The present study was conducted to evaluate the influence of gibberellic acid (25, 50, 100, and 200 ppm) applied on saffron corms previously harvested during different periods (March, June, and before planting) on the growth and the quantitative and qualitative yield of saffron (Crocus sativus L.). The study was carried out in the field during the 2016-2017 and 2017-2018 seasons in the experimental station of the Faculty of Sciences of Oujda (Morocco). The measured parameters correspond, on the one hand, to morphometric measurements and to the determination of the saffron stigma yield and, on the other hand, to the evaluation of the quality of the spice. The results showed that almost all the parameters studied were significantly affected by the factors considered. The treatment of corms just before planting with concentrations of 100 and 200 ppm GA3 showed the highest flower and leaf appearance rate and the highest leaf length and surface area. Moreover, the application of GA3 during the month of March gave the best results in terms of stigmata yield, percentage of large-diameter daughter corms, and the ratio of the number of flowers produced to the total weight of corms. The results of the coefficient of corm propagation revealed that the application of gibberellin during any period improved this coefficient compared to the control. The results indicated that the application of GA3 with concentrations above 25 ppm can improve the growth of saffron and increase its yield under the semiarid climatic conditions of eastern Morocco.

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Saffron (Crocus sativus L.) is cultivated in many countries for its culinary and medicinal values. The production of saffron is limited by several factors, including weed infestation, which causes damage to the crop in terms of quantity and quality. However, little information is available on the different weed management strategies for saffron cultivation, as most of the strategies implemented are developed for large-scale and conventional agriculture. As a result, they are not applicable or affordable for organic or smallholder farmers, as is the case for saffron cultivation. The objective of this study is to compare the effectiveness of plastic mulching versus mulching in controlling weeds in saffron cultivation in the eastern region of Morocco. During the trial, which was conducted in 2018, the parameters measured correspond, on the one hand, to morphometric measurements and determination of saffron stigma yield and, on the other hand, to the determination of density, dry biomass, and weed control capacity. Compared to the control, mulching reduced the population and dry biomass of the most formidable weeds such as Cynodon dactylon, Aster squamatus, Cyperus rotundus, and Convolvulus arvensis. The average stigmata yield from plastic mulch treatment was 9% higher than of the control, and the number of leaves, leaf area, number, weight, and percentage of daughter corms with large diameter were higher for plants grown under mulch. Overall, the results of this study showed that the use of PE (polyethylene) mulch effectively reduced weed populations and improved saffron yield and vegetative growth.

Saffron (Crocus sativus) has been an important medicinal plant since ancient times. This study aimed to seek the optimal light intensity for saffron growth by quantifying the effects of different shade levels on yield, vegetative growth, and weed development in the eastern region of Morocco. The plants were grown for 24 months in full sun (control) and 30%, 50%, and 70% shade. Overall, the results showed that shade positively affected the yield and vegetative growth parameters of saffron plants, with the highest yield (0.61 g/m2) and number of leaves (105 leaves/tuft) recorded when the plants were exposed to light shade (30%). The color of the leaves under the 70% shade levels was dark green. The results from the underground part showed that shade is positively correlated with the weight and diameter of daughter corms where the 70% shade recorded the highest values of weight (65 g) and percentage of large diameter corms (39%). As for weed density, this parameter was significantly affected by shade. The lowest weed density was recorded for the 70% shade treatment. In conclusion, 30% shade is suggested as optimal light irradiation for saffron cultivation.

Among all environmental factors, the temperature is considered one of the key elements that control the growth and development of saffron. This study was undertaken to investigate the effect of thermal forcing of corms on saffron growth and development. To this end, mother corms were collected at four different periods: late March (T2) , mid-April (T3) , late April (T4), and after leaf senescence (Control, T1) . The corms of each period were then pretreated at three successive temperature levels: at 25 °C for 2 weeks, at 15 °C for 2 weeks and finally at 4 °C for 12 weeks. The results showed that the thermal pretreatment of corms had a significant effect on some saffron parameters. The flowers of the corms that underwent thermal treatment were later than those of the control. Similarly, the flower numbers and stigma yield were negatively affected by thermal forcing of corms. Overall, the thermal forcing of corms under the proposed regime was unfavorable for the growth and development of saffron.