AFDC 16(774) DTZS  
  
 
                                                                                                                                                  
DRAFT TANZANIA STANDARD  
 
 
 
 
 
 
Production and handling of m aize grains - Good Agriculture Practice  
(GAP)  
 
 
  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
TANZANIA BUREAU OF STANDARDS  
 
 
 
 
 
 
AFDC 16(774) DTZS  
 0. Foreword 
 
Maize grain is produced in large  quantities in Tanzania regions more than any other cereal crops. It is a major 
food security crop in the country , being the staple food for an estimated 50 percent of the population. Maize is 
an important source of carbohydrates, protein , vitamin B and minerals.   
 
This code of pra ctice take s into account  the need to promote good agricultural practices that will enhance food 
and nutrition security, wider market access, involvement of small -scale traders and hence making farming a 
viable means of wealth creation .  
 
It will guide  producers in gaining knowledg e of safe production, handling , processing  and transport ation in a 
manner that ensures keeping of quality until it reaches the consumer .  
 
The code of pra ctice will be implemented by multise ctorial stakeholders  in the cereal value chain . 
 
In preparation of  this standard considerable help was derived from ARSO 1100,  Production and handling of 
maize grains  (corn)  - Good Agriculture Practice (GAP).  
 
1. Scope  
 
This  Tanzania Standard provides Good Agriculture Practice  for production and handling  of  Maize  grains (Zea 
mays  L.).This applies to all production steps from cultivating to post -harvest handling .   
 
 
2. Normative references  
 
The following referenced documents are indispensable for the application of this document. For dated 
references, only the edition cited applies. For undated references, the latest edition of the referenced 
document (including any amendments) applies.  
AFDC 16 (326)  DTZS , Code of practices for prevention and reduction of mycotoxin  contamination in cereals . 
TZS 438,  Maize grain s – Specification  
 
3. Terms and definitions  
 
For the purpose of this standard, the following terms and definitions should  apply:  
3.1 maize  ears 
including the cobs, the grains and occasionally the husks and portions of the stalks, depending on the 
harvesting method  
 
3.2 good agricultural practices  
 
collection of principles to apply on farm production and post production processes resulting in safe and health 
food or non-food agriculture products, while taking into account economic, social and environment al 
sustainability.  
 
3.2 audit  
systematic,  independent and documented process for obtaining objective evidence and evaluating it objectively 
to determine the extent to which the audit criteria are fulfilled  
 
3.3 biodiversity  
 AFDC 16(774) DTZS  
 assemblage of living organisms from all sources including terrestrial, marine and other aquatic ecosystems and 
the ecological complexes of which they are part  
 
 
3.4 calibration  
 
determination  of the accuracy of an instrument, usually by measurement of its variation from a standard, to 
ascertain necessary correction factors  
 
3.5 compost  
 
product of controlled biological decomposition of organic material in the presence of air to form a humus -like 
material.   
 
EXAMPLE:  Controlled methods of composting include mechanical mixing and aerating in commercially available 
composters, or placing t he compost in piles out in the open air , and mixing it or turning it periodically  
 
3.6 crop -rotation  
 
farming  system in which dissimilar types of crops are successively cultivated on the same plot according to a 
predefined plan. Normally the crops are changed after each crop cycle, but they can also be multi -annual. It is 
usually followed to increase soil fertili ty and maintain  good yields and  it also  forms part of Integrated Pest 
Management (IPM)  
 
3.7 fumigant  
 
gaseous  pesticides that control pests in agriculture fields,structures storag e houses and varies other sites  
 
3.8 groundwater  
 
all water that is below the surface of the ground in the saturation zone  
 
3.9 hazard  
 
biological, chemical, physical  agent  or any other property with the potential  to cause a product to be unsafe for 
handling and /or consumption  
 
3.10 internal audit  
 
audit  carried out by a producer  on its own Management System s  
 
3.11 manure  
 
decomposed materials of animal and or plant origin used to enhance the physical, chemical and biological 
activities of the soil to maint ain or improve plant nutrition  
 
3.12 agrochemicals  
 
chemicals applied  throughout the production chain  to maintain / enhance produce quality; it includes detergents 
and pesticide s, synthetic fertilizer s and other chemical growth agents  
 
3.13 location  
 
production unit or group of production  units, covered by the same ownership, operational procedures and farm 
management  
 
 
 
