African Crop Science Journal African Crop Science Society ISSN: 1021-9730 EISSN: 2072-6589 Vol. 11, Num. 1, 2003, pp. 43-47

African Crop Science Journal, Vol. 11. No. 1,  2003, pp. 43-47

INTERCROP PRODUCTIVITY OF ROSELLE IN NIGERIA

F. E. FBABATUNDE

Crop Production Programme, School of Agriculture & Agricultural Technology, P.M.B. 0248. Abubakar Tafawa Balewa University, Bauchi. Nigeria

Received 4 October, 2002;
Accepted 20 January, 2002

Code Number: cs03006

ABSTRACT

Roselle (Hibiscus sabdariffa L.) is a crop of immense benefit within small scale cropping systems in Nigeria as well as in most developing countries of Africa. However, the productivity of roselle when cultivated under intercropping arrangements as is often the case is largely unknown.  Therefore, field experiments were conducted to investigate the influence of intercropping combinations on the productivity and profitability of roselle. The study was conducted to ascertain whether roselle would be better intercropped with either legumes or cereals. From the results obtained, intercrop performance and net farm income were better with the roselle-groundnut intercrop than with other intercrop systems. The cash advantage due to intercropping (CAI) was highest for roselle intercropped with groundnut (Arachis hypogea) followed by intercropping with cowpea (Vigna unguiculata). Yield of roselle was more reduced when intercropped with the cereals (millet and sorghum) than for the legumes (groundnut and cowpea). Roselle is more compatible with annual legumes for intercropping than with cereals.

Key Words:  Cereals, cropping systems, Hibiscus sabdariffa, legumes, yields

RÉSUMÉ

La roselle (Hibicus sabdariffa L.) est une plante aux bénéfices immenses dans systèmes des petites cultures au Nigeria aussi bien que dans la plupart des pays en développement d'Afrique. Cependant, la productivité de la roselle cultivée en association, comme c'est toujours le cas, est largement inconnue. Par conséquent, des expériences de champs étaient conduites pour déterminer l'influence des cultures associées sur la productivité de la roselle. L'étude était conduite pour certifier si la performance de la roselle était meilleure en association avec les légumes ou avec les céréales. A partir des résultats obtenus la performance en association et le revenu net de la ferme étaient mieux avec l'association roselle-arachide par rapport aux autres associations. L'avantage monétaire du à l'association était élévé pour la roselle-arachide (Arachis hypogea) suivit de l'association roselle-niébé (Vigna unguiculata). Le rendement de la roselle était plus réduite en association avec les céréales (millet et le sorgho) comparé à son association avec les légumes (arachide et le niébé). La roselle est plus compatible en association avec les legumes que en association avec les céréales.

Mots Clés:  Céréales, systèmes de cultures, Hibiscus sabdariffa, légumes, rendement

INTRODUCTION

Roselle  (Hibiscus sabdariffa) belongs to the family Malvaceae. Formerly, it was traditionally cultivated for its leaves, seeds and stem, but is now being grown commercially for its calyces. It is an upright, branched annual plant, reaching a height of 1 to 2.5m depending on the varieties (Norman, 1992). The leaves of roselle, its tender shoots, succulent calyces and immature fruits are chopped and added to sauces. The succulent calyces are processed into refreshing drink "Zoborodo" both locally and industrially hence, the crop is receiving increased attention in Nigeria and elsewhere.

Roselle is commonly grown in mixture with other crops such as sorghum (Sorghum bicolor), millet (Eleusine indica), cowpea (Vigna unguiculata) and groundnut (Arachis hypogea), especially in the northern Guinea savanna ecological zone of Nigeria, but the intercrop systems have not been well studied. It was in realization of these coupled with inadequate research attention received by roselle in the past that this research was conducted to evaluate several roselle cropping systems. 

MATERIALS AND METHODS

Field experiments were conducted during the rainy seasons of 1999 and 2000 at the research farm of the Abubakar Tafawa Balewa University, Bauchi. The site is approximately located at 10^o22' N; 9^o47' E and 609.45m above sea level in the northern Guinea savanna ecological zone of Nigeria. Physico-chemical properties of the soil are presented in Table 1.

