Subscribe Now Subscribe Today
Research Article
 

The Effect of Nitrogen and Phosphorus on Growth and Yield of Roselle (Hibiscus sabdariffa var. sabdariffa L.) In a Semi Arid Agro-Ecology of Nigeria



L.A. Okosun , M.D. Magaji and A.I. Yakubu
 
Facebook Twitter Digg Reddit Linkedin StumbleUpon E-mail
ABSTRACT

Two field experiments were conducted during 1998 and 1999 rainy seasons at the Usmanu Danfodiyo University Sokoto Dry Land Farm, Sokoto (Latitude 13° 09`N and Longitude 5° 18`E), with a view to studying nitrogen and phosphorus fertilization on growth, yield components and calyx/seed yields of roselle. Treatments consisted of four levels each of N (0, 20, 40 and 60 kg N ha-1) and P (0, 10, 20 and 30 kg P ha-1), which were combined factorially in a randomized complete block design, replicated three times. Data were collected on plant height, calyx and seed yield of roselle. Results showed that plant height responded significantly to both nitrogen and phosphorus fertilization. Plants treated with 40 and 60 kg N ha-1 were significantly taller than plants that were fertilized at 0 and 20 kg N ha-1, whereas P rates at 10 and 20 kg ha-1 produced the tallest plants than the other P rates. Calyx and seed yields increased with increasing rates of N and P fertilizers up to 60 kg N and 30 kg P ha-1.

Services
Related Articles in ASCI
Search in Google Scholar
View Citation
Report Citation

 
  How to cite this article:

L.A. Okosun , M.D. Magaji and A.I. Yakubu , 2006. The Effect of Nitrogen and Phosphorus on Growth and Yield of Roselle (Hibiscus sabdariffa var. sabdariffa L.) In a Semi Arid Agro-Ecology of Nigeria. Journal of Plant Sciences, 1: 154-160.

DOI: 10.3923/jps.2006.154.160

URL: https://scialert.net/abstract/?doi=jps.2006.154.160

Introduction

Roselle (Hibiscus sabdariffa L.), is a tropical annual shrub that produces fruit-like structures with often elaborate calyces containing edible pigments (Ghazali, 1999). A member of the Malvacae family, it is a native to India and Malasia where it is commonly cultivated and must have been carried at an early date to Africa (Babajide et al., 2004). In Nigeria, the cultivation and intense utilization of the red and purple genotypes are found mainly in the Guinea and Sudan Savanna ecological zones of the country while the green genotype, hitherto ascribed little utility value, is found in the Southwest (Alegbejo, 2000). Generally the utility of roselle varies among different people the world over (Babajide et al., 2004). In Nigeria, the calyx of the green type is used for making soup and is locally referred to as “Yakwa” and “Ishapa” in Hausa and Yoruba languages, respectively. The calyx of the red type is boiled in hot water, the purple/red coloured extract is stained, sweetened and flavoured as a beverage drink, “Zoborodo” (Alegbejo, 2000). It has a number of uses and promising prospects for industrial purposes (Adekpe and Adigun, 2000). The tender leaves and shoots are eaten in salads and soups. Traditionally, preparations from various parts of the roselle plant such as flower (calyx and corolla) and leaves are used as remedy for various illnesses. The drink is a readily available and inexpensive source of vitamin C in addition to various medicinal values (Babajide et al., 2004).

Work initiated at the Institute for Agricultural Research (IAR), Zaria, Nigeria resulted in screening of a number of roselle germplasms and preliminary studies on effects of nitrogen and phosphorus on yield and yield components of the crop (Alegbejo, 1998). By way of research very limited nutrition studies had been carried out on roselle in the study area. Work done so far is limited to northern Guinea savanna zone (Alegbejo, 1998; Lamido, 1998) excluding the Sudan savanna zone where roselle is predominantly being grown as a dividing hedge between farms and a lot of variants of roselle are found.

In view of the afore-mentioned, the study was undertaken to investigate the effects of N and P on growth and yield of roselle as well as to determine their optimum rates of application.

