Response Of Canola Research Articles

Canola Response to Alternate Furrow and cut-off Irrigation Combined with Bio-Mineral Fertilizer Applications at North Delta Region

Canola Response to Alternate Furrow and cut-off Irrigation Combined with Bio-Mineral Fertilizer Applications at North Delta Region

Combined Effect of Biochar and Plant Growth-Promoting Rhizbacteria on Physiological Responses of Canola (Brassica napus L.) Subjected to Drought Stress

Biochar (BC) and plant growth-promoting microbes (PGPR) could represent a suitable agronomical strategy to mitigate the impacts of drought in arid agro-environmental conditions. However, there is currently little understanding of the synergistic benefit of combining BC and PGPR to increase drought tolerance in oilseeds. In this study, the physiological response of two water-stressed canola (Brassica napus L.) plants subjected to the application of BC obtained from waste wood of Morus alba applied solely or in combination with PGPR strains (Pseudomonas sp.) was evaluated. The experiment consists of two genotypes and nine treatments [(C-Control, T1-15 days drought (15DD), T2-30 days drought (30DD), T3-15 days of drought + PG (15DD + PG), T4-30 days of drought + PG (30DD + PG), T5-15 days drought + biochar (15DD + BC), T6-30 days drought + biochar (30DD + BC), T7-15 days drought + biochar + PG (15DD + BC + PG), T8-30 days drought + biochar + PG (30DD + BC + PG)]. Drought stress decreased emergence energy (EE), leaf area index (LAI), leaf area ratio (LAR), root shoot ratio (RSR), moisture content of leaves (MCL), percent moisture content (%MC), moisture content of shoot (MCS) and moisture content of root (MCR), and relative water content (RWC) in both varieties of Brassica napus L., which in contrast, it is increased by the collective application of both biochar and PGPR. In both varieties, N, P, K, Mg, and Ca concentrations were highest in all the biochar and PGPRs separate and combined treatments, while lowest in 15 and 30 days drought treatments. Osmolyte contents like Glycine betaine (GB) and sugar remarkably increased in the stress condition and then reduced due to the synergistic application of biochar and PGPR. Drought stress has a repressive effect on the antioxidant enzymatic system like Peroxidase (POD), Superoxide dismutase (SOD), and glutathione reductase (GR) as well as total flavonoids, phenolics, and protein content. The antioxidant enzymes and phenolic compounds were dramatically increased by the combined action of biochar and PGPRs. A significant increase in EE, LAR, RSR, and RWC under 15 and 30 days drought conditions, evidently highlighting the synergistic effect of BC and PGPR. The results conclude a substantial and positive effect of the combined use of BC and PGPR strains on canola's response to induced drought stress, by regulating the physiological, biochemical, and agronomic traits of the plants.Graphical

Growth and physiological response of canola (Brassica napus L.) tointeractive effect of temperature, moisture and nitrogen stressesunder controlled environment

Present atmospheric limits growth of C3 crop plants, which show response to elevated CO2 via reduced photorespiration and enhanced photosynthetic rates thereby increased growth and yield. Global research on plant responses to raising atmospheric CO2 has primarily focused on C3 species, advancing our understanding of processes underlying C3 plant acclimation and response. Therefore extensive research has been conducted to project the potential impacts of global warming on agriculture productivity through laboratory by using crop and global climate models. Canola is one of the world’s most important oilseed crops and the most profitable commodity for Canadian farmers. As a C3 cool seasoncrop, it is more susceptible to heat stress than other C3 and C4 field crops (Wu and Ma, 2018). High temperature significantly changes the rate of plant metabolic processes that ultimately reduces biomass accumulation and grainformation. A field study in Eastern Canada reported that seed yield reduced as much as 40% in 2012 due to severeheat and drought stress over normal years (Ma and Herath, 2016). High or warm temperature has been shown toinduce the floral sterility or pollen abortion and shorten seed filling duration and subsequently reduce inflorescence size in canola plants. Even high temperature could alter the partitioning of photoassimilates to roots and suppress root growth extension or change root system architecture. Late seeded canola plants often produced a smaller root system, due to higher temperature and or drought stress encounters during the crop development. Keeping these facts trial was conducted under controlled condition to know the response of canola to drought stress, elevated CO2 and temperature.

