A. Abdelguerfi

Autoécologie et distribution du complexe d'espèces Scorpiurus muricatus (S. sulcatus - S. subvillosus) en Algérie

Abstract Scorpiurus sulcatus and Scorpiurus subvillosus (Fabaceae) are relatively rather frequent in Algeria. This has allowed us to study their ecology which, generally, were masked in the general studies involving other Scorpiurus species. Their distribution showed ecological differences and specificities: S. sulcatus which is mediterranean and has frequently a wide dispersion on heavy and salt soils and its climatic requirements are less strict than those of S. subvillosus. in addition, the mixed sites including both taxons are ecologically very close to those with S. subvillosus. It also results from this that the geographical distribution of S. subvillosus is limited to the north-east of Algeria, under a sub-humid and humid bioclimate, on poor soils in limestone on averages at low altitudes.

Measuring the performance of perennial alfalfa with drought tolerance indices

3 CHILEAN JOURNAL OF AGRICULTURAL RESEARCH 76(1) JANUARY-MARCH 2016 3 ULY-SEPTEMBER Drought is one of the abiotic stresses that reduces agricultural production in the Mediterranean basin. The selection of crop varieties with performance adapted to water stress has been the subject of numerous studies. In this context, 16 alfalfa (Medicago sativa L.) cultivars from different origins (Algeria, Australia, France, Italy, Morocco, Tunisia, and the United States) were studied under two water regimes (irrigated and rainfed) in the Lower-Cheliff plain of Algeria. The trials focused on the performance of these cultivars according to eight drought tolerance indices. To achieve this, DM yields and water use efficiency (WUE) of a 2-yr experimental study were used. Results showed a regression in mean yields from the third to the fourth year with stress indices of 0.29 and 0.88, respectively. The study of correlations showed that DM yields were well correlated to mean production (MP) and the stress tolerance index (STI). For the two trials and based on yield and STI index, ‘Mamuntanas’, ‘Ameristand 801S’, ‘Erfoud 1’ and ‘Ecotipo siciliano’ had the best performance. However, ‘Coussouls’, ‘Magali’, ‘Prosementi’, ‘Africaine’, and ‘Gabès-2355’ performed poorly. Discriminant function analysis showed that the variables that discriminated in the cultivar groups for yield in the irrigated trial were modified STI, WUE, and the superiority index (Pi). The ANOVA test of cumulative yield and the regression rate confirmed that under environmental conditions similar to the LowerCheliff plain, ‘Mamuntanas’, ‘Ameristand 801S’, ‘Erfoud 1’, and ‘Ecotipo siciliano’ were perennial and performed under irrigated conditions while ‘Erfoud 1’ performed in the rainfed trial.

Autoécologie et distribution du complexe d'espèces Medicago ciliaris-M. intertexta en Algérie

Abstract M. ciliaris and M. intertexta taxons are relatively rather frequent in Algeria. This has allowed us to study their ecology which, generally, was masked in the general studies involving other Medicago species. Their distribution showed ecological differences and specificities: M. ciliaris, frequently on heavy and salt soils, has a wider dispersion and its climatic requirements are less strict than those of M. intertexta. In addition, the mixed sites including both taxons are ecologically very close to those with M. intertexta. It also results from this that the geographical distribution of M. intertexta is limited to the North-East of Algeria, under a sub-humid and humid bioclimate, on soils low in calcium and in altitudes below 250 m in mean.