Contents. Companion species with brassicas. Brassica crop husbandry. Grazing management and animal welfare

Transcription

1 Brassica Book

2 Contents 02 Section 1 Introduction Section 2 Cultivar information Section 3 Companion species with brassicas Section 4 Brassica crop husbandry Section 5 Grazing management and animal welfare Section 6 Brassica user guide This publication has been prepared in good faith by Agricom technical staff using sources that are believed to be reliable. However, Agricom Limited does not give any warranty that all information contained is accurate or that all advice given in this publication will be appropriate for all circumstances. Agricom shall not be liable to anyone in respect of any damages suffered as a result of their reliance on this publication. Agricom Limited, 2006

3 1. Product Range Summer/Autumn Brassica Feed Options Hunter Forage Brassica Fast growing (6-8 weeks to first graze), multiple grazing, for stock finishing in fertile, summer moist areas. Winfred Forage Brassica Early maturing (10-12 weeks), multiple grazing rape, all stock types. Rival Turnip Early maturing (14 weeks), short term one graze crop summer turnip. New York Turnip Late grazed summer turnip, late maturing (16-18 weeks). Winter Brassica Feed Options Sovereign Kale Medium tall kale, high yield potential, high leaf:stem ratio, excellent utilisation rates for valuable winter feed. Dominion Swede Yellow fleshed, main crop swede, late flowering swede, favourable culinary taste. Winfred Forage Brassica Versatile early ripening rape, frost tolerant, excellent leafholding in winter. New York Turnip White-fleshed, purple skinned, full leaved turnip, improved virus and disease resistance and yield potential over York Globe. Herb and Red Clover Options with Regrowth Brassicas Tonic Plantain Mineral rich perennial herb, fast establishing, strong year round production, grow with multiple grazing brassicas and pastures to boost overall production and diet quality. Grasslands Choice Chicory A true perennial with good persistence with improved dry matter production. High summer quality. Grasslands Colenso Red Clover Fine stemmed, dense tillering, early flowering, good tolerance to heat and drought, good cool season production, grazing type. Grasslands Sensation Red Clover Upright growing, highyielding cultivar with strong early-season growth. High levels of natural reseeding. Grouse Chicory Cool season active chicory, short-rotation, suited to brassica systems. 03

4 1. Agricom Limited A Profile 04 Forage crops are a valuable tool for meeting the changing feed and energy requirements of a livestock operation throughout the year. Feed supply and stock performance can be manipulated through the use of different brassica and herb species. Agricom recognised the integral role of brassicas, invested in breeding and research and is now proud to supply products, specifically bred for New Zealand temperate farming systems. From Small Beginnings Understanding the breeding process is useful when considering the purchasing of a new product. All Agricom products have progressed through each step (Fig 1), including extensive off-site evaluation in different environments and farming systems. Farmers can buy Agricom products with confidence knowing they come from a highly developed breeding programme and are backed by strong technical support to retailers and farmers alike. Why Consider Brassicas? Brassica crops can offer a superior feed supply, both in terms of quantity and quality, in many situations. They provide an excellent source of energy and protein for grazing stock. Use of a brassica crop should be considered in any situation where pasture quantity or quality is limiting the potential production of your livestock. The most common situations are as follows: Young stock finishing in early summer feed for post weaning period, where feed demands increase at a time when vegetative pasture growth rates are falling. Mid-late summer feed for all stock classes at a time when pastures are of a low quality and low moisture levels are impacting on pasture growth. Summer safe feed a parasite/pathogen free grazing environment, to avoid stock health issues related to endophyte effects, facial eczema etc. Autumn feed to support an increasing stocking rate resulting from the removal of paddocks in rotation for pasture renewal. Winter feed maintenance feed for stock when pasture growth is limited, allows building of pasture cover reserves by holding stock on small areas, allows pasture across the farm to build up for valuable, high quality, early-spring feed, and to avoid widespread pasture damage in very wet conditions. Winter stock finishing large quantities of quality feed suitable for finishing. For example, cattle and winter lamb contracts. Break crop for renovation programme of sub-standard pastures if managed will provide a significant dry-matter contribution, minimal time out of production, useful system for assisting in weed and disease clean up for pre-pasture establishment, good opportunity for improving fertility status. Particularly useful in avoiding ryegrass seeding over summer prior to establishment of an AR1 endophyte grass variety. Figure 1. The Plant Breeding Process Plant genetics collection Plant crossings Argonomic evaluation Market evaluation Commercial release years

5 2. Cultivar Information Which Multiple Grazing Forage Brassica Should I Use? 05 Hunter (brassica campestris spp rapa) is a hybrid cross between a turnip and a rape, producing one of the fastest maturing brassicas, with a look most like a leafy, non-bulb producing turnip. Winfred (brassica napu) is a cross between a turnip and a kale, traditionally termed a rape. These different genetic make-ups have conferred very different characteristics. The following diagram (Fig 2) summarises these characteristics and how they relate to their suitability for different farming systems. Figure 2. A Simplified Decision Making Tool for Choosing the Right Multiple Grazing Forage Brassica for Your Farming System More than 8 weeks Feed requirement Less than 8 weeks Low/med Soil fertility Med/high Sporadic Summer moisture Reliable Winfred Forage Brassica Hunter Forage Brassica

