The Ornamental Plant Germplasm Center (OPGC) conserves begonia species. Limited cultural information is
available concerning the effect of light intensity on the growth of begonia species other than cultivated hybrids in greenhouses.
The objective of this study was to evaluate the response of begonia species to different shade levels and to identify
light intensities that favor the production and maintenance of quality begonia plants in greenhouses during summer. Plants
of six begonia species, [Begonia albopicta, B. cucullata var. cucullata, B. echinosepala var. elongatifolia, B. holtonis, B.
foliosa var. miniata, and B. ‘Fuchsifoliosa’ (B. fuchsioides x B. foliosa)], were grown in a greenhouse in Columbus, OH
(lat. 40 N, long. 82.53 W) for 12 weeks (starting 23 July) either in full light (1000 – 1800 μmol·m-2·s-1) or shade-cloth
tents providing three levels of shade (41, 62, and 76% of full sunlight in the greenhouse). Each plant was evaluated for the
number of inflorescences, leaf greenness (SPAD readings), shoot length, leaf area, and shoot dry weight. Visual observations
of plant quality (chlorosis, necrosis, sunburn, deformed leaves, and plant mortality) were also recorded. Shade percentage
for optimal growth and quality of B. albopicta, B. echinosepala var. elongatifolia, B. holtonis, B. foliosa var.
miniata, and B. ‘Fuchsifoliosa’ plants was 62% and 76 % for B. cucullata var. cucullata plants.