Improving physiological and biochemical responses of dryland canola by selenium foliar application and supplemental irrigation

Improving physiological and biochemical responses of dryland canola by selenium foliar application and supplemental irrigation

Response of canola and cereals to amendment of subsurface soil acidity and a hardpan

Context Limitations to crop yield due to subsurface (5–15 cm depth) compaction layers (>2 MPa) and subsurface acidity (pHCa <4.8) have frequently been reported on the non-sodic soils of south-eastern Australia, but amendment studies have been limited in number and inconsistent in the extent and longevity of any response. Aim We tested the hypothesis that amendment of subsurface acidity and compaction would lead to increased grain yield. Method We investigated crop response to the alleviation of these combined subsurface soil constraints by using deep ripping and dry limestone injection to 30 cm depth over 3 years in a canola–cereal sequence. Key results Deep tillage and injection of limestone into the soil both failed to produce significant grain yield responses in any year, despite the reduction of soil strength and increase in pH in subsurface layers. Early vegetative growth sometimes responded to the treatments, but the loss of stored soil water during drier than average seasons appeared to limit grain response. However, we also observed that a proportion of plant roots penetrated these relatively thin constraint layers in unamended soils. Conclusions Amelioration of subsurface acidity and compaction does not necessarily increase grain yield. Implications The effects of subsurface acidity and compaction should be tested on other species and during varying rainfall deciles. Given the potentially large resource requirements for deep amendment of soils, we propose that the selection of tolerant species and cultivars might be more effective in the short term.

Morphophysiological and Nutritional Responses of Canola and Wheat to Water Deficit Stress by the Application of Plant Growth-Promoting Bacteria, Nano-Silicon, and Silicon

Morphophysiological and Nutritional Responses of Canola and Wheat to Water Deficit Stress by the Application of Plant Growth-Promoting Bacteria, Nano-Silicon, and Silicon

Yield and Quality Response of Canola to Seed Row and Side Banded Ammonium Sulfate and Ammonium Thiosulfate

Ammonium sulfate (AMS) and ammonium thiosulfate (ATS) are two of the most common sulfur products applied during canola seeding in the Canadian Prairies. A better understanding of how application methods affect the efficiency of these products is warranted. A field trial was conducted on a clay loam soil in Pense, Saskatchewan to evaluate the effect of seed row and side banded sulfur applications on canola yield and quality. Plots received 34 kg ha-1 sulfur either from AMS or ATS applied during seeding either in the seed row (SR) or side banded (SB). A treatment without sulfur was included as a control. All plots received the same amounts of all other nutrients. Results showed that average seed yields increased for all sulfur-treated plots, however, only side banded applications (AMS(SB): 4020 kg ha-1, ATS (SB): 3883 kg ha-1) were significantly better than the control (3072 kg ha-1). Side banded sulfur applications generally produced more protein than seed row applications and were significantly different from the control. AMS (SB) had the highest protein content (21.07%) while the control had the least (18.13%). Oil content was similar except for AMS (SB) (46.72%) which was significantly lower than the control (48.68%). However, this oil difference was more than compensated by the increased yield from AMS (SB). Applying AMS and ATS in the seed row can decrease the yield and protein response that might otherwise be seen when these products are side banded. There were no significant differences in the measured parameters between AMS and ATS.

