The Assimilation and Translocation of Plant Nutrients in Wheat During Growth.

Abstract

1. An account has been given of the composition and weights of nutrients in 3200 wheat plants from seven weeks before ear emergence until the crop was harvested. The distribution of the plant nutrients, and the rate of assimilation and translocation of these nutrients, have been discussed.2. In the case of the whole plant, the percentage of nutrients in the dry matter decreased from the time of the first sampling, with the exception of silica, which had a tendency to remain constant throughout. In the case of the ear, diminution in the percentage of nutrients in the dry matter was observed from a fortnight after ear emergence until harvest.3. Marked increases in the weights of all nutrients in the whole plant were noted until ear emergence, from then onwards assimilation was much slower. The plant attained its maximum quantities of the nutrients in the following order: potash seven weeks, lime and chlorine five weeks, nitrogen three weeks, carbon, phosphoric acid and silica two weeks, before harvest.Assimilation of these had, therefore, ceased at the above stated times, although transference to the ear proceeded until within about a week before harvest.

Potassium Retranslocation in Seedlings of Hordeum Vulgare

“…Large net potassium losses from the vegetative parts of cereals were found in field experiments by Wagner (1932) and Knowles and Watkin (1931), but these might have been due to leaching. Ward (1958) stated that potassium was lost from the older to the younger leaves of potassium-deficient wheat seedlings.…”

Phosphorus deficiency is the major limiting factor for wheat on alluvium polluted by the copper mine pyrite tailings: a black box approach

“…2c). Adequate N concentration in upper wheat leaves in flowering is about 2.6-3% (Bergmann and Neubert 1976), which is about 1.7-2.1% in milky ripeness (after Knowles and Watkin 1931, as mineral contents decrease significantly after anthesis). Thus, the wheat crop suffers from N deficiency in the severely degraded soils (Zones 3 and 4).…”

A Study of Mineral Nutrition of Wheat as Influenced by Fertilizer Combinations

“…Nitrogen suffered a subsequent loss and phosphorus remained constant. The English workers (9) found nitrogen and phosphorus assimilation ceased several weeks before harvest and the amount remained practically constant until harvest. They did not determine sulphur, but found calcium reached a maximum slightly in advance of phosphorus and nitrogen and later suffered a slight loss.…”