Registered users receive a variety of benefits including the ability to customize email alerts, create favorite journals list, and save searches.
Please note that a BioOne web account does not automatically grant access to full-text content. An institutional or society member subscription is required to view non-Open Access content.
Contact helpdesk@bioone.org with any questions.
This research evaluated the influence of different washing treatments (i.e., tap water, ozone, microbubbles, and ozone combined with microbubbles) on post-harvest decay of chestnuts (Castanea crenata ‘Tsukuba’) during storage. Overall, treatments with ozone and microbubbles significantly reduced the decay frequency and the associated microbial populations (aerobic bacteria, mold/filamentous fungi, and yeasts) during post-harvest storage compared with the traditional practice (tap water washing). Enhancing the efficacy of chestnut washing treatments will contribute to the improved storage of high-quality chestnuts.
Field experiments in 2013 and 2014 examined corn (Zea mays L.) tolerance to acetyl-coenzyme A carboxylase (ACCase) inhibiting herbicides in a scenario where they would have been used to terminate a failed corn stand prior to replanting. To simulate this, herbicides were applied 1 wk or 1 d preplant (PP) and several parameters were measured. Corn injury 1, 2, 4, or 8 wk after emergence (WAE) was similar to the untreated control, regardless of herbicide, rate, or PP application timing. Across herbicides and rates, PP timing did not affect plant stand and aboveground biomass 2 WAE, plant height 4 WAE, or yield. Across application timings, plant stand and aboveground biomass were similar to the untreated control, regardless of herbicide treatment or rate; however, some herbicides reduced height and (or) yield. For example, compared with the untreated control, fluazifop-p-butyl (75 and 150 g ha-1) and sethoxydim (300 g ha-1) each reduced height by about 3%, while clethodim (30 and 60 g ha-1), fluazifop-p-butyl (150 g ha-1), and quizalofop-p-ethyl (72 g ha-1) each reduced yield by about 2%. Therefore, in situations where a grower may need to terminate a failed corn stand, the selection of ACCase-inhibiting herbicides could be based on efficacy rather than plant-back restrictions.
The pyrimidine herbicide aminocyclopyrachlor was evaluated for crop tolerance and weed control in wild blueberry (Vaccinium angustifolium Aiton). Preemergence applications of aminocyclopyrachlor at a rate of 50 g a.i. ha-1 did not reduce aboveground blueberry biomass, yield potential, or final yield, and this rate appears safe for use in wild blueberry. Preemergence applications of aminocyclopyrachlor at a rate of 100 g a.i. ha-1 reduced aboveground blueberry biomass, but yield potential and final yield were only reduced significantly at application rates of 200 and 400 g a.i. ha-1. Preemergence applications of aminocyclopyrachlor at a rate of 100 g a.i. ha-1 effectively suppressed Euthamia graminifolia (L.) Nutt., and further evaluation of aminocyclopyrachlor to identify safe application timings and rates in wild blueberry is warranted. Aminocyclopyrachlor applied as a directed spot spray provided good control of several herbaceous and woody perennial weeds, and this use pattern could provide an alternative management option for many perennial weeds in wild blueberry.
Camelina [Camelina sativa (L.) Crantz] has potential in aquaculture, livestock feed production, and the biofuel industry. It is necessary to determine the appropriate production technology for the newly introduced crop under different environmental conditions. The objective of this 2-year study was to measure the response of five camelina genotypes in terms of seed yield, yield components, and disease incidence to applied nitrogen (N) at multiple sites in the Maritime provinces of eastern Canada. The factorial experiment was set up as a randomized complete block design. The two factors were six N rates (0, 25, 50, 100, 150, and 200 kg ha-1 N) and five genotypes of camelina (Calena, CDI002, CDI005, CDI007, and CDI008). The interactive effect of N rates and genotypes was considered. Results showed that camelina, which is usually considered a low-input crop, responded positively to increased applied N at rates up to 200 kg ha-1 N. Seed yield responded differently to applied N rates depending on genotype. Branch and pod development were decisive for seed yield. The advanced line CDI007 had the highest yield potential among the five genotypes. Downy mildew infection was positively correlated with applied N rates; however, seed yield was not significantly affected by downy mildew infection.
