Retraction: Montiel-Rozas et al. Effect of Plant Extracts and Metam Sodium on the Soilborne Fungal Pathogens, Meloidogyne spp., and Soil Microbial Community. Agronomy 2020, 10, 513

Following publication [...]

Effect of Plant Extracts and Metam Sodium on the Soilborne Fungal Pathogens, Meloidogyne spp., and Soil Microbial Community

In this field study, the fungicidal and nematicidal activity of two plant extracts (Larrea spp. (LR), Liquidambar spp. (LQ)), and an organosulfur soil fungicide metam sodium alone (MS), and a mix of LR and MS (LR + MS) was assayed under pepper cropping in southeastern Spain. Metam sodium treatments (MS and LR + MS) produced the highest crop yields and were more effective in controlling root-knot nematodes and fungal pathogens (Fusarium, Pythium, and Rhizoctonia solani) than the plant extracts treatments (LQ and LR). Furthermore, the effect of the metam sodium treatments applied negatively affected the soil microbial community, principally bacteria, but not fungi. These microbial community changes of the soil were principally observed after treatment application; the differences between the treatments were reduced at the end of the experiment, when recovery of the soil microbiota communities occurred.

Effects of Pesticides on Nitrous Oxide Production in Sugarcane Cropping Soil

This study aimed to assess the non-target impacts of pesticides on soil biological processes, particularly N2O emissions and improve understanding of the contributions of nitrification and denitrification to N2O production in sugarcane soils. We conducted a laboratory incubation experiment, in which a herbicide Roundup®, an insecticide Confidor®, a fungicide Shirtan®, and a fumigant metam sodium were added to a Ferrosol and then incubated at 25°C for 38 days at 2 moisture regimes (55 % and 90% water holding capacity (WHC)). At day 28, soil water contents in the 55% WHC treatments were also increased to 90% WHC to create a condition to favour denitrification. The 55% and 90% WHC treatments received NH4SO4 at 40µg N g−1 dry soil and KNO3 at 40µg N g−1 dry soil, respectively, with K15NO3 added at 2 µg N g−1 of dry soil in all treatments. Compared with the control treatment, Confidor application significantly increased net nitrification rates and N2O emissions at 55% WHC. After increasing water content from 55% to 90% WHC at day 28, net denitrification occurred in the metam sodium treatment; N2O emissions increased in the order: metam sodium > Shirtan > Glyphosate treatment, with little changes in the Confidor and control treatments. During the 38-day incubation at 90% WHC, the metam sodium treatment emitted more N2O emissions than other treatments in the first 15 days of the incubation but no significant differences were observed among the other treatments at the end of the incubation.

Characterization of Fusarium solani Populations Associated with Spanish Strawberry Crops

Fusarium solani is an emerging pathogen reported on Spanish strawberry crops both in nurseries and in fruit production fields, causing wilt and root rot. Pathogenicity, morphocultural characteristics, and sensitivity to biocides of 103 F. solani isolates recovered from symptomatic strawberry plants and soils from both Spanish strawberry areas were determined. The differences of isolates within and between nurseries and field crops in relation to these parameters were analyzed. Considerable variability in morphological and pathogenic characteristics was observed among the isolates in both areas. The majority of isolates were not pathogenic (62%), and only 38 F. solani isolates (37.62%) caused disease on strawberry plants under controlled conditions; 52.63% of pathogenic isolates induced low severity symptoms. Almost 70% of pathogenic isolates caused stunting on plants. The morphological characters that best explain the F. solani variability (86.85%) were colony color and the presence of macroconidia on culture medium. The sensitivity to the fumigants tested was similar between the isolates from nurseries and fruit production fields, showing greater sensitivity to the field doses of dazomet and chloropicrin. However, the isolates were less sensitive to metam sodium and poorly sensitive to 1,3-dichloropropene. This work can contribute to the advancement of sustainable production of strawberry.