Hostname: page-component-84b7d79bbc-g5fl4 Total loading time: 0 Render date: 2024-07-26T00:44:55.678Z Has data issue: false hasContentIssue false

Effect of sink size on the pod and seed characteristics of soya beans (Glycine max (L.) Merr.) in the lowland tropics

Published online by Cambridge University Press:  27 March 2009

T. O. Tayo
Affiliation:
Department of Agricultural Biology, University of Ibadan, Ibadan, Nigeria

Summary

The size of the sink on two indeterminate (cv. Hampton and cv. TGM 119) and two determinate (cv. Bossier and cv. TGM 294) cultivars of soya beans were reduced by continuously limiting the number of pods developing at each fruiting node to either one or two, starting from 2 weeks after anthesis, in three field experiments (early 1980, late 1980 and early 1981). Thiswas in order to evaluate the effects of sink size on the development of pod and seed characteristics as well as to quantify the inter-relationships between these characters under humid tropical conditions.

Persistently reducing the number of pods developing at each fruiting node consistently significantly reduced the number of pods per plant, the pod and seed dry weights per plant, the total number of seeds per plant and the harvest index (seed weight as a proportion of total dry weight) in all cultivars when compared with the control. On the other hand, the treated plants of all cultivars generally had longer pods, heavier individual pods and seeds, more seeds per podand greater leaf area and leaf dry weight as well as greater specific leaf weight than the control plants. Compensation indices (percentage increases in size over control) were 25–30% for weight per pod and seed weight per pod; 11–16% for weight per seed and number of seeds per pod and 2–5% for pod length in the treated plants.

Most of the characters measured (except individual weight of pods and seeds, seed weight per pod and number of seeds per pod) had significant interaction effects of sink size, cultivar and season; season had the highest correlation ratio, followed by cultivar, and sink size had the least. Also, nearly all components of seed yield were positively highly significantly correlated with one another; the number of seeds per pod and the number of pods per plant accounted for 76% of the variation in seed dry weight per plant.

It would seem therefore that under the prevailing humid tropical conditions, the most important component of seed yield in soya bean is the number of seeds per pod, as affected by the sink size.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1983

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Adams, M. W. (1967). Basis of yield component compensation in crop plants with special reference 50 field bean Phaseolus vulgaris. Crop Science 7, 505510.CrossRefGoogle Scholar
Ciha, A. J. & Brun, W. A. (1978). Effect of pod removal on non-structural carbohydrate concentration in soyabean tissue. Crop Science 18, 773776.CrossRefGoogle Scholar
Dornhoff, G. M. & Shibles, R. M. (1970). Varietal difference in net photosynthesis of soyabean leaves. Crop Science 10, 4245.CrossRefGoogle Scholar
Egli, D. B. & Leggett, J. E. (1976). Rate of dry matter accumulation in soybean seeds with varying source sink ratios. Agronomy Journal 68, 371374.CrossRefGoogle Scholar
Frank, S. J. & Fehr, W. R. (1981). Associations among pod dimensions and seed weight in soybeans. Crop Science 21, 547550.CrossRefGoogle Scholar
Hicks, D. R. & Pendleton, J. W. (1969). Effect of floral bud removal on performance of soybeans. Crop Science 9, 435437.CrossRefGoogle Scholar
Malhotra, R. S., Singh, K. B. & Dhaliwal, H. S. (1972). Correlation and path-coefficient analysis in soya-bean (Qlycine max (L.) Merr.). Indian Journal of Agricultural Science 42, 2629.Google Scholar
Mathews, G. A., Rowell, J. G. & Beeden, P. (1972). Yield and plant development of reduced cotton stands in Malawi. Experimental Agriculture 8, 3348.CrossRefGoogle Scholar
Pandey, J. P. & Torrie, J. H. (1973). Path-coefficient analysis of seed yield components in soybeans (Glycine max (L.) Merr.). Crop Science 13, 505507.CrossRefGoogle Scholar
Smith, R. H.. & Bass, M. H. (1972). Relationship of artificial pod removal to soyabean yields. Journal of Economic Entomology 65, 606608.CrossRefGoogle Scholar
Tayo, T. O. (1977). Effect of flower or pod removal on the performance of soya beans (Glycine max L.). Journal of Agricultural Science, Cambridge 89, 229234.CrossRefGoogle Scholar
Thomas, G. D., Ignoffo, C. M. & Smith, D. B. (1976). Influence of defoliation and depodding on quality of soybeans. Journal of Economic Entomology 69, 737740.CrossRefGoogle Scholar