38 



The Florists^ Review 



Maroh 23. 1922 



Ilnrdly nnywlioro can one find an elm 

 or a maple tree even now, they assert. 

 The camphor scale is hourly killing off 

 the former plenty of sweet olives, ligus- 

 trum ledges, year-round roses and odor- 

 ous camphors. The ol)scure scale covers 

 the water oaks and red oaks. The West 

 Indian peach scale and the San Jose 

 scale eat up the fruit trees, including 

 the famous figs." 



IMPORTS BY PARCEL POST. 



Announcement has just been made, 

 by Acting Second Assistant Postmaster- 

 General E. R. White, that arrangements 

 have been made with the Post Office 

 and Treasury departments by the De- 

 partment of Agriculture to allow the 

 importation by parcel post of certain 

 plant material under a special permit 

 of the Department of Agriculture, pro- 

 vided for in regulation 14 of quaran- 

 tine 37. Such importations must be ac- 

 companied by tags specially prepared 

 for the purpose to show thereon the per- 

 mit number of the Department of Agri- 

 culture. The postal service advised 

 that in case importation by parcel post 

 is desired of any heretofore prohibited 



])lant material, the importer should 

 make application to the federal horti- 

 cultural board for a permit to import, 

 indicating in the application the ap- 

 proximate weight of the plant, material 

 to be imported or the number of pack- 

 ages necessary to contain it, whereupon 

 the applicant, in case his application is 

 approved, will be furnished with a per- 

 mit, accompanied by a sufficient num- 

 ber of tags for transmission to the 

 foreign shipper. 



It is stated that all packages of plant 

 material bearing permit tags, upon re- 

 ceipt in this country, will be promptly 

 dispatched to Washington, D. C, or to 

 San Francisco, Cal., if received at a 

 Pacific coast exchange office, for inspec- 

 tion under the plant quarantine act, 

 after which, if found free of insects and 

 diseases and conforming to customs 

 regulations, they will be sent to the im- 

 porter (or permittee) as soon as prac- 

 ticable. Parcels of prohibited plant 

 material which do not bear the special 

 tags above referred to will be disposed 

 of in accordance with the regulations 

 applicable thereto, the department 

 states. The customs duty, if any, will 

 be collected upon delivery. T. N. S. 



HYBRID TOMATOES. 



Increase Yield Under Glass. 



Over a century and a half ago, 1760 to 

 be exact, the German botanist, Kohl- 

 reutcr, discovered that when two vari- 

 eties of plants were crossed, the hybrids 

 which resulted were extremely vigorous. 

 They were noticeably larger and finer 

 than their parents, even when grown 

 under identical conditions. Now, this 

 phenomenon of hybrid vi^or, or "hete- 

 rosis," as scientists like to call it, is not 

 at all new to animal breeders. They 

 have known of it since the time of 

 Moses and have used it in a practical 

 way in breeding domestic animals, as, 

 for example, in producing the mule, a 

 cross between the horse and the ass, and 

 an excellent example of hybrid vigor. 

 Kohlreuter's discovery in ])lants, how- 

 ever, is just now beginning to bear fruit 

 ill a practical way. 



Within recent years plant breeders 

 have made crosses among all sorts of 

 crops. They find that hybrid vigor oc 

 curs generally throughout the plant 

 kingdom. Among our important crops 

 lliat exhibit increased yields, when 

 crossed, are corn, wheat, cotton, tobacco, 

 beans, pea.s, tomatoes and cucumbers. 

 Several breeders have predicted that 

 eventu.-illy first-generation hybrids be- 

 tween our best varieties will be grown 

 exclusively and that seedsmen will make 

 a business of producing liyl)ri(l seed on 

 a l:(rge scale. This is actually being 

 done at the j)resent time, on a sm;ill 

 scale, by several growers who offer 

 liybrid corn for sale. One such dealer is 

 advertising it as "mule" corn. The 

 )iractice is of no commercial importance, 

 however, except in such crops as are 

 easily crossed and in which the beneficial 

 effects of crossing are marked. The to- 

 mato is one of these crops and, as hybrid 

 tomatoes have several features that 

 should adajit them particularly to green- 



house conditions, we will consider the 

 subject in greater detail. 



Points Favoring the Hybrid. 



