Botany and Entomology in 1937 HEMISTRY is not included in these re views inasmuch as it has been treated in greater detail than is here possible in an article which appeared on page 3 of the January 1, 1938, issue of
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INDUSTRIAL A N D E N G USTEERING CHEMIS
TRY. T h e review on physics for 1937 will appear in our January 20 News Edition.
Advances in Botany F.E.Denny, R o y c e T h o m p s o n Institute f o r P l a n t R e s e a r c h , I n c . , Yonkers, Ν . Υ. Mineral
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Nutrition
OBALT as a factor in animal disease and the importance of cobalt in the plants constituting the forage of the ani mals is shown by the reports of Denham (18), Council of Science and Industrial Research for New Zealand, Underwood (41), University of Wisconsin, and Patter son (SI), Dartington Hall, Totnes, South Devon, England. Sheep affected with "bush-sickness," a disease occurring in certain areas in New Zealand, were cured by drenches containing cobalt. The co balt content of plants from pastures in which the disease occurred was lower than that of near-by disease-free pastures. A top-dressing of the soil with limonite, a cobalt-bearing mineral, served to control the disease. Patterson noted the simi larity between the symptoms of "bushsickness" in New Zealand and a disease of sheep in England which the English farmers had learned to control by merely changing the grazing place from moorland to lowland for about 2 to 3 months. The cobalt content of the soils on which the sheep became diseased was 3.9 p. p. m., while that of the lowland soils was 16.7 p. p. m. The cobalt content of forage marking the range between sickness and health was surprisingly small, 0.2 p. p. m. in forage from areas showing sickness, and only 0.45 p. p. m. from recovery areas. Frenching, a disease of tobacco and other plants, is believed by Spencer (39), Rockefeller Institute for Medical Re search, Princeton, N. J., to be due to thallium poisoning. Thus, 0.067 p. p. m. of thallium in a culture solution will pro duce the frenching symptoms; species susceptible to frenching are also sensitive to thallium, and both conditions are over come by nitrogen fertilizers, by aluminum sulfate, and by pot assium iodide. Whet her frenching soils contain the required amount of thallium could not be deter mined, since present chemical methods are not sufficiently sensitive to detect in the soil such traces of thallium as are needed to produce the symptoms. Cauliflower browning, cracked stems of celery, and yellowing of alfalfa are all due to a boron deficiency in the soil according to Purvis and Ruprecht (32), University of Florida, Dearborn, Thompson, and Raleigh (17), Cornell University, and McLarty, Wilcox, and Woodbridge (29), Dominion Laboratory of Plant Pathology, Summerland, B. C , Canada. That soil organisms may rob higher plants of their necessary minimum of such ions as manganese and zinc is an interpre tation that may be made from the investi gations of Gerretson (21), Agricultural Experiment Station, Groningen, Nether lands, with the gray speck disease of oats, and of Ark ( / ) , Hoagland, Chandler, and Stout (26), University of California, with rosette disease of peach trees. Both diseases can b e cured by adding the ap
propriate element, manganese for oats, and zinc for peach, but in neither case is this addition of nutrient necessary if the soil is merely sterilized, even with such a chemi cal as formalin which does not increase the soil content either as to manganese or zinc. But such sterilized disease-free soils be come again disease-producing if a small quantity (1 to 10 per cent) of the original nonsterile soil is added, owing to the multi plication of organisms introduced with the nonsterile soil. It appears that somehow the organisms make the manganese or zinc unavailable to the plant, and produce a deficiency disease in a soil containing a sufficiency of the needed element. Two articles emphasize the differences in the response of plants to copper. Saeger (37), University of Missouri, shows that if copper is essential for the growth of Spirodela (as has been shown for certain other plants) the requirement cannot be much greater than 1 part in 10 billion. Indeed, 1 part per billion was toxic for this plant. As a contrast to this, note the report of Bedford (3), University of Cali fornia, who found a strain of Pénicillium growing (even if not producing spores) in a saturated solution of copper sulfate. The fungus was first found growing in the copper solution used in preparing Fehling reagent. Organic N u t r i t i o n Vitamin Bi is not only an animal vitamin but plays a somewhat similar role in the life of certain plants. Previously it had been found that tomato root tips required the addition of yeast extract to an otherwise suitable culture medium containing salts and sugars. Bonner (11), California Institute of Technology, and Robbins and Bartley (34), University of Missouri, found that the yeast extract can be replaced b y crystalline vitamin Bi, either as prepared from tissue or by chemical synthesis. According t o Bonner, 0.2 gamma per cc. will replace the yeast extract optimum, and 0.002 gamma has a marked influence. In the Williams and Cline synthesis of vitamin Bi, two derivatives, one of pyrimidine and the other of thiazole, were combined chemically. Robbins and co-workers (33, 35, 36), tested the possibility of these two, or either, acting as a substitute for vitamin Bi. They find that tomato root tips require the thiazole derivative only and grow without addition of vitamin Bi, possibly because the synthesis of Bi can be completed if the thiazole portion is available. The fungus Phycmnyces requires both the pyrimidine and thiazole intermediates, but another fungus Aspergillus requires neither, nor even Bi itself. Furthermore, these workers applied this knowledge of plant nutrition to the problem of vitamin Bi for animals with the result that pigeons were maintained on a diet free of vitamin Bi, for which these two
Courtesy, Skinner