Materials and Methods

Two field trials were conducted during the 1998 and 1999 rainy seasons at the Usmanu Danfodiyo University Dry Land Farm, Sokoto (Latitude 13°09′N and Longitude 5°9′E). Soil samples were collected for analysis before planting, while the weather data were monitored throughout the duration of the experiment. The treatments consisted of a factorial combination of four levels each of nitrogen (0, 20, 40 and 60 kg N ha-1) and phosphorus (0, 10, 20 and 30 kg P ha-1) laid out in a randomized complete block design with three replications. Nitrogen was applied in form of urea (46%) while phosphorus was applied as single super-phosphate (7.87% P). The gross and net plot areas were 6 m x 4.8 m and 4.8 m x 3.6 m made up of eight and six rows, respectively.The land was ploughed and harrowed and the blocks and plots were laid out, which were separated by 1 m and 0.5 m paths, respectively. Three to five seeds of Sokoto Red roselle were planted per hill on the flat at a spacing of 60x45 cm on 15-7-98 for 1998 and 19-7-99 for 1999 rainy seasons, respectively. Nitrogen fertilizer was applied in two equal doses as per treatment. The first dose was applied as a basal dressing along with all of the phosphorus at land preparation while the second dose of nitrogen was applied as a band on one side of roselle row using a furrow 6 cm away from the plant at 6 weeks after planting (WAP). The crop was thinned to one plant per stand at 2 WAP bringing the plant population to 4 plants m-2. Weed control was carried out manually with the first weeding at 2 WAP, which was later followed by two additional weeding at 4 and 6 WAP.

Data were collected on plant height at fortnightly intervals beginning from 4 WAP by cutting two plants at ground level from each net plot area. Plant height was then measured from the base of the stem to the apex of the last leaf. Number of pods/plant was determined when the crop was at 16 WAP by counting the number of pods present in 4 randomly selected plants in the net plot area from which the number of pods/plant was derived. The dry calyx yield/plant was determined at 16 WAP by dividing total dried yield from four randomly selected plants from each plot area with the number of plants harvested. Calyx yield ha-1 was determined at 16 WAP by harvesting the fresh calyx in the net plot area. The calyces were air dried and weighed. The calyx yield per net plot was expressed in kg ha-1. Seed yield per plant per hectare were also obtained by the same procedure as described for the calyx.

The data were analyzed using Analysis of Variance (ANOVA) technique. The treatment means were separated using Duncan’s Multiple Range Test (Gomez and Gomez, 1984).

Results

The texture of the soil was found to be loamy sand and the soil was deep, loose and well drained, classified as Typic Psammants (USDA, 1988). Chemical analysis showed that the soil was slightly acidic, very low in organic-C and total-N content, moderate in exchangeable cations, low in cation exchange capacity and available-P but medium in K, Na, Ca and Mg contents. The number of rainy days during the two experimental seasons were observed to be 28 and 31 days in 1998 and 1999 rainy seasons, respectively with annual rainfall of 550.7 and 597.1 mm, respectively. The Temperature and Relative Humidity were normal for the long-range averages.

Plant height was significantly affected by nitrogen except at 4 WAP in 1998. Also plant height was significantly highly influenced (p<0.01) by phosphorus at 8, 10, 12 and 14 WAP but only significant (p<0.05) at 6 WAP. Phosphorus effect was not significant at 4 WAP. At 6 WAP there was significant response to applied N on plant height at 20, 40 and 60 kg N ha-1 when compared with control. However, the response to N at 20 and 40 kg N ha-1 were similar and higher than that of 60 kg N ha-1. At 8 WAP, the response to N at 20 and 60 kg N ha-1 was not statistically different from the control but at 40 kg N ha-1 the response was higher than that obtained from the control. At 10, 12 and 14 WAP, there were significant responses to N at 20, 40 and 60 kg N ha-1 but the responses at 20 and 60 kg N ha-1 were statistically not different (Table 1).

In the case of phosphorus, at 6 WAP, there were significant but similar responses to applied P at 10, 20 and 30 kg P ha-1. At 8 WAP, there were no responses to applied P at 10 and 20 kg P ha-1 but showed negative response on plant height at 30 kg P ha-1, that is lower than the control treatment. At 10 WAP, addition of 10 kg P ha-1 resulted in no response to applied P but there were negative responses with subsequent addition at 20 and 30 kg P ha-1. At 12 and 14 WAP, there were negative responses to P at 10 and 30 kg P ha-1 but showed no response at 20 kg P ha-1 (Table 1).

In 1999, the response of plant height to applied N and P fertilizers was similar to that of 1998 except for the response that occurred at 4 WAP and the non response to applied N at 6 and 8 WAP, (Table 2).

Yield and yield components of roselle responded significantly to nitrogen and phosphorus in the two seasons (Tables 3 and 4). With respect to number of pods/plant, in 1998, there were significant responses at 20 and 40 kg N-1 ha-1 but showed no significance response from the control at 60 kg N-1 ha-1. In 1999, additions of 20 and 60 kg N ha-1 resulted in significant response to applied N on number of pods when compared with 0 kg N ha-1 but showed no response at 40 kg N ha-1. In the case of phosphorus, in 1998, there were significant responses to applied P at 10 and 20 kg P ha-1 but at 30 kg P ha-1 the response was negative. In 1999, the trend in response of applied P on number of pods was similar except that there was no response at 30 kg P ha-1.

