Effect of radiation environment on radiation use efficiency and growth of sunflower

• Published in: Crop science 1997-07, Vol.37 (4), p.1208-1214
• Main Authors: Bange, M.P, Hammer, G.L, Rickert, K.G
• Format: Article
• Language: English
• Subjects: ACEITE DE GIRASOL; Agricultural and forest climatology and meteorology. Irrigation. Drainage; Agricultural and forest meteorology; Agricultural production; Agronomy. Soil science and plant productions; Biological and medical sciences; BIOMASA; BIOMASS; BIOMASSE; CANOPY; CONTENIDO PROTEICO; COUVERT; CRECIMIENTO; CROISSANCE; Crop climate. Energy and radiation balances; CROP YIELD; CRUDE PROTEIN; CUBIERTA DE COPAS; EFFICACITE; EFFICIENCY; EFICACIA; Environmental aspects; FENOLOGIA; FEUILLE; Flowers & plants; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; GRAINE; GROSSEUR DES SEMENCES; GROWTH; HARVEST INDEX; HELIANTHUS ANNUUS; HOJAS; HUILE DE TOURNESOL; INDICE DE COSECHA; INDICE DE RECOLTE; INFLORESCENCE; INFLORESCENCES; INFLORESCENCIAS; LEAF AREA; LEAVES; LIGHT; LIGHT INTENSITY; LUMIERE; LUZ; PHENOLOGIE; PHENOLOGY; Photobiology; Plant growth; PROTEIN CONTENT; PROTEINA BRUTA; PROTEINE BRUTE; QUEENSLAND; RADIACION SOLAR; Radiation; RADIATION SOLAIRE; RENDEMENT DES CULTURES; RENDIMIENTO DE CULTIVOS; SEED SIZE; SEEDS; SEMILLA; SOLAR RADIATION; SUNFLOWER OIL; Sunflowers; SUPERFICIE FOLIAR; SURFACE FOLIAIRE; TAMANO DE LA SEMILLA; TENEUR EN PROTEINES; USES; USOS; UTILISATION
• ISSN: 0011-183X; 1435-0653
• DOI: 10.2135/cropsci1997.0011183X003700040030x

The level of incident radiation and the proportion of radiation that is diffuse affects radiation use efficiency (RUE) in crops. However, the degree of this effect, and its importance to growth and yield of sunflower (Helianthus annuus L.) have not been established. A field experiment was conducted to investigate the effects of radiation environment on RUE, growth, and yield of sunflower. A fully irrigated crop was sown on an alluvial-prairie soil (Fluventic Haplustoll) and was exposed to three distinct radiation environments. In two treatments, the level of incident radiation was reduced by 14 and 20% by suspending two different types of polyethylene plastic films well above the crop. In addition to the reductions in incident radiation, the proportion of radiation that was diffuse was increased by about 14% in these treatments. Lower incident radiation and increased proportion of diffuse radiation had no effect on total biomass, phenology, leaf area, and the canopy light extinction coefficient (k = 0.89). However, yield was reduced in shaded treatments due to smaller grain size and lower harvest index. Although crop RUE measured over the entire crop cycle (1.25 g/MJ) did not differ significantly among treatments, there was a trend where RUE compensated for less intercepted incident radiation. Theoretical derivations of the response of RUE to different levels of incident radiation supported this finding. Shaded sunflower crops have the ability to produce biomass similar to unshaded crops by increasing RUE, but have lower harvest indices