Leaf Analysis in Strawberries: Effects of Cultivar, Plant Age, and Sampling Time on Nutrient Levels

ABSTRACT

In a four year survey, two control methods of nitrogen (N) supply in strawberry were combined. It was found that N_min analysis could be used as a measurement of control from the beginning of the season, indicating the need of additional N supply. Leaf dry matter analysis, taken during beginning of flowering, could be used as an indicator thus making it possible to make corrections within the season, if needed. This study clearly showed variation in nutrient values among years and cultivars, whereas differences among plants of different age were not significant. It was concluded that the use of N_min and leaf dry matter analyses combined might make corrections in nitrogen fertilization within the same year possible, and a new standard for leaf nutrient content, based on samples taken during beginning of flowering, was suggested.

Keywords::

• leaf dry matter analysis
• N_min
• strawberry

ACKNOWLEDGMENTS

The comprehensive technical assistance of strawberry consultant T. Todsen is greatly appreciated, as well as the technical assistance of J. Eriksen and K. Nielsen, both employed in DIAS. Finally, the author gratefully acknowledges the growers for placing their strawberry plots at our disposal.

Notes

^aFigures followed by the same letter do not differ significantly (P = 0.05).

^aFigures followed by the same letter do not differ significantly (P = 0.05).

^a Leaf samples taken during beginning of flowering.

^b Standard values up till now, based on leaf samples taken after harvest.