DOMINION EXPERIMENTAL FARMS 27 



originating hardy apples for the Canadian Northwest is well 

 known. His crosses were mainly between the Berried Crab 

 {Pyrus haccata) and the large apples, and about 800 trees were 

 grown, from which some very hardy, though small, apples have 

 come. About 400 trees of second crosses of these, with more 

 blood of the larger apple, are now fruiting, and larger speci- 

 mens have thus been obtained. 



Other crosses between standard varieties have been made 

 by the Dominion Horticulturist with the object of obtaining 

 better hardy varieties, especially for winter use. As a result 

 of this work there are now between 800 and 900 trees, some of 

 which are now fruiting. 



Individuality in apple trees. — A record is kept of how much 

 fruit each tree bears at the Central Farm and it has been found 

 that there are marked differences, some yielding about twice 

 as much as others. Propagation of these is being carried on 

 to see if the characteristic fruitfulness will be transmitted. 



Cultural Experiments with Apples. — Fall vs. Spring plant- 

 ing. — Both fall and spring planting have been tried at Ottawa, 

 the latter method proving the better; this holds true in other 

 parts where the winters are long and severe. 



Root-Killing of Apple Trees. — While root-killing of apple 

 trees only occurs at long intervals in most parts of Canada, it 

 is well to guard against it, as fine trees which have reached a 

 bearing age may thus be destroyed in one winter when there 

 is little or no snow; hence, the ground should be covered with 

 something which will hold any snow which there may be. This 

 is called a cover crop. These have received much attention 

 in the Horticultural Division. 



Cover Crops. — Cover crops are grown in orchards for the 

 purpose of adding humus to the soil, making it capable of 

 holding more water and also adding plant food to it in some 

 cases. They are also grown with the view of utilizing any 

 plant food not taken up by the fruit trees, thus preventing its 

 leaching. This plant food is returned to the soil the following 

 spring and may be readily used by the fruit trees that season. 

 The cover crop also takes up and transpires a large amount 

 of water. The removal of this from the soil lessens the amount 

 available for the trees, which ripen their wood earlier on this 

 account, ensuring greater safety from winter injury. The seed 

 for cover crops should be sown from the middle of June to the 

 middle of July. Where ripening of wood is more important 

 than conservation of moisture, the early seeding is preferable. 

 Many kinds of cover crops have been grown at Ottawa. Among 

 the best are Red Clover, Summer Vetch, Hairy Vetch, Rape, 

 and Crimson Clover. 



