Vascular plants have evolved over millennia with features that now enable utilisation of light in climates that differ by orders of magnitude in photon irradiance. Their adaptation to sun and shade is a marvel of nature’s biological engineering, with a wide range of adaptive features at all levels of organisation from chloroplast to community. Moreover, the nature of selection pressures imposed by sunlight has also changed. The blistering UV radiation of a prebiotic world has been attenuated thanks to oxygenic photosynthesis, and vascular plants still carry adaptive features that may again ﬁnd strong expression if global change does result in a substantially greater UV-B irradiance.
The central signiﬁcance of sunlight as an energy source for natural and managed ecosystems is unarguable, and quantitative relationships between forest and horticultural productivity and sunlight interception provide just examples that underscores human reliance on intrinsic properties of photo-energetics. More subtle, and especially costly in terms of gaining necessary research experience, is plant response to light quality.
Optimising interception of sunlight by managed communities of plants in horticulture calls for application of solid geometry, and some highly sophisticated canopy systems have been developed. However, a knowledge of growth and developmental response to changes in spectral composition of sunlight transmitted by plant canopies provides crucial insight into reproductive physiology. Concord grapevines were cited as an example of a species with features that make them especially amenable to canopy manipulation. Having evolved in North America as forest vines, vegetative extension rather than reproductive development would have conferred a selective advantage for reaching exposed crowns in forested habitats. Accordingly, the far-red-enriched sunlight transmitted by their own canopy in a managed vineyard encourages shoot extension, rather than differentiation of flower buds and subsequent cropping. That predisposition to vegetative vigour was successfully countered by shrewd management of vine canopies via pruning, trellising and shoot positioning.
Overall, sunlight is pervasive by driving genotype × environment interactions for both evolution of adaptive features and day to day physiology of vascular plants. Our growing appreciation of photobiology in managed communities, and of nature’s adaptations in natural communities, has already paid huge dividends in understanding plant function. What is even more compelling is that such knowledge will shape our future options for plant utilisation.
Anderson MC (1970) Radiation, climate, crop architecture and photosynthesis. In I Setlik, ed, Prediction and Measurement of Photosynthetic Productivity. Pudoc, Wageningen, pp 71–78
Bornman JF, Teramura AH (1993) Effects of UV-B radiation on terrestrial plants. In AR Young, LO Björn, W. Nultsch, eds, Environmental UV Photobiology. Plenum Press, New York, pp 427–471
Byers RE, Carbaugh DH, Presley CN, Wolf TK (1991) The influence of low light on apple fruit abscission. J Hort 66:7-17
Caldwell MM, Robberecht R, Billings WD (1982) Differential photosynthetic inhibition by ultraviolet radiation in species from the artic-alpine life zone. Artic Alpine Res 14: 195-202
Chazdon RL, Pearcy RW (1986) Photosynthetic response to light variation in rainforest species. I. Induction under constant and fluctuating light conditions. Oecologia 69: 517-523
Chow WS (1994) Photoprotection and photoinhibitory damage. In J. Barber, ed, Advances in Molecular and Cell Biology: Molecular Processes of Photosynthesis, Vol. 10, JAI Press Inc.: Greenwich, Connecticut, pp 151–196
Jackson JE (1980) Light interception and utilization by orchard systems. Hort Rev 2: 208–267
Greer DH (1996) Photosynthetic development in relation to leaf expansion in kiwifruit (Actinidia deliciosa) vines during growth in a controlled environment. Aust J Plant Physiol 23: 541 – 549
Greer DH, Weedon MM (2012) Interactions between light and growing season temperatures on growth and development and gas exchange of Semillon (Vitis vinifera L.) vines grown in an irrigated vineyard. Plant Physiol Biochem 54: 59 – 69
Hay RKM, Porter JR (2006) The Physiology of Crop Yield. 2nd Edition, Blackwell Publishing: Oxford, UK.
Khurana, SC, McLaren JS (1982) The influence of leaf area, light interception and season on potato growth and yield. Potato Research 25, 329-342.
