J. Amir, D. Lachover. W. E. Goldin

At the Gilat Experimental Farm in the northern Negev peanut samples were taken during three years of nitrogen and phosphorus trials in order to test the use of foliar analysis as a diagnostic tool for determining the nitrogen requirement of the crop.

Several different ways of interpreting the nitrogen foliar diagnostic results were studied in order to discover the most suitable index for the expression of the

nitrogen requirement peanut plants.

No significant correlations were found between weight of leaf sample, or

fertilizer treatment or yield and the nitrogen concentration in the leaves.

It is suggested that the lack of correlations may be attributed to the steadily rising

fertility level of the experimental fields during the course of three seasons. The

validity of this assumption seems to be supported by the following facts, which emerged from three years of experimentation:

a. control (without nitrogen) plot yields rose steadily during the three seasons;

b. each year’s correlation curve between leaf nitrogen values and nitrogen

fertilizer rates shows a characteristic increase in the leaf nitrogen

content from year to year;

c. the pattern of pod-yield values when related to leaf-nitrogen content shows

a restricted scatter which is characteristic for each experimental year and

again demonstrates the rising level of fertility during the course of these

experiments.

Amir, J., Lachover, D. and Goldin, E. (1964). Difficulties in determining the

nitrogen fertilizer requirement of peanuts by foliar diagnosis. Prelim.

Rep. No. 445. Division of Publication, Rehovot.