Nutritional and physiological studies on grapevine. II

Seasonal changes in inorganic nutrient contents

Abstract

Two vines each, of uniform bearing Black Queen were dug up nine times during the period from April, 1954 to March, 1955, and leaves, shoots and berries were separately analized for their contents of nitorogen, phosphorus, potassium, calcium and magnesium. Seasonal changes in absorption and translocation of inorganic nutrients were estimated basing on the analytical data.
The contents of inorganic constituents in the leaves decreased as the season advanced, excepting calcium which increased on the contrary. The seasonal changes in the stems and roots were rather slight.
The leaves were highest in the content of any constituent among the various organs. The content decreased generally in the order of roots, berries and stems, although there were some exceptions. A tendency was found that the younger the shoots, the higher the content, excepting that of calcium, which was higher in older shoots.
The tatal amount of each constituent in the whole vine reached its highest value on September 30, when berries matured. On this date, the ratios of the amount in the newly formed organs (leaves, fruits and current year's shoot) to the one in the other organs (canes, stems and roots) were 77: 23 for nitrogen, 63: 37 for phosphorus, 56: 44 for magnesium, 85: 15 potassium and 70: 30 for calcium.
Absorption of nitrogen was estimated to be high in the period from May to July. Absorption of phosphorus and magnesium was similar to that of nitrogen, while calcium and potassium were absorbed gradually from May until September.
Calcium ranked highest in the total amount in the vine, followed by nitrogen and potassium, and phosphorus and magnesium being roughly equal in the lowest.