Ondřej Douda

First report about the trapping activity of Stropharia rugosoannulata acanthocytes for Northern Root Knot Nematode

This study summarises the results of in vitro screening of the nematophagous activity of Stropharia rugosoannulata and Arthrobotrys oligospora. The tests were conducted with Meloidogyne hapla plant parasitic nematode juveniles placed into Petri dishes containing cultures of the tested fungal species. Immobilisation of the nematodes was observed after 4 and 24 hours. Both species of fungi showed nematophagous activity, however it was much stronger and faster in the case of S. rugosoannulata.

Alternative methods of carrot (Daucus carota) protection against the northern root knot nematode (Meloidogyne hapla)

Abstract The presence of northern root knot nematode (Meloidogyne hapla) has considerably increased in the Czech Republic during the last 10 years. The management of this pest is difficult; thus, the aim of this study was to test two alternative pest management techniques on carrots under field conditions. When Indian mustard (Brassica juncea) was ploughed and the treated area was then covered with polyethylene sheets to prolong effect of the treatment, the root gall numbers decreased; whereas a nitrolime application combined with plastic covering had a positive effect on the experimental plants’ fresh weight.

Molecular and morphological exploration of a mixed population of two potato-parasiting nematode species, Globodera rostochiensis and G. pallida

SummaryIn this work, we report results of molecular and morphological analyses of a potato field population of Globodera (Nematoda: Heteroderidae) species, in Slovakia. Unexpectedly, our data show a mixed occurrence of two potato cyst nematode species, Globodera rostochiensis and G. pallida, in this locality. To our knowledge, this is the first report of mixed occurrence of these economically important plant-parasitic species in the same locality in the Central Europe. In addition, this finding reinforces the possibility of the cross-hybridization between these two nematode species that might result in a generation of new genotypes.

Insecticidal activity of two formulations of essential oils against the cereal leaf beetle

ABSTRACT Purpose: Plant-derived essential oils and their encapsulations have recently received increasing interest as an alternative to synthetic biopesticides suitable for integrated pest management and organic farming. In this study, combinations of essential oils (EO) from Rosmarinus officinalis with Cymbopogon citratus and Pelargonium graveolens with Thymus vulgaris in two formulations including encapsulate were tested for their potential for wheat protection against adults and larvae of Oulema melanopus (L.). Materials and methods: The chemical composition of the essential oils was analyzed by gas chromatography-mass spectrometry (GC-MS). Testing of insecticidal activity of the evaluated substances was conducted with 2.5 ml of tested combinations of EOs sprayed on the paper. Ten adults or larvae of O. melanopus were placed into a vessel. Control of mortality of O. melanopus specimens was assessed after 24 h after establishment of the experiment. Results and conclusions: Tarsal contact toxicity assay showed the effectiveness of EO in concentration against O. melanopus larvae and adults in both formulations (essential oil and encapsulation) causing 100% mortality within 24 h. These results indicate the great potential of these essential oils and their encapsulations for future use in crop protection against insect pests.

Using of hydrogen cyanide against Ditylenchus dipsaci nematode present on garlic

The stem and bulb nematode (Ditylenchus dipsaci) is a serious quarantine pest of vegetables spreading worldwide via seed and planting material. Currently, a hot water technique is used as the pre-seed treatment, which is difficult to execute and the risk of seed damage is high. The objectives of this study were to evaluate the (a) penetration of gaseous hydrogen cyanide (HCN) into garlic tissue; (b) HCN phytotoxicity, and (c) nematicide potential of HCN against D. dipsaci. Penetration of HCN into the core of the garlic clove was approximately 30% of the concentration inside the fumigation chamber after 30 h of exposure. Decreased emergency was observed only in the exposure treatment lasting 16 and more hours. Garlic cloves naturally infested by D. dipsaci were treated with HCN at a concentration of 20 g/m3 for 12, 18 and 24 h in a fumigation chamber, and 99% mortality was achieved in all three exposure times.