| Autor: |
Morgan, Gaylon D., MacGuidwin, Ann E., Zhu, Jun, Binning, Larry K. |
| Zdroj: |
Agronomy Journal; September 2002, Vol. 94 Issue: 5 p1146-1155, 10p |
| Abstrakt: |
Population dynamics of Pratylenchus penetransCobb (root lesion nematode) were investigated in commercial potato (Solanum tuberosumL.) fields in the Central Sands of Wisconsin to test the hypothesis that cultural and management practices influence spatial distribution and temporal stability of nematodes over a 3‐yr crop rotation. From 1998 to 2000, P. penetranspopulations were investigated in fumigated and unfumigated commercial potato fields and in the subsequent rotational crops {corn (Zea maysL.) or soybean [Glycine max(L.) Merr.] and fresh market vegetables} and winter cereal cover crops. Pratylenchus penetranspopulations were quantified in each field using a 0.5‐ha uniform sampling grid. Traditional and geostatistical methods and interpolation maps were used to estimate the spatial distribution and temporal stability of nematode populations within each field and crop. In fumigated and unfumigated fields, the mean populations increased as the rotation progressed (potato→corn→vegetable). Population densities of P. penetransincreased more during the corn crop than potato crop. According to the Index of Dispersion, P. penetranswere aggregated (clumped) in all unfumigated fields; however, aggregation was only detectable in the fumigated fields 2 or 3 yr following soil fumigation. Geostatistical methods identified aggregation in only one field. In many cases, higher nematode populations occurred near tillage implement entry locations into each field. Nematode densities alone were not highly correlated with potato yields, corn yields, soil moisture, or soil pH but were consistently correlated with Verticillium wilt (Verticillium dahliaeKleb.) symptoms in unfumigated fields. Populations expressed more temporal stability in unfumigated fields than in fumigated fields. |
| Databáze: |
Supplemental Index |
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