Gamma scanning used in timing of mineral nitrogen top dressing of late white cabbage

Starting from the necessity of input-efficient field vegetable production, a new method is described for determination of the nitrogen requirement of white cabbage crops for late harvest. A gamma scanning unit was used for non-destructive measurement of plant fresh weight in control variants. That weight was used as indicator. The fresh weight is always compared with that of the plants in a standard with adequate nitrogen supply. Periods optimal for top dressing are derived from the results obtained. (author)