Canola Production Tips. Start the Crop off Right. Choose a Variety Suited to the Location. Soil Fertility and Canola Nutrition

Transcription

1 Canola Production TIPS

2 02 CANOLA PRODUCTION TIPS CONTENTS Canola Production Tips Start the Crop off Right Choose a Variety Suited to the Location Soil Fertility and Canola Nutrition Plant to a Firm Seedbed, Otherwise Seeding Depth can t be Controlled IPM - What is it? Plan a Weed Control Strategy Flea Beetles Cutworms (Red-backed and Pale Western) Root Maggots Lygus Bugs Cabbage Seed Pod Weevil

3 Diamondback Moth Bertha Armyworm Blackleg Sclerotinia Brown Girdling Root Rot Fusarium Wilt Alternaria Black Spot Clubroot Maximize Harvest Returns Canola Management Extends Beyond the Crop in the Field Calculation of Seeds/Pound Metric/Imperial Conversions

4 04 CANOLA PRODUCTION TIPS Canola Production Tips for Making the Most from your Canola Crop Canola is a management-responsive crop. Statistics Canada reports the 10-year average yield ( ) in Western Canada as 27 bushels per acre. Yet knowledgeable growers often average 30 bushels or more and many are now regularly producing 40 bushels per acre. Weather certainly plays a role in canola yields. It is management that makes the difference between an average and above average canola crop. This booklet is designed to help growers concentrate on some of the key agronomic factors which can affect the profitability of their canola crops. Agronomy is the science and economics of crop production. Focussing on one without the other will short-change profitability. The goal in canola production should be to maximize contribution margin. The contribution margin is the amount of gross revenue remaining to pay fixed costs, labour and return on investment, after deducting variable costs. In order to maximize canola production, it can t be stressed too strongly that growers must know what s happening in their canola fields at all times. Canola is not a crop growers can afford to plant in the spring and then not look at again until late summer; nor is it a crop which can be monitored from the roadside. Effective canola management results from hands-on, down-on-your-knees involvement with the crop.

5 The topics in this booklet are considerably condensed to provide fast facts in the field. For complete information on all areas of canola production, refer to the Canola Growers Manual 2003 edition. Starting the Crop off Right Get the crop out of the ground quickly to reduce seedling exposure to soil-borne diseases and prevent weeds from getting a competitive edge on the crop. Seed 1/2 to 1" (1.25 to 2.5 cm) deep to moisture. Seeding too deep depletes seed energy reserves and encourages the development of seedling diseases. For rapid germination, soil temperatures of 10 C or higher are ideal, but the yield benefits from early seeding may warrant starting at an average of 6 C. Reference: Canola Growers Manual pp. 504, 505, 706, 1004c-1007c. 8 Seedling disease complex includes a number of fungi that attack canola seeds, roots or hypocotyls causing symptoms ranging from rotting in the ground, to poor growth or death of seedlings after emergence. 05

6 06 CANOLA PRODUCTION TIPS Use Clean, Certified Seed Certified seed ensures a true-to-type crop with the performance characteristics growers expect. Be sure to include a seed treatment. Fungicide seed treatments reduce seed-borne blackleg and alternaria black spot, and protect seedlings against seedling diseases. Including an insecticide with the treatment can also provide protection against flea beetle damage. Ask a seed supplier for blackleg test information and weed seed analysis. Don t import weeds or disease onto your farm. Use seed with a germination of 95% or better for maximum yield potential. Ask for thousand-kernel weight. Larger seed is typically more vigorous, and is related to improved plant development and yield. This number also helps calculate a proper seeding rate to meet target plant populations (see page 12). Reference: Canola Growers Manual pp. 804, 805 Choose a Variety Suited to the Location hkey advantages for each species: B. napus (Argentine canola): higher yield potential; higher oil content (1-2%); resistance to white rust (staghead); better tolerance to brown girdling root rot; specific herbicide tolerance; and specialty oil traits.

7 B. rapa (Polish canola): earlier maturity; and better shattering tolerance allows for straight cutting. B. juncea canola: improved drought tolerance; increased heat tolerance; and better shattering tolerance allows for straight cutting. hreview performance data from a number of different sources before selecting a variety. Choose a variety for both its yield potential and agronomic characteristics. hevaluate the levels of disease resistance of any variety under consideration. hdon t put all your eggs in one basket. To manage risk, try different varieties to compare them to the previous standard variety. h Do not depend on variety choice alone to improve yields, it will lead to disappointment. Current varieties have the genetic potential to produce a much higher than average yield. However, they won t yield to their full potential if short-changed on the management end. Reference: Canola Growers Manual, pp

8 08 CANOLA PRODUCTION TIPS Soil Fertility and Canola Nutrition hprofitable canola production relies heavily on adequate plant nutrition, which in turn is affected by management of soil fertility. In addition, the nutritional level of the plant will affect the crop response to stress factors such as disease and adverse weather. Balanced, effective fertilizer management not only contributes to profitable canola yield but also helps to maintain the productivity of the soil resource. hnitrogen (N), phosphorous (P), and sulphur (S) are the most limiting nutrients in most soils. Canola yields respond well to additional levels of these nutrients. ha 35 bu/ac canola crop will take up the following amounts of the major nutrients (lb/ac): N : P 2 O 5 : K 2 O : S : : : hthe above example shows the ratio of nutrients (5 : 2.4 : 4 : 1) to achieve from the combination of soil available nutrients and applied fertilizer. ha proper N:S ratio is essential for canola production. Be sure to keep this ratio to help maximize yield. hboron (B) is a micronutrient that occasionally limits canola yields in some soils. Boron can be applied to fields that show deficiency through soil or tissue testing.

