Managing White Mold on Common Bean with Type III Growth Habit by Integrating Partial Resistance, Plant Density, and Fungicide

Abstract

The combination of plant density, fungicide, and levels of genotype resistance to white mold (WM) has not been studied for the role played in affecting performance of common bean with type III growth habit under WM pressure. We established four sprinkler-irrigated trials in the fall-winter season in Brazil, combining density (8, 14, 20 or 26 plants/m2), genotype (susceptible or partially resistant to WM), and fungicide to manage WM (two fluazinam applications or without fluazinam) at 0.5 m row spacing in fields infested with sclerotia. One trial was established in a warm region, aiming to obtain low WM pressure. For three trials, the linear mixed model was used. WM pressure in the trials ranged from low to high. Genotype × density × fungicide and genotype × density interactions were not significant for incidence, severity, and yield for all trials. In the three trials, severity was 29% lower at 8 than at 26 plants/m2, and yield at 14 plants/m2 (3,294 kg/ha) was 14% higher than yield at 8 plants/m2 (P = 0.035) where fluazinam was applied. However, without fluazinam, density did not affect yield. In conclusion, plant density for type III bean cultivars does not need to take into account their resistance levels to WM in the fall-winter season. However, fungicide treatment to manage WM affects the decision on density, with 8 to 12 plants/m2 recommended if fungicide is not an option to manage WM (as in organic systems), and 10 to 14 plants/m2 recommended if fungicide applications are likely.

Investigating the effects of seed treatments on the economically optimal seeding rate of conventional soybean in Atlantic Canada

“…Further, this study did not consider additional production costs such as crop fertility requirements or in-season pesticide applications. While many of these costs tend to be fixed, higher plant density may increase disease pressure (Vieira et al 2022) increasing inputs and change the impact of costs on producer return supporting further reductions to the EOSR. Therefore, the estimated EOSR in this study should be considered a starting point for decision-making.…”

Characterization of fungal pathogens and germplasm screening for disease resistance in the main production area of the common bean in Argentina

“…The integrated management of the disease includes the use of resistant or tolerant cultivars, cultural practices, fungicide applications during the flowering stage, upright growth habit plants, wide row spacing in combination with low plant density (Vieira et al, 2012(Vieira et al, , 2022, and biological control by different antagonistic fungi, bacteria and organic amendments, which has been recently reviewed by Smolińska and Kowalska (2018). Regarding biological control, different native strains of the genus Bacillus with the potential to control WM on bean seeds and seedlings in NWA, was reported by Sabaté et al (2018).…”

Antimycotic Potential Assessment of Trichoderma Species and Fungicides for Sustainable Management of Sclerotinia trifoliorum causing Stem and Crown Rot of Trifolium alexandrinum L.

“…Wakil and Ghonim, 2000;Helmy et al, 2001;Mueller et al, 2002;Shaat and El-Argawy, 2011). Use of fungicides and biocontrol agents (especially Trichoderma species) significantly inhibited the disease Sclerotinia stem rot of soybean caused by S. sclerotiorum (Sumida et al, 2015), fluazinam inhibited 100% of the S. sclerotiorum followed by thiophanate-methyl (Costa and da Silva Costa, 2004), fluazinam and procymidone inhibited the S. sclerotiorum in common bean (Vieira et al, 2012;Reis et al, 2010), different fungicides have a different mechanism of action to inhibit the pathogen like procymidone retard the spore germination of S. sclerotiorum (Picinini and Goulart, 2002). Application time of fungicide is a critical factor that reduces the disease incidence and increases the yield (Mueller et al, 2004).…”

“…Thiophanate methyl, Fluazinam, and procymidone proved effective against the white mold of common beans caused by S. sclerotiorum (Lehner et al, 2015). Fluazinam is a fungicide that could control the diseases caused by Sclerotinia species (Lemay et al, 2002;Matheron and Porchas, 2004;Vieira et al, 2012;Mahoney et al, 2014) harzianum and its culture filtrates at 1/10 dilution reduced the disease severity to 51.7% compared to untreated/control 73.5%. Green and dry fodder weight significantly increased by the application of T. harzianum.…”