Crop Module: Garlic - Red Tractor Assurance
Contents
1. C with humidity control by sensors amongst the garlic It is necessary to ventilate when humidity exceeds 75 RH at the top of the stack and continue until humidity is reduced to 65 RH Airflow specification is 170m hr tonne Curing normally takes 1 2 weeks Once all moisture has been removed from the bulb neck and between the cloves it is possible to begin temperature reduction Cooling stage 3 Cooling is accomplished gradually ensuring that the stored crop does not fall below average ambient temperature unless refrigeration facilities are available Automatic control is advised using a differential setting such that ventilation is initiated when outside temperature is 3 C or more below crop temperature An override prevents overcooling and more sophisticated stores incorporate automatic vents to mix internal external air These also control the duct temperature for cooling and humidity in the earlier stages Stores should be insulated such that when outside conditions are unfavourable it is possible to close up with the minimum heat loss Minimum temperature in ambient stores should be 5 8 C dependent on location and average ambient conditions Refrigerated storage is ideal since crop temperature is independent of outside conditions It is possible to cool crops more rapidly after completion of curing and normally switch over to refrigeration at 10 12 C crop temperature Refrigeration at 2 5 to 3 5 C is essential for2. Red Tractor Assurance for Farms Fresh Produce Scheme Red Tractor Assurance Effective 1 September 2015 Red Tractor g Assurance for Farms Q Fresh Produce Scheme Welcome to complement and avoid duplicating the generic principles of the Red Tractor Farm Assurance Fresh Produce Scheme standards It is advisable to read the Red Tractor Farm Assurance Fresh Produce standards before reading this crop specific module This module is designed to stimulate thought in the mind of the reader It contains crop specific guidance and standards where applicable in addition to the requirements stated in the generic Fresh Produce standards Te crop specific module for garlic has been written Within this module the important requirements outlined in the crop specific standards section will be verified during the Red Tractor Farm Assurance assessment and compliance will form a part of the certification approval decision Disclaimer and trade mark acknowledgement Although every effort has been made to ensure accuracy Assured Food Standards does not accept any responsibility for errors and omissions Trade names are only used in this module where use of that specific product is essential All such products are annotated and all trademark rights are hereby acknowledged Notes Pesticide Information The Red Tractor Fresh Produce team has been working with Fera to provide tailored access to the LIAISON database for all
3. Red Tractor Fresh Produce members This system allows individual growers access to all information for plant protection products approved for use under the Red Tractor Fresh Produce Scheme LIAISON can be accessed under the Produce tab via the Checkers and Services page where you will also find a user manual Searches will be filtered specifically for the crops for which you are registered Once you have logged onto the site and clicked on the LIAISON hyperlink you will be directed to the LIAISON home screen You will need a username and password and these will be sent once you have registered http assurance redtractor org uk rtassurance services Registration members eb General Introduction Following a systematic approach will help growers identify and manage the risks involved in crop production This module is based on a typical crop production process and food safety health amp safety environmental and quality hazards are identified Appropriate controls may then be established to minimise risk Food safety and health amp safety issues always take precedent over quality and environmental controls The layout of this module follows the same structure as that used in the Red Tractor Farm Assurance Fresh Produce Standards The content of the module is reviewed prior to the issue of updated editions The review process considers both new developments and all relevant technology which has emerged since the last review was