9 Target Yields and Fertilizer Recommendations Fertilizing to a target yield is important for maximizing fertility dollars. Assess spring moisture conditions with a soil moisture probe to help establish a target yield. Using the depth of moist soil measured with the moisture probe, estimate the amount of stored water in the soil from the following table: Table 1. Water Availability for Different Soil Textures Soil Texture Inches of Soil Water per Foot of Moist Soil (inches) (cm) Sand Loamy Sand Sandy Loam Loam Clay Loam Clay Reference: Saskatchewan Agriculture, Food and Rural Revitalization (SAFRR) 09

10 010 CANOLA PRODUCTION TIPS Calculate target yield by using one of the formulas in the following table: Table 2. Formula for Determining Target Yield on a Soil Test Soil Zone Yield Formula Dry Brown Y=(WU - 2.5) X 2.0 Brown Y=(WU ) X 2.5 Dark Brown Y=(WU - 2.0) X 3.0 Thin Black Y=(WU ) X 3.3 Black Y=(WU - 1.5) X 3.6 Gray Y=(WU ) X 4.0 Reference: SAFRR Y = Yield (bu/ac) WU = Water use (inches of stored soil moisture + estimated in season precipitation) Example: Information taken at soil sampling; loam textured soil in thin black soil zone, soil moisture probe readings average 2.5' (0.8 m) on 15 probes, estimate 7" (18 cm) of in-season precipitation would equal a target yield of 29.7 bu/ac. h Submit your target yield and your average depth of moist soil with your soil sample to assist the lab in making more accurate fertilizer recommendations. Fertilizer Placement h Canola is sensitive to too much fertilizer (especially N) in the seed row. Canola can tolerate some fertilizer in the seed row, but moisture conditions and row spacing limit the amount of fertilizer that can be seed placed. h Be aware of the seedbed utilization of the seeding opener and apply seed-placed fertilizer accordingly.

11 Nutrient Deficiencies h Canola can exhibit a number of nutrient deficiencies but N and S are the most common. h Deficiencies can be corrected with minimal yield loss if detected early and timely rescue treatments are applied. This is most common with N, S and sometimes B. N can be added until bolting, S can be added into flowering, and B can be added up to early flowering. Reference: Canola Growers Manual, pp Canola seedlings with N deficiency (right) vs. healthy seedlings (left). 8 Classic symptoms of a severe sulphur deficiency. This crop will have a dramatic yield reduction. 011

12 012 CANOLA PRODUCTION TIPS Plant to a Firm Seedbed, Otherwise Seeding Depth can t be Controlled h The seedbed is firm enough when a work-boot sinks no deeper than the thickness of its sole. h Base packing decisions on soil conditions each year. Generally, fine-textured soils are easily overpacked. These soils can become so compacted that the supply of oxygen to seedling roots is limited. h Under loose soil conditions, pre-seeding packing is recommended for moisture conservation or improved seeding depth control. h Post-seeding packing may be required behind seeding equipment that does not have on-row packing. Reference: Canola Growers Manual, pp Seeding Rate Considerations h Growing conditions at time of seeding, including the potential for diseases and insect damage, will affect the plant density. Under above average conditions, 60 to 80% of canola seed will produce viable plants. Under average conditions, 40 to 60% of the seed will produce viable plants. h The recommended seeding rate range is five to 10 pounds per acre (5.6 to 11.2 kg/ha), with the ultimate goal of establishing a minimum of 7 plants/ft 2 (70 plants/m 2 ) to achieve optimum yields. h Seed size affects seeding rate. The higher the thousand-kernel weight, the fewer seeds per pound.

13 h Seeding Rate Calculation (lbs/ac) = 9.6 X plants/ft 2 X Thousand Kernel Weight in grams % survival h Lower seeding rates often mean fewer plants per square foot, which take longer to cover the ground. This gives weeds more time to establish and compete with the crop. h Low plant densities lead to increased branching, extending the development period causing delayed maturity and potential green seed problems. Reference: Canola Growers Manual, pp IPM - What is it? Integrated Pest Management (IPM) uses ALL the tools available for controlling weeds, diseases and insects. The goal of IPM is to achieve the best pest management by using all the tools in a method that is (1) safe, (2) environmentally sound and (3) economically viable. 013

