19161 DISEASES OP PLANTS. 753 



observed on any of the trees, although it Is known to follow winter Injury to 

 apple trees in Maine. 



Some further observations are given relative to the ability of the apple-scab 

 fungus to live over the winter on young twigs, confirming and extending those 

 previously noted (E. S. R., 30, p. 542). Specimens were observed in 1914 and 



1915 indicating that the disease was carried over in the young twigs, and in 



1916 these observations were extended to include scab infections on pear limbs. 

 The treatment of peach leaf curl, C. Gandolfi (Coltivatore, 61 {1015), No. 



14, pp. 435-437; abs. in Internal. Inst. Agr. [Rome], Mo. Bui. Agi. Intel, and 

 Plant Diseases, 6 {1915), No. 7, p. 1000). — Experiments carried out for several 

 years in northern Italy showed complete free<lom from peach leaf curl in 

 case of trees which were covered with muslin nets, while trees left uncovered 

 but sprayed with Bordeaux mixture late in November and again about the 

 middle of February were attacked. A glass roof also gave freedom from leaf 

 curl. The method of protection with muslin is said to assure a practically con- 

 stant setting of the fruit. 



The 1915 outbreak of downy mildew in France and Italy, J. Pastre {Prog. 

 Agr. et Vit. {Ed. I'Est-Centrc, 81 {1916), No. 16, pp. 368-380; abs. in Rev. Sci. 

 [Paris'], 54 {1916), I, No. 10, p. SIS). — A resume is given of observations, opin- 

 ions, and conclusions resulting from the investigations of the Central Society 

 of Agriculture of Herault regarding the severe and extended outbreak of 

 mildew in 1915, which copper sprays very frequently failed to check in the 

 Tisual manner. 



The date of treatment is regarded as extremely important. The time of 

 greatest susceptibility to infection appears to be the blooming period. The 

 violence of the 1915 outbreaks is thought to have been due to the multiplication 

 of spores in 1914, lack of vigilance and proper treatment on account of the war, 

 and abundant rains in May, 1915, with high temperatures, dews, and fogs 

 late in May and early in June when the vines were in bloom, to which should 

 be added, it is thought, a certain tolerance established for the copper sprays by 

 the parasitic fungus. Attack by Gloeosporium nervisequum, said to precede 

 usually the mildew of grapes, is said to have been wanting in 1915. Exceptions 

 are noted also as regards the behavior of varieties ordinarily immune or 

 nearly so to mildew. 



The various treatments tested in Italy and France are detailed in separate 

 tables, according to their results as good or bad. The several treatments which 

 have been recommended or are in use are discussed in some detail as regards 

 their composition, preparation, and application. 



Downy mildew, its manifestations and directions for its control, L. Ravaz 

 {Prog. Agr. et Vit. {Ed. VEst-Centre), 31 {1916), No. 15, pp. 341-341).— A sum- 

 mation is given of known facts regarding the times, conditions, and modas of 

 attack and development of downy mildew, which has recently been severe on 

 grapevines in parts of France, also regarding measures looking to its control. 



Cupro-ferric sprays for downy mildew and chlorosis, A. Donadieu {Prog. 

 Agr. et Vit. {Ed. VEst-Centre), 31 {1916), No. 10, pp. 224, 225).— The author 

 states that grapevines persistently showing chlorosis in a fertile but low and 

 basin-shaped area recovered and continued free from mildew and chlorosis, 

 healthy, and productive from 1912 to 1915 as a result of the adoption of a 

 combined spraying liquid for the foliage. This spray was made up by adding 

 to a previously prepared Burgundy mixture sufficient iron sulphate (previously 

 dissolved in a little water) to give a strength of 0.1 per cent of this salt. The 

 preparation should be acid and should be applied early but sparingly to avoid 

 scorching. 