 AFDC 16(774) DTZS  
 3.14 record   
 
document that contains objective evidence which shows how activities are being performed and what kind of 
results are being achieved  
 
3.15 sewage sludge  
 
accumulated settled solids separated from various types of waste water either moist or mixed with liquid 
component as a result of natural or artificial processes  
 
3.16 sewage water  
 
water mixed with waste matter  
 
3.17 substrate  
 
any growing medium used for holding plants in place of soil, and that has been imported to the site, and can be 
removed after use. An inert substrate is one in which no life will grow  
 
3.18 traceability  
 
ability  to trace and track the history, use or location of a product (that is the origin of materials and parts, the 
history of processes applied to the product, or the distribution and placement of the product after delivery) by 
means of recorded identification  
 
3.19 grower/worker   
 
person who responsible for the management of primary production  and handling of food crops   
 
3.20 clean water  
 
water that does not compromise food safety in the circumstances of its use   
 
3.21  re-entry period  
 
minimum  amount of time that should  lapse between the moment a pesticide is applied to an area or crop and the 
moment that people can enter that area without protective clothing and equipment  
 
3.22 preharvest interval  
 
time between the last application of a pesticide to the first day of harvest of the treated crop  
 
3.23  quality seed material  
 
seed having required standards of purity , germination and other attributes  and approved by relevant N ational 
Authority  
3.24 Integrated Pest Management (IPM) 
  
an ecosystem approach to crop production and protection that combines different management strategies and 
practices to grow healthy crops and  minimize the use of pesticides  
 
4.0  Requirements  
 
Production and handling of maize grains should   comply with the following requirements ; 
 
 
 
 AFDC 16(774) DTZS  
 4.1  Farm environment   
 
4.1.1 Location  
4.1.1.1   The produc tion area and adjoining  sites or farms should be evaluated for its suitability of agricultural 
land use.  
4.1.1.2   The area should have  a history of prior land use (e.g., sanitary landfill, cemetery, etc.) in order to 
identify poss ible potential hazards spec ifically che mical (heavy metals) and  physical haza rds (broken glass, 
plastics, etc.).  
4.1.1.3   The land used for cultivation sh ould  not have been previously used as a landfill and for industrial 
dumping.  
4.1.2   Hazard Identification  
Identify potential hazards and p rovide correspond ing preventive or mitigating measu res.  
4.2    Production area  
 
4.2.1   Sanitation  
 
Field sanitation practices should  always be ensured.  
4.2.2    Soil analysis  
 
Prior to land preparation, soil samples should  be analysed for heavy metals , pH, nutrient status for 
appropriate fertilizer recommendation, identification of soil characteristics and prevention of crop 
contamination . Soil analysis should  be done at least after every crop cycle and carried-out by  an recognised  
laboratory.  
Where applicable, soil mapping may be established  to plan crop rotation and/or produc tion programs. 
4.2.3  Water  
Identify the location of water sources and if possible, clean water should  be made available throughout 
the maize  production cycle.  Clean water is recommended for agricultural purpose. In case where there 
is any indication of  contamination from hazardous substances in the water, clear evidence should  be 
provided to  clarify that the water can be used for its purpose.  
4.3    Farm structure and facility maintenance 
Farm structures such  as warehouse  for the maize  produc e, storeroom for fertilizer, pesticide and other  farm 
supplies  and materials  including  protection  shed  of farm machineries should  be appropriately des igned to the 
intended  purpose.  These  should  be cons tructed in a considerable distance from each of  the farm structure 
and in the produc tion area to minimize contamination. 
All farm structures  should  be kept clean  at all times .  Farm equipment  used in cultivation, harvesting and 
post-harvest operations of maize  should  be attuned  and well- maintained for op timal operating cond itions. 
Sewage, waste disposal  and drainage system should  be appropriately constructed to minimize the risk of 
contaminating the production area and water supp ly with che mical ha zards such  as pesticides and heavy 
metals. 
Irrigation system should  be maintained to provide effective delivery of water. Remove litters, wastes and 
weeds  in the waterways and dispose  them properly to prevent blockage. 
4.4 Farming practices     
     
