Evaluation of bicarbonates for the control of colletotrichum gloeosporioides of mango plant

The mango plant suffers from several diseases at all stages of its life. The most important is anthracnose disease caused by Colletotrichum gloeosporioides Penz. The use of fungicides has been increasingly restricted due to public concerns of the accumulation of toxic compounds potentially hazardous to humans and the environment. This in fact has forced producers to evaluate safer alternatives for controlling diseases in the context of sustainable agriculture. Thus, an inorganic solution to this problem is studied. In recent years, there is a broad range of products based on bicarbonates. As reported by the United States Environmental Protection Agency; sodium bicarbonate (SBC),potassium bicarbonate (PBC) and ammonium bicarbonate (ABC) are considered harmless from ecotoxicological and toxicological point of view. The three bicarbonate salts were examined for their effect against C. gloeosporioides. Mycelium growth and percent growth inhibition of C. gloeosporioides is seen to vary among the treatments used at different concentrations of 0.1, 0.2, 0.4, 0.8, 1.6 and 3.2% (w: v) for individual salt testing. Low growth was seen in ABC treatments. Where treatments ABC 0.4%, 0.8%, 1.6% and 3.2% was seen to have a growth performance of C. gloeosporioides at 0.90 cm each. This is due to the inoculation of C. gloeosporioides from the inoculation tool (cork borer) having a diameter of 0.90 cm. In reality, there was no growth recorded for these treatments. Whereas for SBCtreatments, all the concentrations used showed no significant difference, thus not having any success in controlling the pathogen, C. gloeosporioides. The best bicarbonate salt tested on its own, ABC 0.4% is set as the benchmark for testing on mixture of bicarbonate salt at a lower concentration. Mixture of PBC 0.8% + ABC 0.2% together gave significant results from growth and PGI data, with a growth of 0.9 cm and PGI of 90.98%. Thus, we conclude the best treatment to control C. gloeosporioides with the lowest concentration of bicarbonate salt according to PGI is a mixture of PBC 0.8% + ABC 0.2%.