Mulberries, Morus spp., grow in different growing regions of Turkey with a high diversity providing an opportunity to select superior accessions. The goal of the study was to determine the differences in phytochemical components and horticultural characteristics between white and black mulberry accessions in the Igdir province. Fruits of black and white mulberries collected from Igdir province were assayed for various horticultural characteristics including berry width, berry length, berry weight, and berry peduncle length. Samples were also assayed for vitamin C, organic acids (citric, tartaric, malic, succinic, and fumaric), sugars (glucose and fructose), phenolic acids (catechin, rutin, quercetin, chlorogenic, ferulic, o-coumaric, p-coumaric, caffeic, syringic, vanillic, and gallic acids), and antioxidant capacity [Trolox equivalent antioxidant capacity (TEAC) assay]. Differences (P < 0.05) were noted between accessions in berry length and berry weight. Malic acid was found to be the predominant organic acid regardless of species. Rutin (for black mulberry) and chlorogenic acid (for white mulberry) were the predominant phenolic acids. Black mulberry had higher glucose and fructose content than white mulberry. Analysis showed that black mulberry had higher content of tartaric acid, malic acid, TEAC, fructose, glucose, catechin, rutin, quercetin, o-coumaric acid, and caffeic acid compared with white mulberry (P < 0.01); however, white mulberry had higher content of succinic acid, vitamin C, chlorogenic acid, ferulic acid, p-coumaric acid, syringic acid, and gallic acid (P < 0.01). Our results provide a reference for further studies of mulberry fruits in detection of organic acids, sugars, antioxidant capacity, and phenolic compounds. Also, it is clear that we need standardized testing, extraction, and analysis protocols to compare genotypes grown in different countries.
Field studies were conducted at two locations in western Manitoba over three years to evaluate the impact of rate, source, and placement of nitrogen (N) fertilizer on seedling emergence, disease severity, crop yield, and seed quality of flax (Linum usitatissimum L.). Urea, urea ammonium nitrate (UAN), and ammonium nitrate (AN) fertilizers were applied at 0, 30, 60, and 90 g N ha-1, pre-plant banded or side-banded 2.5 m to the side and 2.5 m below the seed-row, using a hoe-type opener with 20 m row spacing. Differences in stand emergence occurred from year to year, depending on the moisture conditions after seeding. Nitrogen fertilizer occasionally decreased stand density when side-banded, with effects being greatest with urea and UAN. The magnitude of stand decrease was generally low, although it may have restricted seed yield with high rates of urea fertilization in some years. Nitrogen applications frequently increased leaf and stem pasmo, but the effects of fertilizer source and placement were variable. Seed yield increased with N application except at a single site where soil N levels were high. Where differences existed among sources, yield was generally lower with urea than with the other sources, possibly related to seedling damage from the urea at higher rates of application, or to physiological effects of high ammonia:nitrate ratio nutrition during early growth. Seed quality for oil production tended to decline with increasing N applications due to lower oil concentration, lower iodine number, and a decrease in the concentration of high-quality linolenic and linoleic fatty acids. However, seed protein concentration increased with increasing N concentration. While risk of seedling damage and pasmo may increase with increasing levels of N fertilizer, either side-banded or pre-plant banded N applications still resulted in increased flaxseed yield. However, increasing N rate slightly decreased quality for oil production.
KEYWORDS: Chickpea, imidazolinone, broadleaf weed control, Herbicide resistance, Pois chiche, imidazolinone, lutte contre les dicotylédones, résistance aux herbicides
Chickpea (Cicer arietinum L.) production in the Northern Great Plains is limited by very few broadleaf weed control options. Field experiments were conducted at two locations in 2012 and at three locations in 2013 in Saskatchewan, Canada, to examine the performance of the conventional and the imidazolinone (IMI) resistant chickpea cultivars to post-emergence application of imazamox or imazethapyr applied alone or in tank-mix. Treatments included imazamox (20 and 40 g a.i. ha-1), imazethapyr (50 and 100 g a.i. ha-1), and a tank-mixture of imazamox (35%) imazethapyr (35%) (30 and 60 g a.i. ha-1). Conventional cultivars, CDC Luna and CDC Corinne, showed moderate to severe injury compared with resistant cultivars, CDC Alma and CDC Cory, which showed minimal to no injury. Plant height was arrested and node development slowed for conventional cultivars treated with IMI herbicides. This susceptibility to IMI herbicides was also noted with a delay in flowering and maturity. Despite a significant negative response, CDC Luna and CDC Corinne were able to recover throughout the growing season resulting in no yield loss from IMI treatments at all locations, except one. Resistant cultivars, CDC Alma and CDC Cory, demonstrated no significant injury from IMI herbicide compared with the untreated controls. These results show the potential to use IMI herbicides in the resistant chickpea cultivars, expanding the currently limited options for broadleaf weed control in chickpea cultivation.
