@article {17966, title = {Brassica oleracea var. costata: comparative study on organic acids and biomass production with other cabbage varieties. }, journal = {Journal of the Science of Food \& Agriculture}, volume = {89}, year = {2009}, month = {2009-03-12 00:00:00}, pages = {1083-1089}, abstract = {

BACKGROUND:\ A study was undertaken to evaluate the effect of agronomic practices, harvesting time and leaf age on the organic acid composition and biomass production of\ Brassica oleracea\ L. var. costata\ DC (tronchuda cabbage). Samples were cultivated under eight different fertilisation regimes (two levels each of nitrogen, boron and sulfur, an organic fertiliser and no fertiliser) and collected at three different times.

RESULTS:\ Principal component analysis of the data indicated significant differences. Three principal components with an eigenvalue higher than one accounted for 79.0\% of the total variance of the data set. Samples obtained with conventional fertilisation were characterised by the highest values of fresh weight. External leaves showed higher total organic acid and malic acid contents than internal leaves, while the latter were characterised by higher proportions of citric acid. For consecutive harvests, total organic acid concentration decreased in both external and internal leaves.

CONCLUSION:\ The use of a conventional fertilisation regime (nitrogen, boron or sulfur) improved the growth of\ B. oleracea\ var.\ costatawithout affecting its organic acid profile. However, for consecutive harvests, total organic acid concentration was observed to decrease independently of the agronomic practices tested. Leaf age influenced the quantitative composition of organic acids. Copyright {\textcopyright} 2009 Society of Chemical Industry

}, keywords = {Brassica oleracea L. var. costata DC, fertilisation, Organic acids, principal component analysis}, author = {Sousa, C. and Pereira, D. M. and Taveira, M. and Garcia, S. D. and Pereira, J. A. and Rodrigues, A. M. and Bento, A. and Valent{\~a}o, P. and Seabra, R. M. and Andrade, P. B.} }