Using Statistical Models to Estimate Economic Optimum Nitrogen Fertilizer Rate for Wheat, Safflower, and Canola before and after Fertilizer Subsidy Programs in Iran

ABSTRACT Optimum use of nitrogen (N) fertilizers is necessary to achieve maximum profitability by farmers and to minimize the risks of environmental pollution. In this study, we used three statistical models to predict the grain yield response of wheat, safflower, and canola to N fertilizer based on combined data from 38 field experiments. Meanwhile, based on the yield response functions and fertilizer-to-product price ratios, the economic optimum N fertilizer rate for each crop for 2009 (before targeting subsidies) and 2015 (after targeting subsidies) was estimated. According to quadratic, exponential, and square root models, 82.5, 90, and 76 kg N ha−1 was estimated to be required for maximum agronomic yield of safflower. More than 300 kg N ha−1 was estimated by all three models to obtain the maximum agronomic yield of canola. In contrast with the government policies for reducing N fertilizer application rates by farmers, due to low fertilizer-to-product price ratios, all application rates of N fertilizer were economic for wheat production even after targeting subsidies. According to the results, to achieve the optimum use of N fertilizers, a proper ratio of the fertilizer cost to the product value should be considered in fertilizer subsidy programs.

Morpho-anatomical, biochemical and molecular genetic responses of canola (Brassica napus L.) to sulphur application

Brassica napus (canola), a major economic crop in Egypt, contains much oils and proteins. In the present study, the foliar applications of ammonium sulphate (A.S.) [(NH4)2SO4] (0, 1% 0.2% and 0.3%) to canola plants had distinctive impacts on the morpho-anatomical, biochemical, and molecular genetic responses. Interestingly, there is a positive impact when sulphur (S) is foliarly applied at 0.2% of A.S. as revealed in antioxidants, flavonoids, total carbohydrates, and protein contents which were significantly affected. On the other hand, higher levels of glucosinolates were recorded for 0.3% and 1% A.S. (4.838 and 1.905, respectively). The electrophoretic analysis of proteins displayed 51 bands of molecular weights ranging from 8.555 to 240.6 kDa with 88.24% polymorphism with a mean band frequency of 0.373. Cytotoxicity assay revealed that the lower cell death was detected in treated root tips of canola plants following 0.2% A.S. treatment, as compared to control. With increasing of sulphur treatment, the root cortex thickness, number of conducting elements, and pericycle thickness decreased while root pith area increased. In canola leaves of high S level, the leaf blade thickness, the thickness of abaxial and adaxial epidermis surface, mesophyll thickness, and metaxylem area increased, while the xylem conducting elements number decreased. Moreover, SCoT molecular markers have been used to evaluate the genetic variation among Brassica napus genotypes subjected to different A.S. treatments. Four of the seven SCoT primers were revealed to be polymorphic in both treated and untreated samples. A total of 39 amplicons, ranging in size from 200 to 1080 bp, were amplified, with 9 (23.07%) of them being polymorphic. Clustering dendogram based on SCot markers data divided Brassica genotypes into two main clusters based on similarity coefficients indices. B. napus treated with 0.2% A.S. was separated in a distinct cluster. Furthermore, treatments with sulphur enhanced the activity of antioxidant enzymes as well as the expression level of their encoding genes (CAT, catalase; POD, peroxidase; APX, ascorbate peroxidase; SOD, superoxide dismutase; GR, glutathione reductase), particularly at 1% and 0.2% A.S. treatments. Taken together, this study revealed that foliar application of sulphur treatments, particularly at 0.2%, have a great potential to improve canola crop.

Proteomic Profiling and Protein-Protein Interaction Network Reveal the Molecular Mechanisms of Susceptibility to Drought Stress in Canola (Brassica napus L.)

Drought stress is one of the most important abiotic stresses that plants face frequently in nature. Under drought conditions, many morphological, physiological, and molecular aspects of plants are changed and as a result plants experience a remarkable reduction in growth, yield, and reproduction. To expand our understanding of the molecular basis of the plant response to drought stress, the proteomic profile and protein-protein network of canola (<i>Brassica napus</i> L.) were studied. The focus was to show molecular mechanisms related to canola susceptibility to drought stress. The experiment used a completely randomized design, implemented in a hydroponic system under greenhouse conditions. To impose drought stress, plants were exposed to Hoagland’s solution supplemented with polyethylene glycol (PEG) 6000 for 7 days. The drought stress resulted in 161reproducible protein spots in twodimensional electrophoresis of canola leaves. The t-student test showed 21 differentially abundant proteins (DAP), of which 2 and 19 were up and down accumulated, respectively. Two spots identified as 1-aminocyclopropane-1-carboxylate oxidase and D-2-hydroxyglutarate dehydrogenase showed an increased abundance of 2.11 and 1.77, respectively. The extended protein-protein interaction of differentially abundant proteins and KEGG analysis showed 47 pathways directly and indirectly associated with canola response to drought stress. DAPs with increased abundance were associated with amino acid and signaling processes, whereas DAPs with decreased abundance were mostly connected with pathways responsible for energy production. The results of the study will help to elucidate further the molecular events associated with the susceptibility to drought stress in canola.

