ISSN:
1573-5036
Keywords:
Glycine
;
Greenhouse
;
N accumulation
;
Nodulation
;
Ontogeny
;
Phaseolus
;
Rhizobia
;
Vigna
Source:
Springer Online Journal Archives 1860-2000
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Summary Greenhouse experiments were done under favorable conditions to compare effective bean symbioses with cowpea and soybean symbioses and with N-fertilized controls. Growth, N-accumulation, nodulation, acetylene reduction, hydrogen evolution and the effect of native rhizobia on symbiotic performance were evaluated. Relative N accumulation (in symbiotic plants relative to N-fertilized plants) was higher for soybean (43%) than for the other symbioses (25–39%) at four weeks, but from four to six weeks both soybean (96%) and cowpea (92%) accumulated relatively more N than did beans (56–78%). Inferior performance of beans could not be atributed to differences in acetylene reduction or nodule weight, but bean nodules were smaller and more numerous and evolved more hydrogen (Relative energetic efficiency was 0.5 to 0.7 in bean, 0.95 in cowpea and soybean). Relative N accumulation was influenced by N accumulation characteristics of the fertilized plants as well as the symbiotic plants. The vegetative N-fixation period of early maturing beans was shorter than for cowpeas of similar maturation date; the beans flowered earlier and had a longer pod-filling period. There was no evidence that the common bean symbiosis was more sensitive than the others to competition from native rhizobia. With mixed populations of effective rhizobia, hydrogen evolution in otherPhaseolus species (P. acutifolius, P. coccineus, P. filiformis, P. lunatus) was similar to that inP. vulgaris and higher than in cowpea or soybean. Although failure to establish effective nodulation is often considered the reason for poor N-fixation by common bean in the field, the species may be genetically predisposed to poor fixation because of symbiotic inefficiency and the short vegetative fixation period.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02374821
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