6 2. Cultivar Information 06 Hunter Forage Brassica Early maturing, 6-8 weeks with minimal ripening requirement Excellent quality forage for finishing animals through the summer months Fast recovery from grazing with excellent subsequent yields Strong plant survival through multiple grazing This type of brassica is an intra-specific hybrid developed by crossing turnips with related Asiatic leaf vegetables of the same species. The resulting quick-growing, leafy turnip, with minimal bulb development, is best suited to multiple grazings for summer and early-autumn feed requirements. Hunter is a fast maturing forage brassica with first grazing possible at 6-8 weeks. Hunter is an excellent quality forage capable of providing extremely high live-weight gain on growing animals. Hunter was bred for tolerance to turnip mosaic virus and cauliflower mosaic virus. This, combined with selecting for vigorous re-growth, has provided a variety with fast recovery from grazing and excellent ability to yield in the second, third, and sometimes fourth re-growth cycle. Plants usually show good resistance to most club root races, but they are susceptible to drought and aphids, and are best suited to heavier soil conditions with periodic summer moisture or irrigation. Figure 3. Hybrid Brassica Dry Matter Production Trial in the Hawkes Bay, Sown 10/10/02, Average Rainfall mm Yield (kgdm/ha) NS * * Statistical significance NS = not significant * = P < (Dec 9) 2 (Jan 3) 3 (Feb 20) Hunter Pasja Suggested Suggested Time to First Number Potential Sowing Time Sowing Grazing of Potential Yield Rate (kg/ha) Grazings (t/ha) Mid Oct Nov wks Feb 4 8 wks depending on estab. conditions (depending on number of grazings)

7 2. Cultivar Information Optimising return from Hunter 07 Leaf turnips (eg. cv Hunter) have become a common feed source for finishing lambs. It is common to set stock lambs on the crop and draft them off as they reach target weights. Experiments at Research Centre suggest it is unlikely this grazing management makes the most efficient use of the Hunter crop. The experiment investigated the effect of daily allowance on the production of live weight per hectare in a rotationally grazed Hunter finishing Liveweight gain/ha (kg lwt/ha/day) Figure 4. Effect on Allowance on Production/ha Daily allowance (kg DM/lamb/day) system, with the view of determining optimum grazing parameters. At allowances of 1kg DM/hd/day, or less where grazing residual was low, the crop produced little regrowth, lamb growth rates were poor (25-75g/day) and production per hectare was not maximised (2-5 kg LW/ha/day). At generous allowances (3.5 kg DM/hd/day) where grazing residual was high (3000kg DM/ha) and where lamb growth rates were high (300 g/day), per hectare production was still not maximised (7 kg LW/ha/day) because of low stocking rates. In this experiment, per hectare productivity was maximised (12 kg LW/ha/day) at an allowance of kg DM/hd/day where lambs grew at 300 g/day. The key message from this work was that in rotationally grazed, Hunter systems shifted on a weekly basis maximum per hectare production was achieved on a daily allowance of kg DM/hd/day. To optimise productivity per hectare, lamb finishers should target a grazing residual as pictured above. Utilising more than this leads to lower lamb production per hectare through reduced growth rates.

8 2. Cultivar Information 08 Winfred Forage Brassica Early maturing, weeks Re-growth potential for 3-4 grazings Fast recovery from grazing with excellent subsequent yields Strong plant survival through multiple grazings Winfred forage brassica is a cross between a turnip and kale, generally termed a rape. Traditionally rape has been used as a summer lamb finishing crop and ewe flushing feed. However Winfred which has good frost tolerance and better re-growth potential, may extend grazing times from early summer to late winter. Winfred is the most versatile of brassicas, being suitable for a wide range of soil fertility and environmental conditions, stock classes and sowing times. Due to the potential of an earlier first grazing, Winfred has the ability to be grazed up to three times through summer and early autumn, at which time it is regularly shut up and carried into winter as a winter feed. The direct drilling of annual ryegrass into this re-growth in early-mid autumn is an option. This differs from many existing rapes which often have longer ripening requirements and are grazed later providing less opportunity for multiple re-growths. Due to early grazing and multiple opportunities to graze regrowth, Winfred can be sown with Tonic plantain, chicory and red and white clover, providing a spring sown crop that may last at least 12 if not 18 months. Figure 5. Winfred Forage Systems Option Spring Summer Autumn Winter Spring Summer Winfred Only Winfred Only Winfred Only Winfred Only Winfred + grass grass Winfred + Tonic Winfred + herbs + clovers Winfred + herbs + clovers Winfred + Tonic Winfred + herbs + clovers herbs + clovers Winfred + grass + herbs + clovers grass + herbs + clovers 7 8 Winfred Only grass + herbs + clovers + Winfred grass + herbs + clovers Key Winfred dominant crop Seedling of new species into existing crop Transitional crop Decision on continuation of crop Non-brassica pasture Note: Best results will be achieved using Winfred forage brassica. Hunter forage brassica can be used in these situations under summer moist conditions. Grass short term or perennial ryegrass Herbs active cool season species are most successful in this system. eg: Grouse Chicory and/or Tonic Plantain Suggested Suggested Suggested Time to Number of Potential Sowing Sowing Sowing First Potential Yield Time Rate Alone Rate in Mixes Grazings Yields (depending (kg/ha) (kg/ha) on number of grazings) Mid Oct to 3-4 alone with wks t/ha early Nov herbs & clovers Feb-March 3-4 alone 1-2 with wks t/ha annual ryegrass

