Apple trees bear an abundance of flowers that produce a surplus of fruit that the tree is unable to support. A self-regulatory mechanism enhances the abscission of immature fruitlets, leading to a reduced fruit load, but this is often insufficient to achieve fruit of marketable size. Supplementary fruit thinning is usually required to optimize economic fruit load and annual bearing. This 2 yr study investigated the response of Royal Gala apple trees to primary single and combination sprays of 6-benzyladenine (6-BA) and carbaryl during fruit set, followed by secondary sprays of either treatment 7 d later. The objective was to determine the effect of a second application of chemical thinner on fruitlet abscission, which compounds are most efficacious, and to characterize the pattern of fruitlet drop. The combinations of chemical thinners varied in their effectiveness at reducing crop density. About 12–14 d were required from the time of the first application of chemical thinner to observed fruitlet beneath trees. A single application of both thinners applied at 8 mm advanced fruit drop by 7 d in most instances. The tank-mix of 6-BA and carbaryl applied at 8–10 mm followed by a secondary spray of carbaryl at 15 mm was the most efficacious thinning combination. Secondary sprays of 6-BA at 15 mm were ineffective at inducing additional fruit drop. Combination sprays of 6-BA and carbaryl were more effective than repeat sprays of the same product. This study enhances our understanding of the dynamics of fruitlet abscission and the benefits of multiple applications of post-bloom chemical thinners.

Cultivated oat (Avena sativa L. and Avena byzantina Koch) is native to Turkey, a secondary center of oat diversity. Oat breeding has received less attention relative to other cereals. In this work, the diversity of oat landraces collected from different regions of Turkey as well as obtained from different gene banks was investigated using 3293 high quality SNP markers. Expected heterozygosity (Hs), observed heterozygosity (Ho), inbreeding coefficient (Fis), and overall genetic diversity (Ht) of the oat gene pool were 0.22, 0.01, 0.96, and 0.38, respectively. The value of the genetic differentiation (Fst) metric for genetic structure was 0.41 and indicated that kinship was more of a determinant for population structure than the geographical provenance. The populations from different geographical regions shared a great proportion of genetic diversity. Clustering using model-based STRUCTURE, principal coordinates (PCoA), and neighbour-joining (NJ) algorithms were mostly comparable except for five discrepantly clustered accessions in NJ and PCoA relative to STRUCTURE, which can be attributed to the relatively reduced resolution power in the NJ and PCoA approaches. SNP markers partitioned all oat accessions into four main groups (A, B, C, and D) with 10 unclassified accessions. Some landraces were identical based on genetic distance and can represent duplications in gene banks. The data presented in this work represent the initial results on genetic diversity as investigated in Turkish oat, and are an important resource for systematicians, geneticists, and breeders interested in Turkish oat germplasm. These results are expected to open new opportunities for further studies in oat genomics and cultivar development.

Fall-seeded rye (Secale cereale) is known to suppress weeds through physical and allelopathic properties. This study examined the effects of fall rye cover crops on weed and dry bean (Phaseolus vulgaris) productivity over four site–years in Manitoba. In addition to rye, we tested early versus late spring rye termination times as well as herbicide use in a factorial experiment with four replicates. In the absence of herbicides, rye reduced early-season broadleaf and grassy weed plant populations by 44%–72% and 43%–88%, respectively. Terminating rye at the four-leaf stage (∼1100 kg dry matter ha^-1) provided the same level of weed suppression as termination at booting (∼3100 kg dry matter ha^-1). Early rye termination increased bean plant populations (significant at three out of four sites), bean development (four out of four sites), bean biomass (two out of four sites), and bean yield (three out of four sites) compared with later termination. Lower bean yield with rye at one site–year was attributed to dry early season conditions, where rye reduced soil water content. While the rye cover crop provided multiple benefits to bean production, early termination resulted in the best agronomic outcome. Rye was beneficial to weed control even when herbicides were used.