14 014 CANOLA PRODUCTION TIPS The IPM Toolkit Includes h Prevention (practices that reduce the severity of the pest problem or prevent build-up of the pest on the farm). h Monitoring/forecasting (keeping track of the pests that are present and the actual size of the problem). h Intervention (actions that reduce the economic impact of the problem). h Record keeping (maintaining a field record of what happened and effectiveness of the intervention). Steps followed in an ipm program h identifying the pests; h understanding the life cycle of each pest; h monitoring/scouting for pests; h economic thresholds; h prediction/forecasting: tools and techniques; h preventive practices; h interventions - cultural, biological, genetic, chemical; and h evaluating the effectiveness/results of the strategy used. Growers typically use a multitude of IPM techniques. The challenge in the future will be to pull together the techniques being used and create better packages. Generally speaking, IPM only works to its fullest potential if a multi-year approach is taken, where plans for a canola field s pest program begin at least one year ahead of seeding the crop.

15 Plan a Weed Control Strategy h A good weed control program is essential because canola is a poor competitor in the seedling stage. h Consider a pre-seed burn-off treatment to control early emerging weeds. In-crop weed control in the early stages of crop development (before the 4-leaf stage) will have greater yield benefits than later in the season. h Weed control is equally important in the non-canola years. A number of weeds, particularly cruciferous weeds (e.g. stinkweed, shepherd s purse) can act as hosts for canola diseases and insects in the non-canola years. h Regularly rotate among herbicide groups, not just herbicides. Herbicide-resistant weed populations are an increasing reality, so keeping accurate records of all herbicides used is important. (See table on page 16) h Walk your fields to identify what weed species are present. Field monitoring will also alert you to the development of resistant weeds. h Have on hand a copy of your provincial government s weed control publication and a weed identification guide. Reference: Canola Growers Manual, pp. 1003a -1020a. 8 Severe weed pressure in the plot on the right would make early weed control more critical. 015

16 016 CANOLA PRODUCTION TIPS Table 3. Herbicide Groups Based on Mode of Action (for canola) Herbicide Group 1 2 Registered Herbicides Assure II, Centrion, Freedom Gold*, Fusion, Hoe-Grass 284, Muster Gold II*, Poast Ultra, Pursuit Ultra*, Select, Venture Absolute, Freedom Gold*, Muster, Muster Gold II*, Odyssey, Pursuit, Pursuit Ultra* These symptoms are seen with soil residues. Group 2 herbicides are the most problematic for canola due to the high sensitivity of the plants to these herbicides. Some Group 2 herbicides, such as Refine have been observed to have no effect the year after application, regardless of soil conditions contributing to breakdown, eg. moisture, ph, or organic matter. Symptoms of Herbicide Injury Group 1 herbicides do not have any soil residual activity on canola. Pursuit Ultra and Muster Gold II would show symptoms of Group 2 listed below. At low concentrations - slight purpling and cupping of 1st through 2nd-3rd set of leaves which upon recovery produces small leaves that may show chlorosis at the base of the leaf; slow growth. Can be somewhat asymptomatic and is similar to other conditions such as waterlogged soil, drought, or nutrient deficiency. At high concentrations - permanent severe purpling and cupping of 1st-3rd true leaves which may permanently damage the main growing point; a proliferation of callus like growth at the crown; and production of thin, weak, side shoots from the crown area.

17 2 8 Canola plant attempting to recover from a high level of Group 2 residue Advance 10G, Bonanza, Edge, Fortress*, Rival, Treflan Absolute, Eclipse, Lontrel Avadex BW, Fortress* Credit, Eclipse, Factor, Glyfos, Maverick, Renegade, Roundup Dry, Roundup Original, Roundup Transorb, Roundup Weather Max, Vantage, Vantage Plus Liberty 150 SN Amitrol 240 No soil residual effect on canola. No soil residual effect on canola. No soil residual effect on canola. No soil residual effect on canola. No soil residual effect on canola. No soil residual effect on canola. * Some products contain more than one active ingredient and, therefore, may appear in more than one group. In some instances, both active ingredients act to kill the same weed using different modes of action. In these instances, use of tank mixes may slow down the process of developing weed resistance. (Refer to a current provincial government weed control publication for more information on herbicides used in non-canola years.) 017

18 018 CANOLA PRODUCTION TIPS Insect Pest Monitoring Flea beetles Description h Beetles emerge from over-wintering sites in April and early May and begin feeding on volunteer canola and weeds. They move into the canola crop as it emerges. The heaviest feeding can last from May to late June. h A second generation of beetles emerges in early August and feeds until mid-october. Critical Time for Action h At seeding and through seedling stage. Action Required h Sow at a higher seeding rate if beetle populations were high the previous fall. 8 Crucifer flea beetle. Adult flea beetles are 1/10" (2.5 mm) long. h In areas where flea beetle damage is consistently high or where previous fall populations were high, use a seed treatment with an insecticide level that provides extended control. h Monitor the newly emerged crop daily. Flea beetles chew holes in the cotyledons, stem or leaves creating a shot hole appearance. This can cause delayed plant development and thinner, weaker plant stands. In heavy infestations, entire plants may be eaten.

