|
FACTORS THAT INFLUENCE NEMATODE DAMAGE |
|
CONTENTS [Return to Post-plant Options] |
Stand Vigor Several factors can influence the amount of damage sustained by a given nematode density and each should be considered when developing nematode management strategies. Pinkerton (1983) determined that one of the most important variables associated with nematode damage was the vigor of the stand in the previous year. Peppermint growth is dependent on previous seasons rhizome and runner production. Therefore, in highly damaged fields with poor vigor, potential yield can not be restored within a single season. Similarly, annual applications may be necessary to maintain yields in fields on sandy loam soils with consistently high populations. Mint VarietyDifferent varieties of mint have difference degrees of tolerance to nematodes (see discussion under rootstocks). Soil TextureSoil texture is another important variable regulating nematode damage in mint. Pinkerton (1983) observed that yield was negatively correlated with percent sand in fields infested with P. penetrans. Similarly, there was a positive relationship between yield and percent silt. However, after adequate treatment with Vydate, there was no longer a relationship between texture and yield. Thus, when root-lesion nematodes are present, there will be more yield loss in fields, or areas of a field, that have lighter soils. Less damage, and therefore less yield improvement with Vydate application, was observed in fields with fine textured soils. On a silt loam soil, pretreatment densities of 2330/g fresh root weight were required before Vydate treatment was cost effective under experimental conditions (Pinkerton, 1983). Other Soil FactorsBulk density, pH and soluble solids were not found to have any relationship between nematode densities and mint yield (Pinkerton, 1983). However, these and other soil factors may influence the performance of different nematicides. |