A NUTRITIONAL SURVEY OF KIWIFRUIT ORCHARDS IN NORTHWEST OF PORTUGAL

A. Veloso, J. Coutinho
The aim of this work was to study the nutritional status of kiwifruit orchards (cv. Hayward) in the Northwest part of Portugal, the main national producer region of this commercial fruit. A regional survey was carried out over a three year period (1993–1995) on one hundred sixty seven orchards representing the major different soil and climatic conditions of the region. Due to lack of significance in some soil-plant relationships, soil analysis is not, nowadays, a satisfactory guide to assess the fertility status of soils with fruit trees. For this reason, the study was conducted based on plant analysis, which reflects the actual nutritional status of the plants and integrates many of the various factors that interfere in absorption of the nutrients. In each orchard and each year, at the phenological stage of visible bud flowers, leaf samples were collected, separating the petioles from the leaf blades. Samples were washed, dried and analysed for the macronutrients (N,P,K, Ca, Mg and S) and some of the micronutrients (Fe, Zn, Cu and Mn) content. Data showed a significantly high correlation between the content of each nutrient the content in the two leaf parts considered. Except for Mg, variations on the nutrient content of the leaves were recorded, reflecting the different conditions among years. Concerning the mineral status of the plants, the results suggest that orchards presented an adequate level of nutrition, except for N, P and Fe. The levels of these nutrients are generally too high when compared with the reference values worldwide accepted for this crop. Considering this survey, it is concluded that nitrogen and phosphorus fertilization followed by the local farmers can be strongly reduced in our conditions, with benefits on the economical and the quality aspects of the crop, as well as in respect to the environmental impacts of this activity.
Veloso, A. and Coutinho, J. (1997). A NUTRITIONAL SURVEY OF KIWIFRUIT ORCHARDS IN NORTHWEST OF PORTUGAL. Acta Hortic. 448, 257-257
DOI: 10.17660/ActaHortic.1997.448.40
https://doi.org/10.17660/ActaHortic.1997.448.40

Acta Horticulturae