Glyphosate-resistant (GR) waterhemp was first discovered in Ontario, Canada, in 2014. In Ontario, GR waterhemp interference in previous studies reduced soybean yield up to 73%. Tank-mixes of herbicides with multiple modes-of-action are important for delaying the evolution of herbicide resistance. The objective of this study was to evaluate the efficacy of pyroxasulfone (150 g a.i. ha^-1), S-metolachlor/metribuzin (1943 g a.i. ha^-1), pyroxasulfone/sulfentrazone (300 g a.i. ha^-1), and pyroxasulfone/flumioxazin (240 g a.i. ha^-1) applied preemergence (PRE) with and without the addition of glyphosate/dicamba (1800 g a.e. ha^-1) for the control of GR waterhemp in soybean. At 8 wk after treatment application (WAA), glyphosate/dicamba applied PRE controlled GR waterhemp 45%. Pyroxasulfone, S-metolachlor/metribuzin, pyroxasulfone/sulfentrazone, and pyroxasulfone/flumioxazin applied PRE controlled GR waterhemp 79%, 87%, 91%, and 95%, respectively. At 2, 4, 8, and 12 WAA, the addition of glyphosate/dicamba to the aforementioned PRE herbicides did not improve GR waterhemp control. There was no increase in GR waterhemp control with the addition glyphosate/dicamba; however, multiple herbicide modes-of-action should be utilized to reduce the selection intensity for herbicide-resistant weeds.

Two approaches for enhancing red blush in Ambrosia^™ apple were evaluated: (i) reflective row covers or (ii) application of foliar phosphorus-rich sprays, both applied several weeks before anticipated harvest. Two experiments were conducted, the first to evaluate a white reflective row cover versus foliar phosphorus spray, and the second to evaluate two types of reflective row cover, one made of a woven white polyethylene sheet and the other a solid silvered Mylar^®. The comparative effects of these preharvest treatments on at-harvest fruit quality and quality after storage were assessed in both experiments. It was determined that foliar phosphorus sprays or one of the two types of reflective row covers resulted in similar enhancement of red blush colour, with no negative effects on at-harvest quality. However, in the first experiment it was found that after 8 mo of controlled-atmosphere storage (1 kPa O₂ + 1 kPa CO₂ at 0.5 °C), apples from the phosphorus foliar spray treatment developed greasiness and sooty blotch compared with those from the reflective row cover or control treatments. In the second experiment, after 5 mo of air storage at 0.5 °C, the apples from the silvered Mylar^® reflective row cover treatment developed severe soft scald and soggy breakdown compared with the control and white reflective row cover treatments, which developed lower or very slight incidence of soft scald, respectively, and no soggy breakdown. These results indicate that when preharvest treatments are applied to apples, post-storage quality effects should be evaluated.

Soybean breeding programs targeting tofu production must identify cultivars that are well suited for making tofu. A small-scale (SS) test of tofu texture was developed to evaluate breeding lines. The SS tofu test was developed to complement the larger scale Harrow tofu test but to use smaller samples of seed and soymilk to make tofu. The SS tofu test uses both magnesium chloride (MgCl₂) and glucono-delta-lactone (GDL) coagulants to produce tofu samples of 20 mL. In comparisons of the SS and Harrow tofu texture tests, using lines with varying protein subunit profiles, both tests ranked lines similarly. In plant breeding trials, the SS tofu test was useful in ranking varieties for tofu texture. Multiple-year testing should be used for a thorough evaluation of varieties. When the SS tofu test was used with a population of lines with a wide range of seed protein, GDL-coagulated tofu texture was independent of seed protein content; however, MgCl₂-coagulated tofu texture was moderately inversely correlated with seed protein. With the SS test, it may be best to compare tofu texture within groups of lines with similar seed protein levels. The SS tofu test is useful to test tofu texture of breeding lines using small amounts of seed.

Lygus bugs and Botrytis fungal pathogen, the causal agent of chocolate spot in faba bean, can cause necrotic spots on faba bean seeds, thereby reducing market value. The mid-pod stage is the most susceptible stage for chocolate spot development and Lygus infestation in faba beans. Therefore, we hypothesised that the concomitant presence of Lygus spp. and Botrytis spp. might increase seed necrosis. Hence, the study was conducted to determine (i) the spatial and local distribution of chocolate spot and Lygus spp. in central and southern Alberta, and (ii) the association of chocolate spot disease severity and Lygus abundance. Chocolate spot and Lygus were present in all the counties surveyed. Chocolate spot had a negative association with Lygus abundance, but only the latter was significantly associated with seed necrosis. Botrytis spp. were frequently isolated from seeds despite the lack of expression of chocolate spot on the foliage. No significant effect of Lygus abundance on Botrytis isolation from seeds was found. Therefore, seed quality losses can occur both due to the fungal pathogen and the insect, which likely occupy different niches influenced by microclimate. Economic thresholds and management strategies will be required to keep insect populations and disease progression under check.