Decomposition of cover crop mulches has received little attention in the scientific literature, particularly in the context of the organic rotational no-till systems adapted for the climatic conditions of the northern Great Plains of Canada. The objective of the study was to determine the effect of plant species and mulch application rate on cover crop decomposition and mulch quality parameters over time. Using the litter bag technique, six plant species and two mulch application rates were tested twice in field studies at Carman, Manitoba, Canada. Among the plant species tested, decomposition was the fastest with oilseed radish (Raphanus sativus L.) and the slowest with barley (Hordeum vulgare L.). The effect of application rate on mulch biomass was not consistent between experiments. Mulches released a large amount (46.4%) of their initial N content after only 30 days of field placement, for all levels of plant species and mulch application rates combined. Forty-four percent of initial N content still remained in the mulches by early May (Day 250), and may be available for the subsequent crops seeded in the spring or later in the crop rotation. This research provides us with valuable information on nutrient release, soil cover, and potential weed control from mulches.
The future release of ‘Balance GT’ soybean, which is resistant to isoxaflutole and glyphosate, opens up the possibility for control of glyphosate-resistant (GR) Canada fleabane using HPPD-inhibiting herbicides (Group 27) in soybean. Field trials were conducted over two years to evaluate the dose response of an isoxaflutole plus metribuzin tank mix, as well as each chemical applied alone, to assess their response using Flint's adaptation of Colby's equation. Factorial experiments were performed in growth room and greenhouse environments to assess isoxaflutole versus glyphosate, isoxaflutole versus metribuzin, and isoxaflutole plus metribuzin versus glyphosate. Tank mixes of isoxaflutole plus metribuzin in a 1:4 ratio provided 80% control of GR Canada fleabane at a dose range between 420 (84 336) and 611 (122 489) g a.i. ha-1 at 8 WAA (weeks after application). Tank mixes achieved an 80% reduction in biomass at a dose range between 498 and 738 g a.i. ha-1, while 80% reduction in density was obtained with doses from 96 to 423 g a.i. ha-1, 8 WAA. With glyphosate as a constant tank partner, field treatments of isoxaflutole plus metribuzin were mostly synergistic with some analyses showing an additive response. When tested in the growth room, isoxaflutole plus glyphosate tank mixes indicate additivity in the majority of treatments on glyphosate-susceptible (GS) fleabane.
KEYWORDS: dry bean, damage, seed water content, yield, weed control, emergence, haricot sec, dommages, teneur en eau de la graine, rendement, lutte contre les mauvaises herbes, Levée
Six field experiments were conducted over a two-year period (2013 and 2014) to evaluate the tolerance of white bean and spectrum of weeds controlled with halosulfuron applied preplant incorporated (PPI) alone or tankmixed with trifluralin, pendimethalin, EPTC, dimethenamid-P, or S-metolachlor. Halosulfuron applied alone or in tankmix with trifluralin, pendimethalin, EPTC, dimethenamid-P, or S-metolachlor caused 2% or less visible injury 1 and 4 weeks after emergence (WAE). Halosulfuron applied PPI controlled common lamb's-quarters, wild mustard, redroot pigweed, and common ragweed greater than 90% and green foxtail less than 60% 4 and 8 WAE. Weed biomass and density followed a similar pattern. White bean yield with halosulfuron applied alone or in tankmix with the same herbicides was equivalent to the weed-free control.
KEYWORDS: grapevine water relations, soil moisture, Leaf water potential, vine vigour, Anthocyanins, relations hydriques de la vigne, taux d'humidité du sol, potentiel hydrique des feuilles, vigueur des vignes, teneur en anthocyanines
The study objective was to determine whether multispectral high spatial resolution airborne imagery could be used to segregate zones in Pinot noir vineyards to target highest quality fruit for premium winemaking. We hypothesized that remotely sensed data would be correlated with vine size and leaf water potential (Ψ), and by extension with yield and berry composition. In 2008-2009, multispectral (blue, green, red, near-infrared) airborne images were acquired from four Ontario Pinot noir vineyards (four dates, 2008; three, 2009), with the final flight date near veraison. A process was developed to extract information from sentinel vine locations, and to calculate normalized difference vegetation index (NDVI). Data were extracted at 1 × 1, 3 × 3, and 5 × 5 pixel re-sampling rates to test for ideal image resolution. A method was developed to mask non-vine pixels to simplify qualitative assessment of images. The 3 × 3 pixel re-sampling provided most useful information. In 2008, 3 × 3 re-sampling NDVI correlated with (r-values; p < 0.0001): berry pH (-0.48), soluble solids (-0.43), vine size (0.46), anthocyanins (-0.65), colour (-0.58), and soil clay and sand content (-0.55, 0.55). In 2009, mean 3 × 3 re-sampling NDVI correlated with (r-values; p < 0.0001): anthocyanins (0.49), soil moisture (-0.89), and soil clay and silt content (-0.75, 0.83). No clear trends in correlations existed between vegetation indices vs. vine size, anthocyanins, phenolics, or soil moisture throughout the growing season in either vintage. Masked images proved effective for viewing spatial trends in airborne images without full data extraction. Qualitative similarities existed between maps of vineyard and grape composition variables vs. maps of extracted data and masked images. Remote sensing may be useful to determine colour or phenolic potential of grapes, in addition to vine water status, yield, and vine size. This study was unique by employing remote sensing in cover-cropped vineyards and thereafter using protocols for excluding spectral reflectance contributed by inter-row vegetation.