There were nine treatments consisting of various sole and intercropping combinations viz: (1) roselle sole; (2) roselle + millet mixture (3) millet sole (4) roselle + sorghum mixture (5) sorghum sole (6) roselle + cowpea mixture (7) cowpea sole (8) roselle + groundnut mixture (9) groundnut sole. These were laid out in a randomized complete block design with four replications.

Dark red variety of roselle was sown at a spacing of 60cm x 80cm (Okusanya et al.,1999; Babatunde et al., 2002 unpubl.). Millet (var = late millet - "maiwa") was sown at 75 x 25 cm; sorghum (var = KSV8) at 60 x 25 cm; cowpea (var = IT 86D - 719) at 60 x 25 cm; and groundnut (var = EX - Dakar) at 60 x 20 cm. Management practices for each crop were similar for sole as for intercrop. Plant height, canopy diameter, number of branches per plant, number of leaves per plant and yields as appropriate for the species over the two years were taken and subjected to analysis of variance and significant difference among mean variables were separated using the method of least significant differences (LSD).

Net farm income (NFI) was determined as; NFI = GFI - TC. Where NFI = Net farm income, GFI = Gross farm income, TC = Total cost. The gross farm income (GFI) was calculated assuming that farmgate prices of roselle, millet, sorghum, cowpea and groundnut were Naira # 50, 30, 25, 40 and 45 per kg,  respectively. Total cost (TC) for each crop was assumed to be #1,000 and 2,000 ha^-1 for sole crop and intercrop production, respectively. Cash advantage due to intercropping (CAI) was the difference of NFI for intercropping as compared to sole cropping (Babatunde, 2000). Relative Yield (RY) was calculated as intercrop yield divided by sole crop yield (Hiebsch and McCollum, 1987). Land equivalent ratio (LER) is the land area that would be required for sole crops to produce the yield achieved in intercropping combination and was calculated as; YiR / YsR x YiO / YsO. Where YiR = yield of roselle in intercrop, YsR = yield of roselle in sole crop, YiO = yield of other crop(s) in intercrop and YsO = yield of other crop(s) in sole crop. Area - x - time equivalent ratio (ATER) was calculated as; [ (RY1 x t^s1) + (RY2 x t^s2)] / ti  (Hiebsch and McCollum, 1987) Where: ATER = Area x time equivalent ratio, RY1 = Relative yield of base crop (roselle) t^s1 = Time / duration of roselle (sole), RY2 = Relative yield of other crop in the intercropping system, t^s2 = Time / duration of other crop (sole), ti = Time / duration for the whole intercropping system. Crop durations were assumed to be 155, 130, 110, 75 and 85 days after sowing for Roselle, millet, sorghum, cowpea and groundnut, respectively. System productivity index (SPI) was calculated as; SPI = (SA / LB x Lb) + Sa  (Odo, 1991). Where: SPI = System productivity index, SA and LB = Mean yield of roselle and other crop in sole cropping, Sa and Lb = Yield of roselle and other crop in intercropping.

RESULTS AND DISCUSSIONS

Productivity. Roselle growth performance was better in association with legumes than with cereals (Table 2), presumably because of more shading competition with the cereals. Similarly, others have found intercrop legume yield to be reduced due to shading by the intercropped cereal (Chui and Shibles, 1983; Francis et al., 1982). They further explained that roselle yield was most in sole (Table 3) followed by intercropping with groundnut and cowpea. Legume intercrop yield, related to sole crop yield, was more reduced than for cereal yields. Competition for light appears to be important as roselle was more suppressed by the taller cereals while the legumes were more suppressed by roselle than were the cereals.

Values of LER, ATER, SPI were all greater than 1.0 for all intercrop associations (Table 4) and least for roselle-cowpea intercropping. Although LER and ATER were closely related,  ATER values were less than for LER since roselle occupies the field for a longer time than the legumes or cereal crops. Values of SPI were high and largely determined by roselle intercrop yield which was not much reduced by intercropping.