Response of canola yields from marginal lands managed with tillage practices

Abstract In recent years the discourse regarding the effective use of dwindling agricultural spaces for food, fiber, or fuel production has grown and it is becoming increasingly important to manage non-agricultural or marginal spaces that make them suitable for crop production. Highly eroded, highly compacted, low nutrient soils, similar to those found along highway rights-of-way (ROWs) offer unique field characteristics that can be used to study crop production potentials and land use decisions. This work evaluated the feasibility of maintaining a canola crop production system on the non-agricultural soils of highway ROWs across the humid subtropical climate within North Carolina, USA as a bioenergy feedstock for renewable fuels. Specific objectives included examination of (1) three different North Carolina geoclimatic conditions and (2) three levels of tillage (conventional (CT), minimum (MT), and no-till (NT)) on canola (Brassica napus L.) grain yields cultivated on ROW soils. Field experiments were conducted for two growing seasons in the Inner Coastal Plain, Piedmont, and Mountains regions and assessed main and interaction effects among tillage, site, and year of cultivation on crop productivity. After season 1, CT produced the highest average yield (1.24 Mg ha−1) followed by MT (0.93 Mg ha−1) and NT (0.86 Mg ha−1), respectively. In the second year, the comparative intensity of productive effects from CT was lower, and plots cultivated under MT resulted in the highest average yields (2.70 Mg ha−1), followed by CT (2.69 Mg ha−1) and NT (1.96 Mg ha−1), respectively. Yields observed were comparable to regional canola grain yields, and no significant difference was observed between yields under CT versus MT. These findings suggest that reduced levels of tillage on ROW soils in North Carolina hold the potential to produce yields comparable to those realized in traditional agricultural soils, and targeted tillage practices can support improved suitability of marginal crop production spaces.

Yield response of canola as a biofuel feedstock and soil quality changes under treated urban wastewater irrigation and soil amendment application

Treated urban wastewater (TWW) is seen as a potential alternative for agricultural irrigation in arid west Texas region, due to scarcity of Freshwater (FW) supplies. However, TWW can potentially cause soil salinization and affect soil quality and crop productivity. Therefore, crops that are salt-tolerant and less water-intensive are needed to sustain agriculture in this region. Canola (Brassica napus L.) as an edible oilseed and biodiesel/biofuel crop, is salt-tolerant and relatively less water-intensive than crops that are traditional to this area. This two–year field study evaluated the performance of canola under TWW irrigation in terms of its seed yield potential and seed quality (oil content, oil yield and salt constituents), along with quantifying changes in soil salinity and sodicity. Experimental design included a randomized block split-plot with water quality (FW and TWW) as the main-plot and soil amendment (gypsum + sulfur and no-amendment) as the subplot factor. Results show that TWW application did not significantly affect canola seed yields in any of the two years. On average, seed yields were 1975 kg ha−1 across all treatments and years. Seed oil content, oil yield and mineral constituents were also not affected by TWW irrigation. Nevertheless, average seed oil content was 42 % and oil yield was 849 kg ha−1. Other than the effects on soil salinity and sodicity, Gypsum + Sulfur application did not influence canola seed productivity and quality. Changes in soil salinity and sodicity were more prominent under TWW irrigation but the levels were below the thresholds after two years. Gypsum + Sulfur application significantly reduced soil sodicity, especially in TWW irrigated soils. These results highlight that TWW can be successfully used to grow canola as a biofuel feedstock in this arid region while following appropriate soil management practices to alleviate sodicity hazard of TWW in the long-term.

