Citrus nematode (Tylenchulus semipenetrans) and ring nematode (Criconemella xenoplax) were the only plant-parasitic nematodes.
At species level, citrus nematode populations in deep soil reduced significantly within the first few months (sampling date 2) after soil amendment and then increased significantly in the next two subsequent samples.
Although the main effects of Oa and Pc on citrus nematode and TPPN were not significant (P>().
In shallow soil under both the asymptomatic and diseased grapevines, the plant-parasitic citrus nematode, ring nematode and TPPN populations were very low and organic amendment treatments did not significantly affect their populations (see mean populations for shallow soil in Tables 5-7).
Prior to application of organic soil amendment, the initial soil populations (Pi) of citrus nematode in deep soil (10-20 cm) were well below the threshold for damage (~11 000 [kg.
The root populations of citrus nematode varied significantly (P< 0.
The isolation of citrus nematode from both soil and roots, and ring nematode from soil, indicates that these nematode species can injure Ramsey rootstock and reproduce on it, even though Ramsey rootstock has formerly been rated as tolerant-resistant to these nematode species (Emmett et al.
Pest control efficacy was evaluated using citrus nematode bioassay counts, fungal dilution plating, and weed emergence counts and biomass collections from each replicated plot.
Nematode control was determined using a citrus nematode bioassay in which two sets of muslin bags containing 100 grams of soil infested with citrus nematode (Tylenchulus semipenetrans Cobb) were buried at 6, 12, 24 and 36 inches below the soil surface in each plot prior to fumigation.
The high 1,3-D rates and well-prepared soils resulted in complete control of citrus nematodes in the bioassay bags in all treatments and depths.
All treatments of 1,3-D or methyl bromide effectively controlled citrus nematodes in bioassay bags buried at 12-, 24- and 36-inch depths in each plot.