4. ase is readily spread by air borne spores and encouraged by warm humid conditions closely following the infection criteria of potato blight Maintaining 500m separation between overwinter most susceptible and spring crops will minimise cross infection Infected crop debris should be ploughed in as soon as possible after harvest to minimise any carryover Use of weather based prediction models is anticipated in the near future Treatment should be based on routine monitoring so that infection can be identified at an early stage Following this a routine spray programme is necessary to ensure adequate control using currently approved fungicides It is recommended to alternate chemical groups to avoid the risk of resistant strains developing Leaf Blight Botrytis squamosa Leaf spot is a disease that affects the foliage in cool wet conditions It most seriously affects either seedlings of overwintered varieties in the autumn or the foliage of spring planted varieties particularly closer to harvest This disease will require treatment in occasional seasons only The risk of infection increases with increasing crop density Development work is in progress to predict infection conditions as with downy mildew Treatment is usually combined with downy mildew control in overall fungicide programmes and should be based on routine monitoring Disease incidence is more tolerable than downy mildew since the disease is less progressiv
5. bulbs scheduled to be marketed from February to end of May Early June Controlled Atmosphere is necessary for storage beyond this period Actual change over date will vary accordingly to season Storage disorders Where attributable to a specific pest or disease storage disorders are reviewed in the appropriate sections of Pest Disease and Weed Control This section covers those factors where specific diseases or pests are not implicated Compression damage This results in deformation of bulbs and hence a more irregular shape It is a factor of season bulb maturity and sometimes variety rather than height of storage Compression can occur in box storage as well as bulk storage although generally less so In either case affected bulbs can be found from 30cm and below Compression damage will be worse if the bulbs are harvested very early and in association with wetter seasons and late maturity Some bulb deformation can result in the field where bulbs are growing in close proximity to each other Compression damage is self correcting to a degree when the pressure is released whether caused in field or store Skin retention A number of factors affect skin retention and it is essential that lots or batches are handled at the correct temperature and humidity relative to ambient conditions No firm specification can be given but guidelines to minimise skin loss are as follows correct variety choice control of
6. completed and which have been found to be both workable by the grower and beneficial to the environment The aim is to transfer such information and technologies to growers Acknowledgements Red Tractor Farm Assurance Fresh Produce gratefully acknowledges the contribution of all consultees in the preparation of this protocol in particular Glen Allingham Really Garlicky Company Front cover image credit Glen Allingham Really Garlicky Company ADDITIONAL REQUIREMENTS AGAINST CURRENT STANDARDS CROP SPECIFIC STANDARDS CHOICE OF VARIETY ROOTSTOCK AND PLANT HEALTH CERTIFICATION SITE AND SOIL MANAGEMENT ENVIRONMENTAL PROTECTION AND CONTAMINATION CONTROL PEST DISEASE AND WEED CONTROL NUTRITION IRRIGATION HARVEST AND STORAGE RESIDUES AND CONTAMINANTS APPENDIX 1 TYPICAL APPLICATION RATES FOR NUTRIENTS APPENDIX 2 GUIDELINES ON MINIMISING PESTICIDE RESIDUES ADDITIONAL REQUIREMENTS AGAINST CURRENT STANDARDS None for this crop module CROP SPECIFIC STANDARDS None for this crop module D Red Tractor Assurance for Farms Crop specific Module Garlic 02 02 03 03 03 04 07 07 07 09 10 11 Assured Food Standards 2015 E GUIDANCE CHOICE OF VARIETY OR ROOTSTOCK AND PLANT HEALTH CERTIFICATION Varietal yield quality and storage characteristics should be utilised to optimise the performance of garlic crops The need for specific seed applied pesticides should be justified and documented As th
7. e and less likely to cause serious crop loss Garlic foliage becomes more susceptible to infection as harvest approaches and as the density of the crop canopy increases Early infection of the outer leaves can affect skin retention in store Leaf blotch Cladosporium allii cepae Leaf blotch is a disease that occurs when the combination of temperature and long periods of leaf wetness allows germination and penetration of the fungus In such years infection can result in complete defoliation Symptoms are bleached elliptical eyespots on the leaves that spread parallel to the leaf veins and can destroy entire leaves Routine control measures for this disease are not normally necessary Treatment should be based on routine monitoring so that infection can be identified at an early stage Once identified use of propiconazole should give control Neck rot Botrytis allii porri aclada The fungus organisms that cause neck rot including Botrytis porri and B aclada survive the winter as sclerotia on dead plant parts in the soil and on infected bulbs Infection occurs through neck tissue or through wounds In garlic neck rot is generally a more serious problem than is leaf blight Symptoms may first appear on the neck of the plant near the soil line in the spring The fungus moves rapidly into the neck region of the bulbs causing a water soaked appearance A gray mold develops on the surface later producing black sclerotia Before bulb
