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African Crop Science Journal
African Crop Science Society
ISSN: 1021-9730 EISSN: 2072-6589
Vol. 6, Num. 2, 1998, pp. 197-204
African Crop Science Journal, Vol

African Crop Science Journal, Vol. 6. No. 2, pp. 197-204, 1998

SHORT COMMUNICATION

ASSOCIATIONS OF SOME CHARACTERS WITH SEED YIELD IN LOCAL VARIETIES OF FABA BEAN

ALEM BERHE, GELETU BEJIGA1 and DEJENE MEKONNEN1

Institute of Agricultural Research, P.O. Box 2003, Addis Ababa, Ethiopia
1Alemaya University of Agriculture, Debre Zeit Agricultural Research Centre, P.O. Box 32, Debre Zeit, Ethiopia

(Received 12 November, 1997; accepted 12 March, 1998)

Code Number:CS98022
Sizes of Files:
      Text: 18K
      Graphics: Line drawings and tables (gif) - 71K

ABSTRACT

Twenty indigenous varieties of faba bean were grown in 1990 main crop season at Denbi (1900 m.a.s.l.), Holetta ( 2400 m.a.s.l.) and Bekoji (2760 m.a.s.l.) to determine the important components of seed yield. Observations were recorded on 14 other characters and seed yield per plant. Simple correlation and path coefficient analyses were computed for each location. Nine characters at Denbi, eight at both Holetta and Bekoji which showed significant relationships with seed yield per plant were used in the path analysis. Correlation and path analyses showed that number of seeds per plant and 100-seed weight were the major direct contributors to seed yield per plant consistently across the three locations. However, these two characters have negative relationship among themselves. The number of seeds per pod and number of pods per plant had positive relationships with seed yield per plant. The number of seed per pod had relatively high and positive direct effects at Denbi and Holetta. But the direct effect of number of pods per plant was negative at the low elevation ( Denbi) and negligible at the high elevation locations. Most of the yield components contributed to seed yield per plant indirectly via number of seeds per plant. Generally, these results suggest that number of seeds per plant and 100-seed weight are the two most important seed yield components in the development of high yielding varieties. However, the number of seeds per pod and number of pods per plant are important due to their indirect contributions via the number of seeds per plant.

Key Words: Ethiopia, path analysis, Vicia faba, yield components

RÉSUMÉ

Vingt variétés indigènes de haricot faba étaient cultivées pendant la grande saison agricole de 1990 à Denbi (1900 m d'altitude), à Holetta (2400 m) et à Bekoji (2760 m) afin de déterminer les principaux composants du rendement en graines. Des observations sur 14 autres caractères et le rendement en graines par plante ont été enregistrées. Une correlation simple et des analyses de coefficient de passage ont été informatisées pour chaque localité. Le nombre de caractères présentant des relations significatives avec le rendement en graines par plante et utilisés dans l'analyse de coefficient de passage était respectivement de 9 à Denbi et de 8 à Holetta et à Bekoji. La correlation et les analyses de coefficient de passage ont montré que le nombre de graines par plante et le poids de 100 graines contribuaient émomément au rendement en graines par plante dans les trois localités. Cependant, ces deux caractères montraient une relation négative entre eux. Le nombre de graines par gousse et celui de gousses par plante présentaient des relations positives avec le rendement en graines par plante. Le nombre de graines par gousse a eu des effets directs relativement importants et positifs à Denbi et à Holetta, par contre l'effet direct du nombre de gousses par plante était négatif aux basses altitudes (Denbi) et négligeable aux hautes altitudes. La plupart des composant du rendement ont contribué à la production des graines par plante indirectement via le nombre de graines par plante. En général, ces résultats permettent de conclure que le nombre de graines par plante et le poids de 100 graines étaient les deux paramètres les plus importants du rendement en graines dans le développement des variétés hautement productives. Toutefois, le nombre de graines par gousse et celui de gousses par plante sont importants à cause de leurs contributions indirectes via le nombre de graines par plante.

