicates that they should. The response obtained is not due to shade, using the term in its ordinary acceptance, but to different degrees of athermancy of the washes to the spectrum. When the spectrum as a whole is considered 1 per cent, alkaline Bordeaux mixture is much more opaque than neutral Bordeaux mixture, and there is concordance between the physical properties of the washes and the response of plants sprayed with them. CHEMl CAL EFFECTS-when we study the response Of sprayed plants to the chemical action of Bordeaux mixtures we find rather a complex situation-we have to consider the effect of the mixture at the time of application, and the effect of the mixture after it has dried. The effect of Bordeaux mixtures after they have dried seems to be due entirely t o the sensitiveness of the plant to soluble copper. The action of Bordeaux mixtures a t the time of their application depends, on the other hand, on the type of mixture used, on the kind and variety of plant sprayed, and on the nature and age of the organ sprayed. In the grape, when Bordeaux mixtures are injurious it will be found that alkaline washes are more injurious than neutral mixtures, and that it is the young leaves that are damaged. In
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the peach, alkaline washes are more injurious to youug than to old leaves, and neutral mixtures more injurions to old than young leaves. But, unlike the grape, the peach is sensitive to soluble copper and eventually the differences in behavior of the foliage following spraying are masked by copper injury. In the tomato, alkaline washes are more injurious than neutral Bordeaux mixtures, the injury due to alkalinity being noticeable on the young leaves. I n the apple, neutral and alkaline Bordeaux mixtures of the usual types are injurious. The degree of alkalinity of the wash seems to have little or no influence on the intensity of the injury produced. However, the apple is somewhat sensitive to soluble copper and the fruit much more so than the foliage. In fact, the apple is so sensitive to soluble copper after the blossoms have fallen that Sanders and Brittain introduced Bordeaux mixtures in which the ratio of cupric sulfate to calcium oxide is 1:3 and 1:5 in order to reduce injury. Bordeaux mixtures of this type can be used on the apple very successfully, and cause very little if any injury. The reduction in the amount of the injury produced is not brought about, however, by any change in the nature of the copper precipitate formed, but by the fact that such a large excess of lime both delays and impedes carbonation and consequently the dissolution of the copper in meteoric water.
BIBLIOGRAPHY 1-Millardet, J . agr. Brat., 2, 572 (1885). 2-Millardet, A n n . soc. agr. Gironde, 1886. 3-Millardet and Gayon, J. agr. firat., 1 , 704 (1887). 4-Patrigeor1, Ibid., 1, 701 (1890). k W a i t e , U.S. Dept. Agr., Farmers’ Bull. 248 (1906); Sanders and Rrittain, Proc. Ent. Soc. Nova Scotia, 4 (1919). 6-Millardet and Gayon, J. agr. prat., 1, 709 (1885). 7--Chester, J . Mycology, 6, 22 (1891). &Fairchild, U. S. Dept. Agv., Div. Veg. Path., Bull. 6, 13 (1894). 9-Sostegni, Staz. sperimenlali agrar. italiane, 19 (1890). 10-vermorc1, Compt. rend., 159, 266 (1914). 11-Pickering, J. Chem. SOC.(London), 91, 307 (1907). 12--Butler, Phylofialhology, 4, 131 (1914); BCdford and Pickering, Woburn Experimental Fruit Farm, Report 11, 25 (1910). la-Kelhofer, Internationoler phylopathologische Dienst., 1 (1908). 14-Butler and Smith, Phytopathology, 9, 431 (1919). IZ-Eutler, New Hampshire Agr. Exp. Sta., Tech. Bull. 21, 18 (1922). 16-Duggar and Bonns, Ann. Missouri Botan. Gardens, 5, I53 (1918). 17-Schrander, Landw,. J e h r b . Schweiz., 33, 517 (1904).
Cellophane Plant under Construction Cellophane, a transparent, cellulose product, used largely in millinery for decoration and in other trLdes for wrapping purposes, is to be manufactured by the du Pont Cellophane Co., a subsidiary of the E. I. du Pont de Nemours & Company. A plant to cost approximately $2,000,000 is now being constructed on the Niagara River a t Buffalo, N. Y . This will be the first plant to manufacture this product in the United States. Cellophane has been produced in France for the past several years and its use is extending for wrapping purposes for confectionery, biscuits, cakes, tea, coffee, cocoa, meat products, and, in fact, for nearly all articles of food, as well as for perfumery, soap, various toilet preparations, pharmaceutical products, and others. It is an important addition to the list of cellulose products produced by chemists for commercial uses during the last several years. It is nongelatinous, will not melt in boiling water, or decay. It is described as entirely harmless, water- and greaseproof, odorless, and can be dyed in any shade, printed or embossed, making it especially attractive as millinery decoration. It is manufactured in either sheets or rolls. The du Pont Cellophane Company has obtained the patent rights for North America and pending the completion of its factory a t Buffalo will be the selling agents in this country for the product, The company is now importing it. It is expected that the new factory will be completed in May or June of next year.