Calibration and Evaluation of the FAO AquaCrop Model for Canola (Brassica napus) under Varied Moistube Irrigation Regimes

The AquaCrop model was calibrated and validated for canola (Brassica napus) under Moistube irrigation (MTI) and various water regimes [(i) 100%, (ii) 75%, and (iii) 55% of crop water requirement (ETc)] over two seasons, 2019 and 2020. The normalised root mean square (nRMSE), Model Efficiency (EF), R2, and the Willmot’s index of agreement (d) statistics were used to evaluate the model’s efficiency in simulating biomass (B), canopy cover (CC), yield (Y), and harvest index (HI). The calibration results indicated the model simulated with accuracy the CC (under 100% ETcR2 = 0.99, EF = 0.92, nRMSE = 6.4%, d = 0.98) and 75% ETc (R2 = 0.99, EF = 0.92, nRMSE = 10.3%, d = 0.98). The model simulated CC well for validation for 100% ETc (R2 = 0.97, EF = 0.93, nRMSE = 22.5%, d = 0.98) and 75% ETc (R2 = 0.84, EF = 0.45, nRMSE = 59.2%, d = 0.86) irrigation regimes. Final biomass simulations were reasonably good under 100% ETc, 75% ETc, and 55% ETc irrigation regimes (R2 &gt; 0.90, d &gt; 0.65). The study showed the usefulness of AquaCrop for assessing yield response of canola to full and deficit irrigation scenarios under MTI.

Response and yield stability of canola (Brassica napus L.) genotypes to multi-environments using GGE biplot analysis

he GxE interaction (GEI) provides essential information for selecting and recommending cultivars in multi-environment trials. This study aimed to evaluate genotype (G) and environment (E) main effects and GxE interaction of 15 canola genotypes (10 canola lines and 5 check varieties) over 8 environments and to examine the existence of different mega environments. Canola yield performances were evaluated during 2015/16 and 2016/17 production season in three different locations (Southern Marmara, Thrace side of Marmara, and Black Sea regions) of Turkey. The trial in each location was arranged in a randomized complete block design with four replications. The seed yield data were analyzed using GGE biplot and the yield components data were analyzed using ANOVA. The agronomical traits revealed that environments, genotypes, and GEI were significant at 1 % probability for all of the characters. The variance analysis exhibited that genotypes, environments, and GEI explained 21.6, 21.7, and 25.7 % of the total sum of squares for seed yield, respectively. The GGE biplot analysis showed that the first and second principal components explained 57.3 and 18.3 % of the total variation in the data matrix, respectively. GGE biplot analysis showed that the polygon view of a biplot is an excellent way to visualize the interactions between genotypes and environments.

Winter survival response of canola to meteorological variables and adaptative areas for current canola germplasm in the United States

The introduction of winter canola (Brassica napus L.) into rotations with winter wheat (Triticum aestivum L.) in the United States (US) revealed economic and agronomic benefits as well as improved weed and pest control. Canola stand establishment during the fall and plant survival over the winter are critical to the success of this crop. The environment plays a key role influencing survival, but in-depth evaluation of meteorological factors has not been conducted. This research study aimed to: i) identify meteorological factors underpinning winter canola survival, ii) build probabilistic response models based on historical meteorological data for different severities of winter kill across the US, and iii) define areas of adaptation of current germplasm. A winter survival dataset was compiled from the National Winter Canola Variety Trials from 2003 until 2018 (190 site-years) and auxiliary meteorological data over the last 40 years. A regression tree analysis indicated that meteorological variables related to minimum temperature, fluctuating temperatures above and below 0°C, and windchill during the cold period were the main factors accounting for winter kill. Cold periods across all site-years were classified into three clusters: cold periods with high (96%), medium (70%), and low (28%) average plant winter survival. For 94 US sites, the probabilities of these conditions were calculated and summarized in a map that defined areas of adaptation: a large area south of 35° N latitude for the US was identified with greater potential for overwintering success. Based on the response under multiple meteorological conditions, four distinct genotype survival groups were identified (tolerant, semi-tolerant, semi-susceptible, and susceptible). Groups with a greater number of genotypes differ in the impact of meteorological conditions on survival for the medium cluster. In regions with more favorable conditions for overwintering success, farmers may be open to introducing this crop to diversify their farming system.

