The effects of long‐term open‐air fumigation with SO₂ on a field crop of broad bean (Vicia faba L.) I. Depression of growth and yield

Abstract

S U M M .'\ R '^'In an open-air field exposure system for tbe controlled release of air pollutants, broad bean {Vicia faba L.) crops were exposed to elevated SOj concentrations in tbree growing seasons, in order to analyse tbe etiects on crop growtb under field conditions, Tbe treated plots were exposed to a mean concentration of 165//gm"' in 1985, 62/^g m •' in 1986 and 74/(g m •' in 1988. Tbe background concentration was about 10/(gm"-', A reasonably uniform distribution of SO., concentration was obtained over an area of 8 m x 8 m and concentrations exceeding tbe target concentration were rare. In 1985 and 1988, the growtb rate of tbe crop was depressed at tbe end of tbe pod-filling period, Tbis resulted in a reduction of total dry-matter production of 17",, in 1985 and9",, in 1988, and a seed yield reduction of 23 ",, in 198523 ",, in and 10",, in 198823 ",, in . In 1986, dry matter growtb was not analysed up to tbe end of tbe growing season due to a severe infection of Botrytis fabae (Cboclate spot disease) infection in tbe control plot in tbe middle of tbe pod-filling period. Sligbt B. fabae infections in tbe control plots only were also observed in 1985 and 1988. In all experiments no significant reductions of dry matter growtb were observed in tbe vegetative and early reproductive pbases.

Modelling short-term effects of sulphur dioxide. 3. Effects of SO2 on photosynthesis of leaf canopies

“…In 1985, we exposed field crops of Vicia faba to elevated SO2 concentrations (100-200 pg SO2 m -3) and analysed growth and production. Crop growth was reduced by 1707o at the end of the growing season, but effects on the growth rate were only observed at the end of the growing season, in the pod filling period (Kropff et al, 1989). No effects could be detected in the linear growth phase.…”

Global climate change: Modelling the potential responses of agro-ecosystems with special reference to crop protection

“…Step-wise modelling of a range of impacts More insight was obtained when the analysis was deepened in the reductionist manner, leading to the conclusion that the reduction in growth rate was largely due to a reduction in light interception (Kropff et a!., 1989), mediated by reduced leaf area formation. Leaf photosynthesis itself was not significantly affected by SO".…”

The effects of long‐term open‐air fumigation with SO2 on a field crop of broad bean (Vicia faba L.)

“…The ambient background concentrations were 16//g SO^ m~^ in 1985, 7/<g SO2 m"^ in 1986 and 9 /ig SO2 m"^ in 1988. Details on the spatial and temporal distributions of the SO2 gas in the system, weather conditions and O3 concentrations are given by Kropff et al, 1989a. The plants were grown in plastic containers (55 x 22 cm, with a height of 25 cm) filled w4th a commercial potting mixture.…”