In semi-arid Mediterranean areas, there is a growing interest in adopting conservation tillage practices for their advantages in improving soils fertility, reducing production costs, and stabilizing crop yields. The aim of this study conducted in the 2019 and 2020 seasons was to investigate the effect of three tillage systems—conventional tillage (CT), minimum tillage (MT), and no-tillage (NT)—on grain yield, yield components, and quality indices of a durum wheat crop (Triticum durum Desf. cv. Simeto) grown in monoculture in semi-arid conditions of Northern Algeria. Tillage systems had a significant effect on the average yield of the 2 years, with NT being 28% and 35% higher than CT and MT, respectively—a trend even more evident in the second year under observation. The superiority of NT (p < 0.001) in the second year (2020) is mainly due to the increased spikes density (318.93 spikes m2 under NT vs. 225.07 and 215.20 spikes m2 under MT and CT, respectively). Yield components and quality parameters were more affected by climatic conditions than by tillage treatments. The number of kernels per spike being the most affected by water and heat stresses occurred in 2020 season. A decrease of 51% is noted regardless of the tillage treatment, which negatively affected the grain yield in that year (1.9 vs. 1.3 t ha−1 in 2019 and 2020, respectively). This stress also induced an increase in grain protein content, but a reduction of its weight. The results of this study conducted in the early transition from conventional to conservation tillage show that durum wheat grown under NT results in higher grain yield than the other systems in the specific operative conditions of the study region, providing better seed emergence and better spikes density, especially in the dry years. Moreover, the quality parameters are more affected by weather conditions than by the tillage system—with an interaction year × tillage system significant only for the grain.

Six genotype of Triticum aestivum L. in 1991 and one genotype of Triticum durum Desf. and three of T. aestivum L. in 1992 were studied under different water regimes: full irrigation (R1), mild water stress (R3) and severe water stress (R2) at Magneraud (France). Traits evaluated were grain yield and its components, stress susceptibility index (SSI) and normalized difference vegetation index (NDVI). The analysis of variance revealed significant differences between regimes and among the cultivars for all traits except between regimes for thousand grains weight in 1991. The regime × variety interaction was significant for grain yield, thousand grains weight and NDVI in 1992 and for grain yield in 1991. For all traits, durum wheat (T. durum Desf.) has higher reduction in the two water stress than the common wheat (T. aestivum L.). Correlations studies revealed that grain yield, grains number/m², thousand grains weight and NDVI were associated with each other except for correlations between thousand grains weight on one hand and grain yield (1992) and grains number/m² (1991) on the other hand. 51.55, 27.88, 4.12% (1991) and 75, 43 and 20.2% (1992) of grain yield, grains/m² and thousand grains weight variability, respectively were explained by means NDVI variability. The grain yield and grains number/m² could be predicted using a single regression with NDVI.

hree field experiments (2008 to 2011) were conducted to evaluate the ability of winter wheat (Triticum durum Desf. var. Carioca) to utilize and acquire soil phosphorus and nitrogen under different sources of phosphate fertilizers (Fosfactyl, Single super phosphate and Mono-ammonium-phosphate) and rates of applications (30, 60, 90 and 120 kg Pha-1) with a fixed level of nitrogen fertilization. Results revealed a significant effect of P rates on phosphorus use efficiency (PUE) and nitrogen use efficiency (NUE); however, P sources fertilizer had non-significant effect in all three cropping seasons. PUE and NUE decreased markedly with increasing P supply that did not result in an improvement of P and N uptake. Grain protein content was significantly influenced by phosphorus fertilization in 2008-09. The best values were obtained by Single super phosphate and P rate 60 kg ha-1.

This study focuses on the genetic potential and genotypic stability of 17 durum wheat genotypes during three crop years under wet conditions in the north of Algeria (Algiers). The results showed highly significant (P<0.001) agro-morphological diversity between the genotypes and a genotype × environment interaction for all the traits except for fertile spikelet number. Wricke's ecovalance (w i ), Shukla's stability variance (σ i 2 ), heterogeneity variance (%HV) and the incomplete correlation (%IC) method were used to analyse the genotype × environment interaction on grain yield. The genotypes Ardente/Waha L2, Ardente and Saadi/Simeto L3 exhibited great instability with the highest values of w i , σ i 2 , %HV and %IC. Ardente/Waha L1, Simeto/Vitron L5, Simeto and Ardente/Vitron L1 had the highest grain yield and average stability (w i , %HV and %IC were weak). Significant correlations were found between %HV, R ij 2 , b i , w i , σ i 2 and %IC, implying that they were similarly efficient in detecting stable genotypes and in measuring stability.

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