Effect of chemical soil fumigant treatments on soil microorganism and nematode complex and yield of field cucumber
Field-grown cucumber is an economically important crop in Poland, cultivated mainly for the food processing industry. The study was aimed at evaluating chemical fumigation on plant growth, fruit set, yield, densities of plant-parasitic and non-parasitic nematodes, soil-borne fungi and bacteria (total number, fluorescent Pseudomonads, and Bacillus spp). On a commercial farm an experiment with soil fumigants (dazomet; 400 kg ha-1) metam sodium at (600 and 900 L ha-1) and 1,3-D + chloropicrin (350 and 500 L ha-1), applied in field-grown pickling-type cucumbers, had been conducted for two consecutive years. Each year the trials were performed in a new field. The treatments were randomized in a complete block design with three replicates. In the first year, none of the tested fumigants significantly reduced the number of parasitic nematodes, whereas in the second year of the trials all fumigation treatments significantly reduced the number of nematodes. However, the sizes of the populations of plant-parasitic nematodes in all treatments were below the economic threshold. In all treated plots the number of fluorescent Pseudomonads (acting as BCA) increased from 2- to 80-fold in comparison with non-treated plots. This outcome can be regarded as a positive effect of soil fumigation. Generally, the number of Bacillus spp. remained unchanged in the treated plots. Plant vigor was similar among fumigation treatments and always visibly better than the control. Symptoms of Fusarium crown and foot rot of cucumber (Fusarium solani f. sp. cucurbitae) were evident only in the untreated control, where up to 16% of plants were affected. The highest increase in cucumber yield was obtained after treatments with metam sodium at a rate of 600 L ha-1 by 71 and 84% in the first and second year, respectively, and with dazomet (63 and 59%). The results obtained indicate that the lower application rates of fumigants were generally as effective as higher ones.
Ślusarski, C., Chalańska, A., Uliński, Z., Sobiczewski, P. and Meszka, B. (2020). Effect of chemical soil fumigant treatments on soil microorganism and nematode complex and yield of field cucumber. Acta Hortic. 1270, 133-140
pickling cucumber, soil fumigation, soil-borne fungi, soil bacteria