Abstract:
The objective of this research was to develop a product of anti-ripening rice husk ashes mixed with clove powder, for inhibitory property against fungi that caused stem rot in Hom Thong bananas. Pathogenic fungi were isolated from infected stem of Hom Thong banana using tissue transplanting. Their morphological characteristics were studied by using slide culture techniques. It was found that fungi causing stem rot in Hom Thong bananas were three isolates of Fusarium sp., one isolate of Colletotrichum sp. and one isolate of Lasiodiplodia sp. Six pellets mixture of anti-ripening rice husk ashes and cloves powder were formulated at ratios of 50:50, 60:40, 70:30, 80:20, 90:10 and 100:0 (w/w). Physical properties and microbial populations of the pellets were evaluated. The formulated products were tested for their inhibitory effects on fungal growth using disc diffusion technique. The 50:50 and 60:40 formulations were the most effective in inhibiting the growth of fungal pathogens causing stem rot disease, with 100% inhibition of Colletotrichum sp. isolate 2 and Fusarium sp. isolate 5 hyphal growth. Fusarium sp. isolate 1 and Fusarium sp. isolate 4 were inhibited up-to 90%. However, Lasiodiplodia sp. isolate 3 was not effectively inhibited. When considering the physical characteristics of the pellet mixture of anti-ripening rice husk ashes and cloves powder, the 50:50 and 60:40 formulations exhibited high hardness, with pellet hardness values of 7.27 kg/cm2 and 7.35 kg/cm2, respectively, and low friability with friability percentages of 0.27 and 0.28 respectively. Additionally, no microbial contamination was observed within these pellets.