Table 1: Mean plant height (cm) of roselle as affected by the nitrogen and phosphorus effects during the 1998 season
Image for - The Effect of  Nitrogen and Phosphorus on Growth and Yield of Roselle (Hibiscus sabdariffa var. sabdariffa L.) In a Semi Arid Agro-Ecology of Nigeria
ns and *, ** - not significant and significant at 5% and 1%, respectively, Means followed by the same letter within a treatment group are not different statistically by DMRT at 5% level

Table 2: Mean plant height (cm) of roselle as affected by nitrogen and phosphorus during the 1999 season
Image for - The Effect of  Nitrogen and Phosphorus on Growth and Yield of Roselle (Hibiscus sabdariffa var. sabdariffa L.) In a Semi Arid Agro-Ecology of Nigeria
ns and *, ** - not significant and significant at 5% and 1%, respectively, Means followed by the same letter within a treatment group are not different statistically by DMRT at 5% level

Table 3: Mean yield and yield components of roselle as affected by N and P in 1998 season
Image for - The Effect of  Nitrogen and Phosphorus on Growth and Yield of Roselle (Hibiscus sabdariffa var. sabdariffa L.) In a Semi Arid Agro-Ecology of Nigeria
ns and *,** - not significant and significant at 5% and 1%, respectively, Means followed by the same letter within a treatment group are not different statistically by DMRT at 5% level

Table 4: Mean yield and yield components of roselle as affected by N and P in 1999 season
Image for - The Effect of  Nitrogen and Phosphorus on Growth and Yield of Roselle (Hibiscus sabdariffa var. sabdariffa L.) In a Semi Arid Agro-Ecology of Nigeria
ns and *,** - not significant and significant at 5% and 1%, respectively. pl= plant., Means followed by the same letter within a treatment group are not different statistically by DMRT at 5% level

With respect to calyx yield/plant (Tables 3 and 4); in 1998, there was no response to applied N when compared with the control. In 1999, there was significant response to N at 20 kg N-1 ha-1 while the response was negative at 40 kg N-1 ha-1 and showed no response at 60 kg N ha-1. With regards to P effects in 1999, addition of applied P on calyx yield/plant resulted in significant responses when compared with control P.

Considering calyx yield ha-1, in 1999, there were significant responses to applied N at 20 and 60 kg N ha-1 and at 40 kg N ha-1 the response was negative. In the case of phosphorus, the addition of 10 and 20 kg P ha-1 showed no response to applied but subsequent addition at 30 kg P resulted in significantly higher response than at control P.

With seed yield/plant (Tables 3 and 4); in the two years, application of 20 kg N ha-1 resulted in significant response to applied N but there were no responses with addition to 40 or 60 kg N ha-1. There were significant responses in 1998 to applied P on seed yield/plant at 10 and 20 kg P ha-1 but there was no response at 30 kg P ha-1 when compared with control P. In 1999, there were significant responses on seed yield/plant at 10, 20 and 30 kg P ha-1 when compared with 0 kg P ha-1.

Considering calyx yield/ha, in 1998, there was significant response to applied N at 20 kg N ha-1 whereas there were no responses at 40 and 60 kg N ha-1 when compared with control N. In 1999, there were significant responses to N at 20, 40 and 60 kg N ha-1 when compared with 0 kg N ha-1. In 1998, additions of 10 and 20 P ha-1 resulted in significant responses to applied P on seed yield/ha but there was no response with further addition at 30 kg P ha-1. In 1999, there were significant responses at applied P levels when compared with control.

Discussion

The general significant positive response of plant height of roselle to nitrogen is indicative of not only its importance but to also its association with vegetative growth. Similar observations were made by Tisdale and Nelson (1996) that nitrogen was linked with vigorous vegetative growth in crop plants. Selim et al. (1993) also reported significant response of plant height of roselle to nitrogen. However, the lack of significance at the initial growth stage may be due to time lag for the roselle root system to develop sufficiently to take up the available nitrogen in soil solution, urea being a highly soluble fertilizer.

The similarity in plant height in the two seasons may prove that it is a trait under genetic control rather than a trait moderated by environment, otherwise, plants in the 1999 season failed to respond favourably to the better rainfall distribution in that year. The plant height of 153.52 cm at 40 kg N ha-1and 149.83 cm at 60 kg N ha-1at 14 WAP in 1998 and 1999, respectively, is in close agreement with the findings of Slim et al. (1993) who reported plant height of roselle of 160 cm at the highest nitrogen level of 180 kg N-1 ha-1.