Experiments conducted at several 

 state experiment stations show that 

 cro.s.sed or hybrid tomatoes produce on an 

 average fifteen per cent greater yields 

 than ordinary varieties. Moreover, the 

 fruit is produced earlier, is more uniform 

 in size and shape, and the plants are 

 more vigorous and therefore more re- 

 sistant to disease. These are all quali- 

 ties to touch the tender spot of the 

 growers' heart and some of the growers 

 have already warmed up to the hybrid 

 tomato. A California man, with the 

 usual native unbounded enthusiasm of 

 all true Californians, has even gone so 

 far as to calculate the increase in an- 

 nual production of tomatoes in this coun- 

 try, if only hybrids were grown. It 

 amounts to some millions of pounds. 

 Perhaps it is not advisable to count the 

 chicks before the old hen has finished 

 her job, but it is certainly true that 

 hybrid tomatoes yield more, are more 

 uniform, are earlier, more vigorous and, 

 in general, are especially adapted to 

 greenhouse culture. 



The process of crossing tomatoes is 

 simple. The tomato is usually self- 

 fertilized; therefore, the anthers or pol 

 len organs must be removed before they 

 are ripe or shed their pollen. This is 

 easily done witli a pair of tweezers, the 

 point of a knife, or even with an ordi- 

 nary toothpick. This process is tech- 

 nically known as "emasculation." Sev- 

 eral days after the anthers have been 

 removed or at the time when the flower 

 would normally be in full bloom, pollen 

 from another variety is applied to the 

 end of the pistil. This may be done by 

 shaking pollen into a spoon or watch 

 glass and dipping the end of the pistil 

 into it, or, more easily perhaps, by gath- 

 ering a little pollen on the finger tips 

 and applying it to the end of the pistil. 



In case there is any doubt as to what 

 constitute the anthers and pistil in the 

 tomato blossom, it should be kept in 

 m.ind that flowers of all kinds are built 

 on more or less the same general plan. 

 Take the lily, for example. The anthers 

 of the lily are the yellow organs which 

 the grower usually removes to prevent 

 them from staining the petals. The pis- 

 til is the central structure with the 

 sticky knob at its end. The tomato 

 differs from the lily in that its five an- 

 thers are grown together closely around 

 the pistil. They must be entirely re- 

 moved before they ripen and shed pollen. 

 If the pollination has been successful 

 the fruit will begin to develop in a few 

 days. One fruit produces a large num- 

 ber of seeds and it is necessary to make 

 only a few crosses to obtain a season's 

 supply or enough for several seasons, 

 since the seed is viable for three or four 

 years v.'hen properly handled. 



Choosing the Varieties. 



Some discrimination must, of course, 

 be shown in choosing the varieties to use 

 in crossing. As a rule the better the 

 parents, the better the hybrid. To pro- 

 duce a really excellent hybrid, only pure 

 strains of good varieties should be used. 

 If a red fruit is desired, one of the 

 parents must be red, since red is dom- 

 inant or "prepotent" over pink or yel- 

 low. If earliness is essential, one, or 

 both, of the parents should be early vari- 

 eties. A cross between a dwarf and 

 standard type produces all standards in 

 the hybrid. Such a combination is often 

 desirable; in fact, one of the best crosses 

 at a certain experiment station was that 

 between Dwarf Stone and Earliana. 

 Stone contributes a smooth, nicely 

 shaped fruit and the Earliana gives 

 standard type, earliness and yield to the 

 Inbrid. 



There is one other point which should 

 be mentioned. It is never practicable to 

 save seed from hybrids, no matter how 

 excellent they may be. Hybrids do not 

 "breed true" and in the second gener- 

 ation "break up" into all sorts of types. 

 The cross must be made every year or 

 enough crosses made to produce seed for 

 several seasons. It is true that in 

 breeding for new varieties, which, how- 

 ever, is an entirely different proposition, 

 the hybrid seed is saved and selection 

 of the best types is made in subsequent 

 generations. 



Growing vegetables under glass is 

 agriculture of the most intensive type. 

 The grower must make use of every 

 means at his disposal to secure a maxi- 

 mum production from each square foot 

 of bench space. He can well afford to 

 give hybrid tomatoes a trial. They 

 make possible a decided increase in yield 

 at the cost of comparatively little trou- 

 ble in producing the hybrid seed. 



Paul C. Mangelsdorf. 



Paris, France. — J. Mary has sold his 

 store, at 37 Rue de la Perouse, to M. 

 Durand, who will continue it as before 

 conducted. 



London, England. — Sir David Prain 

 is retiring after seventeen years in the 

 post of director of Kew Gardens. A. W. 

 Hill, :formerly assistant director, suc- 

 ceeds him. 



Boulder, Colo. — Materials for the con- 

 struction of a greenhouse have been se- 

 cured by John J. Blanchard. Mr. Blanch- 

 ard does not expect to grow cut flowers, 

 but will confine his growing to bedding 

 plants and vegetables. 



