5-4 



THE CANADIAN HORTICULTURIS2 . 



the other haiul, saii(l\ and loam}- soils are 

 nearly always deficient in potash, and those 

 naturally rich in organic matter, such as 

 svvanip soils, also contain little potash. 



SOir.S WJIICII NEED POTASH. 



These latter types of soils are those on 

 which market garden and fruit crops are 

 generally grown, crops which are particu- 

 larly in need of potash, and, as the yield is 

 limited by the constituent of plant food 

 present in smallest quantity, these soils, es- 

 pecially for the kind of crops mentioned, 

 are in need of potash. Further, the quality 

 of the crop, as measured by appearance and 

 palatibility. is affected not only by the na- 

 ture of the soil, but by the crop being able 

 to obtain from the soil a proper balance of 

 the essential constituents of plant food- and 

 in sufficient quantities to permit of a con- 

 tinuous and rapid development. 



Wood ashes are one of our natural sources 

 of potash. Clean fresh burned ashes will 

 contain 6 to 35 per cent, of potash, depend- 

 ing on the kind of wood from which they 



were obtained. They also contain one to 

 two ])er cent, of phosphoric acid, and about 

 35 per cent, of lime. Further, the potash 

 is all soluble in water and, therefore, im- 

 mediately available to plants. 



Thousands of acres of land in Ontario 

 are deficient in potash and many of the 

 crops of the farm, especially vegetables and 

 fruits, are in particular need of potash. It 

 seems too bad that wood ashes, which con- 

 tain such large quantities of potash, and 

 that in the very best form for plants, should 

 be so extensively shipped out of the country. 



If some people will continue to sell ashes, 

 let them be advertised in Ontario so that 

 they may be bought by those who know 

 their value, and thus save us the humilia- 

 tion of having Canada wood ashes adver- 

 tised for sale throughout the Eastern States 

 of the American Republic, and at the same 

 time keep that at home which we need for 

 good crop production, and which we are 

 now beginning to bring back into the coun- 

 try in other forms. 



BLACK KNOT ON PLUMS 



PROF. F. C. SEARS. \\ OLFVILLE, N. S. 



\\/K have conclusively proved that 

 V V black knot can be controlled, even 

 in the midst of infected orchards, by spray- 

 ing the trees, cuttting out the knots and 

 burning them. In that part of the experi- 

 mental orchard which we have had only two 

 years, there were, at the time we leased it, 

 about 40 old plum trees that were so thor- 

 oughly infested with knot that it seemed the 

 wisest course to root them out and burn 

 them. 



Instead of doing so we cut them back so 

 as to reinove all the knots. In removing a 

 knot we cut at least six inches below it so 

 as to remove every trace of the disease. 

 We then gathered up and burned all the 

 trimmings. During that summer the or- 

 chard was sprayed three times with Bor- 



deaux mixture, and in the fall the knots 

 were again removed and burned. The 

 trees had made a vigorous growth after 

 their severe pruning, and there were few- 

 knots compared with the year before. 



The next sunmier we decided to remove 

 the knots as soon as they appeared, and 

 with this object we went through the or- 

 chard twice, once in July and once in 

 August, and cut out the knots. We did 

 this regardless of the fruit on the trees, as 

 our object \vas to stamp out the disease 

 without considering how much fruit we had 

 to sacrifice. We found that by taking the 

 knots at this stage when they were soft it 

 was often possible to pare off a knot instead 

 of cutting away the entire branch on which 

 it grew. 



