DEVELOPMENT OF A NITROGEN MANAGEMENT TOOL FOR BROCCOLI

The
soil mineral N, tissue NO₃-N and foliar nutrition concentration
tests were evaluated as a nitrogen management tool for broccoli production.
Investigation showed that according to high yield data the optimal N supply is
240 kg N ha^-1. It was established that when the content of total N
in broccoli leaves is 26.1-31.3 g kg^-1 dry wt, P – 3.3-4.6 g kg^‑1, K
– 23.6-31.1 g kg^-1, Ca – 34.6-55.9 g kg^-1 and Mg –
5.0-7.9 g kg^-1,
the production of broccoli heads is higher than 10 t ha^-1. High
yield crops were optimally supplied with nitrogen when NO₃-N in
leaves on the 27^th day after transplanting was higher than 3500 mg
kg^-1, 46^th – higher than 3000 mg kg^-1, 59^th
– higher than 2000 mg kg^-1. Good correlations were established on
the: 27^th day after transplanting between the N in leaves and NO₃-N
in soil (0-20 cm, 0-60 cm depth) r=0.74-0.75, 46^th – between the NO₃-N
in leaves and NO₃-N in soil (0-20 cm depth) r=0.59 and the N in
leaves and NO₃-N in soil (0-20 cm, 0-60 cm depth) r=0.68, r=0.6. In
spring it is expedient to establish the amount of mineral nitrogen in soil and
calculate the rate of nitrogen
fertilizers accordingly.
During broccoli vegetation it is expedient to assess
plant supply with nutrients according to the level of mineral elements in
leaves.

XXVI International Horticultural Congress: Toward Ecologically Sound Fertilization Strategies for Field Vegetable Production

R. Karitonas

Broccoli, soil mineral nitrogen, tissue nitrate, foliar nitrogen concentration, nitrogen management tool

https://doi.org/10.17660/ActaHortic.2003.627.15