8. ed by Fusarium culmorum Soilborne inoculum infects garlic through the stem plate rather than through roots or storage leaves Leaves of infected plants may not produce disease symptoms but can be a source of the disease Transmission can occur when infested soil or debris is transported on equipment seed or runoff water The fungus can survive indefinitely in the soil Fusarium culmorum can also infect elephant garlic but not to the same degree as garlic Onion is nota host Symptoms include pre emergence decay of cloves and seedlings Stem plates and storage leaves may decay in the field during the growing season Lesions may have a reddish fringe Disease expression is erratic from year to year and field to field Post harvest decay may involve a single clove or the entire bulb Cultural Control Growers commonly rotate garlic with non host plants to reduce disease pressure Cereals are a host of garlic strains of Fusarium culmorum Growers also avoid planting in fields with a history of basal rot problems The primary cultural control of basal rot is curing bulbs properly before storage and storing the garlic at cool temperatures as F culmorum is favoured by warm conditions Fields with good drainage and freedom from sub surface pans or compaction will minimise problems There are no chemical treatments Downy mildew Peronospora destructor Downy mildew is a serious foliar disease that commonly requires routine treatment The dise
9. ere are no multipliers of garlic at present growers need to keep a nursery stock for future plantings which should be monitored and any diseased or rogue plants should be removed SITE AND SOIL MANAGEMENT SITE HISTORY Soil type and latitude have a major influence on the production system that can be used and on the quality of resulting bulbs The most suitable soil types are sandy loam to sandy clay loam very fine sandy loam silts and some peat based soils The crop produces a coarse rooting system and whilst requiring a degree of firmness for good root soil contact the soil should be free from compaction and well drained Irrigation is an essential requirement for production on sand based soils excluding silts Rotation and crop siting Rotation has a role in minimising disease problems but may not prevent the build up of two major soil borne diseases over the course of time It is generally accepted that the minimum rotation should be 1 in 4 years and ideally up to 6 years Garlic crops should be separated by a minimum distance of 800m from any commercial onion crop Isolation reduces the spread of wind dispersed leaf diseases However this may only be possible to a limited extent in commercial practice Choice of production system Garlic can be produced in a number of different ways i Over wintered cloves planted in late September October for harvest the following June July ii Spring planted cloves for harves
10. ferred option Nitrogen index as defined by previous crop Index 0 Index 1 Index 2 Cereals Sugar Beet Maize Beans or beans potatoes oilseed rape Any crop in field receiving large and frequent dressings of FYM or slurry Vegetables receiving less than 200kg ha Vegetables receiving more than 200kg ha LS aa Forage crops removed Forage crops grazed Leys 1 2 year grazed or cut and grazed Leys 1 2 year grazed or cut and grazed Long leys grazed or cut and grazed low nitrogen high nitrogen high nitrogen Permanent pasture cut only Leys 1 2 year cut only Long leys cut only grazed or cut and grazed Permanent pasture poor quality matted Long leys grazed or cut and grazed low nitrogen Notes less than 250kg ha nitrogen per year and low clover content more than 250kg ha nitrogen per year or high clover content APPENDIX 2 GUIDELINES ON MINIMISING PESTICIDE RESIDUES These guidelines have been produced after consultation between crop stakeholders and the Fresh Produce crop author They will be developed over the coming seasons as knowledge on minimising residues develops Growers should consult with their crop protection adviser to ensure other best practices are not compromised before considering these guidelines The table below lists the active ingredients that may give rise to crop residues and details potential alternative strategies Target pest Active ingredient weed disease Current pos
