lVAI^:^/ AXD COLD WA7^ER FOR PLAA-TS. 



49 



when the tree is planted, aeration will be 

 perceptibly checked whenever a prolonged 

 wet period occurs. The young rootlets de- 

 cay, the tree is weakened an 1 becomes more 

 liable to attacks of fungi, which prey upon 

 the roots. 



3. Another cause for the death of many 

 trees is S/a/ Scald, which produces a wilt- 

 ing of the tissues by a too rapid evaporation 

 from the leaves. The tender young shoots 

 are verv liable to injurv from such a source, 

 especially if they are subjected to a hot sun 

 after a period of rapid growth in moist 

 ^veather. The edges of the leaves turn red- 

 dish yellow, wilt and dry up. 



4. A cause which jiroduces practically the 

 same resvdts as Sun Scald is known as 



Winter Blio^/it. The tissues wilt owing to 

 too rapid evaporation tluring fine, warm davs 

 in winter, when tlie soil about the roots is 

 frozen, or when dry, cold winds prevail. 



It is very difficult to provide remedial 

 treatment for Sun Scald and Winter Blight. 

 Perhaps a liberal mulching with manure or 

 straw would be as efficacious a remedy as 

 an\ that could be devised. 



5. Other causes occasionally produce 



serious results, but only under peculiar cir- 

 cumstances. Sometimes the air of cities 

 and towns becomes poisoned with harmful 

 gases to such an extent that whole avenues 

 of trees are seriously affected. There is of 

 course no remedy available in such a 

 case. 



A few words may be said as to the treat- 

 ment of old trees which are showing signs 

 of lack of vitality. Growth may often be 

 stimulated by assisting nature when the roots 

 have become sluggish. The branches should 

 be pruned so that the demand upon the roots 

 may not be exceeded by the transpiration 

 from the leaxes. The turf, moreover, should 

 be removed and the soil given a top dressing 

 of compact earth before replacing the sods, 

 so as to allow the nutrient salts to be washed 

 down to the rootlets by the rain. 



All decaying patches or holes should be 

 mended by clearing off all rotten wood, 

 and the place finally closed up with pitch 

 or coal tar to prevent the entrance of fungi. 



My second article will deal with the pro- 

 tection of shacle trees from the attacks of 

 insects and fungi. 



O. A. C, Guelph. W. Lochiiead. 



WARM AND COLD WATER FOR PLANTS. 



Some of the experiment stations have been 

 trying the prolonged effect on plants of 

 water at various temperatures, from freezing 

 to 100 degrees. The tests have been made 

 at the Wisconsin and Ohio stations during 

 the last two years on a variety of plants, in- 

 cluding geraniums, coleus, potatoes, beans, 

 etc., and the conclusion is reached that be- 

 tween 45 and 75 degrees, the temperatures 

 mostly available in practice, no apparent 

 difference in effect is caused with any of the 

 plants tested. Water at 32 to 34 degrees 

 grew healthy, short-jointed geraniums, but 

 sometimes affected the more sensitive Coleus 

 unfavorably. At 100 degrees a weak and 

 spindling growth was caused in almost every 



instance. The practical point is that where 

 the available water supply in a garden or 

 greenhouse is of a temperature not much 

 below 40 degrees, it will hardly pay to use 

 artificial means to warm it. Cold water, in- 

 deed, seems to act as a tonic for many culti- 

 vated plants, and glasshouse growers are 

 more and more coming to rely on forcible 

 spraying with cold water to clear growing 

 plants of insect pests. They find that the 

 soil is not appreciably chilled by a reason- 

 able amount of cold water. There are times, 

 however, when the immersion of pot plants 

 kept in a chilly room in warm water is very 

 beneficial, as it renders the fertilizing mat- 

 ter in the soil more available. R. N. Y. 