9 2. Cultivar Information Sovereign Kale Medium tall kale with excellent yield potential Late-flowering variety that maintains leafy crops into early September Good leaf-to-stem ratio for yield potential Relatively thin stemmed variety particularly when compared to giant kales Sovereign kale is a medium tall, late-flowering kale which does not produce large thick stems like giant kales, even at lower plant densities. Sovereign has a very high yield potential up to 18 t/ha although average yields would be more in the t/ha range depending on management and environment. Sovereign generally has leaf to stem ratios around the 50% leaf and 50% stem which is a much higher leaf content than giant kales while not quite as much as some of the shorter, leafier varieties. This leaf-to-stem ratio is a strength of Sovereign as it does have a very high top end yield potential. The majority of Sovereign sowings occur from late November through to mid-late December. Earlier spring sowings can be used and these are often lightly grazed through February a system more prevalent in the North Island. Sovereign has been successfully sown from late January to mid February providing a crop for July and August. This sowing date produces a lower yield, more similar to a rape, but very high quality, that provides excellent utilisation throughout winter. 09 Suggested Suggested Time to Number Potential Sowing Time Sowing First of Yield Rate Alone Grazing Potential (t/ha) (kg/ha) Grazings Late Nov to wks 1 Average = late December Top = 18 Late Jan wks mid Feb Late October wks 2 Accumulated = 14-15

10 2. Cultivar Information 10 New York Turnip Medium maturity at approximately 16 weeks Excellent yield potential with an improved leafto-bulb ratio Bred for improved turnip mosaic virus tolerance Full leaved variety (not segmented) New York is a medium maturity winter turnip bred as a York globe replacement. New York is a white-fleshed, purple-skinned, oval bulbed, diploid turnip. New York is distinguished by having a full leaf and a greater leaf-to-bulb ratio than York globe. The extra leaf holding has come about from improved tolerance to turnip mosaic virus. Bulb development in all late summer sown turnips is heavily influenced by how early the crop is sown and how much space each plant has to develop large bulbs. A large proportion of these types of turnips are sown as early winter feed with annual or Italian ryegrass. In these mixes it is hard to get large bulb development due to competition. In these circumstances extra leaf production becomes valuable (Table 1). New York has been tested as a latter holding summer turnip where it has performed strongly (Table 1). Summer turnips should never make up more than 5kg or one third of a cow s diet. Table 1. North Island Turnip Dry Matter Production Trial, Cambridge 2001, sown 23/10/01, Miroa ash soil. Total at Cultivar Leaf Bulb 95 Days kgdm/ha Rel kgdm/ha Rel kgdm/ha Rel New York Barkant Rival Barabas Mean Suggested Suggested Time to Number Potential Sowing Sowing First of Yield Time Rate Alone Grazing Potential (t/ha) (kg/ha) Grazings Jan-Feb wks 1 Average = 6-8 Late Oct- Varies depending on wks 1 Average = 8-12 early Nov quality of preparation Top = 14+ Range kg/ha Dominion Swede High-yielding, yellowfleshed, first crop swede Good leaf retention in winter for its type Favourably culinary swede Dominion swede is a traditional high-yielding, yellow-fleshed main crop swede. Dominion compared to Doon Major has improved leaf retention in winter, although this is not at the same level as some of the very leafy swedes present in the market today. Dominion has a good record of performance and provides a good example of a traditional first crop yellow-fleshed swede with favourably culinary comments. Dominion is not recommended as a second crop swede and should not be sown after any brassica. Suggested Suggested Time to Number Potential Sowing Time Sowing First of Yield Rate Alone Grazing Potential (t/ha) (kg/ha) Grazings Late Nov to 0.5kg in wks 1 Average = early Dec 60cm ridges (possible tops in Top = Feb-March)

11 2. Cultivar Information Rival Turnip Early maturing summer turnip with excellent leaf production and leaf holding Tankard bulb with high proportion above ground Bred for improved turnip mosaic virus tolerance Rival summer turnip is an early maturing tankard bulb shaped turnip bred for high leaf production (Table 2). Rival is ideally used as part of a pasture renovation program within dairy farms that have a period of dry or a loss of pasture quality through January and February. Rival summer turnips provide high volumes of high ME, high protein low fibre forage at a time of year that fibre content of pastures are increasing, and ME and protein are deceasing. Growing a crop at these times provides the opportunity to maintain or improve pasture cover on farms that may be growing slower than desired due to summer dry or hot conditions. Summer turnips should never make up more than 5 kgs or one third of a cow s diet. 11 Table 2. Plant Density at Harvest and the Yield Components and Total Yield (kgdm/ha), of Summer Turnips Sown in Taranaki on the 3rd November and Harvested on the 18th February, 107 Days After Sowing Cultivar Plant Count Leaf Yield Bulb Yield Total Yield per/m2 kgdm/ha kgdm/ha kgdm/ha Rival (3) a 5238 b Barkant (3) a 5971 ab New York (2) b 7736 a LSD (5%) Suggested Suggested Time to Number Potential Sowing Sowing First of Yield Time Rate Alone Grazing Potential (t/ha) (kg/ha) Grazings Late Oct- Varies depending on wks 1 Average = 8-12 early Nov quality of preparation Top = 14+ range 1.5-3kg/ha