19 8 Striped flea beetle. Adult flea beetles are 1/10" (2.5 mm) long. Use a foliar spray if there is more than 25% damage to cotyledons and first true leaves. Temperatures above 14 C increase both movement of beetles throughout a field and feeding activity. More than one foliar insecticide application may be required. Reference: Canola Growers Manual, pp. 1018b-1022b 8 Flea beetle damage illustrating 25% shot-hole appearance. 019

20 020 CANOLA PRODUCTION TIPS Cutworms (Red-Backed and Pale Western) Description h Both species overwinter as eggs, laid in the fall by moths that are night fliers. In April or early May, the eggs hatch and the young larvae feed mainly at night on weeds and volunteer plants. h At maturity, the pale western cutworm larvae are greenish or slate-grey with a brown head, while red-backed cutworm larvae are dark grey with two broad, dull, brick red stripes along the back. They vary in size from 1.2 to 1.5" (30-38 mm). 8 Red-backed cutworm larvae. 8 Cutworm larvae eat into stems and usually sever them at or just above the soil surface.the plants will then wilt and die.

21 Action Required h Scout canola fields and inspect seedlings on a weekly basis from mid-may to mid-june (seedling to rosette stage), looking for bare areas and wilting plants. h Search the top 2" (5 cm) of soil around notched, wilted, dead or cut-off plants (weed or crop seedlings) for cutworm larvae. The damage will often appear on south facing upper slope areas first, due to warmer soil temperatures, which advance the egg hatch. The larvae also usually prefer loose, dry soil. h To collect cutworm larvae, use a garden trowel and/or a soil sifter. The small, worm-like larvae curl up or attempt to hide in the debris. h Use a registered foliar insecticide when cutworms exceed 3 to 4 per yd 2 (m 2 ). Apply insecticide in the evening since cutworms feed during the night. h Cutworm control may only be necessary in small areas of the field, when bare patches appear and large numbers of cutworms are still actively feeding. The abdomen of actively feeding larvae will contain ingested plant material and hence appear green. Reference: Canola Growers Manual, pp. 1015b-1016b. 021

22 022 CANOLA PRODUCTION TIPS Root Maggots Infestations are more severe after a cool, wet spring. Larvae feed on the root tunnelling into the taproot, producing brown streaks on the root. The lower leaves of infested plants often turn yellow with severe damage resulting in arrested plant growth. Feeding damage may also promote disease, causing further plant stress. Heavy infestations can delay blooming and cause severe lodging and yield losses. Description h Small white maggots hatch from eggs laid in June. They begin to pupate in late July to mid-august. 8 Root maggots are found in the roots and are white, 1/4" (6 mm) in length. Critical Time for Action h There is no registered chemical control, so cultural control practices must be used before or at time of seeding. Action Required h Where climatic conditions permit, plant B.napus canola. It is less susceptible to root maggots than B.rapa canola.

23 h A moderate increase in seeding rates may reduce damage and yield loss caused by maggot feeding. Heavier canola plant densities result in smaller basal stems that are less attractive to egg laying females. Reference: Canola Growers Manual, pp. 1026b-1028b. 8 Root maggots on canola roots. 8 The adult form of the root maggot is a 1/5" (5 mm) fly. Lygus Bugs 8 Adult lygus bugs range in colour from pale green to reddish brown to black, and from fairly uniform colour to mottled. They have a distinct triangular or V-shaped marking on their backs. Young nymphs resemble the adults without wings. 023

24 024 CANOLA PRODUCTION TIPS Description h Lygus bugs enter canola fields at the bud stage. h Hot weather increases lygus bug populations. h Adults and nymphs pierce and suck juices from the pods, stems and blossoms. This feeding causes blossoms to abort and young pods to drop from the plants. Feeding on the older pods causes the seed to become shrivelled. The pods may also become deformed. h Yield losses due to lygus bugs have been estimate as high as 15 to 20%. Action Required h When making the decision to apply a foliar insecticide it is important to consider the stage of the crop, and the stage and size of the lygus bugs. h Consider application of a registered foliar insecticide if numbers exceed threshold levels. h Thresholds are approximately 15 lygus per 10 sweeps at flowering, increasing to 20 per 10 sweeps as the crop approaches pod ripening. Reference Canola Growers Manual, pp. 1022b-1025b

25 Cabbage Seed Pod Weevil Description h Adult cabbage seed pod weevils are typically 1/10 to 1/6" (3-4 mm) long with an oval, ash grey to black body and a strongly curved snout. h Larvae are white and grub-like without legs or eyes and are about 1/12" (2 mm) long. h Adults feed on flower buds causing bud blasting while larvae eat developing seeds, causing yield loss. Pods are susceptible to disease and shattering. 8 Adult cabbage seed pod weevils can feed on developing canola buds causing bud blasting. They also deposit eggs into small developing pods. 8 The larvae that hatch from these eggs can consume about five canola seeds before chewing an exit hole and dropping to the ground to pupate. 025