Mots Clés: Ethiopie, analyse du coefficient de passage, Vicia faba, composants du rendement

INTRODUCTION

Ethiopia is endowed with vast agro-climatic conditions. Hence, the pulses in Ethiopia are categorised as highland and lowland pulses. Of all the pulses, faba bean (Vicia faba L.) is a leading one in hectarage (314,910 ha) with a total production of 373,790 tons (CSA, 1995). In fact, Ethiopia is the second largest producer of faba bean in the world next to China (FAO, 1994). It grows in a wide range of altitudes (1800-3000 m.). Faba bean is a major source of protein for the resource-poor farmers, foreign currency earning and soil amelioration in crop rotation. The Ethiopian National Breeding Programme has been focusing in the development of high yielding and disease resistant faba bean varieties. However, the selection of superior types based on seed yield alone is less efficient because yield is a complex trait determined by a number of component characters (Sindhu et al., 1985a, 1985b). Direct selection for yield is also hampered by large genotype- environment interactions (Johnson et al., 1955a; Yassin, 1973). Thus, it is necessary to select plants on the basis of characters that have positive relationships with seed yield. Knowledge of the phenotypic correlation between yield and yield components help in planning efficient breeding programmes (Johnson et al., 1955b).

The seed yield of a food legume plant is usually expressed as: Seed yield = pods per plant x seeds per pod x average seed weight (Sinha, 1977). The number of pods per plant has often been recommended as an indirect selection criterion for increasing seed yield because of its higher and consistent correlation with seed yield (Ishag, 1973; Naidu et al., 1985; Mercellos, 1987; Bakheit and Mahdy 1988a, 1988b; Katiyar and Singh 1990).

Correlation analysis describes merely the mutual relationship between different pairs of characters without providing the nature of cause and effect relationships of each character (Batt, 1977). Hence, the path analysis was also performed to determine the direct and indirect contribution of each character to seed yield.

MATERIALS AND METHODS

Twenty indigenous faba bean varieties were grown in 1990 main crop season (June-December) at altitudes ranging from 1990 m at Denbi (low altitude) to 2400 m at Holetta (medium altitude) and 2760 m at Bekoji (high altitude). Mean monthly rainfall, minimum and maximum temperatures of these locations are presented in Figures 1 and 2.

A randomised complete block design with four replications was used. Each plot consisted of four rows of 5 m length. Spacing of 40 cm between rows and 10 cm between plants recommended by IAR (1989) was used. Planting was done on June 21, June 23 and June 20 at Denbi, Holetta and Bekoji, respectively. DAP fertilizer was applied at the rate of 100 kg ha-1. The field was kept free of weeds by frequent hand weeding. Since Holetta and Bekoji are hot spot for chocolate spot chlorothalonil was sprayed at the rate of 2.5 a.i. kg ha-1 while at Denbi mancozeb at the rate of 1.68 a.i. kg ha-1 was applied to control rust.

    Figure 1. Monthly rainfall of the three locations.

    Figure 2. Maximum and minimum temperatures (°C) of the three locations.

Observations were recorded on the number of days to 50% flowering and 95% maturity, plant height (cm), average number of flowers per node from two intermediate nodes, height (cm) of the lowest podding node of the main stem, number of stems per plant, number of podding nodes per plant, number of pods per podding node, and number of pods per stem. Observations were also collected on number of pods per plant, seeds per plant, seeds per pod, seed yield (g) per plant and 100-seed weight. Mean of 10 plants from the two central rows was used for the statistical analysis of all the characters studied. Correlations between seed yield and other characters and among the yield components were determined using the method of Gomez and Gomez (1984). The path-coefficient analysis was done following the procedure of Singh and Chaudhary (1987) for those components which showed significant positive correlation with seed yield per plant.