Response of wheat, pea, and canola to micronutrient fertilization on five contrasting prairie soils

A polyhouse study was conducted to evaluate the relative effectiveness of different micronutrient fertilizer formulation and application methods on wheat, pea and canola, as indicated by yield response and fate of micronutrients in contrasting mineral soils. The underlying factors controlling micronutrient bioavailability in a soil–plant system were examined using chemical and spectroscopic speciation techniques. Application of Cu significantly improved grain and straw biomass yields of wheat on two of the five soils (Ukalta and Sceptre), of which the Ukalta soil was critically Cu deficient according to soil extraction with DTPA. The deficiency problem was corrected by either soil or foliar application of Cu fertilizers. There were no significant yield responses of pea to Zn fertilization on any of the five soils. For canola, soil placement of boric acid was effective in correcting the deficiency problem in Whitefox soil, while foliar application was not. Soil extractable Cu, Zn, and B concentration in post-harvest soils were increased with soil placement of fertilizers, indicating that following crops in rotation could benefit from this application method. The chemical and XANES spectroscopic speciation indicates that carbonate associated is the dominant form of Cu and Zn in prairie soils, where chemisorption to carbonates is likely the major process that determines the fate of added Cu and Zn fertilizer.

Photosynthetic Responses of Canola to Exogenous Application or Endogenous Overproduction of 5-Aminolevulinic Acid (ALA) under Various Nitrogen Levels.

Limited data are available on the effects of 5-aminolevulinic acid (ALA) on plant photosynthesis in relation to the nitrogen (N) level. In this study, we investigate photosynthetic responses to ALA in canola plants (Brassica napus L.). We used wild-type plants without ALA addition (controls), wild-type plants with exogenous ALA application, and transgenic plants that endogenously overproduced ALA. The plants were grown hydroponically in nutrient solutions with low, middle, and high concentrations of N. Our results indicate that plants in both treatment groups had higher chlorophyll contents and net photosynthetic rates and lower intracellular CO2 concentrations in the leaves, as compared to controls. Furthermore, simultaneous measurement of prompt chlorophyll fluorescence and modulated 820-nm reflections showed that the active photosystem II (PS II) reaction centers, electron transfer capacity, and photosystem I (PS I) activity were all higher in treated plants than controls at all N levels; however, the responses of some photochemical processes to ALA were significantly affected by the N level. For example, under low N conditions only, a negative ΔK peak appeared in the prompt chlorophyll fluorescence curve, indicating a protective effect of ALA on electron donation via activation of the oxygen-evolving complex. Taken together, our findings suggest that ALA contributes to the promotion of photosynthesis by regulating photosynthetic electron transport under various N levels. These findings may provide a new strategy for improving photosynthesis in crops grown in N-poor conditions or reduced N-fertilization requirements.

Effect of Foliar Application of Sulphur and Integrated Nutrient Management on Yield, Quality and Economics of Bed Transplanted Canola (Brassica napus L.)

