Effects of flooding on the growth of cassava (Manihot esculenta Crantz) plants of different cultivars grown in greenhouse.

MEDINA, RICARDO; CHAVEZ, CÉSAR; SCHALLER, SILVIA; MIGNOLLI, FRANCESCO; VIDOZ, MARÍA LAURA

Congreso; XXXIV Reunión Argentina de Fisiología Vegetal; 2023

Cassava is an economically and nutritionally important crop for many developing countries. However, it is susceptible to abiotic stresses, including flooding. Due to an increase in the intensity and frequency of torrential rains, flooding events have become more critical. Despite this, there has been little research on the effect of flooding on cassava. This study aimed to evaluate the impact of flooding on the growth of two cassava cultivars in a greenhouse in Corrientes, Argentina, during two campaigns in 2021 and 2022. The cultivars used were CA145 and CM3306-4, maintained in the BGCTES germplasm bank (IBONE-CONICET-UNNE/FCA-UNNE). Plants were regenerated in vitro and then grown in a controlled growth chamber for four weeks before being moved to a greenhouse for 14 weeks. During this time, plants were partially flooded with water at 3 cm above the substrate level for 18 days, while control plants were irrigated at field capacity. The parameters evaluated were: stomatal conductance and chlorophyll fluorescence, dry weight of the aerial and root parts (including fibrous and tuberous roots), percentage of dry matter and loss of dry matter caused by flooding. Results were analysed with ANOVA and Duncan's multiple comparison test (p≤0.05). The study found no effect of the campaign or differences between the cultivars. However, significant differences were observed between treatments (control vs flooded plants). After 18 days of flooding, there was a significant decrease in stomatal conductance and chlorophyll fluorescence, and a significant reduction in shoot and root dry matter of about 60 and 80%. While the loss of aerial dry weight was due to growth arrest and leaf shedding, root biomass reduction was caused by tuberous roots emptying the storage parenchyma.