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JCNB 8. H»05. 



The Weekly Florists^ Review^ 



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This Spring's Display of Gilceolarias at Garfield Park, Chicago. 



Pruning. 



It is the consensus of opinion among 

 those who have grown tomatoes under 



glass that the one shoot system gives the 

 est results. In other words, the largsst 

 amount of fruit per square foot of 

 ground surface can be obtained from one- 

 Stemmed plants. Space under glass is 

 expensive and greenhouse gardeners 

 should consider carefully what returns 

 each square foot is capable of producing 

 tinder normal conditions. 



The single-stemmed plants are obtained 

 by keeping all of the laterals and axillary 

 Shoots removed. Plants grown in this 

 manner can be set from twelve to six- 

 teen inches apart in the rows, but we do 

 not think it desirable to have the rows 

 less than four feet apart. The axillary 

 rijoots in any system of pruning should 

 be nipped out, as they are of little or no 

 use to the plant. In our opinion, if they 

 are allowed to grow they take more from 

 the plant than they are capable of re- 

 turning. 



Sometimes old plants are regenerated 

 by cutting the leaders back and allowing 

 axillaries to develop and bear fruit. We 

 have tried this method on old plants that 

 have completed their first crop and have 

 found these axillary shoots to be poor 

 unsatisfactory bearers under all circum- 

 stances. 



Tomato stems readily take root when 

 placed in sandy soil, and some growers 

 have recommended cuttings of tomatoes 

 rather than seedlings. We have tried 

 both methods side by side under glass 

 and consider the cuttings poor material. 



Occasionally tomatoes are pruned to 

 two or more stems. This is accomplished 

 Dy either allowing one or more of the 

 strong laterals to develop or by cutting 

 the young plant back near the ground 

 and inducing two or more leaders to de- 

 veiop. 



Heading. 

 Tomato plants grown in good soil can 

 amply supply plastic material for the de- 



velopment of a number of clusters of 

 fruit, but experience has shown that sin- 

 gle-stemmed plants set closely together 

 are capable of producing the largest 

 amount of fruit per square foot of 

 ground surface. With any system of 

 pruning it is especially desirable, accord- 

 ing to our view, to practice heading in 

 the leader above the fourth or sixth 

 cluster of fruit. 



We have shown' in our experiments that 

 heading in constitutes the best method of 

 diverting the energies of the plant into 

 the fruit. Every part of the plant is in- 

 fluenced and modified in its growth by 

 pruning. For example, pruning the low- 

 er leaves affects the size of fruit, but 

 more especially the growth of the stem, 

 whereas, heading in produces the most 

 favorable modifications in the fruit. 



In pruning the following law should be 

 borne in mind. Namely, that pruning 

 secondary organs (leaves, etc.) the ener- 

 gies of the plant are directed toward the 

 leader, and, conversely, by pruning pri- 

 mary organs (stems, leaders, etc.) the 

 energies of the plant are directed to- 

 ward the development of secondary or- 

 gans (fruit, etc.). 



The advantages of pruning are as fol- 

 lows: To secure early maturity of 

 fruit; to obtain larger average size of 

 the same; to expose the fruit to light, 

 and to restrict the vines to certain defi- 

 nite space. 



(To be Continued.) 



PIPING. 



I have just finished a new greenhouse 

 and would like to be told how to pipe it 

 for hot water. It is a lean-to on the east 

 side of another house, forty feet long, 

 ten feet wide, five feet high on the east 

 side and seven feet on the west where 

 there are forty-two inches of glass. 1 

 want to keep 70 degrees in the Wisconsin 

 climate. W. P. 



For heating this house I would recom- 

 mend one 2-inch flow pipe along the side 



next to the adjoining house, this pipe to 

 cross the far end of the house, and six 

 2-inch return pipes under the bench on 

 the outer side of the house. Two or 

 three of these return pipes should be con- 

 trolled by having a gate valve inserted 

 near the lower end. These pipes should 

 have a fall of at least four inches in the 

 length of the house. The air outlet 

 should be at the highest point in the 

 flow pipe. L. C. C. 



ARSENICAL INSECTICIDES. 



The arsenical compounds have sup- 

 planted, practically, all other substance* 

 for the insects which feed externally and 

 may therefore be destroyed by applying 

 poison to the leaves and stems of plants. 

 The two arsenicals in most common use, 

 and obtainable everywhere, are Paris 

 green and London purple. The other ar- 

 senicals mentioned, viz., arsenite of cop- 

 per, arsenite of lime, and arsenate of 

 lead, are less known and not so easily ob- 

 tainable, but in some respects are better 

 than the first-mentioned poisons, as will 

 be shown later. Powdered white arsenie 

 cannot be employed on account of its 

 scalding action on foliage. 



The arsenicals mentioned have the fol- 

 lowing characteristics, according to a 

 bulletin of the United States Department 

 of Agriculture: 



Paris green is a definite chemical com- 

 pound of white arsenic, copper oxide, 

 and acefic acid (known as the aceto- 

 arsenite of copper), and should hare 

 a nearly uniform composition. It is usu- 

 ally a rather coarse powder, or, more 

 properly speaking, crystal, and settles 

 rapidly in water, which is its greatest 

 fault. Its excessive cost, about 20 cents 

 a pound, is due to its being crystallized 

 with acetic acid, making it a more bril- 

 liant pigment, but giving it a coarse 

 grain and rendering it a much poorer 

 insecticide. 



Copper arsenite is similar to Paris 

 green in color, and differs from it onlj 