12 3. Companion Species with Brassicas 12 Herbs and Clovers with Forage Brassicas The increasing popularity of the pasture herbs plantain and chicory is a result of the real benefits they provide to farm production and animal well being. Establishing herbs and clovers with a multiple grazing brassica, e.g. Winfred, can improve the re-growth potential of the crop in repeat grazing situations, or can be a useful method of establishing these companion species for future pasture sow downs. In a typical pasture renovation, when herbs and clovers are established with grass, they may be disadvantaged in terms of establishment rate and the following grazing management of the sward. Adding red clover and/or plantain and chicory with a multiple grazing brassica is a valuable establishment tool, when used in conjunction with subsequent direct drilling of grass species, (see Fig 5, pg 8). The addition of plantain to a multiple grazing brassica can have the following benefits; Provides variety in the diet, with a greater mineral availability than a brassica crop alone Increase total crop production (see Fig 6, pg 12) Be productive and persistent in dry periods, with rapid recovery when soil moisture improves Provide continued growth under cold conditions May reduce the animal health issues that can arise on a sole brassica diet Provide an established herb base for the direct drilling of grass and clover species into the run out brassica crop By combining herbs and clovers with a brassica crop the potential benefits are; The brassica can act as a cover crop to these slower establishing species The red clover and herbs will provide a small but high quality contribution to the diet Herbs will act as a mineral supplement An extended range of options at the end of the brassica life (see Fig 5, pg 8) Subsequent pastures will have a strong legume and herb content relative to a traditionally established pasture Tonic Plantain Strong cool season growth Upright growth habit Excellent recovery from grazing or after periods of moisture stress Reliable establishment on varied soil types and climatic conditions Tonic Plantain an effective mineral supplement! A replicated grazing trial at Research Centre measured liveweight gain in lambs offered a sole diet of Tonic plantain or perennial ryegrass (without clover) for 85 days. Results showed that liveweight gain was significantly higher on Tonic plantain. Post-trial analysis of liver samples found significantly higher concentrations of copper and selenium in lambs grazing Tonic plantain (Table 3). This result highlights some of the benefits of including this mineral rich perennial herb in all animal diets. Table 3. Post-trial Liver Analysis of Lambs from Tonic Plantain or Perennial Ryegrass Diets Treatment Liver B12 Liver Copper Liver Selenium (nmol/kg/fw) (umol/kg/fw) (nmol/kg/fw) Plantain Perennial Ryegrass Significance NS P<0.01 P<0.01 Tonic Plantain Boosts Crop Regrowth Figure 6. Dry Matter Yields of a Winfred and Winfred/Tonic crop in a Multiple Grazing Situation Yield (kgdm/ha) NS * * 2592 Statistical significance NS = not significant * = P < 0.5 ** = P < 0.1 *** = P < 0.1 Winfred Winfred Tonic 0 1 (Dec 9) 2 (Jan 3) 3 (Feb 20) Grazings A yield trial at Research Centre, Canterbury, evaluated the value of adding Tonic plaintain to a Winfred crop. Two mixes sown; Winfred at 2kg/ha and a Winfred/Tonic mix at 2 and 3kg/ha. Trial sown in October 1999, average rainfall of 620mm.

13 3. Companion Species with Brassicas 13 Grouse Chicory Cool season active Extends the window of feed quality in drier areas Upright growth Supports a high clover content Ideal for production systems which require quality feed in early spring Grasslands Sensation Red Clover Bred for persistence under close grazing Upright growing, high-yielding cultivar Strong early-season growth Reduced levels of formononetin (oestrogen) Grasslands Colenso Red Clover Improved seasonal distribution of production Better persistence under grazing Performs in dry conditions Improved heat and drought tolerance Early-mid flowering

14 4. Brassica Crop Husbandry 14 Successful brassica establishment Planning Planning is the key to success. The planning check-list should include the following; Paddock selection Questions to ask when selecting paddocks; Which paddocks have poor performing pastures, have undesirable species, low legume content? Has fertility status been limiting pasture production? Will this need addressing to ensure a good brassica crop and a successful renovation phase? Is the paddock selected in close proximity to a run-off paddock, supplementary feed source, water supply? How easily will the paddock be subdivided? Is the right farm equipment available for successful subdivision or paddock, water supply requirements etc? What is the proposed crop sequence for this paddock? Do any other issues need addressing prior to a permanent sow-down, e.g. elimination of volunteer ryegrass before AR1 endophyte ryegrass establishment? Pre-sowing preparation Successful weed control starts with careful identification of species, growth stage and vigour. This will determine herbicide selection. Seek advice from a technical representative for specific recommendations. Early workings should aim to stimulate weed germination (ideally 2 months pre-sowing). Aim for a moist, fine, firm seedbed, allowing the small seed to be planted at an even 1 cm depth. Planting Conventional cultivation Conventional cultivation is generally the most reliable way of eliminating weeds and establishing brassicas. Best practice is the broadcasting of fertiliser prior to planting. For a minimal pass operation pull hoses out of coulters and drop fertiliser in a surface band, with incorporation by light harrowing and rolling. Direct drilling Direct drilling is suitable if spray control of weeds is successful and fertiliser applications are considered carefully. For detailed information on no-tillage and direct drilling refer to successful No-Tillage in Crop and Pasture Establishment, Ritchie et al, Nitrogen applications are a key component of successful establishment from direct drilling. Under notillage regimes crop residues are broken down by microbial activity (not burning, oxidation or mineralisation as in tillage systems) that temporarily locks up nitrogen. Therefore N will not be available at the time of the brassica establishment, and hence this delay in N availability needs to be compensated for a sowing time. Ridging Ridging effectively provides a raised seedbed for establishment away from excess moisture. It is best suited to use in wetter climates. Broadcasting Broadcasting, (the scattering of seed onto a worked seedbed), can be successful, but a higher sowing rate and subsequent light harrowing and rolling is recommended. Refer to individual species for specific sowing information. Best practice establishment techniques should include the use of a commercial seed treatment for seedling protection. Fertiliser guidelines for brassicas Typically less productive pastures are sown out into brassicas, often meaning they are established into less than optimum conditions. Brassicas tend to differ from other crops in certain aspects of their fertiliser requirements. Brassica yields are sensitive to nitrogen and phosphorus status. In addition, boron deficiency may impact on plant health, especially in the bulb brassicas. The seed is particularly prone to germination injury if soluble fertiliser or boron is placed too near the seed. Inappropriate levels of certain nutrients can induce animal disorders e.g. the sulphur compound SMCO. Table 4. Optimum Soil Fertility Status (MAF Quick Test) Soil test Ranges (for near maximum production) Olsen P Sulphate-S 3-8 Soil test K 5+ Soil test Mg 8+ ph Table 5. General Fertiliser Application* Nutrient Application (kg/ha) Nitrogen** Phosphate Potassium Sulphur *when optimum soil fertility is present, the following fertiliser needs to be applied to support good crop growth. **Split dressing of 0-50kgN/ha at sowing and 0-50kgN/ha 4-6 weeks after sowing. For paddock specific fertiliser recommendations contact your local fertiliser representative.