26 026 CANOLA PRODUCTION TIPS Life Cycle h One generation per year. h Adults over-winter under litter and in light soils becoming active in spring, flying at temperatures above 15 C and feeding on early crucifer crops or weeds in spring before laying eggs. h Each female lays 60 to 70 eggs that hatch within five to 30 days, depending on temperature. The larvae spend three to four weeks in the pod, each consuming five to seven canola seeds. h Population and activity of adult weevils peak at full bloom and continues into the early pod-set period. h When feeding is completed, the larva chews a round exit hole at the base of the pod and drops to the ground to pupate. New adults emerge within two to four weeks and feed on green stem and pod material but do little damage. Action Required h Monitor field using a sweep net; start sampling at early bud stage. h If control is required, the best time to spray is when crops are in 10 to 20% flower to avoid egg laying in newly formed pods. h Consider a foliar insecticide application when numbers reach 30 to 40 weevils per 10 sweeps.

27 Diamondback Moth Description h Eggs are pale green or yellow, laid singly or in twos or threes on both sides of leaves. Tiny, green larvae hatch about mid-june and mine the leaves by entering the leaf and feeding on internal tissue. They emerge from the leaf in about a week and feed for 10 to 21 days on the outer leaf tissue. When disturbed, larvae will wiggle vigorously or hang from slender threads. h It takes about 32 days to develop from egg to adult, so scout continuously during July and early August. There can be up to three generations per growing season, with the second typically causing the most damage. 8 Moths can arrive from the United States in early May. 8 Larvae are up to 1/3" (8 mm) long, smooth pale yellow-green worms. 8 The larvae pupate in white lacework cocoons anywhere on the plant. 027

28 028 CANOLA PRODUCTION TIPS Action Required h Monitor fields regularly from bud stage through pod set. h The economic threshold for diamondback moths is 10 to 15/ft 2 (100 to 150 larvae/m 2 ) at early flowering increasing to 20 to 30/ft 2 (200 to 300 larvae/m 2 ) during podding. If leaves are beginning to turn yellow and dry up, forcing the larvae to feed on pods, consider using a foliar insecticide at the lower end of the threshold range. h Continue monitoring after foliar insecticide application to ensure that numbers remain below thresholds. Reference: Canola Growers Manual, pp. 1016b-1018b. Bertha Armyworm Description h Adult moths emerge from over-wintering pupae in mid-june to mid-july. Eggs are laid soon after moths emerge. h Larvae or worms emerge in about one week and pass through six growth stages or instars. There is only one generation of bertha armyworms per year. 8 The night-flying bertha armyworm moths are black and olive with whitish markings and a silvery fringe on each wing.

29 Action Required h Start field monitoring for larvae in mid to late July. h Bertha armyworm should be controlled before the insect reaches its most destructive stage of fifth and sixth instar in August. h Pheromone traps are used to monitor the moth flight from mid June through July and develop risk maps. 8 Young larvae are 1/10" (17mm) long, pale green with a pale yellowish stripe on each side. Mature worms are 1 1/2 to 2" ( cm), velvety black to brown with a broad orange stripe along each side and a light brown head. Higher moth counts during the flight period indicate greater risk of larval damage. h The rate of larvae growth and amount of leaf tissue eaten increases in warmer weather, so monitor fields often. h Use economic threshold charts available in the Canola Growers Manual or from provincial extension offices to determine cost effectiveness of spraying. The threshold will vary from 1-3 larvae/ft 2 (11 to 34 larvae/m 2 ). Remember, with higher priced canola, it takes fewer larvae to reach an economic threshold. h The worms are easily dislodged from canola plants, so do the counts in the field. The most effective method is to pace off a square metre, then vigorously shake the plants within the boundary and count fallen larvae on the soil surface and within leaf litter. Sprinkling baby powder or flour on the ground beforehand will make the larvae easier to see. h The best time to spray is in the cool of early morning or evening when the larvae are up in the plants feeding. Reference: Canola Growers Manual, pp. 1008b-1011b. 029

30 030 CANOLA PRODUCTION TIPS Disease Management Blackleg Before Planting h Determine the potential for blackleg based on the amount of disease in the area and records of disease levels in fields. Airborne blackleg spores can travel three to five miles. h Walk fields to see how well previous years infected canola stubble has decomposed. Stubble is a host for the disease organism. h Choose an acceptable rotation length, keeping in mind that in areas of high blackleg risk, rotations less than one in four years increase the potential for disease incidence. Tight rotations with resistant varieties also increase selection pressure for resistant strains. h Select varieties with appropriate resistance levels based on an assessment of the disease potential. It is very risky to grow B.rapa or susceptible B.napus varieties on fields which have had severe blackleg in the last six years. At Seeding h Plant only seed treated with a recommended fungicide. Seed treatment will control seed-borne blackleg but will not prevent seedling infection caused by spores released from diseased stubble. h In areas where blackleg is not a problem, have the seed tested prior to planting and plant only clean seed.

