Response Of Canola Research Articles

Ethametsulfuron Interactions with Grass Herbicides on Canola (Brassica napus, B. rapa)

Field experiments were conducted from 1986 to 1988 at Lacombe and Lethbridge, Alberta and Scott, Saskatchewan to determine growth and yield response of canola to mixtures of ethametsulfuron with specific grass herbicides. Ethametsulfuron did not usually cause canola injury when mixed with sethoxydim. However, ethametsulfuron mixtures with the following grass herbicides listed in decreasing order of injury potential, often caused canola injury and yield loss: haloxyfop > fluazifop > fluazifop-P > quizalofop > quizalofop-P. Canola yield losses were severe in some experiments, ranging from 59% with quizalofop mixtures to 97% with haloxyfop mixtures; in other experiments, the same mixtures did not cause significant yield losses. ‘Tobin,’ aBrassica rapacultivar, tended to be more susceptible to injury than theB. napuscultivars ‘Pivot’ and ‘Westar.’ Canola injury symptoms were consistent with those expected from sulfonylurea herbicides. Therefore, we suggest that specific grass herbicides differentially impair the ability of canola to metabolize ethametsulfuron to inactive forms.

Zero-tillage influence on canola, field pea and wheat in a dry subhumid region: Agronomic and physiological responses

Field trials were conducted over 4 site-years in southern Manitoba to compare the response of Katepwa wheat, Westar canola and Victoria field pea to zero tillage (ZT). The experimental design was a split plot with tillage system as the mainplot (ZT vs. conventional tillage (CT)) and crop species as the subplot. All crops received protection from insect, weed and disease pests. Tillage system had only a limited impact on crop dry matter accumulation or grain quality. Where differences were observed, crop performance was enhanced under ZT. Seasonal evapotranspiration (ET) was either reduced or unaffected by ZT, while ET efficiency (ETE: kg ha−1 mm−1 ET) was either increased or unchanged by the shift from CT to ZT. Higher ETE under ZT was attributed to less soil water evaporation. Significant tillage system × crop species (T × S) interactions for growth parameters, ET and ETE indicated that field pea often benefitted more than wheat or canola from ZT. A significant T × S interaction at one of the four sites indicated that water extraction between 30 and 90 cm was higher for pea and canola in the ZT compared with CT treatment, while soil water extraction by wheat was reduced under ZT. At a second site, lower ET for all three crops under ZT was attributed to reduced water use between 90 and 130 cm. Despite some effects of ZT on crop growth and water use, no significant tillage, T × S, or site × tillage interactions were observed for grain yield. It was concluded that under the conditions of this study (i.e. precipitation and temperature conditions close to the long-term average), Westar canola, Victoria field pea and Katepwa wheat were, for the most part, equally suited to ZT production. Key words: Soil water extraction, evapotranspiration efficiency, crop quality, grain yield, canopy development

Canola response to boron and nitrogen grown on the southeastern coastal plain1

Abstract Canola has the potential for production in a doublecropping system in the southeastern Coastal Plain, but little information is known about its fertility reguirements when grown in this region. This two‐year field study was conducted to determine the effect of boron (B) and nitrogen (N) on canola growth and yield. Nine combinations of five N rates ranging from 45 to 225 kg/ha, with and without 1.68 kg B/ha, were evaluated at Blackville SC, on a Plinthic Paleudult. Canola plants receiving foliar B had a 6.5% higher yield than those receiving no B for the combined 1990 and 1991 data. Compared to plants which received no B, whole plant tissue analysis at beginning bloom detected a 50% higher B concentration for plants receiving B application 25 days earlier. Seed yield was affected by N rate both years, and there was a significant year by N interaction. In 1990 yields increased as the N rate increased, whereas in 1991 yields peaked at 135 kg/ha N and declined at higher N rates. These data suggest that, on a typical Coastal Plain soil, canola will respond to the application of foliar B, and requires approximately 135 kg N/ha.

Response of wheat, triticale, barley, and canola to lime on four soil types in north-eastern Victoria

Lime requirement curves based on relative yield and pH data for 4 soil types were derived to estimate the amount of lime required to reach maximum yield for wheat, triticale, barley, and canola. Simple equations expressing lime requirement as a function of soil pH accounted for >90% of the variation in applied lime on 3 soil types (red brown earth, red podsolic, podsolised red earth). When aluminium and manganese (0.01 mol CaCl2/L extracted) were included in these equations, either individually or together, they did not improve the relationship significantly for these 3 sites; however, manganese significantly improved the predictability of lime for solodic soil. A comparison of this model with a laboratory-based model showed good correlation for 3 soils (red brown earth, red podsolic, podsolised red earth), but the laboratory method underestimated the field lime requirement of solodic soil.

