PROTEIN AND MINERAL CONCENTRATION OF PORTUGUESE KALE (BRASSICA OLERACEA VAR. ACEPHALA) RELATED TO SOIL COMPOSITION

Primitive cultivars of Portuguese kale, which are well adapted to impoverished soils and adverse climatic conditions in the country, assume an important role in the total production and consumption of vegetables.
Information concerning the quality of kales in response to various soil characteristics is lacking.
The objective of this study was to determine if the mineral concentration in leaves, lamina and petioles, was related to soil chemical characteristics.

Primitive cultivars of kale were established in the field in March/April 1992, in the region of Trás-os-Montes e Alto Douro, north of Portugal, and harvested in September.
For this survey samples were analyzed from the laminae and petioles for N, Ca, Mg, K, and P and from the soil for pH, Ca, Mg, K, Na, Al, P, acidity, cation exchange capacity and base saturation.

Portuguese kales were found to have higher levels of protein, Ca, and Mg, than the reported values in Table 1. The mineral concentration in leaves was related to soil composition (accessed by routine analysis), by linear multivariate models.
Only about 50% of the total variance in leaf composition was explained by soil characteristics.
Calcium concentrations in laminae and K in petioles were even less dependent on soil characteristics.
This study emphasizes the complexity of relationships between soil and plant composition and the necessity for further research under controlled conditions.

ISHS Brassica Symposium – IX Crucifer Genetics Workshop

D. Almeida, E. Rosa

https://doi.org/10.17660/ActaHortic.1996.407.33