11. foliar diseases correct timing of harvest m correct drying and storage procedure avoiding high temperatures and low humidities prior to grading RESIDUES AND CONTAMINANTS Red Tractor Farm Assurance Fresh Produce is aware that a key area in the production of fresh produce which requires continued attention by growers and their advisers is that of keeping pesticide residues to a minimum This issue is not just one of meeting the MRL trading standard but ensuring that any individual or multi residues are kept as low as possible below this level The key targets are Optimising late applications of fungicides and insecticides to the edible part of the crop Optimising the use of post harvest treatments m Ensuring minimum harvest intervals are followed m Ensuring that application equipment is applying products correctly See Appendix for pesticide targets and guidelines on this crop APPENDIX 1 TYPICAL APPLICATION RATES FOR NUTRIENTS KG HA Nutrient kg ha Soil Index 0 1 2 Nitrogen mineral soils Spring established 175 125 100 Overwintered 50 10 Potash 150 2 All soils 250 2 100 2 Magnesium wo o o Notes 3 4 4 25 0 0 Phosphate All soils 20 150 100 50M 5 00 se Ls bes Seedbed N is only required on mineral soils Spring topdressing of up to 100kg ha nitrogen may be required Nitrogen index is defined by previous cropping or residual mineral nitrogen sampling which is the pre
12. iene to minimise spread of soil borne problems by cultivation equipment etc This is particularly important with green garlic harvesting There is therefore a greater risk of transporting disease more widely with machinery b Avoiding spread of garlic waste except on farms unlikely to be involved in garlic production c Minimise wind blown debris from harvesting and grading operations Crop residues should be ploughed in as soon as possible Waste trailers should be sheeted at all times in transit Corrective action Where control of pests diseases is still required the following approach should be adopted a Establish the need to take corrective action by regular monitoring and reference to forecasting techniques when available b Consider effect of prevailing weather conditions c Where action is required as a principle the possibility of using biological or natural methods should be considered first d If chemical control is needed the following points should be considered subject to achieving effective control use the least toxic and persistent product use the most selective product to reduce the impact on naturally occurring beneficial organisms use the minimum effective dose rate use appropriate application methods with properly maintained equipment use the minimum number of chemical applications to achieve good control for example in controlling downy mildew and Botrytis Growers should e
13. ing plants may die or recover depending on weather conditions Bulbs infected late in the season break down and are often infected by other disease organisms Cultural Control Growers avoid excessive nitrogen and irrigation especially late in the season They practice good weed control to aid air movement through field and to keep relative humidity low When harvesting growers allow tops to mature then lift or undercut plants to avoid bruising and mechanical injury Finally they make sure that the garlic is properly cured before storing Avoiding spread from the previous season s crops is important Where refrigerated stores are being emptied late in the season when the new season s crop is established April June every effort should be made to minimise wind blow of debris The new season crop should be planted as far away from cold stores as practical ideally a minimum of 800m If appreciable levels of neck rot are identified in store these lots should be marketed before emergence of the new season s crop Chemical Control Fungicides are not generally used by growers against neck rot as cultural methods control the disease at this time Blue mould Penicillium spp Penicillium spp cause blue moulds to develop on bulbs in store between the skin and scale tissue These blue moulds are mostly of a secondary nature but can be associated with a physiological disorder known commonly as watery skin In such cases scale t
14. is not confined to garlic growing areas and source often relates to cottage gardens where onion or garlic waste has been composted in the past The disease initially infects roots and spreads back into the bulb causing destruction of tissue from the base upwards This destruction is accompanied by a white cotton wool like fungal growth Early infection causes bulbs to completely rot in the field and later infections cause the total collapse of bulbs in store Progress of infection is checked at the initial drying stage 28 30 C but continues when the store is cooled There is development of control measures but it is therefore essential to Note infection areas on farm maps and not only avoid such areas but also where possible avoid spreading contaminated soil to other parts of the farm particularly with cultivation equipment Monitor crops to ensure that any occurrence of infection is recorded Premature yellowing of foliage in patches is the most usual indicator Make every attempt to avoid harvest of infected bulbs Field population of resting spores sclerotia can be reduced by hand collection of infected bulbs but this is recommended only for small areas where such action is practical EAMU for use of Folicur tebuconazole and Signum boscalid pyraclostrobin Both Folicur and Signum if applied early will give some control of field infections Fusarium base rot Fusarium culmorum f sp cepae Basal rot of garlic is caus
