In barley cropping systems of northern Spain, agronomic practices and weather conditions are key components of weed control efficacy. We compared the short-term effects of conventional tillage with minimum tillage (MT) and zero tillage (ZT), in barley monoculture and barley rotation systems. Weed density and weed species number were measured at tillering and flowering barley stages. We found that tillage system can influence weed density and weed species establishment due to, in part, the available light for weed seeds. The results obtained indicate that the MT system facilitates the prevalence of the grass weed Bromus diandrus Roth (50.37%) and the annual dicots Galium aparine (L.) and Buglossoides arvensis (L.) I.M. Johnst. abundant were high in the MT system too, 43.71% and 43.97% respectively. The germination of these species showed a high dependence on light availability. We saw that barley-monoculture plots had a large infestation of Bromus (71.29%) and barley-rotated plots presented more infestation of Galium and Buglossoides (74.36% and 84.4%, respectively). After herbicide application, weed infestation in conservation systems was reduced in barley-rotated plots compared with barley-monoculture. If conservation systems avoided the presence of dominant weeds, the weight of each weed species was balanced within competitive relationships of the cropping systems. Our results confirmed that MT and ZT systems favour different weed species emergences in barley-rotated plots. The combination of MT and barley-rotated cropping system resulted in greater weed diversity and lower total weed density.

The current study was carried out to assess the potential functions of exogenous glucose (Glu) on plant growth, nitrogen metabolism, and antioxidant defense system in cucumber seedings under salt stress. Our results revealed that the cucumber seedlings exposed to salinity for 7 d exhibited a significant reduction of plant height, and fresh and dry weight. The salt-induced growth inhibition was effectively alleviated by foliar application of 100 mmol L^-1 Glu. Exogenous Glu supplementation strikingly reduced the malondialdehyde content and controlled overaccumulation of superoxide anion () generation rate in the salt-stressed cucumber leaves. In addition, Glu significantly increased the antioxidant enzymes activities such as super oxidase dismutase, peroxidase, catalase and ascorbate peroxidase, and regulated gene expressions of encoding these enzymes, which decreased oxidative damage induced by salt stress. The content significantly decreased, but the level significantly increased due to salt treatment. However, Glu significantly increased the activities of nitrate reductase and nitrite reductase in salt-stressed cucumber leaves, which coincided with modulating the gene expressions of key enzymes of nitrogen metabolism, and thus, promoted the conversion of ammonium nitrogen to amino acids and proteins. These results suggest that exogenous Glu could alleviate salt-induced growth inhibition through regulating antioxidant capacity and nitrogen metabolism, which is associated with an improvement of cucumber growth and salt tolerance.

Greenhouse floriculture operations pose significant environmental risk due to extensive inputs of fertilizer, especially nitrogen and phosphorus (P). Recent evidence shows that the use efficiency for nitrogen or sulphur is markedly improved in subirrigated potted chrysanthemums (Chrysanthemum morifolium Ramat.) by supplying a moderate level of the nutrient during vegetative growth, and removing the entire nutrient suite at the onset of reproductive growth, without adverse effects on plant quality. Here, two split-plot experiments were conducted with subirrigated, potted, disbudded chrysanthemums grown in a peat:perlite mixture under greenhouse conditions (high- or low-ambient light) with inorganic orthophosphate (P_i) treatment (2.6 mmol L^-1 P_i supplied during the vegetative and reproductive stages, and 2.6, 1.95, or 1.3 mmol L^-1 P_i supplied during the vegetative stage only) as the main plot and cultivar (‘Olympia’ and ‘Covington’) as the subplot. Market quality plants with sufficient tissue P were produced even when P_i delivery was reduced by approximately 75% over the crop cycle, compared with industry standards. The primary mechanism for sustaining plant growth with decreasing P_i delivery was improved acquisition or uptake efficiency, although some changes in internal P-utilization efficiency were evident, including the remobilization of both organic P and P_i during inflorescence development. Differences in biomass yields, tissue P concentrations, content-based P-use efficiency (PUE_C = mg shoot dry mass/mg shoot P content) with constant P_i acquisition, and uptake- versus remobilization-based P supply for inflorescence growth established that ‘Olympia’ has a greater P-utilization efficiency than ‘Covington’. This modified subirrigation practice could contribute significantly to low-input production of floricultural crops.

