56 PATHOLOGY [Bot. Absts. 



mechanical but specifically, an infection or an injection. Control consists in applying a 

 contact spray, as blackleaf -iO, taking care to reach the lower surface of the leaves. Hopper- 

 burn occurs on other plants, as nursery stock, young apple trees, growing tips of raspberries 

 etc. — .4. B. Massey. 



3SS. Board of Agriculture, Great Britain. Potato spraying campaign. Jour. Bd. 

 Agric. [London] 25: 1004. 1918— In the 10 months— November 1, 1917 to August 1, 1918— 

 over 14,500 knapsack and other spraying machines were bought in Great Britain for the 

 purpose of spraying potatoes. Between November 1, 1916 and August 1, 1917, 12,000 

 machines were bought. Previous to a campaign of the Food Production Department, the 

 yearly average was less than 1000 machines. — In a demonstration experiment at Christ- 

 church, blight was general on unsprayed plots on August 22 whereas on the sprayed plots- 

 it did not become general until September 17. — At digging time rod rows yielded healthy 

 tubers as follows: sprayed, 345 pounds; unsprayed, 226 pounds. — D. Reddick. 



389. Board of Agriculture, Great Britaiv. The wart disease of potatoes order of 

 1918. Jour. Bd. Agric. [London] 25:212-215. 1918. — Infected area is defined. No person 

 in infected area shall plant potatoes not of a variety approved by the board as immune to 

 wart disease. — Sale of immune varieties for seed purposes is restricted by license. — Potatoes 

 from infected areas are not to be used for planting outside the area. — Owners discovering 

 the disease are required to report it. — Tubers visibly affected are not to be sold for any pur- 

 pose. — Inspectors have right of search and may order potatoes destroyed if conditions war- 

 rant. — D. Reddick. 



390. Byars, L. P. A serious eelworm or nematode disease of wheat. U. S. Dept. Agric. r 

 Circ. 114. 5 p., 2 fig. 1918. — Tylenchus tritici has been found causing damage to wheat in 

 United States. Present known distribution limited to states of Virginia and California. — ■ 

 Control measures are: use of disease-free seed, a 3-year rotation and sanitary precautions. — 

 D. Reddick. 



391. Byars, Luther P. The eelworm disease of wheat and its control. U. S. Dept. 

 Agric. Farmers' Bull. 1041. 10 p., 10 fig. 1919. 



392. Carnot, P., and J. Dumont. Technique d'etude de la penetration des antiseptiques 

 en milieux solides. [Technic for studying the penetration of antiseptics into solid substances.} 

 Compt. Rend. Soc. Biol. Paris 81: 1199-1200. 1918. — The appliance used consists of a por- 

 celain cylinder placed in a Petri dish. The cylinder has a number of indentations about it3 

 base. A heavily inoculated agar culture of the test organism is poured into the Petri dish 

 and after this has hardened the antiseptic is poured within the cylinder. — The diffusion takes 

 place through the indentations in the base of the cylinder and after incubation the degree of 

 diffusion and the activity of the antiseptic can be measured by noting the width of the clear 

 zone about the cylinder. — An inorganic salt which will give a color reaction with some com- 

 ponent of the antiseptic can be added to the agar if desired. [Abst. by G. H. S[mith] in Abst. 

 Bact, 2, Entry 1946.] 



393. Clinton, G. P. Artificial infection of Ribes species and white pine with Cronartium 

 ribicola. Amer. Plant Pest Committee Bull. 2: 14-15. 1919. — Of 29 species and varieties of 

 Ribes inoculated with aeciospores and urediniospores, infection was secured on all but five. 

 Detached Ribes leaves, placed in inverted petri dishes produced uredinia in the case of 25 

 species of Ribes out of 35 that were tried. Infection takes place through the stomates. Suc- 

 cess was obtained in maturing several other rusts on leaves in petri dishes. — Artificial infec- 

 tion of pines proved that infection is accomplished in the leaves by way of the stomates. 

 Small golden yellow snots appear sometimes as soon as 25 days after inoculation in the green- 

 house. Later a distinct band is formed around the leaf. Mycelium is abundant around the 

 fibrovascular system in these golden yellow spots. Later the mycelium was found to follow 

 the bundles into the stem. — W . H. Rankin. 