Pulses are staple foods that are gaining recognition as sources of non-gluten proteins, slow digestible starch, and dietary fiber. Several factors contribute to the cooking quality of pulses including genetics, environment, and their interactions. In this study, four cultivars each of faba bean, lentil, and pea were evaluated for nutrient content, flour viscosity measured by a rapid visco analyzer, and acid and alkaline extract viscosity determined by a cone-plate viscometer. These properties were analyzed in relation to seed hydration and firmness of cooked pulses measured by a texture analyzer to better understand their relationships with and contribution to pulse cooking quality. Pea had the lowest protein (18.7%–22.3%) and highest starch (43.0%–46.3%) followed by lentil (protein 25.1%–26.7%, starch 38.4%–45.5%) and finally faba bean (protein 26.5%–29.2%, starch 38.4%–41.8%). Significant differences (P < 0.05) were observed among cultivars within each crop in hydration capacity and firmness of cooked seeds. Rapid visco analyzer viscosity of pulse flours showed significant differences (P < 0.05) among crops and cultivars, and was significantly correlated with firmness. Firmness was significantly correlated with protein and ash content. The results suggest that firmness of cooked pulses is significantly influenced by seed components and starch behavior during heating, indicating the importance of viscosity in determining the cooking quality of pulses.

Canada fleabane is a winter or summer annual weed that is found throughout North America. Fall-emerged Canada fleabane can fix carbon early in the growing season, giving it a competitive advantage over nearby crop and weed species. Glyphosate-resistant (GR) Canada fleabane was originally found in one county in Ontario, Canada, in 2010 and had spread to at least 29 additional counties within the province by 2016. Previous research with several preplant herbicides resulted in variable control of GR Canada fleabane in soybean. The objective of this study was to evaluate the efficacy of glyphosate/dicamba (1800 g a.e. ha^-1) alone or with the addition of a second effective mode-of-action for the control of GR Canada fleabane in glyphosate/dicamba-resistant soybean. At 4 weeks after application, glyphosate/dicamba + saflufenacil, saflufenacil/dimethenamid-P, saflufenacil/imazethapyr, or paraquat controlled GR Canada fleabane 97%, 96%, 97%, and 98%, respectively. All herbicide treatments decreased Canada fleabane density and biomass by 93%–99%. When choosing herbicide programs, it is important to consider the use of multiple modes-of-action to decrease selection pressure for the evolution of herbicide-resistant Canada fleabane. Treatments containing saflufenacil, saflufenacil/dimethenamid-P, or saflufenacil/imazethapyr with the addition of glyphosate/dicamba are recommended for the control of GR Canada fleabane.

In this short communication, we report the observation of a tricotyledenous giant ragweed (Ambrosia trifida L.) individual. In contrast to the normal dicotyledenous pattern of phyllotaxy, this individual was observed to express three axillary meristems at each node that intersected the main stem at angles of 120°.

‘Empire' apples were stored at 0 °C or 3 °C with 0.03 or 5 kPa CO₂ and 2.5 kPa O₂ for 16 wk. Pools of free, soluble conjugated and bound putrescine, spermidine, and spermine fluctuated in a dynamic manner in response to both temperature and CO₂. These results suggest that putrescine homeostasis is under different regulatory control than spermidine/spermine homeostasis.

Variance analysis was performed on the effect of monthly accumulated precipitation data (May–July) on crop losses between 2005 and 2016 with combined Manitoba and Saskatchewan regional barley grain yield data. A significant negative relationship with total precipitation during May to June was observed. This period coincides with leaf emergence to the booting stage in barley.

A 24-h pulse of cut dahlias in a solution containing both benzyladenine and gibberellic acid at 10–20 mg L^-1 improved flower quality after 4 d in the vase and prolonged vase life regardless of handling method (dry packed or held in water from harvest through delivery).

AAC Viewfield hard red spring wheat (Triticum aestivum L.) has a grain yield significantly higher than the check cultivars Katepwa and Lillian and is similar to Carberry. AAC Viewfield matures significantly later than Katewpa and Lillian but is similar to Carberry. AAC Viewfield has an awned spike, a low lodging score (indicative of strong straw), and significantly shorter plant stature than all checks. AAC Viewfield expressed resistance to prevalent races of yellow rust and stem rust, moderate resistance to leaf rust and common bunt, and intermediate resistance to Fusarium head blight. AAC Viewfield has quality attributes within the range of the check cultivars and is eligible for grades of Canada Western Red Spring wheat.