No abstract

Variations in soil pH have been shown to affect mesotrione adsorption, which in turn, may have an impact on crop susceptibility. Therefore, a greenhouse experiment was conducted to evaluate the effect of simulated mesotrione residues on pea crop grown in the typical agricultural soil (gleysol) of north-western Croatia. The soil pH was manipulated to obtain neutral (pH 7.0) and acidic (pH 5.0) values. Simulated mesotrione residues were 1.1, 2.3, 4.5, 9.0, 18, 36 and 72 g a.i. ha−1. Crop visual injuries as well as reductions in chlorophyll fluorescence and aboveground dry biomass were higher at pH 7.0 than at pH 5.0. With increasing mesotrione residues, the reductions in chlorophyll fluorescence ranged from 38.8% to 89.7% at pH 5.0 and from 63.7% to 99.3% at pH 7.0. Compared to chlorophyll fluorescence, the reductions in dry biomass were smaller and ranged from 49.2% to 96.8% at pH 7.0 and from 32.0% to 82.6% at pH 5.0 for the mesotrione residues from 1.1 to 72 g a.i. ha−1. These results indicate that soil pH is an important factor determining the susceptibility of pea crop to simulated mesotrione residues.

Herbicide residues can potentially injure sensitive crops grown in rotation. Thus, the objective of this study was to evaluate the sensitivity of six replacement crops to mesotrione residues 1 yr after herbicide application. In field bioassay, mesotrione was applied at recommended (144 g ai ha-1), twofold (288 g ai ha-1), and fourfold (576 g ai ha-1) rates at two soil types (Gleysol and Fluvisol). In field and laboratory bioassays, mesotrione residual activity was followed for a 21-d period using various measurements of phytotoxicity. No visible injuries to mesotrione residues were observed on oat (Avena sativa L.), rapeseed (Brassica napus L.), soybean (Glycine max [L.] Merr.) and sunflower (Helianthus annuus L.) in the field bioassay. Although mesotrione residues were not detected by HPLC-UV/DAD analysis, field bioassays indicated their presence due to visible injuries on field pea (Pisum sativum L.) grown in Gleysol soil with twofold and fourfold herbicide treatments. In contrast to other test crop responses, sugar beet exhibited visible injuries in both soils, and consequently, was subjected to laboratory bioassay. With increasing mesotrione rates, the reductions in sugar beet (Beta vulgaris L. var. saccharifera Alef.

Alopecurus myosuroides Huds. is an important pinoxaden-resistant grass weed in many countries of Europe. Recently, the low efficacy of pinoxaden was reported in winter cereals in Croatia, but a preliminary dose–response trial showed no herbicide resistance for the investigated weed population. Therefore, a two-year experiment was conducted under greenhouse conditions to determine the efficacy of various pinoxaden doses (20, 40 and 80 g a.i. ha−1) on weed visual injuries and biomass reduction after herbicide application at different growth stages. As expected, the maximum weed biomass reduction (97.3%) was achieved by applying the highest dose (80 g a.i. ha−1) at the earliest growth stage (ZCK 12–14). A pinoxaden dose of 20 g a.i. ha−1 resulted in satisfactory weed biomass reduction (88.9%) only when applied at ZCK 12–14. The recommended dose (40 g a.i. ha−1) also provided sufficient weed control up to the growth stage ZCK 21–25. Slightly delayed (ZCK 31–32) application of the recommended dose brought about a low weed biomass reduction (60.1%). Double than the recommended dose also failed to provide satisfactory weed control at the advanced weed growth stages (ZCK 31–32 and ZCK 37–39). Thus, reported low efficacy of pinoxaden is most likely because of delayed herbicide application when A. myosuroides is overgrown.

There is limited integration of behaviour theories and persuasive technology on behavioural change. Previous research calls for employing behaviour change theories to inform their persuasive designs and illustrate how the theories used are linked to the design features. This paper proposes integrating two theoretical models -the compelling system design and the transtheoretical model -to identify which persuasive interventions work best for the user to progress through different stages of behavioural change.Study design/methodology/approach: We performed an in-depth literature review of the transtheoretical model and persuasive system design, followed by an initial framework conceptualization. The initial framework was validated and finalized through in-depth interviews of individuals who have practiced the behaviour change for at least half a year.Findings: This paper has successfully identified the persuasive system design features and mapped them onto the transtheoretical model stages of change. The stages can be reduced into early and late stages. Consequently, we have developed a framework for designing behavioural change using persuasive technology and validated it through empirical research.Originality/value: The findings have practical implications for understanding which principles UI and UX and designers should follow when designing products for behavioural change. Moreover, our work provides insights and recommendations for the future design of persuasive interventions that consider the transtheoretical model of change.