INFLUENCE OF NITROGEN SUPPLY ON THE OCCURENCE OF CALCIUM DEFICIENCY IN FIELD GROWN LETTUCE

In field experiments with lettuce (Lactuca sativa L.) the influence of N supply on the incidence of tipburn was investigated.
Tipburn is a common physiological disorder in lettuce caused by Ca deficiency.
Tipburn increased with N supply in all experiments.
This was mainly related to an increase in head size as well as to a specific N effect going beyond the stimulation of growth.

This specific N effect on tipburn was not accompanied by low Ca concentration in the dry matter of inner leaves or by changes in head morphology but by a decreasing root/shoot ratio.

The experiments showed additionally that a supraoptimal N supply not only increased the risk of tipburn but also the N_min residue at harvest in the soil and thus the risk of nitrate leaching.

Workshop on Ecological Aspects of Vegetable Fertilization in Integrated Crop Production in the Field

I. Brumm, M. Schenk

Lactuca sativa, physiological disorder, N_min residue, root/shoot ratio

https://doi.org/10.17660/ActaHortic.1993.339.11