The hard seed coat of Cercis chinensis Bunge is an important factor of its dormancy. A study of the characteristics of water absorption is vital for understanding seed dormancy and germination. This investigation found that soaking in water at an initial temperature of 80 °C for 5 min was optimal for breaking the hardness of C. chinensis seeds. Scanning electron microscopy (SEM), dye-tracking, and blocking experiments were used to examine the major water entry sites and the relationship between water uptake and seed coat structure during C. chinensis seed imbibition. The SEM images showed that the seed coat consisted of three layers: epidermis, palisade, and sclereid. Special light line, vascular bundle, and counter-palisade layer structures were found in the side of the hilum. The blocking experiments showed that the hilar region was an important water absorption site because, if the region was not blocked, it showed the highest water absorption when imbibed for 3–12 h. However, all parts of the seed coat can absorb water if enough time is allowed after the seed coat hardness has been broken. The dye-tracking test showed that after 3 h water entered the seed only via the hilum fissure. Therefore, the hilum fissure acts as the initial site of water absorption. When more time was allowed, water moved more rapidly on the side with vascular bundles than on the opposite side.

Seed coat colour is an important determinant of the visual quality of dry beans, as seeds are sold as a dry commodity. Phenolic compounds have a major effect on the colour of bean seeds. The objectives of the study were to determine the changes in phenolic compounds during seed development and in whole seeds of yellow bean genotypes with contrasting seed coat colour, and the effects of storage temperature and duration on seed phenolics and colour. Condensed tannin, phenolic acid, flavonoids, and antioxidant activity were observed as early as 10 d after flowering in the developing seeds of Arikara Yellow, which darken at harvest and during postharvest storage. In contrast, for CDC Sol and AAC Y073 seeds which remain yellow, phenolic compounds and antioxidant activity were consistently low. Seed brightness (L*) and yellow colour (b*) were negatively correlated with phenolic compounds and antioxidant activity, and conversely seed redness (a*) was positively correlated with phenolic compounds, confirming a negative influence of phenolic compounds on seed coat colour. Yellow bean genotypes had low anthocyanin but were high in β-carotene. Storage temperature influenced condensed tannin and seed coat colour, whereas the duration of storage influenced phenolic compounds, antioxidant activity, and seed coat colour. Higher temperatures (20 or 30 °C) and longer storage duration (120 or 180 d) generally resulted in darker seeds with increasing redness compared with seeds stored at 6 °C or for 60 d. AAC Y073 and CDC Sol with improved seed coat colour may increase consumer preference, value, and marketability of yellow beans.

Red light significantly affects the expression of plant photoreceptor genes and influences stomatal development through crosstalk of the constitutive photomorphogenic 1–cryptochrome–phytochrome signaling pathway. When blue light was replaced with red light, the expression levels of ZmCry1, ZmPhyB1, ZmEPF2, and ZmEPFL9 were enhanced, whereas that of ZmCOP1 was restricted. Moreover, the expression levels of ZmSPCH and ZmMUTE were also enhanced, but they were generally lower than those under white light. Consequently, stomatal formation, which was determined by net photosynthesis, stomatal conductance, intercellular CO₂ concentration, and transpiration rate, was inhibited through decreased stomatal index and stomatal density. We conclude that red light positively regulates EPFL9 in the intercellular signaling but reduces the positive regulation of blue light on COP1 and epidermal patterning factor 2 in the intracellular and intercellular signaling; therefore, though red light promotes the gene’s function on stomatal development of seedling maize, blue light maybe dominant to red light in seedling stage.

