Field pea seed residues: the potential for low cost weed control

Non-Peer ReviewedPlant growth suppression trials were undertaken with soil sampled 18 mo apart (2008, 2009) from two locations affected by field pea seed residues. Test plant species were grown in the residue-affected soil and compared to residue-unaffected soils, sampled from nearby fields. Germination was either fully inhibited or emergence delayed by more than one week in residue-affected soil. Dry matter accumulation of test species grown in residue-affected soil was significantly reduced compared to dry matter of these species grown in unaffected soil (P <0.0001). Canola and field pea were inhibited more than wheat and green foxtail over both years. Greenhouse trials also revealed that germination of wild oats was inhibited in the residue-affected soils, although overall, wheat and grassy weeds were less affected than dicots. Significant reductions of weed species diversity and abundance were correlated to residue-affected soils (P <0.0001) when compared to control soils using multi-response permutations procedures. In bioassays in sterile media, germination of wheat and canola seed was inhibited, using aqueous extracts of weathered pea seeds or extracts of the residue-affected soil. An allelopathic response was proposed to explain these results

Developing markers for canola seed quality – relationship of seedcoat colour and lignin content in Brassica carinata.

Non-Peer Reviewe

Attenuated Total Reflection Mid-Infrared (ATR-MIR) spectroscopy and chemometrics for the identification and classification of commercial tannins.

In this paper attenuated total reflection Fourier transform infrared (FT-IR) spectroscopy was used to characterize 40 commercial tannins, including condensed and hydrolyzable chemical classes, provided as powder extracts from suppliers. Spectral data were processed to detect typical molecular vibrations of tannins bearing different chemical groups and of varying botanical origin (univariate qualitative analysis). The mid-infrared region between 4000 and 520 cm-1 was analyzed, with a particular emphasis on the vibrational modes in the fingerprint region (1800\u2013520 cm-1), which provide detailed information about skeletal structures and specific substituents. The region 1800\u20131500 cm-1 contained signals due to hydrolyzable structures, while bands due to condensed tannins appeared at 1300\u2013900 cm-1 and exhibited specific hydroxylation patterns useful to elucidate the structure of the flavonoid monomeric units. The spectra were investigated further using principal component analysis for discriminative purposes, to enhance the ability of infrared spectroscopy in the classification and quality control of commercial dried extracts and to enhance their industrial exploitation