'^^4 EXPERIMENT STATION RECORD. [Vol.38 



Experiments have shown that there is a close relationship between the soil 

 water supply of the orchard and the development of bitter pit in storage, heavy 

 irrigation greatly increasing the disease, light irrigation reducing it. The 

 lowest percentage of bitter pit was found on apples which received a heavy irri- 

 gation followed by a light one. Heavy irrigation seemed to favor slightly the 

 development of Jonathan spot, but the contrast was so slight as not to justify 

 definite conclusions. During the first weeks of storage more Jonathan spot 

 developed on apples that were picked early than on those which were picked 

 late, but as the period of storage was prolonged these contrasts seemed to dis- 

 appear. The results, however, are believed to indicate a greater susceptibility 

 to this trouble in the early-picked apples. Bitter pit was worse on Jonathan 

 apples that were picked early than on those that were picked late. 



The tar treatment for court-noue, L. Ravaz {Prog. Agr. et Vit (Ed I'Est- 

 Centre), S8 (1917), No. S, pp. 173-175).— A discussion of reports and opinions 

 by different investigators on court-noue as related to varieties and as affected 

 by treatment with tar. 



The results of treatment were either negative or inconclusive. The author 

 states that the studies carried out at Montpellier for several years are still in 

 progi-ess regarding the characteristic internal changes, the conditions under 

 which the trouble becomes evident, and the factors which may lead to its 

 appearance. 



Filage of grapes, L. Ravaz (Prog. Agr. et Vit. (Ed. I'Est-Centre), 38 (1917), 

 No. 20, p. J,G2).—T\i\s phenomenon, described as due to the arrest of floral 

 development and excessive growth of the parts bearing flowers, is said to be 

 related to disproportionate alimentation in cloudy or rainy weather and to be 

 controllable by appropriate pruning operations. 



Little leaf of grapevines in California, F. T. Bioletti and L. Bonnet 

 (Prog. Agr. et Vit. (Ed. I'Est-Centre), 38 (1917), No. 22, pp. 517-522).— This is 

 a resume of a previous report (B. S. R., 36, p. 849) by the authors, who call 

 attention to the resemblancas and differences between this trouble and some 

 others prevalent in Europe. It is distinguished from mal nero by a different 

 kind of leaf coloration and by the fact that the latter is not transmissible but 

 is confined to particular areas. An important character which little leaf has 

 in common with court-noue is the shortened internodes characterizing the latter 

 Grape downy mildew, L. Ravaz (Prog. Agr. et Vit. (Ed. VEst-Centre) 38 

 (1917), No. 12, pp. 269-277).— ThiB is a discussion regarding what is known 

 of grape downy mildew (Peronospora viticola) ; its mode of attack and develop- 

 ment on vines, leaves, branches, and grapes ; its propagation ; climatic, cultural, 

 and varietal conditions favorable or xmfavorable to the disease; and remedial 

 measures. 



Grape downy mildew at Montpellier in 1916, L. Ravaz (Prog Aar ct Vit 

 (Ed. I'Est-Centre), S8 (1917), No. 16, pp. 365-373, flg. i).-Having conducted 

 an official investigation of the phenomena of grape downy mildew, the author 

 states that the several invasions are each derived from a previous one. Except 

 for a portion which is small and unimportant from a practical standpoint, they 

 are due to rains or mists which are sufficiently heavy to bathe the upper sur- 

 face of the leaf and run over to the other side, carrying the infecting spores. 

 Each time favorable conditions occur a contamination takes place. Between 

 this and the appearance of the invasion (in the form of sterile or fertile spots) 

 is the period of incubation, the length of which varies from 4 or 5 to 7 or 8 

 days, according to the hygrometric condition of the atmosphere. 



Grape downy mildew, L. Ravaz (Prog. Agr. et Vit. (Ed. I'Est-Centrc), 38 

 (1917). No. 24, pp. 557, 558 ) .—Continuing the above work, the author reports 

 that vines sprayed on May 19 remained clear of mildew, which was, however 