4.4.1 Pre-harvest practices  AFDC 16(774) DTZS  
  
4.4.1.1 Land  preparation 
 
Proper land preparation practices  should  be observed to ensu re healthy and uniform plant growth and 
provide advance  effective and efficient weed control measures. 
4.4.1.2 Planting and seed  materials 
4.4.1.2.1   Use quality seed  materials. Use high-yielding varieties or hybrids that are adap table to the locality 
and approved by relevant N ational Authority . 
4.4.1.2.2   Record the sources of seed materials including product  identity (i.e., company na me, lot number, 
variety, germination percentage, da te tested). 
4.4.1.2.3   Exercise timely planting depending on the agro -ecological zone . 
4.4.1.2.4   Follow the appropriate planting distance  and seeding rate as recommended. 
4.4.1.3 Use of pesticides and other agrochemicals 
Pesticide (insec ticide, fungicide, bactericide, roden ticide, etc.) and ag roche mical (adjuvant, detergent, 
disinfectant, plant g rowth regulators, etc.) usage during maize  production and  post-harvest hand ling should  
comply with the following ; 
i.   Only trained/certified pesticide applicators are allowed to carry out pesticide applications on the 
farm; 
 
ii.   Use registered pesticides and agrochemicals acco rding to the  manufacturer’s recommendation; 
 
iii.   Pesticide and agrochemicals should  be clearly labeled and stored in the original container and  
kept under lock and key. A warning sign should  be displayed in the storage area; 
 
iv.   Disposal  of pesticides  and agrochemical containers and residues should  be done acco rding to 
instructions included  on the manufacturer’s label. Empty pesticide containers should  not be  recycled 
for other usages; 
 
v.   Records of purchas e, application and disposal  of the pesticides and agroche micals should  be 
kept (log records, procedu res, or instruction manua l); 
 
vi.   Spraying equipment  should  be regularly maintained to ensure that  the equipment ope rates at 
its optimum cond ition so that t h e  right application rates are delivered and unnecessa ry 
leakage is avoided; 
 
vii.   Withholding periods or preharvest intervals should  be strictly obse rved; and  
 
viii.   Farm personnel involved in the use of pesticides and agrochemicals should  wear app ropriate 
protective clothing and safety gadgets. 
 
4.4.1.4 Fer tilizer management 
4.4.1.4.1 Use only fully decomposed  organic  materials .  Raw and /or slightly  decomposed  animal manure 
should  be confined in a designated area for treatment. 
4.4.1.4. 2 Use only the registered commercial fertilizers. Observe the appropriate method and time of 
application of the recommended c ombination and amount of fertilizers based  on the result of soil ana lysis. 
4.4.1.4. 3  Seed inocu lant may be used  to supp lement part of the maize  plant nutrient requirement. 
4.4.1.4. 4  Fertilizers  should   be  stored  separately from  pesticides  in  a  clean  a nd  dry  area AFDC 16(774) DTZS  
 (Preferably  slightly elevated above the ground  on pallets). 
4.4.1.4. 5  Storage area of fertilizers should  be isolated from maize  drying and storage areas to prevent 
contamination due to leach ing, runoff, or wind drift. 
4.4.1.4. 6  A complete set of records of fertilizers and fertilizer preparation should  be kept. Information 
includes  source of fertilizer materials, details of the composting procedures, dates, amounts and 
methods  of applying the fertilizer as well as the person respons ible for the application. 
4.4.1.5  Pest and disease management 
4.4.1.5.1 A pest and disease  management programme should  be put in place taking into account  historical 
data, trends , and current cond itions. 
4.4.1.5. 2  Practice Integrated Pest Management (IPM) to control the incidence  of crop pests. 
4.4.1.5. 3  Practice crop rotation to  minimize built-up of insect  pests and diseases.  The con tinuous  planting 
of the same plant spec ies within a piece of land leads to the build-up of insect  pests and diseas es. 
4.4.1.6 Weed management 
Practice appropriate weed control measu res like using  appropriate cultural practices such  as proper land 
preparation, off-barring and hi lling-up and/or using herbicides. Ensuring proper tillage operations provides 
head -start of maize  plant against weeds.  
4.4.1.7 Water management 
Maintain the water requirement to avoid moisture stress particularly during flowering up  to the maturation 
stage.  At these  stages, the crop is  more susceptible to aflatoxin con tamination. 
4.4.1.8 Other cultural manag ement practices 
4.4.1.8.1  If detopping of maize  plants is to be practiced, this should  be done  after physiological maturity 
has been  attained. 
4.4.1.8. 2  Follow the other recommended  cultural practices of maize  including the maintenance of the 
recommended  row and plant spac ing to avoid overcrowding. 
   4.4.1.8.3   Conduct  regular monitoring at all crop stages to provide measu res to problems that may arise. 
4.5 Harvesting practices 
4.5.1   Harvest maize  at full maturity as recommended.  Harvesting should  be completed in the sho rtest time 
poss ible especially during the rainy season.  Care should  be exerted to prevent da mage and con tamination 
of maize  ears with soil. Use clean mats, screens , and/or other suitable unde rlays to prevent maize  ears 
from so il or foreign matter co ntamination. 
4.5.2  Before using machines for harvesting and post-harvest operations, ensu re that all the equipment to 
be used  is functional, clean, and well-maintained. 
4.5.3   Sort out and discard maize  ears that show visible signs and symptoms of insect or microbial da mage. 
4.6 Post  harvesting practices 
4.6.1 H auling  
Haul newly harvested maize  ears immediately after harvest. Hauling facilities to be used  for collecting 
and transpo rting the harvested maize  from the farm should  be clean and d ry. 
 
