INFLUENCE OF PHOSPHORUS FERTILITY REGIMES AND COMMON LAMBSQUARTERS fChenopodium album) DENSITIES ON LETTUCE (Lactuca sntiva) YIELDS
No hay miniatura disponible
Fecha
Título de la revista
ISSN de la revista
Título del volumen
Editor
Resumen
Descripción
Field trial were conducted in low-phosphorus (P) organic soils to determine the influence of two Ρ fertility regimes and five lambsquarters population densities on lettuce marketable yields. Phosphorus was either banded (125 Kg P/ha) or broadcast (250 Kg P/ha) prior to lettuce planting. Lambsquarters population densities of 0, 2, 4, 8 or 16 plants per 5.4 m2 were allowed to interfere with "South Bay" lettuce within each Ρ regime. Marketable lettuce yield and head number were collected 8 weeks after lettuce emergence. Results indicate that banding Ρ can reduce the negative impact of lambsquarters on lettuce. In all cases, lettuce yields increased approximately 13% when Ρ was banded. At the same time, when Ρ was banded no differences were observed between 2 lambsquarters per 5.4 m* and the weed-free control. However, when Ρ was broadcast, 2, 4, and 8 lambsquarters per 5.4 m2 were enough to reduce lettuce marketable yield in about 33, 50 and 65%, respectively. No significant differences were observed between 8 and 16 lambsquarters per 5.4 m2 when Ρ was broadcast. Maximum lettuce yield reductions occurred at either 4, 8, or 16 lambsquarters per 5.4 mJ when Ρ was banded, corresponding to approximately 34%.