15 4. Brassica Crop Husbandry 15 A fertiliser spill in a kale crop. An example of the potential of the crop given optimum fertility conditions. Phosphorus (P) Early purpling, stunted and erect leaves are an indicator of P deficiency (this can also be induced by cool weather, so herbage testing is the best form of identification). In many cases farmers do not see brassica crops reach their full potential because P levels are limiting growth. Ideally P status should be 20+. Low inputs (20-30kg/ha) are only suitable to high fertility soils or where crop yield is not important. Most crops will benefit from rates of 40-50kg/ha, and Swedes at a higher rate of 60-70kg/ha. DAP is a good way to provide P to brassicas. The opportunity for lifting of P status should also be considered at this time. Sulphur (S) Sulphur deficiency is characterised by stunted, pale or yellowed growth (particularly the young growth) and leaf curling and distortion. It is not necessary to use sulphur on brassicas unless S levels are low (2-3). See Section 5 on kale anaemia. Boron (B) The condition brown heart in bulb brassicas is the most common symptom of boron deficiency. Other brassicas may show swelling, hollowing, browning and rotting of stems. Brassica crops have a greater requirement for B than grasses. Boron deficiencies are more likely to occur on light textured soils with less organic matter to retain soil B from leaching. Do not put boron down the spout with your seed. See Table 3 on brown heart. Nitrogen (N) Paleness (yellow and/or reddening and old leaf dieback) usually indicates N deficiency. The amount of N required for successful crop growth is dependent upon the paddock history. When establishing a brassica into a runout pasture the crop will require starter N and several side dressings of urea. This is especially true in direct drilling situations. Applications of kg/ha of urea per dressing are sufficient. Nitrogen can be applied directly after grazing for the multiple grazing summer brassicas, although vigilance to any stock health issues is recommended at the next grazing. Starter N only may be enough in arears where N levels are good. Excessive N will increase the risk of nitrate problems with grazing stock, and increase leaf growth at the expense of bulb growth in bulb crops. Soil ph Brassicas can tolerate a range of ph, but preferably above 5.7 Liming will reduce clubroot infection and increase soil molybdenum availability. Lime works best when incorporated into soil.

16 4. Brassica Crop Husbandry 16 Brassica Pests and Disease Summer Guide Brassica establishment can be compromised by occasional localised and seasonal pest and disease attack. Their impact can usually be minimised by management. Once established, brassicas are normally relatively disease-free compared with other crops. Table 6A. Key Pests and Diseases Affecting Brassica Seedlings Condition Impact on Plant Control Seedling Insect Pests Springtails Attack cotyledons and emerging Chemical, seed coating treatment, (Bourletiella spp.) plants, smooth edge damage, crop rotation and hygiene damaging until the 4 leaf stage Greasy Cutworm Plants, especially seedlings are Chemical, crop rotation and hygiene (Agrotis ipsilon aneituma) ripped off at or just below ground level, young plants wilt Grass Grub Adults attack young growing points, Chemical, seed coating treatment, (Costelytra zealandica) larvae damage seedling roots crop rotation and hygiene Wheat bug Ring barking of seedlings at ground Chemical, seed treatment (Nysius huttoni) level damage susceptible to other attacks, damage is similar to that caused by Wire stem Weevils Chew cotyledons or stem at ground Chemical (Catopes spp.) level, scalloping of leaf edge Slugs Creates severe damage to Minimise crop residual or trash before (many sp.) established brassica plants direct drilling of slug baits. Cultivating by destroying seedlings paddocks. Fungal Diseases Wire stem Brown lesion at ground, narrowing of Chemical (Rhizotonia solani) /Strangles root and stem base, often caused by Strangles, damage similar to that caused by Wheat bug. Strangles damage to sap flow from abrasion at ground level by wind etc, affected tissue susceptible to fungal attach (Wire stem) Pest damage during establishment Slug damage in kale Leaf miner damage