Kiniry JR, Jones CA, O’Toole JC, Blanchet R, Cabelguenne M, Spanel DA (1989) Radiation-use efﬁciency in biomass accumulation prior to grain-ﬁlling for grain-crop species. Field Crops Res 20: 51–64
Kriedemann PE, Torokfalvy E, Smart RE (1973) Natural occurrence and photosynthetic utilisation of sunflecks in grapevines. Photosyn 7: 18-27
Lang ARC, Xiang YQ, Norman JM (1985). Crop structure and the penetration of direct sunlight. Agric Forest Meteorol 35: 83–101
Long SP, Humphries S, Falkowski PG (1994) Photoinhibition of photosynthesis in nature. Annu Rev Plant Physiol 45: 633-662
Lumsden P (ed.) (1997) Plants and UV-B. Responses to Environmental Change. Soc Exp Biol Seminar Series 64, Cambridge University Press
Monteith JL (1977) Climate and the efficiency of crop production in Britain. Phil Trans Royal Soc Series B 281: 277-294
Monteith JL Unsworth MH (1990) Principles of environmental physics. Edward Arnold: London
Palmer JW (1989) The effects of row orientation, tree height, time of year and latitude on light interception and distribution in model apple hedgerow canopies. J Hort Sci 64: 137-145
Pfitsch WA, Pearcy RW (1989) Daily carbon gain by Adenocaulon bicolor (Asteraceae), a redwood forest understory herb, in relation to its light environment. Oecologia 80:465-470
Shaulis N, Jordan TD, Tomkins JP (1966). Cultural Practices for New York Vineyards, Cornell Extension Bulletin 805, New York State College of Agriculture: Geneva, New York.
Smart RE (1989) Solar radiation interception as a guide to the design of horticultural plantings. II. Twenty years of experience with grapevines. Acta Hort 240: 87-94
Stapleton AE (1992) Ultraviolet radiation and plants: burning questions. Plant Cell 4: 1353-1358
Strid A, Chow WS, Anderson JM (1990) Effects of supplementary ultraviolet-B radiation on photosynthesis in Pisum sativum. Biochim Biophys Acta 1020: 260-268
Tevini M (1994). UV-B effects on terrestrial plants and aquatic organisms. Progress Bot 55: 174–190
Thompson WA, Kriedemann PE, Craig IE (1992a) Photosynthetic response to light and nutrients in sun-tolerant and shade-tolerant rainforest trees. I. Growth, leaf anatomy and nutrient content. Aust J Plant Physiol 19: 1-18
Thompson WA, Kriedemann PE, Craig IE (1992b) Photosynthetic response to light and nutrients in sun-tolerant and shade-tolerant rainforest trees. II. Leaf gas exchange and component processes of photosynthesis. Aust J Plant Physiol 19: 19-42
Trenbath BR, Angus JF (1975) Leaf inclination and crop production. Field Crop Abstracts 28: 231–244
Tustin DS, Corelli-Grappadelli L, Ravaglia G (1992) effect of previous-season and current light environments on early-season spur development and assimilate translocation in Golden Delicious apple. J Hort 67:351-360
Van den Ende B, Chalmers DJ, Jerie PH (1987) Latest developments in training and management of fruit crops on Tatura trellis. Hort Sci 22: 561-568
Wagenmakers PS (1991) Planting systems for fruit trees in temperate climates. Crit Rev Plant Sci 10: 369–385
Watling JR, Ball MC, Woodrow IE (1977a) The utilization of sunflecks for growth in four Australian rainforest species. Funct Ecol 11: 231-239
Watling JR, Robinson SA, Woodrow IE, Osmond CB (1977b) Responses of rainforest understorey plants to excess light during sunflecks. Aust J Plant Physiol 24: 17-25.
Wünsche JN, Lakso, AN, Robinson TL, Lenz F, Denning SS (1996) The bases of productivity in apple production systems: The role of light interception by different shoot types. J Amer Soc Hort Sci 121: 886-893