Browsing by Author "Kirkland, K.J."
Now showing 1 - 9 of 9
Results Per Page
Sort Options
Item Effect of early spring seeding on diseases of canola(2000-02-22) Keri, M.; Kutcher, H.R.; Kirkland, K.; Johnson, E.N.Studies to determine the effect different seeding dates and fungicide application on incidence and severity of blackleg disease were established at Melfort and Scott, SK. A similar study to determine the effect of seeding date on incidence and severity of Sclerotinia stem rot was also conducted at Melfort. The Brassica napus cultivar Quest was seeded in late October 1998 (fall), mid to late April (early spring) and mid to late May (traditional). Following germination, seedling counts were taken. In the blackleg experiments at Melfort and Scott, azoxystrobin (125 g a.i./ha) was compared with a non-treated control. For the Sclerotinia experiment, vinclozolin (500 g a.i./ha) applied at 20–30% bloom was compared with a non-treated control. Evaluation of plants for disease incidence and severity and for plot yield was done at plant maturity. At all locations, seedling populations were reduced for the fall seeding date compared to the early spring and traditional seeding. Sclerotinia stem rot infection levels were higher in the fall and early spring seeded treatments compared to the traditional seeding date treatment. However yield from fall and early spring seeding dates was higher than yield from the traditional date. There were no differences in Sclerotinia levels with fungicide application within each seeding date. At Melfort, blackleg levels for fall and early spring treatments were lower than levels for the traditional seeding date. Fungicide reduced incidence and severity of blackleg infection for all seeding dates. Yield for all seeding dates were higher with fungicide application as opposed to yield from the non-treated control. However, significant yield differences were only observed with fall seeding date. Yields of the treated and non-treated early spring seeding date were at least 20 to 80% higher than both treatments for traditional seeding date. At Scott the fall seeding date had lower yields compared to the traditional and early spring seeding date treatments. At all seeding dates, fungicide application only reduced the blackleg incidence; disease severity was only reduced for the early spring and traditional seeding dates. Fungicide increased yield for the early spring and traditional seeding dates but not the fall seeded treatment. Variation in yield of canola over the seeding dates was small but yield was greatest for the traditional seeding date treatment. This study indicated that blackleg infection and subsequent yield loss differed with location. Under the conditions of the study, fungicide application on the fall or early spring seeded crop did not reduce Sclerotinia stem rot symptoms or increase yield in 1999.Item Effect of seeding date on canola seed quality(2000-02-22) Gusta, L.V.; Nesbitt, N.T.; Johnson, E.N.; Kirkland, K.J.Canola (Brassica napus), a cool season crop, is very sensitive to heat particularly at the flowering stage of growth. Nutall et al. (1992) reported a 3°C increase in mean maximum daily temperature (21 to 24°C) during flowering resulted in a 0.4 tonne ha-1 decrease in seed yield. Canola sown in the Fall or mid-April flowers 18 to 24 days earlier and can yield up to 30% higher than can canola sown in mid-May (Johnson et al. 1998). Canola seed weights have averaged 30% and 20% higher for Fall and early spring seed dates, respectively, as compared to the late spring seeding date. These plants flower and mature in June and thereby escape midsummer heat and drought stresses. The objectives of this study were to determine the effect of seeding date on the size, maturity, germination rate and emergence rate of canola seed.Item Effect of seeding date, environment, and storage on canola seed vigour(2004-02-19) Gusta, L.V.; Johnson, E.N.; Nesbitt, N.T.; Kirkland, K.J.Seed vigour has been identified as one of the leading factors limiting stand establishment and yield in western Canada. Field studies at Scott, SK demonstrated that seed derived from Fall and April-sown canola produced higher plant densities, higher biomass at bolting, and higher seed yield than seed derived from May-sown canola. This study established the impact of seeding date on seed quality and vigour, which in turn affected emergence, seedling vigour and yield. Also, seed vigour slowly declines within one year, primarily from seed derived from the May-sown canola. Currently we are in the process of uncovering which genes and proteins are in common with vigour irrespective of seed source. We will combine our analysis with synchrotron technologies for a much more in-depth understanding of what constitutes “seed vigour” to develop a rapid, simple, and inexpensive method that will identify intrinsic characteristics of superior seed lots, as well as seed lots that lose vigour when stored under adverse conditions. In addition, we have initiated a study to compare hormones and metabolites during cold acclimation and freeze-induced injury/recovery to correlate these changes with winter survival. This research will identify traits that can be used in marker-assisted/molecular breeding programs for winter hardiness and possible genetic engineering studies on abiotic stress tolerance of seeds and plants. To further understand the processes involved in stress tolerance, we utilized gene transfer techniques to produce a PNT canola that over-expresses a novel gene which results in higher yields under stressful conditions. These PNT lines were tested in the field over 3 years across Western Canada in non-stressed, moderately stressed, or severely stressed areas. At each location, several lines flowered and matured 1 to 3 weeks earlier. The faster maturating PNT lines (up to 55% more mature at harvest) had increased yields (up to 32% increase) and enhanced seed quality (up to 87% increase in larger and more mature seed) versus the control. These results, both in controlled laboratory tests and