DISEASES OF PLANTS. 349 



are considered necessary. Leaf dieback, due primarily to drought, was not 

 entirely controlled by the removal of the affected parts and the use of Bor- 

 deaux mixture. Cases of root disease were observed on badly drained land 

 and on impervious clay subsoils. " Eaten leaf " disease, due to fungus attack 

 in the bud, requires the introduction of a fungicide into the crown of the trees. 

 A bud rot trouble was thought to be due to Phytophthora parasitica, which is 

 said not to have been recorded previously as a disease of the coconut. 



P. faberi still causes considerable loss to cacao. Promising results in Its con- 

 trol have been obtained with Bordeaux and with Burgundy mixtures. Some 

 cases of pod anthracnose {Colletotrichum cradioickii) have been observed, and 

 this is controlled in the same way. 



Cases of gall or knot, due to Sphceropsis tumefaciens, were observed on 

 limes. The remedy suggested is destruction by fire of all prunings. 



A Sclerotium destroying the lower leafsheaths of sugar canes was noted in 

 two places. It is thought that this may cause loss in wet seasons. The rind 

 fungus {Melanconium sacchari) rotted prematurely ripened canes on one estate. 



Mention is made also of a few insects injurious to coconut, cacao, citrus, 

 mango, coffee, yams, sugar cane, and cotton. 



Root knot or eelworm attacks new hosts, L. E. Melchees (Ohio Nat., 15 

 (1915), No. 8, pp. 551-555, figs. 4)-— The author states that after contact with 

 soil containing Heterodera radicicola, infection followed in the case of the 

 hitherto unreported hosts Vinca rosea. Chrysanthemum frutescens, Celosia 

 empress, Matthiola incan-a anmia, and Phlox. Specimens of Carum petroselinum 

 from Kansas were also badly affected with this nematode, not previously re- 

 ported as parasitic thereon. 



Control of yellow rust, F. Stbakak (Deut. Landw. Presse, 42 {1915), No. 42, 

 p. 379). — This is mainly a discussion of studies reported by several investi- 

 gators regarding conditions apparently favorable or unfavorable to the develop- 

 ment of Puccinia glumarum on wheat and measures for its control. 



Weather and cultural conditions thought to be influential in this connection 

 are discussed, including not only those during the spring growth of the crop 

 (as daily fluctuations of temperature, etc.), but probably also some obtaining 

 In the previous year. Lists are given of varieties found to be highly suscepti- 

 ble, moderately so, or resistant, and the.se are briefly discussed in connection 

 with their several vegetating periods and morphological characters. 



A bacterial disease of western wheat grass, P. J. O'Gaea {Science, n. ser., 

 42 {1915), No. 10S7, pp. 616, 617). — A description is given of an unusual type of 

 bacterial disease found on western wheat grass {Agropyron smithii) in the 

 Salt Lake Valley, Utah. The affected plants are said to be usually somewhat 

 dwarfed, but the most striking characteristic of the disease is the presence of 

 masses of surface bacteria which form a lemon-yellow ooze or slime. Some- 

 times this appears in small droplets, but often it is spread over the surface of 

 the upper portion of the plant, including the sheath, upper internode, and 

 inflorescence. The disease seems to be limited to the upper portion of the 

 plant, not having been found on the roots or lower internodes and sheaths. 

 When the bacterial slime hardens, it is said that it may be separated from the 

 plant surface in the form of thin, lemon-yellow flakes. The injury to the 

 plants is due to the bacterial growth which flrst develops conspicuously on the 

 surface and later penetrates the interior tissues. 



This disease is said to have many characteristics in common with the disease 

 of orchard grass first described by RSthay and later by Smith as due to 

 Aplanobacter rdthayi (E. S. R., 30, p. 539). 



Beet blight, R. E. Smith {Abs. in Phytopathology, 5 {1915), No. 5, pp. 291, 

 292; Science, n. ser., 42 {1915), No. 1086, pp. 580, 581).— The structure of dis- 



