656 EXPERIMENT STATION RECORD. 



increase rapidly in diameter and are mature by June or a little later. The 

 cankered bark becomes dry and brittle and separates from the living tissues, 

 leaving prominent scars. Spraying with double strength Bordeaux mixture in 

 November is recommended for the control of this disease. 



The canker of soft maple is said to have made its appearance quite recently 

 and is causing considerable damage. It affects the host plant early in the 

 spring, causing numerous leaf and flower buds to be killed before the time of 

 opening. Later in the season twigs and larger branches are girdled and the 

 wood is more or less discolored, showing that the fungus penetrates into it to 

 a greater or less degree. When the girdling of the limbs takes place the leaves 

 begin to roll up, due to a lack of sufficient moisture. For combating this dis- 

 ease it is recommended that the dead and dying leaves be cut out and burned, 

 and that one or two thorough sprayings with Bordeaux mixture in the spring 

 be given the trees. 



The root rot of prune trees, which seems to be of considerable importance, is 

 more fully described in a previous publication of the station (E. S. R., 15, 

 p. 689). 



Two interesting apple fungi, F. Ij. Stevens (Science, n. .scr., 26 {1901), No. 

 673, pp. 72-'f, 725). — Tlie author gives brief accounts of two species of finigi re- 

 cently found attacking apples. 



The first, Hypochnus ochraleucit, which has not hitherto been reported from 

 any region other than Brazil, was found to be very destructive fo apples and 

 quinces in the mountain regions of North Carolina in 1006. loafer, specimens 

 were received from the coastal plain in the eastern part of the State, and in the 

 fall of 1907 the fruiting forms were olttained, enabling the author t<> identify 

 the fungus. 



The second species described seems to be identical with PhyUosticta finlitaria, 

 which is believed to be the cause of a disease of the fruits as well as the canker 

 of the limbs of apple trees, and also to cause the familiar leaf spot of apples. 

 This fungus seems to be widespread and the cankers formed are quite de- 

 structive. 



Bitter rot of apples, botanical investigations, T. J. Burrill ( Illinois >S7«. 

 Bui. 118, pp. oo'i-60H, pis. 10). — The results of extended investigations on tlie 

 cause of bitter rot of api)les, the methods of infection, and the effect of fungi- 

 cides on the si)ores are given. 



The bitter rot of apples is said to be due to the fungus GlomereUa rufomn- 

 culans, whicli in Illinois is practically confined to apples and apple tree limbs. 

 On the limbs the fungus produces spots called cankers, and it is the mycelium 

 in these cankei's and in old infected fruits that survives the winter. The 

 apple liml)s s(>em to become infected only in spots wliere the bark has been 

 previously injured, and they may originate in wounds made as late as the time 

 of the apple harvest. The sitores of the fungus are readily destroyed by copper 

 sulphate, but it appears impossible to kill the fungus in the limb cankers except 

 by cutting out the cankers and treating the excised areas. Ordinarily the dis- 

 ease makes its appearance in July or August but may start as early as June 1. 



The disease seems Jo be distributed to some extent by pomace flies, but the 

 principal infection is by means of spores washed from the cankers wliich infect 

 the fruits hanging l>elow on the tree. The spores and spore masses are found to 

 be readily distributed by the wind, sometimes to a considerable distance. The 

 first infection of the tree comes from spores produced in the limb cankers or in 

 mummy apples of the previous year that have been allowed to hang on the trees 

 during the winter. 