17 4. Brassica Crop Husbandry Table 6B. Key Pests in Established Crops 17 Condition Impact on Plant Control Plant Pests Aphids Sap suckers that weaken plants, Chemical, tolerant cultivars, some (many species) reduce yields, carry viral diseases, resistant cultivars to some aphid mainly attack summer crops species Diamondback moth Young larvae burrow in and feed on Chemical (Plutella xylostella) internal leaf tissue, older larvae feed on lower leaf surface, larvae damage is similar to that caused by leaf miner White butterfly Leaf feeding, leaves a skeletonised Chemical (pieris rapae) leaf with leaf ribs remaining Leaf Miners Larvae create tunnels and live within Chemical (many species) leaf tissue, tissue damage may reduce photosynthetic activity and limit growth at this time, damage is similar to that caused by the Diamondback moth Viruses Turnip Mosaic Stunted growth, mottling and Control of vector aphids crinkling of leaves, yellowing, leaf death, poor bulb development Beet Western Yellows General stunted growth, purpling of Control of vector aphids leaves Cauliflower Mosaic Poor vigour, can attack all brassica Control of vector aphids species Fungal Diseases Clubroot Causes irregular swelling of root, leaf Crop rotation (6 years in high risk (Plasmodiophora spp.) wilting, stunted growth, plant death areas), hygiene, resistant cultivars Dry rot Swedes mainly, small sunken brown Crop rotation and hygiene, resistant (leptosphaeria maculans) grey circular spots on leaf or bulb cultivars, later sowing neck, plant death Ring spot Small dark spots on older leaves in Crop rotation (Leptosphaeria maculans) cool wet conditions Leaf spot Small dark lesions and dark sooty Chemical Alternaria spp.) mould on leaves, may lower yields Black rot Attack on vascular system in warm Crop rotation (Xanthomonas campestris) humid conditions, yellowing of leaf margins, wilting, leaf loss Nutrient Deficiencies Brown heart Boron deficiency, swedes and turnips Soil testing, B fertiliser applications Adapted from: Charlton and Stewart, Pasture and Forage Plants for New Zealand.

18 4. Brassica Crop Husbandry 18 Brassica Seed Treatment ULTRASTRIKE brassica is a broad-spectrum seed treatment that combines highly advanced protective additives which have been specifically formulated to enhance the establishment and performance of your brassica crop. ULTRASTRIKE with its additional insect protection, in conjunction with fungicide protection, provides the most comprehensive level of pest protection in the brassica seed treatment market. ULTRASTRIKE Brassica seed treatment includes: 1. A systemic insecticide to control springtail, aphids, wheat bug (Nysius) and argentine stem weevil during plant establishment. Springtail and aphids are the pests most frequently responsible for brassica crop failures during establishment. Under good growing conditions ULTRASTRIKE will provide 10 weeks protection against aphids. 2. Two contact fungicides offering protection against seedling damping off diseases (Pythium and Fusarium) and wirestem (Rhizoctonia solani). 3. Molybdenum, an essential trace element for general brassica growth and to reduce the risk of whiptail, which causes a reduction in leaf size and irregularities in leaf formation. 4. Bird repellent, which is important for broadcast sowing situations. What can ULTRASTRIKE Brassica seed treatment do for you? Protect your investment in seed. Increase brassica plant establishment. Increase crop yields. Provide enhanced pest protection. Reduce chemical handling. Reduce pesticide levels in soil. Improve animal production through having more feed available for your stock. Trial Results The results of trials demonstrate that in comparison to untreated seed, ULTRASTRIKE provides improved plant establishment and protection against insects in establishing brassica crops. Plant Establishment Figure 7. Number of Rape Plants/m 2, Three Weeks After Sowing (Amberley, North Canterbury), under Springtail Pressure ULTRASTRIKE Untreated Seed Plants/m 2 Aphid Protection A field trial was conducted to assess the effectiveness of ULTRASTRIKE against aphid attack. Field cages (0.4m 2 ) were infested with 56 adult aphids on a 2 weekly basis, with the aphids populating the cages for 7 days, with aphid survival assessed at 3, 5, 7, 9 and 11 weeks after sowing. Aphid numbers 0-4m 2 Figure 8. ULTRASTRIKE Versus Untreated Seed Under Aphid Pressure Weeks Post Sowing ULTRASTRIKE Untreated ULTRASTRIKE treated seed provided significantly improved protection against adult aphids in comparison to untreated seed at 3, 5, 7 and 9 weeks after sowing, with no statistical difference in aphid survival at 11 weeks. ULTRASTRIKE treated swedes at Mt Hutt Station, Mid Canterbury, established under aphid and springtail pressure.

19 4. Brassica Crop Husbandry 19 Brassica Seed Treatment SUPERSTRIKE Brassica is a unique multispectrum seed treatment which combines highly-advanced protective additives which have been specifically formulated to enhance the establishment and performance of your brassica crop. SUPERSTRIKE Brassica seed treatment includes: 1. A systemic insecticide to control springtail for at least 6 weeks after sowing. Springtail is the pest most frequently responsible for brassica crop failures, destroying unprotected seedlings at emergence. 2. Two contact fungicides offering protection against seedling damping off diseases (Pythium and Fusarium) and wirestem (Rhizoctonia solani). 3. Molybdenum, an essential trace element for general brassica growth and to reduce the risk of whiptail. 4. Bird repellent, which is important for broadcast sowing situations. What can SUPERSTRIKE ' Brassica seed treatment do for you? Protect your investment in seed. Increase brassica plant establishment. Increase crop yields. Reduce chemical handling. Reduce pesticide levels in soil. Improve animal production through having more feed available for your stock. Establishment of brassica seed: What s more SUPERSTRIKE Brassica is a proven performer. See below for trial results which illustrate the benefits offered by SUPERSTRIKE Brassica. Trial Results Figure 9. Comparison of Plant Establishment (Kale) SUPERSTRIKE Versus Untreated Seed Days 21 Days Number of Days After Planting Aphid numbers 0-4m 2 SUPERSTRIKE Untreated Kale plants per metre square 8 and 21 days after sowing at Gore, Southland, treated with SUPERSTRIKE versus untreated seed (Dec 1998). DM Yield (kg/ha) Figure 10. Comparison of Dry Matter (Kale) SUPERSTRIKE Versus Untreated Seed SUPERSTRIKE Seed Treatment 10.1 Untreated Seed Dry matter production (t/ha) 207 days after sowing at Gore from kale treated with SUPERSTRIKE versus untreated seed (June 1999). Untreated Brassica SUPERSTRIKE Treated Brassica