in field trials, have been optimistic for genetic engineering of plants for enhanced stress tolerance without losing agronomical important characteristics.Item Fall seeded canola – agronomic studies and growth analysis(2000-02-22) Johnson, E.N.; Johnston, A.M.; Kirkland, K.J.Item Implication of reduced herbicide rates on resistance enrichment in wild oat (Avena fatua)(2003-02-18) Beckie, H.J.; Kirkland, K.J.Model simulations predict that lowering herbicide efficacy by reducing the application rate would slow the rate of enrichment of herbicide-resistant individuals in a weed population, but the resulting increase in density of susceptible plants would reduce crop yield and increase the weed seedbank. A study was conducted at three sites in Saskatchewan from 1997 to 2000 to examine the implication of reduced rates of Group 1 herbicides in a 4-year crop rotation, in conjunction with variable crop seeding rates, on the enrichment of resistant wild oat in a mixed (resistant and susceptible) population. Main plot treatments were crop (barley, canola, field pea, spring wheat), subplot treatments were crop seeding rate (recommended and high), and sub-subplot treatments were Group 1 herbicide rate (0, 0.33, 0.67, and 1.0 times the recommended rate). Herbicide rate frequently interacted with seeding rate in affecting wild oat seedling density, seed return, the viable fraction of the weed seedbank, and crop seed yield. As simulation models predict, reduced herbicide efficacy decreased the proportion of resistant individuals in the population. The high crop seeding rate compensated for a one-third reduction in herbicide rate by limiting total wild oat seed return and by reducing the number of resistant seedlings recruited from the seedbank. In a diverse cropping system, the level of resistance in the seedbank can be reduced without increasing the total (resistant plus susceptible) seedbank population by manipulating agronomic practices to increase crop competitiveness against wild oat when Group 1 herbicide rates are reduced to a maximum of two-thirds of that recommended.Item Increasing the frequency of canola and pea in rotations(1999-02-25) Ulrich, D.; Martin, K.; Kutcher, H.R.; Brandt, S.; Johnston, A.; Kirkland, K.Economic constraints can force producers to grow high value crops such as canola and peas more frequently in a rotation than is currently recommended for disease control. A study was initiated: to examine the impact of cultivar selection and pest control technologies on disease management, to determine how this impacts on recommendations for frequency of pea and canola in rotations, and to evaluate the influence of preceding crops on yield and cost of disease control. The study is located at Scott, Saskatchewan in the semi-arid prairie and at Melfort, Saskatchewan in the sub-humid Parkland. Peas and canola are grown continuously to once every two, three or four years in rotations with each other, wheat and flax. The pea cultivar (Highlight) has powdery mildew resistance, and the canola cultivars are a hybrid, with herbicide tolerance and moderate blackleg resistance (Invigor 2153), and a blackleg susceptible, open-pollinated cultivar (Westar). The experiment at each site is designed as a four replicate split-plot factorial; main plots consist of crop rotations and crop cultivars as factors with each phase of each rotation appearing every year. Each main plot is split for fungicide application (Azoxystrobin for blackleg of canola and Mycosphaerella of peas, vinclozolin for sclerotinia of canola). In this first year of the study there was no rotation effect. Fungicides were effective at reducing the severity of mycosphaerella blight of peas at Scott and increasing yields at both locations (12.4% at Scott and 15.8% at Melfort). Blackleg incidence was reduced with fungicide application at Scott but not Melfort. Yield of either cultivar of canola was not increased by fungicide application and differences in yield between Invigor 2153 and Westar were not detected at Scott.Item Mechanical weed control in pulse crops(2000-02-22) Johnson, E.N.; Holm, F.A.; Kirkland, K.J.Item The potential of seed priming to enhance germination and yield of canola(1996-02-22) Zheng, G.H.; Gao, Y.P.; Wilen, R.W.; Kirkland, K.; Gusta, L.V.Canola (Brassica rapa L., B. napus L.) seed germination is reduced and delayed by low soil temperatures and low soil water potentials in the spring of the main canola production areas of western Canada. Canola seed is also very sensitive to the salinity effects of high rates nitrogen fertilizer placed with the seed, especially when the seed bed is relatively dry. The effect of priming on canola (Brassica rapa, B. napus) seed germination, seedling emergence and yield under various stress conditions was investigated. Compared to non-primed control seeds, the primed seeds demonstrated more rapid, synchronous and greater germination and seedling emergence, particularly when the seeds were subjected to stress conditions of salinity, low moisture and soil-borne fungus at low temperatures. Field studies were conducted in 3 growing seasons at 3 different locations, demonstrating 5 to 50% increase in yield from the seeds either primed with water or primed with 50 PM ABA solution compared to non-primed control seeds, particularly when the seeds were sown in early spring.Item Spring wheat cultivars that differ in competitive ability(1997-02-20) Hucl, P.; Holm, F.A.; Kirkland, K.; Johnson, E.N.The objective of this research was to determine whether spring wheat varieties differ in their ability to compete against weeds. Specifically, we wanted to determine whether the competitive ability rankings of cultivars obtained by using model weeds translate into cultivar differences under field conditions with “real” weeds. The ultimate long-term goal is to use information from this study to identify cultivars, experimental wheat lines and possibly, breeding populations that are better suited for production in systems that are less reliant on pesticides for weed control (e.g., organic conditions).