Nitrogen Concentration and Photosynthetic Photon Flux in Greenhouse Tomato Production: I. Growth and Development
Year: 1989
Type: article
Abstract: Tomato plants ( Lycopersicon esculentum Mill. cv. Vedettos) were grown in growth chambers under two photosynthetic photon flux (PPF; 125 and 250 μmol·s −1 ·m −2 , high-pressure sodium lamps) conditions for 18 hr and four N fertilization regimes (5, 10, 15, and 20 meq·liter −1 ) to characterize the ratio of vegetative to reproductive growth. At the lower PPF, vegetative growth was limited and did not respond to N increments in the nutrient solution. At 125 μmol·s −1 ·m −2 , maximum yields were obtained at the lowest N fertilization level. At 250 μmol·s −1 ·m −2 , maximum leaf dry weight and yields were obtained at intermediate N fertilization levels (10 and 15 meq·liter −1 ). Light levels did not alter the nitrate content of stem sap (but high PPF resulted in nitrate accumulation in leaves) but, at low PPF, nitrate accumulated in leaves at 20 meq N/liter. Nitrate in stem sap varied only slightly with N increments in the nutrient solution. The ratio of fruit fresh weight to leaf fresh weight decreased as N increased in the nutrient solution.
Institution: Université Laval
Language: English
Subfield: Soil Science
Domain: Life Sciences
SDG: Zero hunger
Open Access status: hybrid
Estimated APC paid: $3,500
OpenAlex ID: W2280023640