DISEASES OF PLANTS. 273 



the stem. So far as the author's observations jio, there does not appear to be any 

 successful method of combating this tlisease. 



A disease of tulips, caused by Botrytis parasitica, J. Ritzema Bos and G. 

 Staes {Tijdschr. Plantenziekten, S {1902), pp. 177-202) .—The author describes the 

 characteristics of a serious disease that causes annually a loss of from 5 to 30 per 

 cent of the bulbs in some of the bulb-growing districts. 



Tulips are most liable to be attacked by this disease, but hyacinths and Spanish 

 iris also suffer. The disease does the greatest damage l)y attacking and destroying the 

 llower bud before it has pushed through the ground; afterwards the decay extends 

 to the entire old bulb and sometimes involves the new young bulb. The fungus also 

 attacks the flower stalk and leaf, causing spots on the leaf and causing the blossom 

 to fall over. The infection is spread by the cultivatian of the ground, and also by the 

 sclerotia being blown from one field to another with the sand during dry weather. 

 Besides this soil infection there is an infection through the air by means of conidia. 

 These give rise to the leaf spotting and to the diseased condition of the flower stalk 

 resulting in its fall. 



A number of methods for combating this disease w^ere tried, but none proved both 

 effective and practical except the use of creolin and carbolineum, and the latter 

 being the cheaper was used for the field tests. The application of 50 liters of car- 

 bolineum per "are" (100 sq. meters) in the late summer destroyed all plant life. 

 Bulbs could not be planted and even the following summer no weeds grew. The 

 following autumn, however, tulip bulbs were planted, and of these not more than 2 

 per cent became diseased, and in some cases the disease was entirely absent, while 

 in adjacent check beds 8 to 15 per cent of the bulbs was diseased. A more uniform 

 distribution of the carbolineum was secured by mixing it with sand before ap})lying. 



Further tests are being made to determine the most efficient and economical 

 metliods i)f application of the carbolineum. — h. m. pieters. 



Powdered fungicides, J. Dufour ( Chron. Agr. Canton Vaud, 16 {1903), No. IS, pp. 

 388-390). — On account of the widely recommended use of fungicides in powdered 

 form, the author has made a study of the different fungicides recommended, and he 

 divides them into 2 classes — those composed of sulphur and sulphate of copper, and 

 those composed of x>owdered sulphate of copper and some base, such as talc or stea- 

 tite. Each of these forms has its advocates, and their relative efficiency is not com- 

 mented upon. The formulas for the preparation of a number of the more common 

 powdered fungicides are given. 



Notes on the powdered sulphate of copper, J. de Girard {Prog. Agr. et Vit. 

 {Ed. V KM), 2.'f {1903), Xo. 26, pp. 773, 774). — Attention is called to the recent rec- 

 ommendations of the use of powdered coj^per sulphate in combating the downy mil- 

 dew of grapes and of its combination with sulphur against the powdery mildew. 

 The author claims that powdered fungicides are less efficient than liquid ones, are 

 more liable to injure foliage through their acidity, and are less adhesive and more 

 troublesome to apply. To avoid the corrosive effect of the copper suli)hate, talc- is 

 frequently used, the mixture being called copper steatite or sulpho-steatite. When 

 pure magnesium silicate is used, the mixture Wi\\ l)e found to contain a fairly con- 

 !-tant amount of copper sulphate, l)ut as much of the talc contains calcium carl)onate 

 the copper undergoes a change by oxidization and instead of 10 per cent coi)per sul- 

 jihate, as claimed in some samples tested, the actual amount found to be present as 

 sulphate was 0.78 per cent and the reaction was but very slightly acid. On the 

 other hand, a sample said to contain 8 per cent copper sulphate when examined 

 showed 5 per cent free sulphate and was very acid. This difference is said to account 

 for the widely divergent results frequently obtained where these fungicides are used. 



Sulphur and copper fungicides, J. M. Guillon {Rev. Vit., 19 {1903), Nos. 494, m^- 

 651-055; 495, pp. 681-684; 496, pp. 704, 705; 20 {1903), No. 498, pp. 9-14, .fi;/''- -'>)■ — 

 Studies are reported ujxjn tlie physical and chemical characteristics of a number of 