As a family of signaling plant hormone, jasmonic acid plays an important role in coordinating plant defense responses to pests and pathogen attack through transcriptional and metabolic changes. In the jasmonate biosynthetic pathway of plants, allene oxide cyclase (AOC) is an essential enzyme. Here we cloned a cDNA from tea plant (Camellia sinensis), named as CsAOC (GenBank: HQ889679), which was 916 bp, containing an open reading frame (738 bp) encoding 245 amino acids. Comparative and bioinformatic analyses revealed that the deduced protein of CsAOC was highly homologous to AOC from other plant species. Phylogenetic analysis indicated that CsAOC was clustered in a closely related subgroup with AOC of Ipomoea nil. The full-length coding region of CsAOC was ligated with pET-32a and successfully expressed in E. coli BL21 (DE3), and purified. Real-time quantitative PCR analysis revealed that methyl jasmonate (MeJA) treatment on its own potently enhanced its expression over the control (healthy leaves), suggesting feedback activation of CsAOC. The expression under salicylic acid (SA) and wounding treatments was up-regulated. The mRNA expression of CsAOC could be induced by tea geometrids and tea green leafhoppers.
Plants defense responses to abiotic stresses, including salinity stress, involve stimulation of defense related pathways such as biosynthesis of secondary metabolites and induction of endogenous antioxidant enzyme responses. In the present study, a single seed origin clonal line of Swertia chirayita inoculated with Lactobacillus plantarum (LP) was grown under different salinity levels. Control had no LP inoculation. S. chirayita inoculated with LP showed higher accumulation of proline, low proline dehydrogenase activity, up-regulation of pentose phosphate pathway, down-regulation of succinate dehydrogenase activity (Krebs cycle) and low total phenolic content with increased salt concentrations. In comparison, S. chirayita without LP adopted a different biochemical mechanism to counter salt stress (NaCl) by up-regulating both pentose phosphate pathway and Krebs cycle along with stimulation of phenolic biosynthesis. Guaiacol peroxidase (GPX) activity increased with and without LP treatment in response to increasing concentrations of salt. These results indicate that S. chirayita inoculated with LP exhibits a greater salinity stress tolerance than S. chirayita without LP by adopting a more energy efficient defense responses and potentially efficiently partitioning carbon flux between primary and secondary metabolism to counter salt induced oxidative stress.
Sorbitol is a primary photosynthetic product and the principal photosynthetic transport substance in plants of the Rosaceae. Sorbitol transporters in the major facilitator superfamily (MFS) are important for phloem loading and sorbitol uptake into sink tissues. Here we report the cloning, localization, and expression analysis of a sorbitol transporter in fruit of Pyrus bretschneideri Rehd. cv. “Yali.” This clone, named PbSOT2, encoded a 537-aa protein with a calculated molecular mass of 57.92 kDa. The predicted protein had 12 transmembrane domains and belonged to the MFS carriers. PbSOT2 was sub-cellularly targeted to the plasma membrane. The expression of PbSOT2 was highest during the rapid enlargement phase of fruit (100 days after full bloom). In addition, the sorbitol content in fruit fluctuated within certain limits, but its proportion of total sugars decreased continuously. This work shows that PbSOT2 may play a role in fruit enlargement and the accumulation of hexose during fruit development.
