Root behavior in two cowpea varieties during water stress (Poster VIII 16)

Nwalozie M.C., Cissé Ndiaga, Khalfaoui Jean-Luc, Annerose Daniel. 1995. Root behavior in two cowpea varieties during water stress (Poster VIII 16). In : Interdrought = [Intersécheresse]. Belhassen E., Schlicht F., Cuellar T., Lewicki S. Montpellier : INRA, Résumé, 1 p. InterDrought I. 1, Montpellier, France, 31 Août 1995/2 Septembre 1995.

Autre titre : Comportement des racines pendant le stress hydrique chez deux variétés de niébé

Résumé : Deux variétés de niébé sont cultivées en milieu contrôlé (rhizotron) pour étudier le comportement racinaire en conditions de sécheresse du sol. Les racines s'enfoncent jusqu'à 80 cm de profondeur alors que les racines de plantes irriguées ne dépassent pas 55 cm de profondeur. La distribution des racines dans l'horizon superficiel est plus faible pour les plantes cultivées en sol desséché que pour les plantes irriguées. Cependant, la présence de racines plus profondes en sol desséché ne compense pas suffisamment les besoins en eau des plantes car la biomasse aérienne est significativement réduite par rapport aux conditions de sol humide

Résumé (autre langue) : Two cowpea (Vigna unguiculata) cultivars, IT84S2246-4 and B89-504, were raised in minirhizotron tubes to study their rooting behavior in soil drying conditions in a glasshouse (temperature was 35C ± 4C, day; and 19C ± 2.5C, night, humidity was 40% ± 3% at 1500 hours and 72% ± 1 % at 0300 hours; and natural daylight). In situ root growth and distribution were studied from commencement of soil drying treatment, 10 days after sowing (DAS), to the end of the experiment, 31 DAS. Roots penetrated to 60 to 80 cm depth in drying soil profile, whereas the roots of plants grown in well irrigated soil did not penetrate beyond 40 to 55 cm of the soil profile. The distribution of roots in upper section of the drying soil profile was restricted, whereas deeper penetration of roots prevailed resulting in a higher depletion of soil moisture at such depths by day 31. On the other hand, proliferation of roots near the surface of moist soil was significantly (P S 0.01) higher than in drying soil. In spite of the significantly greater depths penetrated by roots in drynig soil, there was no significant difference in volume mass and dry weight between roots in drying and wet soils. The above ground biomass, measured at end of the experiment, was, however, significantly reduced in plants grown in drying soil. The deeper distribution of roots in drying soil profile did not sufficiently balance water uptake so as to off-set the detrimental effects of drought to the above ground biomass.

Mots-clés Agrovoc : Vigna unguiculata, sécheresse, adaptation, enracinement, profondeur, biomasse

Mots-clés géographiques Agrovoc : Sénégal

Classification Agris : F60 - Physiologie et biochimie végétale

Auteurs et affiliations

• Nwalozie M.C.
• Cissé Ndiaga
• Khalfaoui Jean-Luc
• Annerose Daniel

Source : Cirad - Agritrop (https://agritrop.cirad.fr/387710/)

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