Evaluation of the botanical origin of estonian uni- and polyfloral honeys by amino acid content.
The free amino acid content of 61 honey samples from Estonia has been determined by HPLC-UV with precolumn derivatization with diethyl ethoxymethylenemalonate. Analyzed samples were seven types of unifloral honeys and polyfloral honeys. The main amino acids found in Estonian honeys were proline and phenylalanine. The resulting data have been analyzed by t test and principal component analysis (PCA). t Test revealed that some amino acids (alpha-alanine, beta-alanine, asparagine, gamma-aminobutyric acid, glutamine, glycine, histidine, ornithine, phenylalanine, proline, serine, and tryptophan) are more potent for assigning honey botanical origin than others. PCA enabled differentiation of some honey types by their botanical origin. In the space of the two first principal components, heather honeys form a cluster that is clearly separable from, for example, polyfloral honeys. It is concluded that analysis of the free amino acid profile may serve as a useful tool to assess the botanical origin of Estonian honeys.
Free amino acid composition and botanical origin of honey
Abstract The main amino acids found in 31 Spanish honeys of five different single botanical origins, were proline, phenylalanine, tyrosine and lysine, followed by arginine, glutamic acid, histidine and valine. Principal component analysis explained 64% of the variance with the first three PC variables, the lavender honeys being the only group well differentiated. Although the best grouped honeys were those from orange blossom, overlapping with eucalyptus honeys, on the one hand, and with the indistinguishable group formed by rosemary and thyme honeys, on the other hand, was observed. The Student–Newman–Keuls test allowed the grouping of rosemary, thyme and orange blossom honeys, whereas eucalyptus and lavender honeys showed specific amino acid compositions which made them different when compared with this group and also between themselves. Lavender honeys had the highest concentrations of tyrosine. The results obtained for the former honeys together with those obtained for another set of 17 samples, were used to establish a range for amino acid composition of Spanish honeys.
LABORATORY AND FIELD TESTING OF SEED SPACING UNIFORMITY FOR SUGARBEET PLANTERS
Five planter configurations were evaluated for seed spacing uniformity at three field speeds using a seed 
location method in the field and a laboratory method involving an opto-electronic sensor system. Planter seed spacing 
uniformity was described using the Coefficient of Precision (CP3) measure. Results showed that CP3 measures 
determined using the laboratory test method were significantly different from those determined using the field test method. 
This indicated the laboratory test method cannot be used to predict planter seed spacing uniformity in the field. Seed 
spacing uniformity determined in laboratory tests was higher than, or equal to, seed spacing uniformity determined in 
field tests. This indicated the laboratory test method may be useful to screen out planters or planter units with poor 
uniformity of seed metering. Field testing of the planters that perform well in laboratory tests must be conducted to 
adequately determine the seed spacing uniformity of those planters in the field. Results from laboratory and field tests 
could be useful in determining areas for improvement of planters or planter units.