RESULTS AND DISCUSSION

Correlation analysis showed that number of seeds per pod, seeds per plant and pods per plant had significant positive associations with seed yield across the three environments (Tables 1, 2 and 3). In this study, days to maturity had significant positive association with seed yield per plant only at Bekoji since it is a site of long growing duration. At Denbi days to maturity had no association with any of the characters and thus it was omitted from Table 1. Number of stems per plant showed significant positive association with seed yield at the two high altitude locations (Holetta and Bekoji) and this positive association becomes closer with an increase in altitude. Number of pods per stem had significant positive associations with seed yield only at low and mid-altitudes (Tables 1 and 2) while it was non significant at high altitude (Table 3). Hundred seed weight also showed significant positive relationship with seed yield at Denbi and Bekoji but non significant at Holetta (mid-altitude). The number of flowers per flowering node had significant positive relationship with seed yield at Bekoji, non significant positive at Holetta and significant negative relationship at Denbi. This negative correlation between number of flowers per flowering node and seed yield at Denbi could probably be due to relatively higher temperatures which may cause flower abortion that results in low yield per plant. Number of pods per podding node showed positive significant relationship with yield at Holetta and Denbi. Plant height had positive significant correlation with seed yield at Denbi and Bekoji (Tables 1 and 3).

    TABLE 1. Phenotyplc correlation coefficients (r) among various plant characters in 20 varieties of faba bean studied at Denbi, 1990 crop season

    TABLE 2. Phenotypic correlation coefficients (r) among various plant characters in 20 varieties of faba bean studied at Holeta, 1990 crop season

    TABLE 3. Phenotypic correlation coefficients (r) among various plant characters in 20 varieties of faba bean studied at Bekoji, 1990

Among all the characters studied, number of seeds per pod, seeds per plant, pods per plant, podding nodes per plant and pods per podding node had consistently significant and positive relationships with seed yield suggesting that these yield components can be used as selection criteria in faba bean. The significant association of number of pods per plant with seed yield per plant is of practical importance because it is easy to visually evaluate and select plants in the field. Similar result was also reported by Kambal (1969). Number of seeds per pod had also consistently significant and positive association with number of seeds per plant at all the locations. It showed non significant relationships with the remaining yield components except negative and significant relationships (r = -0.238* ) with number of flowers per flowering node at Denbi and pods per stem at Bekoji (r = -0.413**) and positively significant (r = 0.380**) with stems per plant at Bekoji (Tables 1, 2 and 3). The negative relationship shows that an improvement in one component is followed by a decrease in another component. Number of seeds per plant showed highly significant positive relationships with number of pods per plant, podding nodes per plant, pods per podding node and plant height indicating that this character will have no negative influence on the important yield components. The relationship of 100-seed weight with days to maturity was significantly positive at Holetta and Bekoji. There was a negative correlation between pods per podding node and number of flowers per flowering node at Denbi (Table 1).

Path analysis showed that the number of seeds per plant and 100-seed weight were the direct contributors to seed yield per plant (Tables 4, 5 and 6). The number of seeds per pod were among the major direct contributors to seed yield per plant particularly at Denbi and Holetta (Tables 4 and 5). The major contribution of the number of seeds per pod was through number of seeds per plant at all the three locations confirming that this character can be used as the selection criterion in combination with number of pods and seeds per plant. Number of pods per plant had low direct effect on seed yield, but contributes indirectly via number of seeds per plant and podding nodes per plant. Generally, most of the yield components studied were found to contribute via number of seeds per plant

    TABLE 4. Direct (bold) and indirect effects of yield components on faba bean seed yield per plant as revealed by path coefficient

    TABLE 5. Direct (bold) and indirect effects of yield components on faba bean seed yield per plant as revealed by path-coefficient analysis, Holetta, 1990 crop season

    TABLE 6. Direct (bold) and indirect effects of yield components on faba bean seed yield per plant as revealed by path-coefficient analysis, Bekoji, 1990 crop season