15. issue and inner skins become brown and watery This favours Penicillium which then sporulates freely Penicillium is common on stored bulbs but mostly at low levels that do not cause marketing or storage problems Potential problems can be minimised by adherence to storage procedures High humidities in store irrespective of temperature will increase incidence and level of Penicillium infections OTHER BACTERIAL PATHOGENS A number of bacteria species will cause either foliar dieback in the field or deterioration during storage Field and store symptoms can be linked but the absence of visual effects in the field may still result in storage problems Bacterial diseases are initiated in the field and spread principally by water splash Wet seasons are therefore more likely to result in storage losses The main pathogens are detailed as follows Pseudomonas allicola This disease can cause serious problems in store since the bulb s scale tissue soft rots completely but the outer skins retain the rotten tissue Once the crop is moved the bulbs split and cause loss of quality by down grading of adjacent bulbs Up to 40 infection has been recorded The disease is temperature sensitive and where problems are anticipated can be minimised by reduced drying temperatures Recent work at HRI has resulted in a prediction system based on serological agglutination techniques It is therefore possible to test bulbs at harve
16. ition Suggested guidelines maleic hydrazide Plant growth regulator Residues found regularly Growers should not apply maleic between the limit of hydrazide to garlic bulbs which are determination and MRL destined for marketing prior to 1st December as internal sprouting is rarely significant prior to this date Use reduced product rates for crops held in ambient storage NOTES A Red Tractor Assurance for Farms Crop specific Module Garlic Assured Food Standards 2015 EE NOTES Red Tractor Assurance for Farms Crop specific Module Garlic OFT Melel ESIE ale ETK 40M ES Certification Body Beef and Lamb Certification NSF Certification Hanborough Business Park Long Hanborough Oxford 0X29 8SJ Tel 01993 885739 Email agriculturefansf org Web www nsf foodeurope com SFQC SFQC Ltd Royal Highland Centre 10th Avenue Ingliston Edinburgh EH28 8NF Tel 0131 335 6605 Email redtractorfasfqc co uk Web www sfqc co uk e kiwa p Partner for progress Kiwa PAI The Inspire Hornbeam Square West Harrogate North Yorkshire HG2 8PA Tel 01423 878878 Email paienquiriesfakiwa co uk Web www kiwa co uk pai FJ NIFCC Northern Ireland Lissue House 31 Ballinderry Rd Lisburn Northern Ire
17. land BT28 2SL Tel 028 9263 3017 Email infofanifcc co uk Web www nifcc co uk FY SAI GLOBAL ASSURANCE SERVICES SAI Global Assurance Services Ltd PO Box 6236 Milton Keynes MK1 9ES Tel 01908 249973 Email agrifoodfasaiglobal com Web www saiglobal com assurance 4 QWFC Wales PO Box 8 Gorseland North Road Aberystwyth SY23 2WB Tel 01970 636688 Email infofawlbp co uk Web www wlbp co uk T 01932 589 800 E producefdaredtractor org uk www redtractorassurance org uk
18. nformation is available using the LIAISON search accessible via their RED TRACTOR Farm Assurance home page after logging in A search on the Extensions of Authorisation for Minor Use page of LIAISON by crop or product name should yield a results page A click on the product name should link to a Summary of the approval information Near the bottom of the summary is the specific off label number e g 0246 09 and this link will open up a pdf of the current EAMU document giving details of the extension of use Deficiency Risk Soil Type Magnesium WE CUGE Copper NUTRITION Garlic requires a fertile soil with adequate reserves of the major nutrients nitrogen phosphate potash and magnesium Application of fertiliser see Appendix should be on the basis of regular soil analysis ideally preceding each crop Soil pH is important and should be in the range 6 5 7 0 Garlic is most responsive to phosphate and less responsive to nitrogen than leafy vegetables Nitrogen application should be minimised where possible and ideally based on residual nitrogen sampling in conjunction with the Well N predicition model developed by HRL This will ensure adequate nitrogen without excess that could lead to leaching into ground water Late application from bulbing onwards should be avoided Zinc iron Boron me tm oe fon sone reme o a o m e ee e e e p e o reee e e ee IRRIGATION Adequate soil moist
