Cassava Genotypes Reaction and Climatic Peculiarities in Trial During Anthracnose Disease Development in Côte D'ivoire

Background and Objective: Distribution, incidence and severity of cassava anthracnose interact with environmental factors and threaten cassava cultivation in Côte d'Ivoire. Current study was aimed at analyzing physiological parameters of plants, climate variability and their interaction in response to cassava anthracnose disease during crop cycle. Materials and Methods: Study focused on the establishment of experimental plots during two agricultural season (2016-2018), according to Fisher block design with eight genotypes. Observations occurred at 1 and every 2 months after planting to assess incidence and severity. Temperature (EC), relative humidity and dew point data were collected. Data were analyzed with variance ANOVA (two way) of Statistica 7.1 software with p<0.05. Results: Cassava genotypes Bocou2 (improved) and Diarrassouba (local) were resistant and tolerant with means incidences 0 and 4.02% for means severity indexes of 0 and 0.5, respectively. All over 6 genotypes have been sensitive. Cassava genotypes phenological stages of tuberization (incidence = 14.70, severity index = 0.9) and maturation (incidence = 25.13%, severity index = 1.8) were most severely infested. Mean temperature, relative humidity and dew point variations of 8.4EC, 26% and 7.4EC, respectively, led to outbreak of first symptoms at tuberization stage. Rising temperatures and dew point levels are correlated to heavy infestation and severe deterioration of infected organs. Conclusion: Cassava genotypes behavior differs in response to anthracnose disease at tuberization and maturation stages. Physiological modifications occurred at tuberization stage conducted to infestations of sensitive genotypes. Rising temperature, relative humidity and dew point variations could support severe outbreak of cassava anthracnose disease.