Profitability. Indices of profitability are cash advantage due to intercropping (Table 3), net farm income (Fig. 1) as well as yield reduction percentage (Table 5). An average farmer in Nigeria would not be interested in the LER, ATER, SPI and CR or TR of intercropping but rather in the profitability of intercropping one crop with the other (that is, which of the intercropping combination would generate higher income than the other).

Yields of roselle was minimally reduced when intercropped with the legumes, but the yields of the legumes were greatly reduced by roselle (Table 5). Sole roselle gave a significantly (P < 0.01) higher profit than the other crops in sole cropping (Fig. 1). It is more profitable to intercrop roselle with legumes than with cereals. Results of the CAI (Table 3) further buttress the profitability of roselle in intercropping combination. Roselle/groundnut combination generate the highest cash advantage due to intercropping followed by roselle/cowpea combination. This can be attributed to complementarity among intercrops with leguminous crops as reported by Wien and Nangju (1976); Remison (1978); Pal et al. (1993). However, intercropping roselle with either millet or sorghum generated negative values of CAI hence, a cash disadvantage (rather than advantage) due to intercropping. Gupta (1989) also reported that the leguminous crops give higher gross returns than vegetable crops when intercropped with roselle.

Thus, for optimum and sustainable productivity and profitability of intercropping combination, roselle has been found to be better intercropped with legumes (groundnut and cowpea) rather than cereals (millet and sorghum).

ACKNOWLEDGEMENTS

Thanks are due to Prof. Dr. T.O Oseni, Drs. B.M Auwalu, G.N Udom and  the management of Abubakar Tafawa Balewa University, Bauchi. Nigeria

REFERENCES

• Babatunde, F.E. 2000. Effect of intercroping and cropping sequence on the marketable yield and productivity of Celosia and Okra. Journal of Agriculture and Environment 1: 55-61.
• Chui, J.A.N. and Shibles, R. 1983. Influence of spatial arrangements of maize on performance of an associated soybean intercrop. Field Crops Research 8:187-198.
• Francis, C.A., Prager, M. and Tejada, G. 1982. Density interactions in tropical intercroping. Maize (Zea mays. L) and bush bean (Phaseolus vulgaris. L). Field Crops Research 5:253-264.
• Gupta, S.K. 1989. Studies on intercropping in roselle (Hibiscus sabdariffa. L). Journal of Agronomy 34:361 - 363.
• Hiebsch, C.K. and McCollum, R.E. 1987. Area-x-time equivalency ratio: A method for evaluating the productivity of intercrops. Agronomy  Journal 79:15 -22.
• Norman, J.C.1992. Tropical vegetable crops. Published by Arthur H.Stockwell Ltd, Great Britain. 252pp.
• Odo, P.E. 1991. Evaluation of Short and Tall sorghum varieties in mixtures with cowpea in the Sudan savanna of Nigeria: Land equivalent ratio, Grain yield and System productivity index. Experimental Agriculture 27:435 - 441.
• Okusanya, B.A.O., Arifalo, E.I. and Kyenge, P.M.  1999. Effect of spacing on the growth and yield of roselle (Hibiscus sabdariffa. L.) in Yola. In: Proceeding of the 33^rd Annual Conference of the Agricultural Society of Nigeria (ASN). pp. 135- 140.
• Pal, U.R., Oseni, T.O. and Norman, J.C. 1993. Effect of component densities on the productivity of soybean/maize and soybean/sorghum intercrop. Journal of Agronomy 170:66 - 70.
• Remison , S.U. 1978. Neighbour effects between maize and cowpea at various levels of N and P. Experimental Agriculture 14:205 - 212.
• Wein, H.C. and Nangju, D. 1976. Cowpea as an intercrop under cereals. In: Proceeding of the Intercropping in Semi-Arid Areas, Morogoro, Tanzania, 10-12 May. Monyo, J.H.  and Ker, D.R.  (Eds.), p 32. Association for the Advancement of  Agricultural Sciences in Africa, Addis Ababa, Ethiopia.

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