July 



HORTI CULTURE 



The Doctrine of Selection 



A fundamental principle of horticultural advance- 

 ment lies in the doctrine of selection. Slighting 

 reference to this truth is sometimes heard from those 

 who have some new or grotesque dogma which they 

 seek to promulgate, but it stands. 



The doctrine of .selection applied to plant jiroduc- 

 tion must lead to success if we keep a well-iuatured 

 purpose steadily in view. We have only to look in 

 the various directions in which progress has been 

 made in the past to see repeated evidence f)f the 

 truth of this. Mistakes are often the best educators. 

 I recall the mishap of an old and usually successful 

 florist, the late John Dick of Philadelphia, who un- 

 dertook to bum the candle at both ends by taking 

 his camellia cuttings from the small, inferior wood, 

 and leaving the strong-growing fioriferous shoots to 

 get flowers from. The result was that he eventually 

 found himself in possession of a stock of "he plants" 

 so-called ^ not a very elegant appellation but easily 

 understood, and the older members of the craft will, 

 no doubt, remember the incident of that very suc- 

 cessful cultivator. 



William Bennett, by careful selection, sectired mag- 



nificent forms of Drar;cna terminalis and also a beau- 

 tiful special forni of D. terminalis stricta. His 

 houses, filled with both, were a sight to be long re- 

 membered by all who saw them, and a profitable one 

 for him. I notice that Robert Craig is following 

 along on similar methods with several florists' special- 

 ties. Dracaenas have not, of late, been seen so 

 abundantly in fine color as they once were, but it is 

 possible to do them just as well as they ever were 

 done and there is nothing finer in decorative effect 

 for home adornment, — select well-colored top- 

 cuttings. 



Starting as aforesaid, with a well-defined idea of 

 what we want, the principle of selection may be 

 applied in hybridization, selecting as parents those 

 forms showing most distinctively the qualities de- 

 sired, and again selecting from the seedlings those 

 in which the requisite points are most strikingly in 

 evidence. Enumerable citations might be made, but 

 our young men must think, reflect, and consider. 



(^V^Vv^v^^ 



The Oyster-Shell Bark Louse 



This insect is widely distributed throughout the 

 country. It is especially prevalent in New England; 

 in fact so much so that the statement has been made 

 that there is hardly an apple tree anywhere in this 

 region which is not more or less infested. Apple 

 trees are favorite host plants, but the insect is found 

 on a great many trees and shrubs, among which are 

 the plum, pear, cherry, maple, willows, currant, lilac, 

 etc. 



In this altitude the insect has only one generation 

 a year. The winter is passed in the egg stage, under 

 protection of the female scale covering. The eggs 

 are hatched the latter part of May or early June. 

 The young light-yellow lice crawl around for a short 

 time and then insert their beaks into the bark and 

 proceed to suck out the sap. A waxy substance is 

 secreted from the back of the insect which on harden- 

 ing forms, together with the cast-ofT skin, a protective 

 covering of scale. The female scale remains fixed 

 in the place where it settles down. Egg-laying be- 

 gins about the first of August and when this is com- 

 pleted the insect dies. 



The oyster-shell bark louse is kept in check by 

 several parasites and in a great many places so effec- 

 tively that it seldom becomes destructive to trees or 

 shrubbery. In other places these parasites do not 

 seem to be doing their duty and the oyster-shell 

 bark louse is looked upon as a worse pest even than 

 the San Jose scale. The best time to fight the insect 



is soon after it is hatched and before it has formed 

 a sufficient protective covering. The remedy is nor- 

 mal kerosene emulsion and it should be applied two 

 or three times during the first part of June. The 

 insect may also be destroyed in the winter time, in 

 the same way as the San Jos6 scale — by spraying 

 with strong kerosene emulsion, crude oil, or the lime- 

 sulphur wash, but summer spraying is no more ex- 

 pensive and it is more efficient. 



The normal kerosene emulsion is prepared as 

 follows: dissolve one half pound of laundry or whale 

 oil soap in one gallon of boiling water; add two 

 gallons of kerosene and stir until the soap-suds and 

 kerosene are thoroughly mixed. This can best be 

 accomplished by pumping the mixture into itself 

 with a force pump, using a nozzle which throws a 

 solid stream. This forms the stock solution which 

 can be kept for two or three weeks. For making 

 the spraying solution, use three parts of this stock 

 solution to seventeen of water. 



In applying, a good force pump should be used, 

 with a nozzle which throws a very fine mist-like 

 spray. A nozzle of the Vermorel type is best. The 

 application should be made during a bright sun- 

 shiny day. 



R.T.Coll.of A.& M. A. 



