|
|
|
|
|
| Tyystjärvi, Esa; Nørremark, Michael; Mattila, Heta; Keränen, Mika; Hakala-Yatkin, Marja; Ottosen, Carl-Otto; Rosenqvist, Eva. |
| Automatic identification of crop and weed species is required for many precision farming practices. The use of chlorophyll fluorescence fingerprinting for identification of maize and barley among six weed species was tested. The plants were grown in outdoor pots and the fluorescence measurements were done in variable natural conditions. The measurement protocol consisted of 1 s of shading followed by two short pulses of strong light photosynthetic photon flux density 1700 lmol m-2 s-1) with 0.2 s of darkness in between. Both illumination pulses caused the fluorescence yield to increase by 30–60% and to display a rapid fluorescence transient resembling transients obtained after long dark incubation. A neural network classifier, working on 17 features... |
| Tipo: Journal paper |
Palavras-chave: Weed management. |
| Ano: 2011 |
URL: http://orgprints.org/20654/4/20654.pdf |
| |
|
|
| Nkurunziza, Libère; Rosenqvist, Eva; Streibig, Jens Carl. |
| Cirsium arvense and Tussilago farfara are noxious creeping perennial weeds of temperate crops. Cirsium arvense infests both conventional and organic crops, while T. farfara is more common in organic cropping systems. Mechanical control used in organic farming often leaves intact shoots within crop rows. It is unknown whether shoots and rhizomes are affected by cutting adjacent interconnected shoots. In glasshouse experiments, comparison of net photosynthesis, chlorophyll a fluorescence and quantum efficiency (Fv/Fm) of disturbed and undisturbed clones, did not show any disturbance effect. Maximum net photosynthesis decreased over time in both disturbed and undisturbed clones, depending on environmental conditions. Maximum net photosynthesis was not... |
| Tipo: Journal paper |
Palavras-chave: "Organics" in general; Farming Systems. |
| Ano: 2010 |
URL: http://orgprints.org/18238/1/18238.pdf |
| |
|
|
|
