The effect of biological agent and botanical fungicides on maize downy mildew

Abstract. Prasetyo J, Ginting C, Akin HM, Suharjo R, Niswati A, Afandi A, Adiwijaya R, Sudiono, Nurdin M. 2021. The effect of biological agent and botanical fungicides on maize downy mildew. Biodiversitas 22: 1652-1657. This study was conducted to evaluate the effect of the combination of Trichoderma asperellum and mycorrhizae with botanical fungicides made from betel leaf extract or turmeric extract against maize downy mildew. The study used a randomized complete block (RCB) design with three replications. The treatments applied were: single applications of T. asperellum (Ta); arbuscular mycorrhizal fungi (AMF); turmeric extract (T); betel extract (B); the combination of T. asperellum and AMF (TaM); turmeric extract and T. asperellum (TTa); turmeric extract and AMF (TM); turmeric extract + T. asperellum + AMF (TTaM); betel extract + T. asperellum (BTa); betel extract + AMF (BM); betel + T. asperellum + AMF (BTaM); and Control (C). The observed variables were disease incidence, incubation period, and shoot dry weight. The data were analyzed using ANOVA. Differences between treatments were tested by the LSD test at 5% significance level. The results showed that the combination of botanical fungicides with biological agents could reduce the incidence of downy mildew, extend the incubation period, and increase the dry weight of corn shoots. The best combination treatment was achieved from the combination of T. asperellum with betel extract. There was a synergistic effect between botanical fungicides and biological agents in reducing the disease incidence.

Diversity of Fungi on Decomposing Leaf Litter in a Sugarcane Plantation and Their Response to Tillage Practice and Bagasse Mulching: Implications for Management Effects on Litter Decomposition

To minimize the degradation of soil organic matter (SOM) content in conventional sugarcane cropping, it is important to understand how the fungal community contributes to SOM dynamics during the decomposition of sugarcane leaf litter. However, our knowledge of fungal diversity in tropical agroecosystems is currently limited. Thus, we determined the fungal community structure on decomposing sugarcane leaf litter and their response to different soil management systems using the internal transcribed spacer region 1 (ITS1) amplicon sequencing method afforded by Ion Torrent Personal Genome Machine (PGM). The results indicate that no-tillage had positive effects on the relative abundance of Zygomycota and of some taxa that may prefer a moist environment over conventional tillage, whereas bagasse mulching decreased the richness of operational taxonomic units (OTUs) and had positive effect on the relative abundance of slow-growing taxa, which may prefer poor nutrient substrates. Furthermore, a combination of no-tillage and bagasse mulching increased the abundance of unique OTUs. We suggest that the alteration of fungal communities through the changes in soil management practices produces an effect on litter decomposition.