Résumé
Rice is vital for food and livelihoods, but its cultivation can harm the environment and isn't accessible to all farmers. We conducted a study in Madagascar to see how mixing different types of rice in fields and their arrangement affects rice growth.During the 2021-2022 rainy season, we tested four rice types in two different sites with varying soil conditions. We compared plots with pure rice stands to those with mixed rice varieties in different proportions and arrangements. We measured grain and biomass yields, and how well the rice resisted certain pests and diseases.Plant Selection: Four upland rice varieties were chosen for the experiment based on their growing cycle and traits, including resistance to diseases. EARLY MUTANT IAC 165, FOFIFA 152 , FOFIFA 154 , and DOURADO PRECOCE .Plant Management: Both individual stands and mixtures were managed the same way. Seeds were planted in hills, and cattle manure and mineral fertilizers were added at planting. The crops relied on rainwater, and weeding was performed three times during the experiment.Plant Measurements: Throughout the experiment, data on striga infestation, Pyricularia oryzea, and Bacterial Leaf Blight (BLB) were recorded. For Pyricularia oryzea, both disease incidence and severity were assessed. Phenotypic characteristics of each variety were monitored, including vegetative phase duration, flowering time, plant height, and leaf and stem count. Harvesting involved separating grain and vegetative biomass, and dry weights were determined through drying samples.