Nitrogen Stress Effects on Growth and Nitrogen Accumulation by Field‐Grown Tomato

Autor: S. J. Locascio, James W. Jones, B. L. McNeal, Kenneth J. Boote, Johannes Scholberg, Stephen M. Olson
Rok vydání: 2000
Předmět:
Zdroj: Agronomy Journal. 92:159-167
ISSN: 1435-0645
0002-1962
DOI: 10.2134/agronj2000.921159x
Popis: There are few growth studies evaluating within-season effects of N on vegetative growth and.N accumulation of tomato (Lycopersicon esculentum Mill.). Growth analysis of field-grown tomato for a number of Florida locations and management systems is presented here. Severe N stress resulted in fewer and smaller, but thicker, leaves. With increasing N, average leaf area index (LAI) increased from 0.75 to =3, but radiation use efficiency (RUE) typically increased less then 30%. Lower RUE under N-limited conditions reflected a decrease in N concentration of the most recently matured leaves from 40 mg g -1 to as little as 15 mg g -1 . Over the life of well-fertilized crops, leaf N concentrations dropped from 55 to 65 mg g -1 during initial growth to 20 to 35 mg g -1 at final harvest. Corresponding N concentrations for fruit and for stems were 30 to 35 mg g -1 and 15 to 25 mg g -1 . Severe N stress affected leaf and stem N concentrations most drastically, whereas N in fruits was less variable. With lower N supply (N < 180 kg ha -1 ) under careful management, nitrogen use efficiency (NUE) for field-grown tomato was 0.4 Mg fresh fruit (kg N) -1 and average crop N accumulation increased from 37 to 210 kg N ha -1 as N fertilization increased from 0 to 333 kg N ha -1 . As a fraction of the fertilizer N applied N fertilizer recovery ranged from 0.36 to 0.74 and 0.61 to 0.96 for drip-irrigated and subirrigated crops, respectively.
Databáze: OpenAIRE
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