Mabch 0, 1916. 



The Florists' Review 



21 



FEBTIIilZEBS FOR BOSES. 



[The report of F. W. Muncie, of Urbana, 111., 

 nil fertilizer work at the Agricultural Experi- 

 iiuMit Station, University of Illinois, presented 

 licfore the convention of the Illinois State Flo- 

 rists' Association nt Moline, March 7.1 



I am giving as a report to the asso- 

 ciation this year a summary of our bul- 

 letin, ' ' Commercial Fertilizers for 

 Koses, " which now is in the hands of 

 our editor and soon will reach you. 



The soil in the vicinity of the experi- 

 ment station is a brown silt loam. On 

 such a soil applications of phosphatic 

 fertilizer yield greatest increases in 

 crops. Nitrogenous fertilizer also is 

 needed, but applications of potassium 

 sulphate not only give no increased crop 

 but even decrease the yield. 



The periods of heavy feeding should 

 be during the periods of most rapid 

 growth, viz., in fall and spring, when 

 sunshine is abundant enough not to 

 limit growth. Fertilization is particu- 

 larly needed in spring, when the 'soil 

 mixture is to the greatest extent de- 

 pleted of itSi readily available content 

 of plant food. While keeping this in 

 mind, attention should be paid to the 

 periods of heavier production by the 

 plants, when more fertilizer is needed. 

 Phosphate gives an increase in produc- 

 tion continuous throughout the year. 



Specific Kinds of Fertilizer. 



Acid phosphate, used in these experi- 

 ments, was found a satisfactory form 

 of phosphatic fertilizer. No compari- 

 son wag made, however, between it and 

 bone meal, basic slag, and other phos- 

 phate-containing fertilizing materials, 

 l^ried blood and ammonium sulphate 

 inay each be used as nitrogenous fer- 

 tilizers. The care necessary to prevent 

 "verfeeding with ammonium sulphate 

 IS so great, however, that its use is 

 'lardly to be recommended. The same 

 precaution is necessary, but to a some- 

 *^hat less degree, with sodium nitrate. 

 Applications of dried blood at the 

 late of five pounds per 100 square feet 

 'jf bench space are safe, if put on only 



luring periods of bright sunshine and 

 ;jt heavy production by the plants, and 

 '*^ not made oftener than four to six 

 :^eek8 apart. The amount of nitrogen 

 'n such an application corresponds to 

 ihat contained in 270 pounds of manure 

 ■^f the average nitrogen content (fifty 

 per cent moisture); it is somewhat 

 jnore readily available than part of 



iiat in good manure. These compara- 

 ' ;ve figures give a basis for the use of 

 ' .'I'ler material, however, and show that 

 j '<? need for nitrogenous fertilizer may 



'^ supplied as manure, quite as well as 



by the use of a commercial fertilizer. 

 The symptom of nitrogen starvation — 

 lightening of the color of the foliage — 

 is so evident to every rose grower that 

 there is no difficulty in determining 

 when applications of a nitrogen-con- 

 taining fertilizer sliould be made. 



The Need of Phosphorus. 



Plants do not show such marked signs 

 of the need for phosphorus, and experi- 

 ment alone can determine its need. Ap- 

 plications of acid phosphate up to 

 twenty pounds per 100 square feet of 

 bench space, or forty pounds per 100 

 cubic feet of soil, were found to giva 

 marked increases in production. The 

 quantity of phosphorus contained iv 

 this application is equal to that con 

 tained in an application of 2,800 pounds 

 of manure of average composition (fifti 

 per cent moisture) to lOQ square feei 

 of bench space or twice this amount 

 mixed with 100 cubic feet of soil. Since 

 manifestly it is impossible to use such 

 a mixture, the need for phosphate ii> 

 form of a commercial fertilizer is evi- 

 dent. Acid phosphate, the only form ot 

 phosphatic fertilizer used in the experi- 

 ment, is, as stated, satisfactory. Since 

 the benefit from its use is continuous 

 throughout the year, it should be mixed 

 with the soil before the benches are 

 filled. Top-dressings with it are not so 

 satisfactory, since surface root growth 

 is stimulated in this way, resulting in 

 the roots having contact with the soil 

 particles only in an upper layer of the 

 soil in the bench. There is no danger 

 from overfeeding with acid phosphate, 

 for four times the quantity here recom- 

 mended has been applied without in- 

 jury. In this respect acid phosphate 

 possessed an advantage over bone, 

 which cannot be mixed with soil or ap- 

 plied as top-dressings in excessive 

 amounts without injuring the plants. 

