Wind tunnel studies have been used to simulate hot dry wind events that occur in Mediterranean climates and to investigate their possible impact on field crop production. This study investigates the effects of wind speed, duration, flower development stage and soil moisture on flower abortion and pod set in faba bean (Vicia faba L.) using a wind tunnel. At an air temperature of 30°C and relative humidity of 15–25%, rates of flower abortion increased with wind speed across a range of 2 to 12 m/s with the proportion of flowers setting a healthy pod following treatment declining for all stages of flower development tested. At 12.5 m/s, flower abortion reached close to the maximum observed, with a 35% reduction in pod set below that observed in the control plants at flower development stages up to and including anthesis. As the flowers develop, they become less sensitive to the hot windy conditions with abortion rates declining gradually from early developmental stages and showing a sharp decline in sensitivity after anthesis. Once the pod has set and extended beyond the withered petals, it is not vulnerable to extreme wind conditions and has a high chance of continuing to develop if moisture is available. Lower soil moisture levels and increased duration inconsistently increased the rate of flower abortion. When soil moisture is not limiting, hot dry wind will significantly contribute to flower abortion and may reduce crop yield. This level of flower abortion does not necessarily translate directly to yield reduction as pods that have already set on proximal nodes have a low vulnerability to adverse conditions and may remain unaffected by a severe wind event, while flowers at an early stage of development on distal nodes are vulnerable and may be affected leading to flower loss. If plant development is interrupted due to ending of the growing season, the more distal flowers may not have an opportunity to reach a harvestable stage and the impact of the wind event will not be expressed in the final yield. Net yield reduction therefore depends on seasonal conditions and the timing of the event. These results infer that the risk and extent of yield reduction in faba beans following severe climate events during the flowering phase could be minimised by creating sheltered zones of reduced wind speed with planted windbreaks.

The objective of this work was to evaluate the fungitoxic effect of the aqueous extracts of Baccharis trimera on the mycelial growth of Colletotrichum lindemuthianum 89 race, as well as its effect on the accumulation of phaseolin in hypocotyls of different cultivars and common bean varieties. It was obtained 20% aqueous extract from plants collected in municipalities of the Western Region of Paraná. Blocks containing C. lindemuthianum mycelium were transferred to Petri dishes containing medium with the different extracts and incubated at 25 °C. The colonies diameter was measured until the 12th day. Effects of aqueous extracts on phaseolin production was evaluated in hypocotyls of Carioca, Cnpf 8104, Soberana, Tibatã, Uirapurú cultivars, as well as Rosinha and Vermelho varieties. Each one cultivar and variety hypocotyl was transferred separately to test tubes containing 500 μL of 20% aqueous extracts. Sterile water, Bion®, and UV was used as controls. The phaseolin production was measured in spectrophotometer [280 nm]. Results of the evaluation of the antifungal activity of aqueous extracts of Baccharis sp. specimens collected indicate that approximately 50% of the samples presented capacity to reduce between 74 and 92% of C. lindemuthianum growth. Cultivar Tibatã and Vermelho variety showed greater sensitivity over the applied HIGHLIGHTS  Baccharis trimera aqueous extracts can inhibit Colletotrichum lindemuthianun 89 race growth.  C. lindemuthianum filtrate can be used as a phaseolin inductor on common bean.  There is no evidence of phaseolin induction through application of aqueous extracts of B. trimera in common bean hypocotyls.