Fusarium head blight, caused mainly by Fusarium graminearum Schwabe, results in major losses in wheat. In two separate field experiments, spikes of winter wheat cultivars ‘Overland’ (moderately resistant) and ‘Overley’ (susceptible) were sprayed at anthesis with the triazole fungicide Prosaro (prothioconazole + tebuconazole) or the strobilurin fungicide Headline (pyraclostrobin) or not sprayed. Following harvest, deoxynivalenol (DON) concentrations were monitored during 120 d of grain storage at 10 °C, 40% relative humidity, and 10%, 16%, or 20% grain moisture. In ‘Overland’, DON decreased significantly at P = 0.05 from an average of 3.6 to 3.0 μg g^-1 in the check and decreased from 2.7 to 2.2 μg g^-1 in the Prosaro treatment. DON did not significantly decrease (4.4–4.1 μg g^-1) in the Headline treatment. DON concentrations did not differ between 16% (3.1 μg g^-1) and 20% (3.0 μg g^-1) grain moisture. In ‘Overley’, DON increased significantly from 3.1 to 3.6 μg g^-1 in the check and from 2.9 to 3.5 μg g^-1 in the Headline treatment, but remained the same at 2.2 μg g^-1 in the Prosaro treatment. DON concentrations were not different between 16% (3.2 μg g^-1) and 20% (3.1 μg g^-1) grain moisture but were significantly lower (2.7 μg g^-1) at 10% grain moisture. These results indicate that the effects of fungicides applied at anthesis in the field can impact DON concentrations through grain storage. Triazoles are recommended over strobilurins to achieve this extended postharvest protection from DON, and grain moisture during storage should be below the maximum safe level of 13.5% at 10 °C.

To clarify detailed patterns of responses to blue light associated with decreasing phytochrome activity, the growth and morphology traits of arugula, cabbage, mustard, and kale microgreens were compared under the treatments: (1) R, pure red light; (2) B, pure blue light; (3) BRF0, (4) BRF2, (5) BRF4, and (6) BRF6: unpure blue lights created by mixing B with low-level (6%) R, and further adding 0, 2, 4, and 6 μmol m^-2 s^-1 of far-red light, respectively. The calculated phytochrome photostationary state (PPS) value, indicating phytochrome activity, gradually decreased in the order of R (0.89), BRF0 (0.69), BRF2 (0.65), BRF4 (0.63), BRF6 (0.60), and B (0.50). Generally, the elongation growth (including stem extension rate, hypocotyl length, or petiole length) under blue lights increased with the decreasing PPS values, showing the highest and lowest sensitivity for arugula and mustard, respectively. However, the elongation promoted by blue lights gradually became saturated once the PPS values decreased below 0.60, a level which deactivates phytochrome. Other plant traits, such as biomass allocation and plant color, varied with increasing shade-avoidance responses to blue lights with decreasing PPS values relative to R, and these traits reached saturation at a similar PPS value as elongation. The response sensitivity was highest in elongation growth for arugula and cabbage, and highest in plant color for kale and mustard. This suggests that deactivated phytochrome contributes to the maximum elongation promotion as a shade-avoidance response induced by blue light, although the response sensitivity varies with plant traits and species.

This is the first record of protoporphyrinogen oxidase (PPO) inhibitor resistance in eastern Canada, and the second record of a glyphosate-resistant weed in Quebec. In 2016 and 2017, waterhemp seed was collected from 25 locations across Ontario and Quebec. All populations tested positive for imazethapyr resistance. Three-way resistance to imazethapyr, atrazine, and glyphosate was confirmed in 80% of the samples. Additionally, between 2015 and 2017, waterhemp seed was collected from 74 locations in Ontario or Quebec and resistance to lactofen was confirmed in 28% of the seed lots screened.

Field pea (Pisum sativum L.), a major pulse crop in western Canada, is sensitive to elevated temperature and possibly to high night temperature. Our objective was to examine if increasing night temperature while maintaining a constant daytime temperature affected pollen viability and seed set in two pea cultivars (CDC Golden and CDC Sage). Cultivars were exposed to 27/18, 27/22, 27/26 °C (day/night temperatures) for 7 d during flowering stage. Results indicated that increased night temperatures had no significant effect on pollen viability, the number of reproductive nodes and flowers, percentage of flower abortion, seed number per pod, and seed yield per plant.

AAC Y073 is a high-yielding, yellow dry bean (Phaseolus vulgaris L.) cultivar with a partially upright, determinate bush (type I) growth habit, early maturity, and large seeds with a bright yellow seed coat. Large, bright yellow seeds of AAC Y073 is an improvement over the current check cultivar CDC Sol. AAC Y073 was developed at the Agriculture and Agri-Food Canada, Lethbridge Research and Development Centre, Lethbridge, AB, and is well suited for commercial production under irrigation in Alberta and Saskatchewan.