19-0] DISEASES OF PLANTS. 345 



Cooperative marketing of woodland products, A. F. Hawes (U. S. Drpt. 

 Af/r., Fanners' Bui. 1100 (1920), pp. 15, figs. 6). — This points out briefly what 

 lias been done in the cooperative niarJcetins of other farm produce, and presents 

 sufijrestions relative to the orjianization of farm proilucts associations and 

 methods adapted to the uiurketini; of woodland products. 



DISEASES OF PLANTS. 



[Report of the department of botany] (Indiana Sta. Rpf. 1919, pp. 19-25, 

 figs. 4)- — The major investigations carried on by the department have been 

 concerned with corn diseases, cereal rusts, and diseases of vegetables. 



The work on corn diseases has been carried on to add information con- 

 cenuiig certain ear, shank, and stem rots of corn in the hope of developing 

 methods for avoiding losses from these diseases. The effect of the root-rot 

 diseases on sweet corn is al.so being studied in cooperation with the horticul- 

 tural dei>artment of the station. Physiological and chemical studies are in 

 progress to determine the changes in composition of corn plants as induced by 

 the different disease-producing organisms, the principal ones being species of 

 Gil)berella, Fusarium, Ilhizopus, and Pseudomonas. The investigation includes 

 field, greenhouse, and laboratory work on normal and abnormal i)hysiology of 

 the com ])lant, chemical studies of the effect of the diseases on the composition 

 of corn, and other important phases of the general problem. 



The rust investigations have been mostly on the cereal leaf rusts, particularly 

 "relating to the species which causes the leaf rust of wheat. In connection with 

 this work, the relation of leaf rust of wheat to a similar rust which is known 

 to occur on SO species of native gra.s.ses has been studied. Similar work is in 

 progress with the leaf rusts of rye and barley. 



Studies are reported in progress on Septoria leaf spot, mosaic, and Fusarium 

 di-seases of tomato, cabbage yellows, a malnutrition of onion apparently due to 

 an excess of soluble salts in the surface soil, and tip burn and Fusarium wilt 

 of potatoes, as well as a number of more common cucurb"ft diseases. 



According to the report, a disease of wheat, identified by officials of the 

 I U. S. Department of Agriculture as probably the Au.stralian " take-all" disease, 

 \ was found in 3 counties in Indiana, and measures were taken to keep the 

 I trouble in check. 



Some experiments have been inaugurated in cooperation with the department 

 of horticulture of the station to study the effect of a dormant spray of strong 

 lime-sulphur as a i)0ssible control measure for apple blotch. Laboratory tests 

 show«Hl that such applications would kill the spores of the fungus in exposed 

 pycnidia, but not the mycelium in tissues of the bark. Field tests are in 

 progress to determine the significance of these facts. 



[Notes on some plant diseases] (Neiv Mexico Sta. Rpt. 1919, pp. 16, 17, 

 18). — Brief notes are given on a number of plant disease projects which are 

 being investigated at the station. These include chlorosis of trees, which was 

 only temporarily checked by the use of iron sulphate solutions ; also root-rot 

 di.seases of fruit trees and other plants; the Fusarium wilt of alfalfa; the 

 occurrence of si)ecies of Valsa and Cytospora in connection with apple canker; 

 and the presence in New Mexico of a disease of apple trees known as the 

 Ozark Mountain measles. The last-name<l disease is thought to be coimected 

 in some way with the large amount of nitrates occurring in the soil. 



Report of the phytopathological service [of the Dutch Poniological 

 Union] {.]fann(lbL Nvdcrland. PonuA. Vcr., 9 (1919), No. 9, pp. tJ,0-l.',2).—A 

 B^i.sarium disease in heads of summer vvbeat was controlled by the use of 



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