Effect of Water Quality on the Germination of Okra (Abelmoschus esculentus) Seeds

Abstract

Okra (Abelmoschus esculentus), a fruit vegetable consumed in several countries, especially in Africa, contributes to the fight against poverty and malnutrition due to its nutritional value. However, in Burkina Faso, its cultivation during the dry season that lasts about 9 months remains dependent on the availability of water resources. Thus, during this period that lasts about 9 months, because of this situation, okra producers are dealing with very diversified sources of water. However, the rehydration of seeds, which is the first step towards germination, depends mainly of the water. Therefore, the aim of the present study was to test the germinability of okra seeds under different irrigation waters in order to propose alternative sources. Thus, seeds of three ecotypes of okra (B2, G259, and L2) were germinated using five water types (dam water, wastewater from the sewage treatment plant (WTP), well water, dishwashing greywater, and distilled water). The results showed a significant influence of the water type on the germination velocity and the growth speed of the radicle. Indeed, using wastewater from the WTP, the germination velocity was very significantly lower than those obtained with the other sources (P<0.0001). Furthermore, seeds irrigated with WTP wastewater germinated less than other water types. Nevertheless, the germination rate obtained with dishwashing greywater (86.93 ± 0.14%), which is not used generally in agricultural production, is comparable to the rates obtained with other water types. Furthermore, the study showed a significant effect of the ecotype on the germination rate (P≤0.001). In addition, dam water significantly enhanced root growth compared to WTP (P<0.0001). In view of the results and because of water scarcity in Sahelian regions, dishwashing greywater, which is generally discarded, could be collected and used for the germination of okra.