DISEASES OF PLANTS. 847 



WiNSLOW {U. 8. Dept. Agr., Forest Serv. Circ. 198, pp. 13, figs. 2).— This circu- 

 lar, which supplements a previous bulletin dealing with the preservative treat- 

 ment of poles (E. S. R., 25, p. 344), gives the results of inspections of 2 experi- 

 mental lines, 5 and 8 years, respectively, after their establishment. 



The poles for the Warren-Buffalo line were cut and peeled during 1902 and 

 1903 and seasoned in single tiers about 2 ft. above the ground in June and July, 

 1905. Some were butt-ti"eated with various preservatives by the brush method 

 and others with coal-tar creosote by the open tank method (E. S. R., 10, p. 243). 

 Six hundred and thirteen treated poles, together with 551 untreated seasoned 

 and green poles were placed in a line extending through a variety of soil con- 

 ditions. 



At the end of 5 years both the green and seasoned poles butt-treated with 

 coal-tar creosote by the open tank process showed practically no decay at or 

 near the ground line. Poles brush-treated with 2 coats of coal-tar creosote, 

 Avenarius carbolineum, S. P. F. carbolineum, and wood creosote showed but 

 little difference in the extent of decay and. ranked next best to the poles treated 

 with coal-tar creosote in the open tank. Poles brush-treated with only 1 coat 

 of preservative showed a much higher percentage of decay than those given 2 

 coats. With poles brush-treated with only 1 coat of creolin and of coal tar, the 

 loss was nearly as great as with the untreated. The untreated poles were 

 practically all more or less affected with decay at the ground line, the average 

 loss of circumference for those seasoned prior to placement being 1.01 in. and 

 for those placed green 1.15 in. An inspection relative to insect damage to 

 poles in this line was made by the Bureau of Entomology and is discussed in a 

 previous bulletin (E. S. R., 25, p. 51). 



Only 72 poles were placed in the Poughkeepsie-Xewton Square line and 

 records showing the details of their preparation and treatment are not avail- 

 able. As inspected after a lapse of 8 years, however, the untreated poles set 

 in crushed stone showed less decay at the ground line than similar poles set in 

 sand, the average loss of circumference at that point being 1.77 in. and 2.27 in., 

 respectively. The poles with charred butts showed less decay at the ground 

 line than similar uncharred and untreated poles set in either crushed stone or 

 sand, their average loss in circumference at the ground being only 0.71 in. 



DISEASES OF PLANTS. 



Report of the pathologist, G. L. Fawcett (Porto Rico 8ta. Rpt. 1911, pp. 

 37-39). — Spraying experiments with Bordeaux mixture on coffee trees were 

 carried on with particular reference to its adhesiveness when used as a spray. 

 Bordeaux mixture made up with but half the usual amount of water without 

 the addition of any adhesives was found to adhere to the foliage better than 

 Bordeaux mixture made by the usual formula to which adhesives were added. 



A bud rot of the coconut has been found sporadically in a number of places 

 but does not appear to be sei-iously affecting the groves. Bacteria have been 

 isolated from the diseased tissue in every case studied, but no uniformity in 

 the results of the studies has been obtained. 



Work in soil biology has consisted largely in an examination of soils for 

 protozoa, and in some of the so-called " sick " soils, where the conditions were 

 the worst, the complete absence of protozoa was noted. Samples of these soils 

 were disinfected with heavy applications of carbon bisulphid, but from the 

 results of the study it appears that any benefit that is derived from the disin- 

 fection of the soils can not be attributed to the destruction of protozoa. 



Root nodules were found to occur abundantly in the royal palm, and these have 

 been studied with reference to their possible relation to nitrogen assimilation. 