31 In Crop h In conjunction with varieties that have some resistance, a registered foliar fungicide can be applied as a preventative measure. h Foliar fungicide should be applied at the rosette stage, prior to bolting. Generally at this stage there is no evidence of the disease. The fungicide delays the onset of damaging cankers, allowing the canola pods to fill more completely. h The best time to assess the level of blackleg in a field (for future reference) is from after the crop is blooming until swathing. Stem lesions are white to pale grey with a distinctive dark border. Hard, black bodies slightly larger than a pinpoint may appear within these lesions. Pods may ripen and split prematurely in severe cases. At Harvest h Using a straw chopper and chaff spreader to evenly distribute infected crop residue and/or incorporating the trash will increase the rate of decomposition of infected stubble. After Harvest h To assess the potential for blackleg in following years, walk fields at swathing time to check canola plants or stubble for evidence of blackleg lesions or cankers. 8 Example of blackleg stem lesion. 031

32 032 CANOLA PRODUCTION TIPS h Checking fields the following spring may not give as accurate a picture of disease levels. A number of other organisms, including the non-virulent form of blackleg, can produce blackleg-like symptoms on the stubble in the late fall and early spring and can give the impression that blackleg is more severe than in reality. General Tips h In non-canola years, control volunteer canola, as it will act as a host for the disease. h Having a one-in-four-year rotation will help control blackleg. Shorter rotations are not a guarantee that the disease will cause substantial yield loss, but it certainly can increase the risk, as well as the selection pressure for the fungus to overcome varietal resistance. If growers shorten the rotation, it is essential to take every management precaution to minimize disease potential. Reference: Canola Growers Manual, pp. 1008c-1012c 8 Blackleg leaf lesion.

33 Sclerotinia At Seeding h Use a seed source free of sclerotinia. In Crop h Sclerotinia requires moist, warm conditions for at least 10 days in order to germinate and form apothecia. 8 Sclerotia are small, black, round or oval bodies up to 3/4" (2 cm) long that develop in infected stems. They can survive in the soil up to five years or more. h Spores produced by the apothecia cannot infect leaves or stems directly. They first need dead canola petals or other organic material as a food source to germinate, grow and penetrate the plant. In order to infect canola plants, the spores need rainfall or heavy dews that keep stems and leaves wet for two to three days. Spores can remain alive for up to 21 days after release from the apothecia. h In the 10-day period before flowering, walk through the crop, checking for signs of apothecia. 8 Apothecia are mushroom-like bodies, which produce the infectious sclerotinia spores. 33 0

34 034 CANOLA PRODUCTION TIPS h Use the sclerotinia stem rot checklist to indicate whether fungicide application should be considered. h A petal test kit is also available to indicate the average percentage of infected flower petals in the canola crop and, in turn, the risk of sclerotinia developing. h Optimum time for fungicide application is at the 20 to 50% bloom stage. Depending on weather conditions, it takes three to six days to move from first flower to 20% bloom. Table 4. Identification of Flowering Stages of Canola B. napus Canola B. rapa Canola Flowering Stage (Flowers - main Stem) (Flowers - main Stem) 10% 10 6 to 7 20% 14 to to 12 30% to 16 At Harvest h Sclerotinia can progress rapidly in wet, compacted swaths. The heavier and more compact the swath, the greater the likelihood for sclerotinia to rot the swath before it can be combined. As much as one-third of the crop can be lost to sclerotinia in the swath.

35 8 Sclerotinia infected plants turn straw coloured as they prematurely ripen. To reduce or avoid further disease development in the swath, in fields with sclerotinia infection: h straight combine (B.rapa canola only); h avoid compacting the swaths; h leave tall stubble for better drying; h do not swath if rain is in the immediate forecast; and h do not swath immature stands (less than 30% of the seed ripened). General Tips h A four-year rotation including non-host crops may help reduce the amount of sclerotinia in the soil. However, crops may still be infected from airborne spores produced in nearby fields. h Don t follow or precede canola in a rotation with beans, sunflowers, mustard, pulse crops, alfalfa, clover or potatoes as they can act as hosts for the disease. Control Canada thistle as it is also a host for the disease. Reference: Canola Growers Manual, pp. 1012c-1019c 035

36 036 CANOLA PRODUCTION TIPS Brown Girdling Root Rot The soil-borne fungi that cause the disease occur in all soil types and textures, primarily in the Peace River region. There is no chemical control. Before Planting h The disease appears to be more severe when canola follows canola, clover or fescue, than when canola follows summerfallow. However, brown girdling root rot can also occur in new breaking and in fields not previously planted to canola. At Seeding h If weather conditions permit, plant B.napus varieties, as they are less susceptible to the disease. h Optimum, balanced crop fertility can reduce the impact of the disease. In Crop h Light brown lesions usually appear on the taproot 3" (7.6 cm) or more below the soil surface after flowering. The lesions eventually girdle the root. The amount of yield loss depends on how much root is lost to girdling. The disease is more prevalent under moist conditions. Reference: Canola Growers Manual, pp. 1007c-1008c 8 Early stages of brown girdling root rot.

