With the increasing importance of soilborne plant pest nematodes and the relatively recent phase-out of methyl bromide as a key soil fumigant, there is an urgent need for new fumigants with good nematicidal properties. Ethanedinitrile (EDN) is a promising fumigant and preparation because of its physical, agrochemical, and nematicidal properties. However, its efficacy against nematode pests of different crops under field conditions has not been fully validated and understood. Therefore, the aim of our study was to evaluate the effect of two concentrations of EDN on the survival of northern root-knot nematodes (Meloidogynehapla) and on carrot yield and quality under field conditions. The evaluation was performed using naturally infested carrot plots, and EDN application to the soil was followed by covering the treated area with film. A high biological effect was observed for both EDN concentrations tested, with even the lower dose (30 g·m⁻²) being sufficient for M. hapla suppression. Positive effects of EDN application—likely due to EDN partial conversion into biologically available nitrogen in soil—on carrot root weight, in comparison with the untreated control, were also observed.

At a global scale, the sustainability of forests is endangered by multiple invasive species, including the pine wood nematode (Bursaphelenchus xylophilus), a quarantine pest. International laws and standards require that all exported wood coming from countries in which B. xylophilus is present be chemically or physically treated. Since a major fumigant, methyl bromide, was banned, there has been a need to generate data for alternative fumigants, such as ethanedinitrile (EDN), for this purpose. Since the field screening of fumigants (i.e., the application of various doses to and exposure times of naturally infested wood logs) is prohibitively expensive, the aim of this study was to develop a quick and inexpensive laboratory method. Here, we suggest and describe an innovative method based on sawdust cultures for EDN efficacy screening. In the validation part of this study, we demonstrated (i) the high survival of the nematodes in the sawdust and (ii) the high efficacy of EDN against this pest under in vitro conditions; 100% mortality was observed after 6 h of EDN exposure to a dose of 25 g/m³. In particular, our newly developed model system could be used for the initial screening of various doses of and exposure protocols for EDN and similar types of fumigants developed with the intention of regulating B. xylophilus occurrence in exported wood. It is believed that the validated method may help to develop new and effective EDN fumigation procedures and thereby contribute to the long-term protection of forests worldwide.

Recently, the largest bark beetle calamity (Ips typographus) of the last 100 years has erupted in Central Europe, including the Czech Republic. This calamity may threaten the sustainability of growing large areas of monoculture Norway spruce (Picea abies) in this area. Limited economically feasible physical and chemical pest control options are available to prevent the bark beetle spread. However, from these options, only mechanical bark removal or gas-insecticide fumigation result in instant deactivation of all pest stages throughout the entire stack of stored logs. Due to the ban on the use of methyl bromide (MeBr) for the fumigation of log piles under tarpaulin, the adaptation of the phyto-quarantine method EDN to the destruction of I. typographus bark beetles in harvested wood directly in forests was newly proposed in the Czech Republic. The methodical experience with fumigation of the harvested logs, however, was only available for wood fumigation in chambers or in tent-tarps fumigation placed on paved (concrete/asphalt) surfaces mainly in ship harbors. Prior to the introduction of the new EDN fumigation method of bark beetle infested wood stored directly in the forests, it was initially unclear whether it was necessary to use or neglect bottom sheets to optimize exposure and maximize Ct products for the permitted fixed initial dose (50 g·m⁻³). Therefore, the initial validation pilot trials were aimed at the estimation and comparison of EDN temporal dynamics and Ct products under real forest conditions and two fumigation scenarios: Wooden log pile placed on bottom plastic sheets or directly on soil without the bottom sheets. Field trials were performed under both identical as well as different environmental conditions. In addition, they revealed that the concentration decrease was significantly faster and Ct products were significantly lower in the case of trials without the bottom sheets. The experiments indicated high EDN sorption by the uncovered soil under the tent. Quantitatively, the average Ct product was 4.8 (identical conditions) and 3.7 (different conditions) times lower in EDN trials without the bottom sheets when compared to the use of bottom sheets. The initial field-forest fumigation validation trials indicated a necessity to carry out EDN fumigation under tent-tarps also using bottom sheets, although this fumigation procedure increases the labor-demands to some extent. Based on the presented results and additional data, the Czech authority issued for the EDN plant protection product an authorization for the limited and controlled use of wooden logs. Therefore, this work became the basis of the historically and first officially authorized use of any fumigant for pest control under commercial forest conditions.

Clubroot, caused by Plasmodiophora brassicae Woronin, is one of the most challenging diseases to control in oilseed rape (Brassica napus L.) and other crucifers globally. Ethanedinitrile (EDN) is a promising fumigant shown to be effective against various pests and soil-borne pathogens. However, its efficacy against P. brassicae is yet to be tested. Therefore, the current study is focused on evaluating the effectiveness of EDN against P. brassicae at different rates, applied for different durations of exposure. Clubroot-susceptible oilseed rape plants, grown in fumigated soil, were evaluated for disease severity and growth parameters in greenhouse conditions. EDN exhibited good efficacy against the pathogen, with 81.39% disease suppression compared to the control. Complete control of the disease was achieved at the rates of 42 g/m³ and 50 g/m³ as well as in the treatment variant of 35 g/m³-48 h. In addition, EDN improved plant health by increasing shoot weight by 58.24%. However, the combination of a prolonged fumigation period and higher rates resulted in a decline in the seedling emergence rate and plant shoot weight, indicating a potential adverse residual effect of higher rates and longer durations of exposure in plants.