32 PATHOLOGY [Bot. Absts., Vol. VI, 



Pycnia may develop. Swelling of the stem proceeds in the third year, with pycnial develop- 

 ment during the summer. If pycnia were formed the previous year, aecial formation occurs 

 in the spring. — Henry Dorsey. 



226. Coons, G. H. Botanical Department notes. Michigan Agric. Exp. Sta. Quart. Bull. 

 2 : 70-75. Fig. 3-6. 1919. — Brief popular notes on winter handling of potatoes, Jonathan fruit 

 spot and bitter pit of apple. Progress of barberry campaign is shown by tables. — E. A. 

 Bessey. 



227. De Wildeman, E. A propos du genre Tetracladium. [The genus Tetracladium.] 

 Compt. Rend. Soc. Biol. Paris 83: 192-194. 1920.— See Bot. Absts. 6, Entry 211. 



228. Dickson, James G., and Helen Johann. Production of conidia in Gibberella sau- 

 binetii. Jour. Agric. Res. 19: 235-237. 1 fig. 1920. — Repeated and abundant crops of 

 conidia may be produced in short periods of time from ascospores, sporodochia conidia, 

 vegetative conidia, or mycelium, when favorable moisture and temperature conditions obtain. 

 This ability of the wheat-scab organism, to produce an abundance of virulent spores in 

 short periods of time, has an important bearing on epiphytotics. — D. Reddick. 



229. Doidge, Ethel M. The eradication of citrus canker. Jour. Dept. Agric. Union of 

 South Africa 1 : 124-134. 1920. — This is a tabular statement of the progress of the campaign 

 for the eradication of citrus canker. There are now only three farms in the Rustenburg and 

 Pretoria districts on which it is expected that canker may recur. — E. M. Doidge. 



230. Elliott, Charlotte. Halo-blight of oats. Jour. Agric. Res. 19: 139-172. PI. C 



(col.) and 26-35. 1920. — Disease is practically confined to oats (Avena) but has been found on 

 rye (Secale) and was produced artificially on wheat (Triticum) and barley (Hordeum). Dis- 

 ease appears under conditions unfavorable for growth of host. "Only under particularly 

 favorable weather conditions does the blight develop sufficiently to attract attention or to do 

 serious damage." — Typical lesions are 0.5 to 2 cm. in diameter and are characterized by halo- 

 like margins of chlorotic tissue about a center of dead tissue. A white organism Bad. corona- 

 faciens, n. sp., is responsible for the disease. The organism is described and cultural charac- 

 ters presented in detail. Group number, 221.2323023. — A variant strain is described briefly. 

 A yellow motile rod, found commonly on oats, is described, without name, and its cultural 

 characters presented; group number, 221.3333533; non-pathogenic to oats. — Bact. corona- 

 faciens persists on seed. Formaldehyde treatment (1:320) "as for smut" does not entirely 

 control the disease and hot-air treatment for 30 hours at 100° is not effective. — The organism 

 is practically confined to the center of the lesion and the halo is probably caused by a diffusible 

 substance, perhaps ammonia. — An extended discussion of and comparison with other bac- 

 terial diseases of cereals is included. [See Bot. Absts. 1, Entry 610.] — D. Reddick. 



231. Elliott, John A. Field diseases of sweet potatoes in Arkansas. Arkansas Agric. 

 Exp. Sta. Ext. Circ. 90: 20-28. PI. 1-2. 1920. 



232. Federal Horticultural Board, U. S. Dept. Agric. Quarantine on account of 

 the European corn borer and other dangerous insects and plant diseases. Notice of quarantine 

 No. 41, with regulations. Serv. and Reg. Announcem. 67. P. 27-28. 1920. [Also issued as 

 unnumbered pamphlet from Office of Secretary of Agriculture.] — Of the following plants no 

 stalks or other parts, whether used for packing or for other purposes, in the raw or unmanu- 

 factured state are permitted entry into U. S. A. : maize (Zea mays), broom corn (Andropogon 

 sorghum var. technicus) , sweet sorghums and grain sorghums (A. sorghum), sudan grass (A. 

 sorghum sudanensis), Johnson grass (A. halepensis), sugar jcane (Saccharum officinarum), 

 pearl millet (Pennisetum glaucum), napier grass (P. purpureum) , teosinte {Euchlaena tuxur- 

 ians), and Job's tears (Coix lachryma-jobi). Exceptions are sorghum hay from Canada and 

 clean shelled or threshed grain. Permission may be secured to import broom corn but disin- 

 fection is a condition of entry. — D. Reddick. 



