DIAGNOSIS OF THE NUTRITIONAL STATUS OF PROTECTED CROPS

The stages of investigation of nutritional problems are discussed with reference to visual diagnosis, soil and plant analysis and environmental background.

Soil analysis is considered in terms of sampling, preparation of extracts, analysis and interpretation.
The obvious lack of standardisation of extraction procedures detracts from the international value of soil analysis.
By comparison, standardisation of analytical procedures is only of secondary importance.
Fertiliser recommendations based on soil analyses are illustrated in terms of potassium applications for protected vegetable crops in the U.K.

Plant analysis is discussed in terms of sampling position and stage of growth.
Examples of interactions between leaf analyses and fertiliser treatments are tabulated, including depression of leaf phosphorus by liming and of leaf boron by both lime and phosphate.

Plant environment, both aerial and in the root zone, can influence the nutrient status of crops.
Some knowledge, of plant diseases and of injury by crop protection chemicals and herbicides can help to avoid confusion with non-nutritional problems.

The stages of investigation of nutritional problems may for convenience be set out as follows:

1. Preliminary visual diagnosis.

2. Soil analysis.

3. Plant environment.

Symposium on the Use of Fertilizers in Protected Vegetable Production

G.W. Winsor

https://doi.org/10.17660/ActaHortic.1984.145.25