37 8 Advanced stage of brown girdling root rot; taproot is completely severed. Swathed plants tend to pull out of the ground increasing pod shattering problems and slowing harvest. Fusarium Wilt Fusarium wilt, a soil-borne fungal disease of canola, has been observed throughout western Canada. It is caused by Fusarium oxysporum, which i s different from the species that cause fusarium head blight in cereal crops. Before Planting h Select varieties with good tolerance to fusarium wilt, especially in areas where the disease has been previously identified. In Crop h Scout fields for the following symptoms: h Yellow or reddish-brown streaks, often occurring only on one side of the stem or on the branches. Some plants may have an orange discoloration at the base of the stem. Plants with minor infection may also ripen prematurely and tend to shatter. 037

38 038 CANOLA PRODUCTION TIPS h Chlorosis and necrosis of stems, vascular discoloration, poor seed set and premature desiccation. h Premature death in severely infected plants. Stems and/or branches turn brown, but plants remain upright with roots intact. No visible lesions are visible on stems or roots. Plants are often stunted and have small pods with no seeds, resulting in significantly reduced yield. Reference: Canola Growers Manual, pp. 1025c-1026c Alternaria Black Spot At Seeding h Plant seed treated with a recommended fungicide. This will help control infection transmitted from the seed to seedlings and reduces seed rot. 8 Under moist conditions, leaves will develop grey spots. Under dry conditions, spots may be grey with purplish or black borders or entirely black. Severely infected leaves wither and drop. 8 Pods may show sunken, dark brown to black circular lesions.

39 h B. rapa varieties are more susceptible to alternaria than B. napus varieties. h Early planting of B. napus canola may help to reduce the risk of alternaria. In Crop h Foliar fungicide application at 95% bloom can provide economical control of this disease. h Monitoring fields will give an indication of disease levels for future field management. At Harvest h Alternaria acts as a desiccant drying the pods and causing them to split open. Where symptoms of alternaria are visible, early swathing can help reduce yield losses. h If alternaria is visible in B. rapa canola, do not straight combine the crop. After Harvest h The fungus survives on infected crop residue and produces spores that infect the new crop, so growers may consider incorporating diseased stubble. General Tips h In non-canola years, control weeds such as mustard, flixweed, stinkweed and volunteer canola as they act as hosts for the disease. h Alternaria is present in most canola fields but only causes significant yield loss when high humidity and warm temperature combine to encourage its rapid development at pod set. Reference: Canola Growers Manual, pp. 1019c-1023c. 039

40 040 CANOLA PRODUCTION TIPS Clubroot Clubroot is a serious soil-borne fungal disease in cabbage, cauliflower and rutabaga crops, chiefly in eastern Canada and the coastal regions of British Columbia. It was identified in canola fields near Edmonton, Alberta in Before Planting h Fields become infested mainly by the transplanting of soil via cultivation equipment and by seedling transplants. h Resting spores of the fungus can survive in soil for many years. In the presence of susceptible roots, the spores germinate and release tiny organisms that swim in free water to the surface of the rootlets, penetrate and form a fungal colony inside the root cells. h Use long rotations (one in four years). It may not prevent the introduction of the disease, but it will restrict disease development and severity within the field. h Do not move cultivating equipment from infested to non-infested areas without thoroughly cleaning the equipment. Rinse with a weak disinfectant (1 to 2% household bleach). At Seeding h Avoid common, untreated seed (all crops) because earth-tag (soil particles) on seed can be a source for introducing the disease to new areas.

41 In Crop h Scout canola fields regularly for wilting, stunting or yellowing or premature ripening, and identify the cause. h Galls appear on the roots of infected plants, ranging from tiny nodules to large, club-shaped outgrowths. They are easiest to find at swathing. h Symptoms of clubroot will often be more severe on acidic soils, but results with liming have been unreliable and costly. 8 Very severe clubroot on canola. 8 Moderately infected canola root. After Harvest h Avoid the use of bales and manure from infected areas, as the spores can survive through the digestive systems of livestock. Reference: Alberta Agriculture, Food and Rural Development 041

42 042 CANOLA PRODUCTION TIPS Maximizing Harvest Returns Assessing Seed Colour Change h In hot, dry weather, canola can go from 10 to 50% seed colour change in just days. h Seed colour change does not mean the entire seed has changed colour. Any indications of colour change (yellow or brown) anywhere on the seed should be counted as seed colour change. h Seed colour change should be assessed by actually opening pods on the main stem, starting at the bottom. Reference: Canola Growers Manual, pp Timing Swathing 8 Eleven of the 20 seeds in this pod have colour change. h The optimum time to swath canola and maximize yield potential is when 50 to 60% of the seeds on the main stem have changed colour. Oil content, grade and seed size will often benefit as well. h To reduce harvest losses, avoid swathing beyond optimum seed colour change.