20 5. Grazing Management and Animal Welfare 20 Best practice brassica grazing The successful grazing of livestock on brassicas requires farmers to be aware of a number of factors that may impact on the productivity and health of animals. Feed quality comparisons The quality parameters of a feed, influence stock performance. Adequate energy, protein and mineral supplies are especially important for high producing stock. A general guide to crude protein (CP) requirements for ruminants is (as percentage of DM): 10-14% CP minimum required for adequate growth, 15-18% CP minimum required for adequate lactation. Table 7. Appropriate Nutritive Values for a Range of Feeds Feed Type Dry Matter Content Metabolisable Crude Protein (%) Energy (% DM) (MJME/kgDM) Swedes - Tops Bulb Kale Turnips - Tops Bulb Rape Ryegrass/ White Clover winter leafy Ryegrass/ White Clover winter autumn saved Ryegrass/ White Clover Summer dry Grass Adapted from Drew and Fennessy, 1980 and the Lincoln University Farm Technical Manual. Crop Utilisation Break feeding (strip grazing) is the best practice for manipulating utilisation rates, diet quality, crop life, and crop re-growth potential. Generally, as crop utilisation increases animal intake per head decreases. Crop Access Ruminant livestock take some time to attain maximum voluntary intake when changed from a pasture to a brassica diet, and this may vary with cultivar and stock type. The rumen bacterial population needs to adjust from a normal grass diet to a brassica diet, and this may take several weeks. To limit the effects of this diet change, the following guidelines should be practiced; Introduce animals slowly to a crop, from an initial 2-3 hours to full allocation by 7-10 days. This allows rumen microbes to adjust and may reduce the grazing check effect. Do not introduce hungry animals to the crop. Gorging may occasionally lead to bloat or nitrate poisoning problems. Offer an alternative source or feed, pasture, hay or silage, during introductory stage, and throughout grazing of crop. Stock performance will be improved if transitions from grass to brassica to grass are minimised as much as possible, e.g. use appropriate stocking rates so animals stay on brassica for the desired time. Where to Get Fibre Brassica crops typically are highly digestible, have high ME and protein content but are often low in fibre. Fibre (NDF and ADF) is required for efficient rumen function. Fibre: Helps maintain rumen ph by encouraging saliva production through chewing. May dilute any possible anti-nutritional plant chemicals and therefore reduce their effect on livestock. Increases the number of grazing days on the crop. Must be palatable so stock consume it. May be detrimental to animal performance, if there is excessive use of low quality fibre.

21 5. Grazing Management and Animal Welfare Animal health considerations Rape scald Rape scald is a reaction by livestock to photodynamic plant chemicals in brassicas. Symptoms include reddening and swelling of the skin commonly on the ears and faces and possibly udders of sheep and cattle. Affected livestock generally attempt to seek shade, rub affected areas, and may appear generally distressed. This condition is most commonly seen in lambs grazing immature or second growth rape or hybrid brassicas. The risk of rape scald can be minimised by delaying first grazing until crops have ripened (Purplish/blue tinge on leaf margin), avoiding excessive nitrogen and sulphur fertilisers and being vigilant to early signs. Some cultivars have minimal ripening requirements and are suited to situations when feed is required quickly and/or where ripening may be delayed by climatic conditions. However, under certain environmental conditions photosensitivity has been known to occur beyond the normal period of ripening. Photosensitivity on Turnip Photosensitivity is also possible with dairy cows grazing summer turnips and with other stock classes on summer turnips and regrowth turnips. The cause of this condition is not well understood; for dairy cows the risk factors include: Consuming large volumes of turnips (greater than 30% of diet) and feeding crop under environmental stress. In lambs grazing summer turnips this condition is rare and unpredictable but may be associated with adverse and overcast weather conditions. Nitrates When protein manufacture cannot keep up with nitrogen uptake in plants the excess accumulates as nitrates, which are then converted to nitrites in the rumen, and when consumed can cause toxicity problems to grazing animals. This may occur in most pasture species when nitrate levels (as KNO3) reach 5% of the dry matter. When animals ingest high levels of nitrates, nitrites build up in the bloodstream. Here they bind with the oxygencarrying compound, haemoglobin, to form a compound that no longer is able to carry oxygen. Simply, the animal suffers oxygen deprivation. The most common symptom of nitrate toxicity is sudden death but prior to death excessive salivation, rapid gasping breath, rapid pulse (>150 beats/min), pale blue or brown colouration of membranes, tremors, and muscle weakness. Pregnant animals surviving may abort. Nitrates can build up in any situation where environmental conditions promote plant growth but limit photosynthetic activity. These include sudden temperature changes, frost shading, overcast days, insect damage, some herbicides, some nutrient deficient soils, excessive nitrogen fertiliser use, soils with deficiencies in sulphur, phosphorus, molybdenum, or high acidity levels. Nitrate toxicity can occur on a range of grasses, brassicas and weeds. Young plants and plant material close to the ground are more likely to have high nitrate levels. Awareness and management of nitrate problems Recognise environmental conditions that cause nitrate build up. Get suspect crops analysed before grazing. Introduce stock gradually to allow rumen adjustment. Do not put hungry animals onto suspect crops. Avoid overstocking of suspect crops, high grazing pressure will increase the amount of high nitrate plant parts eaten. When strip grazing watch utilisation levels or graze for short periods. Dilute high nitrate feed with a low nitrate feed source, e.g. hay, pasture, silage. Make high nitrate forages into silage. Fermentation generally reduces nitrate levels. Manage nitrogen applications carefully to match plant requirements, and therefore avoid excess uptake and nitrate build up. Do not allow animal access to nitrogen fertilisers, fertilisers storage areas, fertiliser spills, or grazing on recently fertilised paddocks. Take care when using nitrogen fertiliser around waterways, to avoid nitrate build up in drinking water. Ensure that soil nutrient levels are in the optimum range for your farming system, as some nutrient deficiencies lead to nitrate build up. Healthy animals are less likely to be affected than animals in poor health. Remember that nitrate levels in animals are a combination of the nitrate consumed in their feed and their drinking water. Treatment of nitrate toxicity Seek emergency veterinary assistance. SMCOs, Kale anaemia, red water As the name suggests this disorder is most commonly found when animals graze kale. However, it can occur in all brassicas. It is most likely to occur in brassicas that have bolted or are flowering in spring. It may also become a problem if crops are grown in soils high in sulphur, or after sulphur fertilisers have been used. 21