19. nsure that the minimum number of chemical applications are made to achieve good control for example in controlling downy mildew N B exceeding the maximum individual and maximum total dose rate is illegal under COPR PEST DISEASE AND WEED CONTROL PEST CONTROL Stem and bulb eelworm Ditylenchus dipsaci Eelworm attack is initiated by wet conditions Control measures are influenced by soil type and local considerations Routine control measures are most likely to be necessary on very fine sandy loams and on heavier sandy clay loams again based on previous knowledge of the area field This pest also affects sugar beet and will survive on certain host weeds Affected fields will remain so for many years even in the absence of garlic crops Avoidance of such fields is therefore the first consideration Stem and bulb eelworm can cause serious losses in both field and store Early field infection will cause foliage distortion followed by death of seedlings and resultant bare patches in fields only in very serious cases will an entire field be uniformly infected The margin of such patches invariably contains less infected bulbs with characteristically distorted foliage and soft bulbs when mature Infected bulbs deteriorate rapidly in the initial drying process the effects are exacerbated by stage 1 temperatures 25 30 C Stem and bulb eelworm can be spread to previously uninfected fields by contaminated bean seed and care sh
20. ould be taken to use only certified seed if beans are grown on the farm Good drainage is also essential as localised wet areas will encourage eelworm build up Thrips Thrips tabaci Thrips are a pest of variable incidence Control measures should be based on regular monitoring when the weather conditions are appropriate for attack More commonly known as thunder bugs thrips are most likely to attack garlic from June to August The need for treatment should be judged on appearance of the orange nymphs as well as the symptoms on the plant This pest multiplies in the growing centre of the plant and leaves appear with silvery flecking and leads to distortion in more serious cases A certain level of flecking is acceptable before treatment is necessary noting that control approaching harvest is of importance Adult thrips can feed for a considerable period under skins of bulbs during storage causing downgrading in quality When treatment is considered necessary use deltamethrin A repeat application may be necessary depending on prevailing weather conditions DISEASE CONTROL White rot Sclerotium cepivorum A persistent soil borne disease that infects soils for many years this disease is the most serious threat to garlic growing in many parts of the world where the climate is suitable Its long persistence in order of 100 years is reflected in local knowledge and many fields are of known infection status Incidence
21. owing sections Drying stage 1 Initial drying stage 1 to be achieved by a minimum 25 C and a maximum of 32 C 28 C will be the norm but special circumstances may require a slightly lower temperature e g the incidence of bacterial diseases In practice initial drying requires a minimum airflow of 425m lt hr tonne with suitable fans and ducting system Crop drying can be undertaken in boxes but such systems are generally less efficient due to air leakage and greater difficulty in obtaining uniform airflow The store design should allow recirculation of air to minimise fuel usage and to maintain humidity Specification of the humidity regime during initial drying will vary according to condition of crop A target duct range 50 65 relative humidity RH is normally accepted An important point in minimising storage problems and achieving quality is that these specifications are combined with a maximum Stage drying time of 7 days from initial loading of the store The specifications become more important with later harvests Some relaxation is acceptable however for early crops harvested in ideal conditions and not scheduled for long term storage Curing stage 2 After initial drying to a rustle dry condition it is necessary to maintain temperature and control humidity to cure skins and complete the drying in the air spaces between cloves stage 2 Stage 2 is accomplished using intermittent ventilation at 25
22. rvesting of the scapes Storage of the scapes should be at 5 7 C in cleaned trays or boxes Harvest Topping of the crop is essential to ensure ease of handling into store and minimising restriction to airflow during the initial and most critical drying phase Itis a case of individual judgementas to the best harvesting system depending on soil type local circumstances and prevailing weather conditions Top lifting harvesters are recommended to minimise damage and soil contamination All trailers or boxes must be cleaned before they are used to transport loose garlic from the field and the cleaning must be recorded The maximum loading height accepted in practice is up to 4m The maximum quantity that can be loaded at any one time will depend on the airflow specification of the store Stores must be cleaned before garlic is stored in bulk and this cleaning must be recorded When washing Green garlic only the water used for washing the harvested crop should be used with conservation as a priority Storage It is an essential prerequisite of garlic production that adequate store loading and storage facilities are available The use of expert management correct airflow and temperature in properly designed and constructed stores cannot be overemphasised in minimising storage disorders and maximising quality Controlled storage facilities should be capable of achieving temperature and humidity targets set out in the foll