It can be concluded that number of seeds per plant and 100-seed weight were the major direct contributors to the seed yield per plant. The positive correlation of these characters with seed yield per plant is largely due to their direct effect. Similar results were reported for number of seeds per plant (Sindhu et al., 1985b) and for 100-seed weight (Bakheit and Mahdy, 1988b). All the remaining yield components such as the number of seeds per pod, pods per plant, pods per stem, pods per podding nodes and number of podding nodes per plant contribute through the number of seeds per plant. Therefore, among these characters the number of seeds per plant, seeds per pod and pods per plant can be used as selection criteria to develop high yielding lines of faba bean. One hundred seed weight can also be considered as one of the selection criteria, but this character can only be used until the maximum seed weight is obtained and levelled off.

REFERENCES

Bakheit, B.R. and Mahdy, E.E. 1988a. Selection for seed yield in faba bean (Vicia faba L.). Fabis Newsletter 20:3-8.

Bakheit, B.R. and Mahdy, E.E. 1988b. Variation, correlations and path coefficient analysis for some characters in collection of faba bean (Vicia faba L.). Fabis Newsletter 20:9-14.

Batt, G.M. 1977. Significance of path coefficient analysis in determining the nature of character association. Euphytica 22:338-343.

CSA (Central Statistical Authority). 1995. Agricultural sample survey 1994/95 (1987 E.C). Report on area and production for major crops. Private peasant holdings (main season). Statistical bulletin 132 vol. 1 Addis Ababa.

FAO ( Food and Agricultural Organization). 1994. FAO Production Year Book. FAO, Rome.

Gomez, K.A. and Gomez, A.A 1984. Statistical Procedures of Agricultural Research. Second edition. John Wiley and Sons, Inc. Toronto. 680pp.

Ishag, H.M. 1973. Physiology of seed yield in field beans (Vicia faba L.) 1. Yield and yield components. Journal of Agricultural Science Cambridge 80:181-189.

Johnson, H.W., Robinson, H.F. and Comstock, R.E. 1955a. Estimates of genetic and environmental variability in soybean. Agronomy Journal 47:314-318.

Johnson, H.W., Robinson, H.F. and Comstock, R.E. 1955b. Genotypic and phenotypic correlations in soybeans and their implications in selection. Agronomy Journal 47: 477-483.

Kambal, A.E. 1969. Components of yield in field beans,Vicia faba L. Journal of Agricultural Sciences Cambridge 72:359-363.

Katiyar, R.P. and Singh, A.K. 1990. Path-coefficient studies for yield and yield components in faba bean (Vicia faba L.). Fabis Newsletter 26:

Mercellos, H. 1987. Relationship between seed yield and plant traits and the consistency of harvest index in faba bean. Fabis Newsletter 18:27-29.

Naidu, M.R., Chhabra, A., Singh, S. and Singh, V.P. 1985. Analysis of yield components in broad bean. Indian Journal of Agricultural Science 55:236-239.

Singh, R.K. and Chaudhary, B.D. 1987. Biometrical Methods in Quantitative Genetic Analysis. Kalydni Publishers, New Delhi.

Sindu, J.S., Singh , O.P. and Singh, R.P. 1985a. Selection indices in faba bean (Vicia faba L.). Fabis Newsletter 12:7.

Sindu, J.S., Singh, O.P. and Singh, R.P. 1985b. Component analysis of the factors determining grain yield in faba bean (Vicia faba L.). Fabis Newsletter 13:3-5.

Sinha, S.K. 1977. Yield, yield components and plant ideotype in food legumes. In: Food Legume Crops: Improvement and Production. FAO Plant Production and Protection Serials 9:123-131.

Yassin, T.E. 1973. Genotypic and phenotypic variances and correlations in field beans (Vicia faba L.). Journal of Agricultural Sciences Cambridge 81:445-448.

Copyright 1998, African Crop Science Society


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