Background: Canola is an important oilseed crop throughout the world which is grown in more than 53 countries. Proper nutrient management plays a key role in its production. Use of unbalanced and inadequate fertilizers accompanied by restricted use of organic manures resulting in a decline in crop yield and quality. Little information is available on the response of canola to these factors. Therefore, this study is focused on to evaluate effect of foliar application of sulphur and integrated nutrient management on canola.Methods: A field experiment was conducted on sandy loam soil during winter (Rabi) season of 2017-18 and 2018-19 at Student’s Research Farm, Khalsa college, Amritsar to study the effect of foliar application of sulphur and integrated nutrient management on yield, quality and economics of bed transplanted canola (Brassica napus L.). Canola variety GSC 7 was sown by transplanting method on beds at spacing of 30 cm × 10 cm under Randomized Complete Block Design (RCBD) with 6 treatment combinations of organic (Vermicompost and pressmud), inorganic and foliar fertilizer were used under three replications. Result: The results revealed that treatment containing 100% RDF + 40 kgha-1 sulphur + 1% foliar sulphur spray (T2) led to maximum siliqua length (8.5 cm), no. of siliqua plant-1 (547.5), no. of seed siliqua-1 (28.8), test weight (4.64 g), seed yield (24.92 q ha-1) and stover yield (78.53 q ha-1) whereas treatment consisting 100% N through vermicompost + 40 kgha-1 sulphur + 1% foliar sulphur spray (T3) led to highest quality attributes i.e. oil content (43.73%), protein content (30.8%) in seed which was at par with 100% N through pressmud + 40 kgha-1 S + 1% foliar sulphur spray (T4) which also resulted highest sulphur content (0.48%) in seed. The maximum gross return (Rs. 104664 ha-1), net return (Rs. 59049 ha-1) and benefit cost rato (1.29) obtained from treatment containing 100% RDF + 40 kgh-1 sulphur + 1% foliar sulphur spray (T2). It was observed that foliar application of sulphur enhanced the yield whereas application of organic manures improved the quality of canola.

Response of canola, wheat, and pea to foliar phosphorus fertilization at a phosphorus-deficient site in eastern Saskatchewan

Foliar fertilization is a potential strategy to supplement phosphorus (P) requirements when conditions permit. In 2016 and 2017, canola, wheat, and pea were grown in a randomized complete block design trial near Pilger, SK, Canada. Each crop received a total P application of 20 kg P2O5 ha−1, with varying proportions of the P applied as seed-placed monoammonium phosphate (MAP) supplemented with foliar KH2PO4 (0%, 25%, 50%, and 100%) applied prior to anthesis. Under field conditions, yield response decreased as the proportion applied as seed-placed MAP decreased. The 100% foliar-applied P treatment in canola was able to maintain significantly higher yield than the unfertilized control in the absence of seed-placed MAP, indicating some uptake and response. Of the crops evaluated, canola was most responsive to P fertilization. Phytate content ranged from 68% to over 90% of total seed P, with the highest proportions found in wheat grain. Foliar P application had limited effect on phytate and grain iron content, but there appeared to be an inverse relationship between seed-placed MAP and grain zinc concentration that was less evident when P was applied in foliar form. In this study, foliar P application was unable to substitute for seed-placed MAP and overall had a marginal effect on grain yield and P uptake as well as seed nutritional value.

Winter canola response to soil and fertilizer nitrogen in semiarid Mediterranean conditions

AbstractIn the semiarid dryland wheat (Triticum aestivum L.) region of the U.S. inland Pacific Northwest, winter canola (WC) (Brassica napus L.) is an economically viable rotation crop. Winter canola produces marketable end‐products while improving soil health and disrupting pest and disease cycles. Although annual production of WC in Washington State has increased in the recent decade, little regional fertility research has been conducted. As a result, WC is commonly fertilized in a manner similar to hard red spring wheat. Compared with wheat, WC has a deep and aggressive tap root system that can grow to depths of 180 cm to reach nutrients and water. Thus, WC requires a different N management strategy than wheat. Field experiments were conducted to evaluate the influence of soil residual N and fertilizer N application rate (range, 0–240 kg N ha−1) and timing (fall, spring, or split fall/spring) on WC yield and oil and protein concentrations. The study took place over a 2‐yr period at seven locations across four agroecological classes. There was no yield response to N rate at six of the seven sites due to canola's high N uptake efficiency and the soils’ high residual N (92–224 kg inorganic N ha−1) after wheat–fallow. Increasing N rates and split or spring application resulted in lower oil/protein ratios. In addition, maximum yields correlated with total available water. Therefore, N management for WC should be based on soil test residual + mineralizable N, total available water, and end‐use quality.