43 h Seed colour can change an average of 3 to 5% per day at temperatures of 22 to 25 C. This is particularly important when large acreages are at the same maturity. Growers may have to start swathing at 30% seed colour change to manage the risk of over ripening. h Earlier swathing should be avoided in hot dry conditions. h Swathing prior to a frost will only be beneficial if sufficient time is allowed for the swath to dry down. Reference: Canola Growers Manual, pp When to Combine h Check both seed moisture content and green seed before combining. h Canola requires at least 20% moisture in the seed for curing to take place. Under hot, dry or windy conditions, the crop may dry down to acceptable moisture content before the seed has cured and cleared the chlorophyll. h Letting swaths sit through several heavy dews or showers will help clear the chlorophyll. This process may take up to 14 days or longer. Reference: Canola Growers Manual, p

44 044 CANOLA PRODUCTION TIPS Straight Combining h Polish canola can be straight-combined. Check information from Canola Council of Canada Canola Production Centre trials, the Canol@Grow section on the Canola Council s website, and other publications before considering straight combining. Straight combining is not generally recommended for B. napus canola due to the high risk of pod shattering. h The crop canopy should be well knitted and slightly lodged to reduce the chance of pod shattering and pod drop. h As in a swathed crop, always test for green seed and moisture content before combining. Reference: Canola Growers Manual, p Canola Management Extends Beyond the Crop in the Field h For safe, long-term storage, canola should be at or below 9% moisture and cooler than 15 C. The high oil content of canola seed prevents it from absorbing as much moisture as cereal grains, which is why a closer watch must be kept on stored canola. h Canola can continue to respire (breathe) for up to six weeks after harvest before becoming dormant. Bins should be monitored regularly during this period to avoid heating. h The effect of changing temperatures on bin walls in both fall and spring causes moisture to concentrate in certain areas of the bin, which can lead to spoilage and heating. Again, at these times, the temperature of stored canola should be monitored regularly.

45 h Consider aeration or other forms of conditioning when storing canola. Reference: Canola Growers Manual, pp Marketing Considerations The ultimate speculation is holding unpriced canola in the bin and then failing to monitor its condition. There are a number of marketing and pricing options available. These include: h production contacts; h deferred delivery contracts; h basis contracts; h deferred pricing contracts; h hedging through a futures or options contract; and h price averaging through selling a portion of the crop every few weeks or every month. h There is a cost and risk to holding unpriced canola in the bin, waiting for higher prices: risk of seed quality deterioration, lost opportunity costs, interest costs associated with holding the canola, and the risk of price declines. Reference: Canola Growers Manual, pp Calculation of Seeds/Pound Seeds/pound = 454 Thousand Kernel x 1000 Weight in Grams 045

46 046 CANOLA PRODUCTION TIPS Metric/Imperial Conversions Symbols Length Weight 10 mm = 1 cm 1000 mg = 1 g 100 cm = 1 m 1000 g = 1 kg 1000 m = 1 km 1000 kg = 1 t Area Volume 10,000 m 2 =1 ha 1000 ml = 1 L 1000 L = 1 m 3 relationship between grade, Per Cent Green Seed and Chlorophyll in Parts Per Million* CGC Grade Per Cent Green Seed Chlorophyll PPM No. 1 Canada <2 25 No. 2 Canada 2 to 6 26 to 45 No. 3 Canada 6 to to 100 Sample >20 >100 *Reference: Daun, J.K. and Symons, S. (2000) How green is green? Sampling and perception in assessing green seeds and chlorophyll in canola. JAOCS, Vol 77, n.11

47 Approximate Relationships Length Volume 2.54 cm = 1 in ml = 1 fluid oz 1 m = in ml = 1 fluid oz (U.S) 1 m = 3.28 ft 1 L = 1.76 pints 1 m = 1.09 yd 1 L = 0.88 quart 1 km = 0.62 mile 4.55 L = 1 gal (Imperial) Canola Bulk Density 3.79 L = 1 gal (U.S.) 50 lb/bushel = lb/ ft 3 1 m 3 = ft 3 Weight 1 m 3 = 1.30 yd g = 1 oz 1 bushel = ft 3 = L 1 kg = 2.20 lb Area 1 tonne = 2204 lb 1 ha = 2.47 acres 1 tonne = 1.10 ton 1 acre = 43,560 ft 2 Pressure Power 1 psi (lb/in 2 ) = 6.90 kpa 1 hp = kw 047

48 048 CANOLA PRODUCTION TIPS CROP Canola, Mustard Wheat, Peas, Beans, Clover Corn, Flax, Rye Buckwheat, Barley Oats 1 tonne = 44.1 bushels 1 bushel = 22.7 kilograms 1 tonne = 36.7 bushels 1 bushel = 27.2 kilograms 1 tonne = 39.4 bushels 1 bushel = 25.4 kilograms 1 tonne = 45.9 bushels 1 bushel = 21.8 kilograms 1 tonne = 64.8 bushels 1 bushel = 15.4 kilograms For more information on canola production, contact your local Canola Council of Canada regional agronomist. Please check the Canola Council of Canada website at or phone Images for this project provided by: Agriculture and Agri-Food Canada (Kelly Turkington), Alberta Agriculture Food & Rural Development (Valerie Sowiak), Alberta Research Council - Vegreville (Sandi Checkle), Beth Hoar, Canola Council of Canada (Agronomists), Prairie Pest Management (Roy Ellis), and Syngenta Crop Protection Canada Inc. (Rick Istead).

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