PHYTOTOXIC POTENTIAL OF Ipomoea batatas EXTRACT , DETECTED THROUGH A NEW TYPE OF SANDWICH MICROBIOASSAY ON THREE SPECIES OF WEEDSABSTRACT
Nowadays, it is very important for researchers to find alternatives that enable the development of a profitable agriculture and a clean environment, therefore, the strategy evaluated in the present study is geared towards the use of the allelopathic effect of many plants. The main objective was to assess the efficiency of a compound derived from extracts of sweet potato (Ipomoea batatas on three weed species under controlled conditions. Different concentrations (1, 5, 10% w/v) were evaluated through a sandwich-type microbioassay in comparison with the traditional Petri dished culture technique. Both tests demonstrated the phytotoxic activity of aqueous extracts of I. batatas, which caused inhibition of germination of A. hybridus, P. oleracea and B. campestri. It was observed that use of the microbioassay allowed the optimization of resources used for analysis, required much less amounts of extracts and facilitated the analysis of a larger number of samples per unit of time. This offers a new economic and efficient alternative to quickly assess the phytotoxic effect of many donors’ species before field tests.
Keywords: allelopathy; sweet potato; residues; A. hybridus; P. oleracea; B. campestri.
Below (A) the control treatment (water), where A. hybridus optimal germination and growth are observed. Above (B) a sample with the treatment using the I. batatas extract at 10%, where inhibition of seed germination is observed.
Note the lower number of seeds treated and the ample space required for incubation per plate. Under the same conditions tested with the microbioassay, 96-well plates and the small space needed to evaluate and repeat about 200 seeds of different receptor species.