Edible Products. 



314 



[April 1908. 



longitudinally and in having the calyx 

 not so closely appressed to the seed pod 

 as in the common variety. It is fre- 

 quently inclined to be convolute at 

 the apex. 



CULTIVATION AND FERTILIZATION. 

 The roselle will thrive on any soil that 

 is moderately rich or that is supplied 

 with the necessary plant food in the 

 form of commercial fertilizer. Stable 

 mauure should be used sparingly only 

 and should be supplemented by phos- 

 phates and fertilizers containing potash, 

 as an excess of ammonia in the soil tends 

 to the development of large plants at 

 the expense of their productiveness. 

 This is particularly true on low-lying 

 laud where moisture is abundant, and 

 the high pine lands in Florida are for 

 this reason preferable to the muck and 

 prairie lands. Laud that is subjected to 

 inundations and soil sufficiently drained 

 should be avoided The plant has been 

 found well adapted to the clayey soil of 

 California. Henricksen* says that a 

 sandy loam is preferable to other soils. 



The roots of the roselle descend to 

 greater depths than those of many other 

 crops, and the land should be plowed 

 deep, and, when the. soil is clayey, well 

 pulverized. This plant is very much 

 subject to root-knot nematodes (Hetero- 

 dera radicicola), and should not be 

 planted on land infested with this pest, 

 as that would onlv result in almost 

 absolute failure. The roselle always 

 comes to the market at the same time 

 of the year, and, as no literature on the 

 subject that had come to the attention 

 of the writer mentioned any attempt to 

 grow it successively, several sowings 

 were made in 1906 at the Subtropical 

 Laboratory at different times of the 

 year, to note the influence on the habits 

 of growth, the season of maturity, and, 

 possibly, the size of calyx. These plant- 

 ings were made as follows : — No 559, 

 April 1 ; No. 560, May 1 ; No. 561, June 1 ; 

 No. 562, June 23. 



Besides these, seeds from large select- 

 ed pods were sown June 26 (No. 542). 

 Plant No. 542 came into bloom October 

 26, a few days in advance of Nos. 560, 561, 

 and 562. A few days later bloom was 

 noted on No. 559. Notes made in 1905 

 show that plants from seed sown on 

 June 10 bloomed October 25. The plants 

 from the earlier sowings naturally 

 developed into large plants, with greater 

 bearing capacity. This advantage was 

 offset, however, by the fruits being to 

 a marked degree smaller than those from 

 later sowings. A comparison of the 

 different plants in this experiment indi- 



* Bull. 171, Offica of Experiment Stations, p. 38 



cates that to combine high yield with 

 the production of large pods the seed 

 should be planted about May 15 in South 

 Florida. 



Make the seed bed in a place sheltered 

 from high winds and work in thoroughly 

 a moderate quantity of stable manure 

 or commercial fertilizer. Sow the seed 

 thinly in drills 6 inches apart, covering 

 the seed from \ to ^ inch, then firm the ' 

 soil, and, if dry, water thoroughly. The 

 seed will germinate in a few days. If 

 the weather is dry, the young plants 

 should.be watered as occasion requires. 

 When the plants are 3 to 4 inches high 

 they are ready for transplanting to 

 the field. 



The plants should be set out in rows 

 6 to 10 feet apart and 4 to 8 feet apart in 

 the row, according to the fertility of 

 the land and the supply of moisture. 

 The seedlings are easily transplanted if 

 proper precautious are taken. The work 

 should preferably be performed on a 

 cloudy day or late in the afternoon. 

 Where a few plants are desired for 

 home use only it will be found advant- 

 ageous to sow a few seeds where the 

 plants are to remain permanently and 

 when the plants are well developed to 

 thin out to one plant to a hill. 



Experiments with different fertilizers 

 have been started at the Subtropical 

 Laboratory, but have not been carried 

 ou for a sufficiently long time to indicate 

 the best form in which the fertilizer 

 should be applied. Meantime, a formula 

 of nitrogen, 4 per cent ; potash, 7 per 

 cent., and phosphoric acid, 6 percent., 

 has given good results. One-third of the 

 actual ammonia is derived from nitrate 

 of soda and the other two-thirds from 

 dried blood. The sources of potash and 

 phosphoric acid are muriate of potash 

 and acid phosphate, respectively. 



The fertilizer should be applied at the 

 rate of from 1,000 to 2,000 pounds to the 

 acre, according to the fertility of the 

 land. On lands rich in ammonia the 

 nitrogenous elements should be greatly 

 reduced. It should be understood that 

 this applies to Florida soils and condi- 

 tions. The amount, and possibly the 

 formula, would probably have to be 

 modified in other sections. In the sandy 

 and leach 5^ soils of Florida it will be 

 found advantageous to make several 

 small applications instead of applying 

 the total quantity at the time of plant- 

 ing. No cultivation is necessary, except 

 to stir in the fertilizer and to keep down 

 the weeds while the plants are small. 

 When the ground is well shaded by the 

 plant cultivation may be discon- 

 tinued. 