The sweet potato (Ipomoea batatas (L.) Lam.) requires a long, hot growing season to attain good yields. In a cool climate, the use of black plastic mulch to heat the soil can improve growth but cultivars, plant spacing, and harvest date must be carefully selected to optimize yields and to attain market quality standards. In this two-year study in Quebec, Canada, two sweet potato cultivars (‘Georgia Jet’ and ‘Beauregard’) were grown at four in-row spacings (15, 30, 45, and 60 cm) and harvested at three dates (mid September, late September, and early October). Cumulative growing degree-days (GDD) with base temperatures of 10°C and 15.5°C were calculated for each harvest date. ‘Georgia Jet’ had higher total and marketable yields than ‘Beauregard’. In-row spacing had no effect on yields per hectare of ‘Beauregard’ and only affected ‘Georgia Jet’ in one year of the study. Average root weight of sweet potatoes, yields per plant, and number of roots per plant increased with wider spacing. Delaying harvest by one or two weeks had little effect on ‘Beauregard’ but increased yields of ‘Georgia Jet’. GDD may be a useful predictor of optimum harvest date but a lower base temperature used to calculate GDD may be desirable with ‘Georgia Jet’ as its yields continued to increase even when growing under cool conditions of late September and early October.
HS-151 is a lipoxygenase free food grade soybean line (Glycine max. L.) with large seed size, high protein content, yellow hilum, and satisfactory food processing quality. It is adapted to areas of southwest Ontario with 3100 or more crop heat units and has a relative maturity of 2.2 (MG 2.2).
KEYWORDS: flowering duration, reproductive phase, diverse environments, seeding rates, pod to flower ratio, duree de la floraison, phase reproductive, variation de lenvironnement, densite des semis, ratio gousse-fleur
Optimal plant density is required to improve plant phenological traits and maximize seed yield in field crops. In this study, we determined the effect of plant density on duration of flowering, post-flowering phase, and seed yield of canola in diverse environments. The field study was conducted at 16 site-years across the major canola growing area of western Canada from 2010 to 2012. The cultivar InVigor® 5440, a glufosinate-resistant hybrid, was grown at five plant densities (20, 40, 60, 80, and 100 plants m-2) in a randomized complete block design with four replicates. Canola seed yield had a linear relationship with plant density at 8 of the 16 site-years, a quadratic relationship at 4 site-years, and there was no correlation between the two variables in the remaining 4 site-years. At site-years with low to medium productivity, canola seed yield increased by 10.2 to 14.7 kg ha-1 for every additional plant per square metre. Averaged across the 16 diverse environments, canola plants spent an average of 22% of their life cycle flowering and another 27% of the time filling seed post-flowering. Canola seed yield had a negative association with duration of flowering and a positive association with the days post-flowering but was not associated with number of days to maturity. The post-flowering period was 12.7, 14.7, and 12.6 d (or 55, 68, and 58%) longer in high-yield experiments than in low-yield experiments in 2010, 2011, and 2012, respectively. We conclude that optimization of plant density for canola seed yield varies with environment and that a longer post-flowering period is critical for increasing canola yield in western Canada.
The anticipated availability of dicamba-resistant crops will increase the potential for crop injury to non-dicamba-resistant soybean due to dicamba spray tank contamination. A total of eight field trials were conducted at various locations in Ontario, Canada during 2012-2014 to determine the response of non-dicamba-resistant soybean to dicamba spray tank contamination at 0, 0.75, 1.5, 3, 6, 15, 30, and 60 g a.e. ha-1 applied postemergence (POST) at the V2-3 (2-3 trifoliate) or R1 (1st flower) stage. At one week after treatment (WAT), dicamba applied at 0.75, 1.5, 3, 6, 15, 30, and 60 g a.e. ha-1 at V2-3 caused 12, 18, 25, 31, 43, 53, and 66% visible injury in soybean, respectively. Injury increased at 2 and 4 WAT and decreased by 8 WAT with 68% visible injury observed at the highest dose. Dicamba applied at R1 caused 23, 28, 36, 40, 48, 61, and 73% visible injury in soybean at 0.75, 1.5, 3, 6, 15, 30, and 60 g a.e. ha-1, respectively. The predicted dose of dicamba to reduce soybean seed yield 1, 5, 10, 20 or 50% was 1.1, 5.8, 11.8, 25.2, and >60 g a.e. ha-1 when applied at V2-3 and <0.75, 1.0, 2.0, 4.3, and 11.5 g a.e. ha-1 when applied at R1, respectively. Results show that dicamba spray tank contamination of as little as 0.75 g a.e. ha-1 can cause significant crop injury in non-dicamba-resistant soybean when applied during the vegetative or reproductive stages.
This article is only available to subscribers. It is not available for individual sale.
Access to the requested content is limited to institutions that have
purchased or subscribe to this BioOne eBook Collection. You are receiving
this notice because your organization may not have this eBook access.*
*Shibboleth/Open Athens users-please
sign in
to access your institution's subscriptions.
Additional information about institution subscriptions can be foundhere