The importance of reduced light intensity on the growth and development of six weed species

TY - JOUR

T1 - The importance of reduced light intensity on the growth and development of six weed species

AU - Yasin, M.

AU - Rosenqvist, E.

AU - Jensen, S.M.

AU - Andreasen, C.

PY - 2019/4

Y1 - 2019/4

N2 - Crops limit light for photosynthesis and growth of weeds. We studied the effect of reduced light on performance of six weed species [one invasive species (Amsinckia micrantha), three common species (Veronica persica, Capsella bursa-pastoris, Viola arvensis) and two less common weeds (Anagallis arvensis and Scleranthus annuus)]. In two glasshouse experiments, six light levels were achieved aiming at 0%, 20%, 50%, 80%, 90% and 95% reduction of light and corresponding with daily light integrals (DLI) of 12.4, 9.63, 7.13, 2.74, 0.95 and 0.69 mol m -2 day -1 in experiment 1 and 21.2, 18.0, 10.7, 3.71, 1.64 and 1.20 mol m -2  day -1 in experiment 2. The number of leaves was strictly controlled by DLI. Chlorophyll content index, maximum photochemical efficiency of photosystem II (F v /F m ), stomatal conductance, flowering and dry matter were strongly reduced when DLI was reduced to 0.69–3.71 mol m -2  day -1 for all species. Threshold DLI for flowering was ca. 3.71 mol m -2 day -1 for S. annuus, V. arvensis, A. arvensis and V. persica, while C. bursa-pastoris deviated by flowering at DLI of 0.95 mol m -2  day -1 . This may explain why C. bursa-pastoris is common in the seedbank of Danish arable soils in spite of intensive farming with well-fertilised and dense crops.

AB - Crops limit light for photosynthesis and growth of weeds. We studied the effect of reduced light on performance of six weed species [one invasive species (Amsinckia micrantha), three common species (Veronica persica, Capsella bursa-pastoris, Viola arvensis) and two less common weeds (Anagallis arvensis and Scleranthus annuus)]. In two glasshouse experiments, six light levels were achieved aiming at 0%, 20%, 50%, 80%, 90% and 95% reduction of light and corresponding with daily light integrals (DLI) of 12.4, 9.63, 7.13, 2.74, 0.95 and 0.69 mol m -2 day -1 in experiment 1 and 21.2, 18.0, 10.7, 3.71, 1.64 and 1.20 mol m -2  day -1 in experiment 2. The number of leaves was strictly controlled by DLI. Chlorophyll content index, maximum photochemical efficiency of photosystem II (F v /F m ), stomatal conductance, flowering and dry matter were strongly reduced when DLI was reduced to 0.69–3.71 mol m -2  day -1 for all species. Threshold DLI for flowering was ca. 3.71 mol m -2 day -1 for S. annuus, V. arvensis, A. arvensis and V. persica, while C. bursa-pastoris deviated by flowering at DLI of 0.95 mol m -2  day -1 . This may explain why C. bursa-pastoris is common in the seedbank of Danish arable soils in spite of intensive farming with well-fertilised and dense crops.

U2 - 10.1111/wre.12352

DO - 10.1111/wre.12352

M3 - Journal article

SN - 0043-1737

VL - 59

SP - 130

EP - 144

JO - Weed Research

JF - Weed Research

IS - 2

ER -