 The same is true to a greater extent 

 with high phosphate tankage, and blood 

 and bone. 



Use of Tilme. 



With such a need for phosphorus by 

 rose plants, the use of lime or lime- 

 stone with acid phosphate is to be dis- 

 couraged, since the solubility of the 

 phosphate would be decreased by its 

 use. The decrease in production from 

 sections in which limestone was used 

 in the soil mixture, compared with that 

 from sections receiving-no lime, is fully 

 proven by the data. The mixing of 

 lime or limestone with the soil, though 

 quite a common practice among grow- 

 ers, cannot be recommended. In case 

 an application of lime is needed to pre- 

 vent the groyrth of algse and molds on 

 the soil surface, finely ground limestone 



applied as a top-dressing at the rate of 

 ten pounds per 100 square feet of bench 

 space and lightly cultivated into the 

 surface, will accomplish this without 

 being carried down into the soil fur- 

 ther than an inch below the surface, 

 during the year. 



The benefit of fertilizing is found tc 

 be in number of flowers produced and 

 to a slight extent in the average stem 

 length; no measurable change in length 

 of petal follows fertilization with acid 

 phosphate. 



Comparisons of Soils. 



The soil used in the experiment de- 

 scribed in the preceding pages was of 

 the type known as the brown silt loam. 

 A description of the various soil types 

 of the state of Illinois, with their fer- 

 tility, is given in our Bulletin 123, 

 which should be studied by every florist 

 in connection with these experiments. 

 The significant facts of the table ow 

 page 196 x>f the bulletin, giving the- 

 fertility of the different fypes, are, 

 firstly, that the nitrogen content varies 

 from 1,440 to 8,900 pounds per acre, 

 six and two-thirds inches deep, and, 

 secondly, that practically every type 

 of soil has a low phosphorus content. 

 Peat soils alone show a low potassium 

 content. The need for nitrogen may 

 be judged from the appearance of the 

 plants, and the loss made good by the 

 addition of manure or dried blood. An 

 even better method is to obtain, at the 

 beginning of the season, a soil of higher 

 nitrogen content, by selection of sod 

 soil, heavy manuring, or turning under 

 of green manure. These experiments 

 have shown a need for the addition of 

 a phosphatic fertilizer and with a low 

 phosphorus content, a property common 

 to practically all Illinois soils, the rec- 

 ommendations are applicable to any of 

 these soils. Since acid phosphate pro- 

 duces no injury when applied in large 

 quantities, there is no reason to fear 

 making an excessive application of it. 



On peat and sandy soils alone is there 

 danger of a lack of potassium, and con- 

 siderations of watering and proper soil 

 texture prevent the use of these soils 

 in the growing of roses. 



Recommendations. 



On the basis of these conclusions the 

 following recommendations are made as- 

 regards the growing of roses: 



Keep up the nitrogen content of the 

 soil by turning under green or farn* 

 manure before use. If roses show signs 

 of nitrogen starvation — a lightening of 

 color of the foliage — make up the need 

 with applications of liquid manure, 

 mulches of manure, or top-dressings of 

 dried blood, the last in applications not 

 exceeding five pounds per 100 sqnarv; 

 feet of bench space and applied noH 

 oftener than four weeks apart. Fe«(I 

 only during sunshiny weather and most 

 generously during periods of heavy pro- 

 duction. 



Use generous quantities of acid phos- 

 phate in the soil. It may be added 

 either at the rate of four to eight tons 

 per acre in the field; in a compost with 

 soil at the rate of forty to eighty 

 pounds per 100 cubic feet of soil, or 

 mixed with the soil at the same rate, 

 just previous to filling the benches. 



Do not mix lime or limestone with 

 the soil. If needed for sweetening the 

 soil and preventing the growth of algse, 

 niake a top-dressing of finely ground 

 limestone at the rate of ten pounds |>er 

 100 square feet of bench space. 