 AFDC 16(774) DTZS  
 4.6.2  Shelling 
4.6.2.1  Before shelling, dry the maize  ears within a range of 18% to 24%  moisture content. This 
optimum moisture content  will bring about less damage to maize  kernels during shelling. 
 
4.6.2.2   Use clean, dry and properly calibrated mechan ical she ller for efficient sh elling. 
4.6.2. 3    Use clean and dry containers of the shelled maize . 
4.6.3 D rying 
4.6.3. 1   Immediate drying of the maize  grains to reduce  the moistu re content after harvest should  be 
done by a ny available means,  to minimize if not avoid grain deterioration, mould and fungi attack, and pest 
infestation. 
4.6.3. 2.   If immediate drying is not poss ible, temporarily store the maize  ears in cribs or any s tructure 
with good ventilation. 
4.6.3. 3.  As much as poss ible, immediately dry the shelled maize  to 13.5 % moisture . Ensure that maize  has 
been  dried uniformly to this moisture.  
4.6.3. 4.   Use clean suitable containers for the dried maize  grains. 
4.6.4 T ransport 
4.6.4. 1  The maize  should  be transported  to a suitable storage or processing area as soon  as 
poss ible after drying. 
4.6.4 2  Avoid grain moisture accumulation during transp ort by us ing an appropriate covering for the 
container. Maize  grains to be transported  should  be properly stacked inside the transp ort vehicle and 
covered with any protection against moisture and pests. 
4.6.4.3   Containers  and vehicles to be used for collecting and transporting the harvested maize grain/ears 
from the farm to storage facility should be clean, dry,and free from infestation before use and reuse . 
4.6.5 S torage 
4.6.5.1  The storage containers, warehouse , or silos should  be properly designed and should  be able to 
meet the following minimum requirements such as: 
i. prevent re-wetting of dry maize  grains; 
ii. prevent the entry of pests such as  insec ts,  birds, and 
rodents;   
iii. provide good ventilation to the stored maize . 
 
4.6.5.2   Adhere  to good storage practices as follows;  
 
i. cleaning and pest control programmes ; 
ii. first-in-first-out (FIFO); 
iii. stack ing arrangement ; and 
iv. ensure the recommended moisture content 
of maize grain  is not exceeded  during 
storage to minimize aflatoxin 
contamination  as stipulated in TZS 438 . 
 
4.7 Worker’s health and safety 
4.7.1. Farmworkers and/or personnel  who will be involved in t h e  produc tion and post-produc tion 
activities should  wear appropriate clothing and protective gadgets. AFDC 16(774) DTZS  
 4.7.2.  Farmworkers should  be trained and should  follow the recommended personal h ygienic and sanitary 
practices. 
4.8 Farm management 
4.8.1  Farm  records 
 
4.8.1.1  There  Farm records should  be available and retrievable at least for the entire crop cycle when 
required and for traceability purposes.  
 
4.8.1.2  Copies of laboratory analysis and certificates that verify compliance  with the relevant Authority’s  
regulations should  be filed. 
 
4.9 Traceability 
4.9.1  Each package/bulk packed produce  leaving the farm should  be traceab le to farm/sources. 
4.9.2  Records of the lot or b atch numbers should  be maintained for all products leaving the farm. 
4.10  Staff training 
4.10. 1  Training Records of personnel a nd/or farm workers should  be maintained. 
4.10. 2  The records should  be maintained and should  be available.