H>-^0) DISEASES OF PLANTS. 247 



lUiiiii.u lOKi this cniHlilion was (piilt' iioticoabh; in orchards lU'ar Fresno and 

 .Mcrci'd, also in Los Anjioles (!ount,v. Two forms of this tn)ui)le aro dt'scribod 

 in connection witli their elTects on tlie limbs. The diseas«' has been tiiouijlit 

 to l)e cansed l).v liotrytis. Tlie present authors consider it more lil<ely tliat tlie 

 tree, slij^litly weakened by Botrytis, was rendered more susci'i)tible to sunl)urn 

 and to the attacks of otlier diseases which later caused its destruction. Just 

 how the funtius enters the lig limb has not been thoroughly worked out. Very 

 little is known regarding the 8cleiotinia libertiana phase of the die-back. 

 An account is given of laboratory studies on the organism. 



lUid abortion — twig and leaflet drop of the orange — its possible relation 

 to June drop, P. A. Bo.ncquet {Cal. Uitiixjr., J, ilDW), No. 12, pp. SJfC, S/,7). — 

 Study of June droj) during two years has shown the coincident presence of a 

 liud abortion of all kinds of orange trees, the navel orange being the most 

 severely attacked. Twigs attacked, ranging from 5 mm. to 5 cm. in length, 

 readily drop on being touched. Such an occurrence is frequently followed by 

 double budding; the new buds may abort and a sickly twig die and drop. Late 

 sitring wood is usually affected, but it is sometimes found on the beginning 

 lall growth. Apparently June drop is cliecked by use of Bordeaux mixture. 



A new disease of coffee, W. J. Dowson {Brit. East Africa Dept. Agr., Div. 

 Myvol. Leaflet 1 (11)11), pp. 4)- — A new disease made its appeanince on coffee in 

 1!)17 in the Nairobi area and also up country. The trouble was found to be 

 widespread following considerable rain. 



The youngest apical leaves of the tree or those of a young primary near the 

 top blacken and shrivel. The stalks and shoots sliow a dark discoloration in 

 the interior. The disease appears to be caused by a species of Plioma. An 

 account is given of tlie physiological effects, mode of infection, and appropriate 

 remedial measures. 



Trees showing early stages of the disease can be saved by topping them well 

 below the discoloi'ed cortex. Trees in whicli the stems appear dead for a con- 

 siderable distance can be saved by stumping witliin 8 in. of the ground. In 

 cases in which tlie discoloration has come near the ground level the trt>es can 

 not be saved. All trees which have been saved and adjacent trees shoidd be 

 siirayed with Bordeaux mixture at a 2:4:40 strength. Overbearing should be 

 prevented. Precautionary spraying just before the commencement of the rains 

 is recommended in oi'der to kill the spores of Phoma and Hemileia. 



Root diseases of the tea plant caused by fungi, C. BERNAKn and B. Palm 

 iDcpt. Landb., Nijv. en Handel [Dutch East Indies], Meded. Proefsta. Thee, 

 So. 61 (1919). pp. Jfl). — This account is bibliographical and largely descriptive, 

 indicating a number of causal organisms. Ustulina zonata forms the subject 

 111 the last chapter. 



Experiments on the control of eelworni disease of Narcissus, J. K. Uams- 

 BOTTOM (Jour. Roy. Hort. Soe., 43 (1918), No. 1, pp. 65-78). — The author con- 

 cludes that the preventive method wliich promises best results is that of .soaking 

 the bulbs for a period of 2 to 4 hours in water at a constant temperature of 

 110° F. It is believed that this will afford an economical means of combating 

 the disease. Of cour.se, sucli treatment will not prevent attack by nematodes 

 pre.sent in the soil. 



Mildew-resistant roses: With some suggestions as to increasing tlieir 

 number, W. Easi.ka. {Jour. Roy. Hort. Soc, 43 {1919), No. 2-3, pp. 253-260).— 

 A general discussion of ro.se varieties more or less resistant to mildew is fol- 

 lowed by a classified list of such varieties. 



Specialization of Peronospora on some Scrophulariaceic, E. Gaumann 

 {Ann. MycoL, 16 {1918), No. 1-2, pp. 189-199, figs. 6).— An account is given of 