Yield Response of Canola to Nitrogen, Phosphorus, Precipitation, and Temperature

AbstractCanola (Brassica nupus L.) is a major crop in western Canada, and been used extensively as an alternative crop to wheat (Triticum aestivum L.). Yet, little information is available on the response of this crop to N and P fertilizers in relation to soil tests for these elements under varying environmental conditions. Accordingly, this study was conducted for a 16‐yr period to determine the yield response of canola to N and P fertilizers in relation to soil tests for these elements in northeastern Saskatchewan on black Melfort silty clay (Typic Cryoboroll) previously cropped to spring wheat. Nitrogen fertilizer was applied at 45 and 134 kg N ha−1 in factorial combination with 0, 10, 20, 30, and 40 kg P ha−1. Extra treatments consisted of 10N–20P kg ha−1 and a control with no fertilizer applied. Canola grain and straw response to N and P fertilizer was significant, but the N by P interaction was not significant. The interaction effects of Year by P and Year by N were significant, indicating a wide range of response to applied elements among years because of temperature, precipitation and soil nutrient effects. Grain yield was positively correlated to total precipitation and negatively correlated to mean maximum daily temperature for the months of July and August (R2 = 0.32). The highest grain yield (2.46 t ha−1) was obtained in 1987 with P fertilizer applied at 40 kg P ha−1 (averaged across N rates), 162 mm of rainfall and an average maximum temperature of 21.2 °C. The lowest yield (0.37 t ha−1) was obtained in 1989 with P fertilizer applied at 20 kg P ha−1, 95 mm of rainfall and an average maximum temperature of 25.1 °C. In conclusion, soil tests for N and P accounted for much of the variation in yield response to these elements (r2 = 0.58 and R2 = 0.46, respectively) despite large yield differences among years because of temperature and precipitation.

Effect of sowing date and seeding rate on yield and yield components of irrigated canola (Brassica napus L.) grown on a red-brown earth in south-eastern Australia

Response of canola (Brassica napus) to factorial combinations of five sowing dates and seeding rates was investigated from 1987 to 1989. The experiments were conducted on red-brown earths in the Goulburn-Murray Irrigation Region of south-eastern Australia. Crops were sown at monthly intervals beginning in April each year. In 1987, seeding rates were 4.6, 7.0 and 14 kg ha-1, but in 1988 and 1989 the lowest rate was eliminated. The cultivar Marnoo was used each year and Eureka was included in 1989. There was no difference between yields of seed and oil for crops sown in April and May, but yields of seed and oil declined when sowing date was delayed beyond May. Oil contents were greater than 45% for the April, May and June sowings in 1988 and 1989. In contrast, seeding rates had no effect on yields of seed and oil. Marnoo produced a maximum seed yield of 398 g m-2 from the May sowing in 1987, and a minimum seed yield of 172 g m-2 from the September sowing in 1988. In 1989, Eureka out-yielded Marnoo in all but the August sowing. Eureka produced a maximum seed yield of 483 g m-2 from the April sowing and its lowest seed yield of 315 g m-2 from the August sowing. The number of pods per m2 was the major factor responsible for the significant changes in yield in all experiments. Seed yield was also strongly correlated (P < 0.01) with biomass, and to a lesser degree, with individual seed weight in all comparisons with the exception of Marnoo in 1989.

Response of wheat, canola and alfalfa to simulated acidic precipitation

Wheat, canola and alfalfa were subjected to simulated acidic precipitation with pH ranging from 5.6 to 2.6 under controlled growth room conditions. The number of simulated precipitation events were 12, 10 and 21 for wheat, canola and alfalfa, respectively. In this short-term experiment, wheat, canola and alfalfa do not appear to be sensitive to the simulated acid rain treatments used. Wheat and canola showed no visible symptoms of injury with any of the treatments. The pH 2.6 resulted in whitish spots on alfalfa leaflets. The economic yield was not affected at any of the acidity levels used in this tudy. Dry weight of the aboveground vegetative parts of wheat and canola was stimulated by the most acidic treatment (pH 2.6), apparently as a result of the higher nutrient content of the simulated acidic rain. Although below ground biomass for any of the species tested was not affected by rain acidity, the shoot: root ratio was significantly higher at pH 2.6 than with the control. Chorophyll a concentration in alfalfa leaves was reduced at only the highest acidity treatment. Chlorophyll b was not affected. While K levels in alfalfa leaves were significantly reduced at pH 2.6, no change in the concentration of Ca, Mg and P was noted. Sulfur and N concentrations increased, mainly at pH 2.6, reflecting the composition of the simulated rain solution.