Influence of light on the growth of young tomato, cucumber and sweet pepper plants in the greenhouse: Calculating the effect of differences in light integral

• Published in: Scientia horticulturae Vol. 31; no. 3; pp. 175 - 183
• Main Author: Bruggink, G.T.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.05.1987; Elsevier
• Subjects: Agronomy. Soil science and plant productions; Biological and medical sciences; cucumber; Economic plant physiology; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; growth analysis; light; Net assimilation, photosynthesis, carbon metabolism. Photorespiration, respiration, fermentation (anoxia, hypoxia); Nutrition. Photosynthesis. Respiration. Metabolism; Protected cultivation; Soilless cultures. Protected cultivation; sweet pepper; tomato; young plants; PAR; cucumber; young plants; NAR max; tomato; growth analysis; R; Y %X; B, C; light; K 1, K 2; T d; sweet pepper; RGR max; LAR; RGR; NAR; Light effect; Growth; Cucurbitaceae; Light transmission; Cucumis sativus; Leaf area; Vegetable crop; Net assimilation; Seasonal variation; Dicotyledones; Light; Angiospermae; Lycopersicon esculentum; Capsicum annuum; Spermatophyta; Solanaceae; Greenhouse; Growth factor
• ISSN: 0304-4238; 1879-1018
• DOI: 10.1016/0304-4238(87)90044-6

A method is presented to calculate the effect of different levels of mean daily light integral (PAR incoming per unit ground area) on the growth of young tomato, cucumber and sweet pepper plants. The relative sensitivity of the growth parameters RGR and NAR to a difference in light integral was determined, as well as the relative sensitivity of LAR to a difference in NAR. Differences between the three species were small. At higher values of mean daily light integral, LAR appeared to have a strong compensating effect on changes in NAR. This is expressed as the flexibility index of LAR. Levels of light integral differing by 1% caused values for RGR to differ by 0.6% in wintertime and 0.4% in spring. Using the relationship between light integral and RGR, calculations are presented on the effect of different light transmission values of the greenhouse and different intensities of artificial light on the time needed for plants to double in dry weight.