Phosphorus also proved to be significant which showed its importance in vegetative growth of roselle. The lack of response to the nutrient in plant height at the early growth stage of roselle crop in spite of low native soil phosphorus status, may be due to the small root system which might have been inadequate to take up the available phosphorus in soil solution. In addition, it might have been due to the low soluble nature of single super phosphate fertilizer. Although its effect is long lasting as a result of its residual effect, it takes considerable time for single super phosphate fertilizer to enter into soil solution. This explained the initial purpling of leaves observed in few plants that cut across phosphorus treatments which disappeared with time, with more rains which might have caused more of the phosphorus to be released and therefore available for the roselle plant.

Calyx yield per plant responded positively to nitrogen in both seasons. The highest calyx yield per plant was 16 g at 20 kg N ha-1. Selim et al. (1993) also reported the highest calyx yield per plant of 49.4 g at 160 kg N ha-1. Their higher dry calyx yield per plant may have to do with their higher rates of fertilizer applied or with the cultivar of roselle. In general, it may be inferred that dry calyx yield per plant tended to follow the same trend as the number of pods per plant and calyx harvest index.

Calyx yield/plant responded positively to phosphorus only in 1999 season. It showed the importance of phosphorus in determining calyx yield/plant. Calyx yield per hectare responded positively to nitrogen and phosphorus also only in 1999. The highest calyx yield per hectare was 669 kg ha-1 at 60 kg N and 720 kg ha-1 at 30 kg P ha-1. The high calyx yield ha-1 at 60 kg N ha-1 was not reflected in any of its calyx yield components or calyx harvest index. Calyx harvest index seemed not relevant also to high calyx yield per hectare at 30 kg P ha-1 instead it seemed to have been brought about by the high calyx yield per plant at 30 kg P ha-1.

Calyx yield/ha responded positively to nitrogen and phosphorus in the combined analysis. With both nutrients the optimum levels may not have been reached because even at their highest levels calyx yield/ha was still increasing.

Seed yield/plant responded positively to nitrogen rates in both seasons. The highest seed yield/plant was at 20 kg N ha-1and it may be associated with its high number of pods per/plant and high seed harvest index. Seed yield/plant of roselle also responded positively to phosphorus in both seasons. The high seed yield/plant at 10 kg P ha-1 may not have been due to the influence of number of pods/plant but instead may have been mediated by the high seed harvest index.

Seed yield/ha showed positive response to nitrogen. The highest seed yield/plant was at 20 kg N ha-1and it may have been mediated by its high seed yield/plant, Seed yield/ha responded positively to phosphorus in both seasons. The high seed yield/ha at 10 kg P ha-1 could have been due to a combination of high pods/plant, seed/plant and seed harvest index.

From the results obtained, it could be concluded that both Nitrogen and phosphorus are important for the growth and yield of the roselle plant, just as with most crop plants. But the rates of these nutrients to be used depend on the on the characteristic of the crop in question.

REFERENCES

  1. Adekpe, D.I. and J.A. Adigun, 2000. Evaluation of herbicides for weed control in roselle at Samaru-Zaria. Proceedings of the 18th Horticultural SWociety of Nigeria Conference, 2000 IAR/ABU Zaria, pp: 170-173


  2. Alegbejo, M.D., 1998. The potentials of roselle as an industrial crop in Nigeria. Noma Mag., 14: 43-45.


  3. Alegbejo, M.D., 2000. Processing utilization and nutritional values of okra and roselle. Noma Mag., 14: 43-45.


  4. Babajide, J.M., J.G. Bodunde and A.A. Salami, 2004. Quality and sensory evaluation of processed calyces of six varieties of roselle (Hibiscus sabdariffa L.). Nig. J. Hortic. Sci., 9: 110-115.


  5. Ghazali, M., 1999. Characterization and Utilization of Roselle Food science and Biotechnoloy on-line. University of Putra, Malaysia


  6. Gomez, K.A. and A.A. Gomez, 1984. Statistical Procedure for Agricultural Research. 2nd Edn., John Willey and Sons Limited, USA., pp: 98-108


  7. Lamido, A., 1998. Roselle production (Hibiscus sabdariffa L.). Production as affected by pruning and sowing date. J. Agric. Technol., 6: 16-20.


  8. Selim, S.M.A., A.M. Rokba, M.R. Hassan and M.A. Hassan, 1993. Effects of sowing dates nitrogenous and potassium fertilization on roselle plant. Egypt J. Hortic., 20: 87-96.


  9. Tindale, S.L. and L. Nelson, 1996. Soil Fertility and Fertilizers. 3rd Edn., The Macmillan Co., London, pp: 66-104


  10. United States Department of Agriculture (USDA), 1988. Soil Taxonomy A Basic System of Soil Classification for Making and Interpreting Soil Surveys. Krieger Publishing Company, Inc., London, pp: 179-209


©  2022 Science Alert. All Rights Reserved