1) Effects of cereal cyst (Heterodera) and rootlesion (Pratylenchus) nematodes on wheat are difficult to identify and control. Symptoms are non-specific and easily confused with stress from nutrient deficiency, drought, or disease. 2) Multiple species of Heterodera and Pratylenchus are capable of damaging wheat. Identification of species is difficult and procedures based on comparative morpholo...

A field trial was conducted for 2 years in an Arredondo fine sand containing a tillage pan at 15-20 cm deep to determine the influence of subsoiling on the distribution of corn roots and plant-parasitic nematodes. Soil samples were taken at various depths and row positions at 30, 60, and 90 days after planting in field corn subsoiled under the row with two chisels and in non-subsoiled corn. At ...

Nematodes cause great damage to soybean crops in Paraguay. Studies have investigated correlations between phytonematodes and soil chemical physical properties, but little is known about with the nutritional status of crops. This study aimed assess Pratylenchus, Meloidogyne, texture, soybean. The experiment was carried out Paraguay areas commercial cultivation infested nematodes, totaling 83 col...

operated applicator and incorporated Waudo, S. W., and Norton, D. C. 1986. Pathogenic effects of Pratylenchus scribneri in maize into the top 4 cm of soil. Soil samples inbreds and related cultivars. Plant Disease 70:636-638. were taken from the top 25 cm of soil with a 2-cm-diameter soil probe at planting Maize inbreds C123Ht, C103, and Mol7Ht inoculated with 8,500 ± 500 Pratylenchus scribneri...

Malling-Merton 106 apple rootstocks inoculated with Pratylenchus penetrans, or uninoculated, were grown in a growth chamber in pots of loamy sand maintained at two moisture levels, 0 to -0.4 bar or 0 to -10 bars. Either inoculation or low soil moisture suppressed shoot growth and increased root necrosis. However, the nematode-soil moisture interaction was not significant.

A nematicide, 5-hydroxymethyl-2-furoic acid (1), was isolated from cultures of the fungus Aspergillus sp. and its structure was identified by spectroscopic analysis. Compound 1 showed effective nematicidal activities against the pine wood nematode Bursaphelenchus xylophilus and the free-living nematode Caenorhabditis elegans without inhibitory activity against plant growth, but 1 did not show a...

The effects of Pratylenchus vulnus on rootstocks of eight commonly used Prunus spp. and one Pyrus communis were evaluated under greenhouse conditions during a 15-month period. In a first experiment, two almonds (Moncayo and Garrigues), one peach (GF-305), and two peach-almond hybrids (GF-677 and Adafuel) inoculated with 2,000 nematodes per plant proved to be good hosts of P. vulnus. Highest (P ...

VX211 is a highly vigorous Paradox hybrid clone that outgrew other walnut seedlings in the presence of nematodes. A four-year macroplot trial involving Paradox VX211 and a standard Paradox selection, AX1, demonstrated that the damage threshold level of Pratylenchus vulnus on commercially available walnut rootstocks is < 1 nematode/250 cm³ of soil. Using 1 as the initial population level (Pi) wi...

The reproductive fitness of seven isolates of Pratylenchus vulnus from different geographical areas and hosts was assessed in monoxenic cultures (carrot), and greenhouse cultures (plum, sour orange, and quince). The genetic makeup of the different isolates was compared by Random Amplified Polymorphic DNA (RAPD-PCR). The apple (PvAP-S) and apricot (PvAT-F) isolates reproduced less in monoxenic c...