Density estimation of Heterodera schachtii Populations
Density estimation of H. schachtii by using hyperspectral sensors in the lab or greenhouse trial
The chronosequence of hyperspectral leaf reflectance data with Heterodera schachtii inoculated sugar beet plants is introduced here as an early stage introduction of the main objective to estimate the population density of the nematode. The data present a classical pot experiment in nematology, standardized inputs, easily completed in 5 to 7 weeks. Data have been provided by Christian Hillnhütter(1). The reason to present this trial as part of this project, it is one of those interim steps from modeling the population dynamics, climate chamber experiments, up to test the potential and requirements for estimating of H. schachtii populations with non-invasive techniques as hyperspectral sensors.
The experiment has been performed in a climate chamber 25/20°C (day/night). The charts demonstrate the time course of the pot experiment. The result have been included here for several reasons. First, the signatures do not show any impact of H. schachtii at all, despite the plants have been flooded with nematodes. The analysis methods, introduced in the hyperspectral project, gave proof about significant differences, but have not been related to a nematode impact, but the large variance found in the control plants. The control plant did show an atypical growth (red area). What makes the findings even more interesting? At the end of the experiment large amounts of new juveniles have been measured(1), means, the experiment did work out as expected from the nematode point of view. Concurrent no differences were found in the classical yield data, as root or leaf weight contemporary with low variance. The results of the experiment confirm the hypothesis about the temperature dependency of the host-parasite-interaction. The plants have been able to tolerate the high numbers of nematodes due to the positive growth conditions at given temperatures.
But, other hypotheseses as for example a weak pathogenicity of the used nematode species, are similar plausible
(1)C. Hillnhütter, 2010, Non-destructive evaluation of complex interactions between Heterodera schachtii and Rhizoctonia solani on sugar beet as affected by cultivar resistance - Dissertation, Bonn, 106 S.