248 EXPEEIMENT STATION EECOED. [Vol, 35 



The first conidium differentiates an inner wall and a sheath which ruptures 

 near its apex, freeing the conidium. Each of the later conidia grow and push 

 out through the empty sheath of the first, being freed from the next below by the 

 splitting of the basal wall which is formed between the two cells by the in- 

 growth of a basal ring which finally closes in the center. 



A bibliography is appended. 



Watermelon stem-end rot, F. C. Meieb (U. S. Dept. Agr., Jour. Agr. Re- 

 search, 6 {1916), No. 4, pp. 149-152, pi. 1). — A preliminary report is given of 

 investigations made to determine the cause of a decay of watermelons that 

 has been frequently noted in shipments of those fruits. Material was secured 

 from a shipment received in this city in July, 1915, and an examination showed 

 that more or less injury had occurred in a very uniform manner. In the early 

 stages the presence of decay was indicated by a watery discoloration of the 

 rind in an area closely surrounding and apparently extending from the stem. 

 From this all stages of decay were noted until half or more of the melon was 

 involved. In the later stages the rind portion becomes soft and wrinkled and 

 the flesh below is slimy and blackened. 



From the material secured a fungus belonging to the genus Diplodia was iso- 

 lated and inoculation experiments produced typical decay. The specific identity 

 of the fungus has not been determined but inoculations made from a culture of 

 D. tuhericola produced a decay that took the same course as that described 

 above. Species of Diplodia are known to attack a number of economic plants, 

 and the relation of some of these to the watermelon, it is thought, might possibly 

 show whether a species found on one host would grow equally well upon another. 



Brown rot of fruit, D. M. Cayt.ey (Gard. Chron., S. ser., 5S {1915), No. 1505, 

 pp. 269, 210, figs. 2). — It is stated that the wet weather of 1915 was probably 

 the cause of the prevalence of Sclerotinia {Monilia) fructigcna, causing brown 

 rot of apple and pear. This form is discussed in connection with the closely 

 related forms S. cinerea on stone fruits and S. laxa on apricots. The mycelium 

 of S. fructigena is said to persist in the twigs, branches, spurs, and mummied 

 fruits during the winter and to produce conidia by the time the apple and pear 

 blos.soms open. It Is said that the fungus may be spread by contact of injured 

 with sound fruits in handling, as the fungus is a wound parasite developing 

 rapidly from very minute injuries. 



A Bordeaux spray in early spring before the blossoms open is recommended. 

 Affected parts should be removed and burned during the winter, and rotten 

 apples should be carefully removed in summer. 



Experiments for control of apple scab, H. S. Jackson and J. R. Winston 

 {Oregon Sta., Bien. Rpt. Hood River Sta., 1913-14, pp. 6-18, figs. 7).— Results 

 are given of experiments conducted in the Hood River Valley for the control 

 of apple scab, in which lime-sulphur, atomic sulphur, soluble sulphur, and 

 Bordeaux mixture were used separately or in combination with other materials. 



As a result of one season's work, the most important application for the 

 prevention of scab proved to be the delayed dormant spray of lime-sulphur and 

 Black Leaf 40. Lime-sulphur was found the most efficient preventive of any 

 one mixture used. Severe fruit injury was often found to follow summer appli- 

 cation of lime-sulphur when made just previous to extremely hot weather. It 

 is said that neither atomic nor soluble sulphur can be recommended as a remedy 

 for scab when u-sed in all applications, but good results followed the application 

 of atomic sulphur in the calyx and subsequent applications where lime-sulphur 

 had been used in the first application. No appreciable fruit or foliage injury 

 was observed where this method was followed. 



