"-' DEPARTMENT OF AGRICULTURE. 



to be buried at this time at least 3 inches. The satisfactory disposal of these 

 mummies, especially in the case of large cherry-trees, is one of the main difficulties 

 in the control of the disease. Fruits should be thinned so that no two touch each 

 other, since enough moisture may be held at such points of contact to enable spores 

 of the fungus to germinate and produce infection. Trees should be thoroughly 

 sprayed with winter-strength lime-sulphur before the buds break. Later sprayings 

 will be necessary for protection of the fruit, but the natulfe of the spray material 

 and the times of application will depend partly on the susceptibility of the tree to 

 spray-injury, and partly on the time when the fruit is sufficiently advanced to be 

 disfigured by the presence of spray material. In the case of peaches, and some 

 plums, which are particularly sensitive to this form of injury, it is generally found 

 necessary to use the self-boiled lime-sulphur, although it is claimed for atomic 

 sulphur that it is both safe and effective. For most cherries 2-3-40 Bordeaux mix- 

 ture is safest, while for some plums, including probably prunes, 4-4-40 strength mignt 

 be used. The first of these sprayings should be given two or three weeks after the 

 petals fall, and another one about a month before the fruit is expected to ripen. 

 An intermediate spraying may also be necessary. 



POTATO. 



Farmers' Circular Xo. 4 of the Division of Botany, Dominion Department of 

 Agriculture, entitled "Potato-diseases transmitted by the Use of Unsound Seed- 

 lifitatoes" gives excellent coloured illustrations of various tuber-diseases, as tceff 

 as recommendations for their control. It should be in the hands of every aroirer. 

 It may be obtained free of charge by writing to the Publications Branch, Depart- 

 ment of Agriculture, Ottaica. Letters of application so addressed need not be 

 stamped. 



EARLY BLIGHT (Hacrosporium solani). 



This disease attacks the leaves only. It appears as circular or elliptical, dark- 

 brown or black spots, which often show a concentric zoning. Where these spots are 

 sufficiently numerous the whole leaf may finally present a scorched appearance 

 resembling a bad case of " tip-burn." Infection often follows minute injuries such 

 as those caused by flea-beetles, but these are not necessary for infection. Dry 

 seasons and climates usually favour the disease, although it can be quite bad under 

 fairly moist conditions. The name " early " blight merely implies that it is notice- 

 able earlier in the season than the "late" blight, and not that it is restricted to the 

 early part of the season. 



Control. Spray with Bordeaux mixture. 4-4-40. beginning when the plants are 

 6 inches high or leas. The disease, however, is only occasionally serious enough to 

 warrant special measures. 



LATE BLIGHT (Phytophthora infestans). 



This is a very serious disease in the moister sections of the Province, especially 

 on the Lower Mainland. It is first noticed on the leaves, where purplish or brownish- 

 black, irregular spots appear which rapidly extend if conditions are favourable. 

 They commonly occur first on the tip or edges of the leaf. Often a mouldy growth 

 may be observed around the margins of these spots on the under-side of the leaf. 

 This is composed of spore-bearing threads pushed out through the breathing-pores 

 (stomata) of the leaf. If the conditions are right that is. if the weather is moist 

 and moderately warm the disease may spread with great rapidity, so that the tops 

 of an entire field may be completely destroyed in a few days. A peculiar unpleasant 

 odour is given off from the diseased tops. The rapidity with which the disease may 

 spread is largely due to the peculiar character of the spores produced. These are 

 at first much like the summer spores (conidia) of many other fungi, and are scat- 

 tered easily by the wind and rain. Their usual behaviour, however, is different. 

 Should one fall on a 11. -nich as the film of water on a leaf after rain, and 