23. st This technique is now available as a specific test kit Erwinia spp Erwinia infects over a wide temperature range and tends to affect single scales within a bulb When cut these bulbs reveal one scale of firm tissue that has turned brown Infection of bulbs is linked to the dieback of single leaves in the mature plant Infection then spreads back to the scale at the base of the affected leaf Incidence of this disease varies according to season and levels rarely exceed 2 3 Infection is normally more prevalent in late harvest drilled crops Lactobaccillus spp These bacteria cause water soaking and an odour characteristic of vinegar This bulb disease is very temperature sensitive and becomes increasingly active above 30 C It has not been a problem since adopting the now accepted drying and storage procedures detailed in Section HS SECONDARY BACTERIA A range of secondary bacteria can follow on damaged or previously infected tissue In wet seasons root death is often followed by soft rotting bacterial infection It is not unusual in most seasons to find occasional plants which have died with soft rot symptoms but these are not normally associated with storage disorders APPROVED USES NOT INCLUDED ON THE PRODUCT LABEL In many circumstances particularly for minor crops product labels do not include all of the approved uses and growers wishing to check the approval notice of a particular product should note that this i
24. t in July August iii Spring drilled from bulbils for harvest late August September This will produce a single round clove which if planted the following year will develop into a conventional bulb The choice of cultivar within each section has only a minor influence on disease susceptibility Leaf diseases are encouraged by increasing population density and by humid conditions Over wintering types are the most susceptible to leaf diseases with spring drilled being the least susceptible Soil type as well as requirements for continuity of production will influence choice of production system Larger bulb size from lower plant populations has assisted reduction of foliar disease incidence Latitude Bulbing is influenced by day length and hence site selection is influenced by latitude In general terms spring planting is only recommended in England ENVIRONMENTAL PROTECTION amp CONTAMINATION CONTROL Integrated crop management Garlic is subject to a number of disease problems and it is a guiding principle that pesticide inputs should be minimised through prevention rather than cure An integrated approach should be adopted using the following steps Good management and planning a Careful site selection to avoid potential or previous problems b Sensible crop rotation to avoid build up of soil borne problems or disease carry over from one crop to the next Cultural preventative techniques a Good crop and field hyg
25. ure is usually present for crop establishment of autumn spring drilled cloves There is a marked growth response to irrigation on all light soils during dry periods It leads to an increase in leaf number and size which maximises bulb size and yield Late irrigation can produce softer bulbs increases bacterial incidence and causes bulb staining and should be avoided Where available an irrigation scheduling system should be used to ensure efficient use of water resources HARVEST AND STORAGE Maleic hydrazide MH It is accepted and clarified by HDC funded trials that as an aid to the maintenance of quality it is necessary to apply maleic hydrazide pre harvest as a growth suppressant at 10 leaf fallover All sprout suppressant treatments should be justified The area treated should be related to the projected marketing dates of the bulbs Application of MH is not necessary on crops to be marketed prior to the 1t December in so far as can be judged in advance Crops should be sprayed according to manufacturer s recommendations lower rates normally prove adequate for crops in ambient storage Scape removal and storage Some varieties of hardneck garlic will bolt the flowering shoot scape will normally need to be removed in order to allow the bulb to achieve its full potential weight This operation is normally done by hand Scapes are edible and if sold for human consumption all harvest intervals must relate to the ha
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