FUTURE ANALYTICAL REQUIREMENTS IN THE FRUIT INDUSTRY

Before looking at the future requirements of the industry, we must take stock and consider present requirements.

Considering the availability of analyses and determining how requirement and availability match, what use has the industry made of analytical data in the past and at present? To provide some answers to this question, analyses may be divided into three groups: soil, tissue and fruit.
Fruit is separated from other tissues because of its unique importance; fruit alone is the reason for growing fruit tress, and our assessment of tree quality and performance must be related to fruit yield and quality.

The relationship between soil content and plant performance has been established for about one hundred years.
Tables have been produced by a number of advisory services throughout the world, giving suggested standards of nutrient level for fruit trees under the climatic conditions encountered in that area.
Often, levels of nutrient are given which it is considered will deficiency symptoms, deficiency without symptoms, sufficiency and luxury or toxicity depending on the elements.
Alternatively, fertilizer requirements for levels of nutrients are given (e.g.
Ministry of Agriculture, Fisheries and Food, 1967) (Tabe 69.1). This seems to be a perfectly straight-

Table 69.1 FERTILIZER NEEDS OF SOILS CONTAINING DIFFERENT AMOUNTS OF EXTRACTABLE NUTRIENT

Phosphorous (ppm)

Potassium (ppm)

	0-9	10-15	16-25	24-45	>45	0-50	51-100	101-200	205-350	>355
Apples (desert)	60	30	15	15	nil	200	150	100	50	nil
Apples (culinary)	60	30	15	15	nil	200	150	100	50	nil
Plums	60	30	15	15	nil	200	150	100	25	nil

forward procedure giving easily interpreted results upon which action can be taken.
Unfortunately, this is not so.
The first problem is that of sampling.
The usual technique is to remove cores of soil from the orchard, distributed so as to cover the whole area; often two or more depths are sampled.
There is, of course, no guarantee that these cores are located in areas of intense root activity.
The effectiveness of root uptake is determined by a number of factors other than the mineral content of the soil, e.g. moisture content, the

Symposium on Mineral Nutrition and Fruit Quality of Temperate Zone Fruit Trees

R.W. Rowe

https://doi.org/10.17660/ActaHortic.1980.92.70