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Abstract(s)
Composts may be used either in soilless cultivation or applied to soil,
increasing its organic matter content and improving the physical, chemical and
biological properties. This study evaluated the effects of compost application to the
soil cropped with carrot on nematodes diversity, biocontrol of phytopathogenic
nematodes and crop yield. A commercial compost (Organical®, TerraFértil,
Portugal) was applied to a sandy soil, at the rate of 0, 12.5, 25, 50 and 100 t ha-1 and
incorporated to a 15 cm depth. A carrot crop (Daucus carota L.) was sown with a
density of 62.5 plants m-2. At the end of the growing period, when the longer roots
had reached about 15 cm, plant growth and yield were quantified. Compost
increased carrot yield. Following harvest, soil samples were collected near the roots
(root zone) and randomly at three soil depths: 0 to 15 cm, at 30 cm and at 50 cm.
Nematodes species were identified and quantified in these four zones, and the
damages observed were ranked. Compost influenced nematode populations. Near
the roots beneficial nematode populations increased with the compost rate
application. Phytopathogenic nematodes were present mainly in the treatments
with less compost. Furthermore, nematode genera were distributed according to
soil depth. Bacteriophage/saprophyte nematodes were found mainly at 50 cm
depth, at the surface and in the root zone. Plant parasitic nematodes were located
near the surface (0-15 cm) and at 50 cm depth. Predator nematodes prevailed near
the surface, in the root zone and at 50 cm depth. The lower populations of
nematodes were found at 30 cm depth. This work showed that the dynamics of
nematode populations in the soil is affected by soil depth and compost dose,
suggesting that compost can reduce the population of phytopathogenic nematodes
and increase bacteriophage/saprophyte and predator nematode populations.
Description
Keywords
Biological control Entomopathogenic Predators Soil
Citation
Publisher
International Society for Horticultural Science