22 5. Grazing Management and Animal Welfare 22 Brassicas contain a non-protein amino acid called methyl cysteine sulphoxide (SMCO). During rumination SMCO is converted into a compound that can potentially damage the red blood cell membrane, allowing leakage or haemoglobin from the cell and ending up in the urine (hence the term red water). Moderate levels of SMCO may cause loss of appetite, ill thrift, mild anaemia and digestive upsets. High levels can cause severe anaemia and red-coloured urine (red water). Death can occur suddenly, or after an attack of poisoning. Follow best practice guidelines for feeding brassica crop, e.g. slow introduction, access to an alternative feed source etc. Do not graze crops that have started flowering. Be vigilant if you suspect there may be a problem. Soil testing prior to sowing will indicate the levels of key nutrients, including sulphur, and assist in applying the right fertiliser for good crop growth. Ideally, limit the applications of sulphur and nitrogen. If Kale anaemia is suspected, remove animals from crop and keep under close watch until health is regained. Goitre In some situations lodine (l) deficiency can occur when livestock are fed on brassica crops. This is because brassicas are naturally low in I and contain plant chemicals (glucosinolates) which are goitrogenic and inhibit the uptake of I. Iodine is important for growth and cell differentiation of tissues through its inclusion in thyroid hormones. Consequently, I deficiency has its greatest effect on the developing foetus and therefore may play an important role where pregnant livestock graze brassicas for extended periods in the final stages of pregnancy. The most marked sign of I deficiency is enlarged thyroid glands (goitre), but weak new-born lambs, low birth weights and a high rate of perinatal mortality, may be subclinical signs along with poor wool growth and lower fertility in older stock. Be aware of the Iodine status of pregnant livestock grazing a brassica crop and consider an Iodine supplement. Trace elements There is some evidence that animals grazing solely brassica crops do not receive sufficient trace elements and begin to deplete their liver stores. A trace element supplementation programme should be considered if animals are offered a sole diet of brassica for an extended period or animals have a low trace element status prior to crop introduction. This may require solid, herbage and blood analysis and consultation with your veterinarian to establish current trace element status and the appropriate supplementation programme. Mixing herbs with brassica crops is a strategy that may assist to increasing trace element availability to stock (refer Section 4).

23 6. Brassica User Guide 23 Cultivar Sow Time Sowing Rate Time to Period of Number of Potential Yields Notes (kg/ha) First Grazing Grazing Grazing (kg DM/ha) Hunter Hybrid Brassica Mid Oct-Nov 4 Feb possible wks Dec-March ,000-12, wks April-Aug ,000-12,000 Number of grazings is most influenced by grazing management with faster rotations allowing more grazings Winfred Hybrid Brassica Mid Oct to early Nov Feb-March 3-4 alone with herbs wks Jan-Aug ,000-12,000 & clovers 3-4 alone 1-2 with wks Late May 1-2 5,000-8,000 annual ryegrass to Aug Number of grazings is most affected by management and climatic conditions. The addition of herbs, clovers or ryegrass will increase the potential for other grazings once the Winfred has died out or slowed in regrowth Late Nov to wks Late May 1 Average = late Dec to Sep 12,000-14,000 Top=18,000 Late flowering makes Sovereign a good choice for late winter grazing Sovereign Kale Late Jan- 4 Mid Feb wks June-Sep 1 8,000-10,000 Sowing at this time greatly elevates crop quality and potential utlisation rate right through winter Late Oct wks Lightly in Feb, 2 Accumulated = June, Sep 14,000-15,000 The aim of the this system is to graze lightly with lambs thoughout February then shut up for winter feed Dominion Swedes Late Nov to 0.5kg in 60cm wks Late May to 1 Average = early Dec ridges Sep 13,000-15,000 1kg in 20cm Top = 18,000+ rows Main crop Swede should not be sown after other brassica Ideal culinary Swede Rival Turnips Late Oct to Range wks Jan-Mar 1 Average = early Nov Varies depending 8,000-12,000 on quality of Top = 14,000+ preparation Care should be taken to make sure that Rival makes up no more than 5kgs or 1/3 of a cows diet Jan-Feb wks Late May 1 Average = to Aug 6,000-8, g/ha can be added to annual ryegrass for winter feed however bulb development is often reduced New York Turnips Late Oct- Range wks Feb-Mar 1 Average = early Nov 8,000-12,000 Top = 14,000+ New York is a good choice to be sown for the last paddock of summer turnips to be grazed. Care should be taken to make sure that New York makes up no more than 5kgs or 1/3 of a cows diet