PHILIPPINE NATIONAL STANDARDS  PNS/BAFS 20:20xx  
Code of Good Agricultural Practices (GAP) for Corn  
 
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INTRODUCTION  
 
The Code of Good Agricultural Practices for Corn (GAP Corn) is a set of conso lidated 
safety and quality standa rds formulated  by  the  Department  of  Agriculture  (DA) for  
the p roduc tion, harvesting and on -farm posth arvest hand ling and s torage of corn. This 
code of practice takes into account the Philippine GAP for Fruits and Vegetables which is 
based  on the conce pt of Hazard Analysis of Critical Control Points (HACCP ) and quality 
management principles from farm to table continuum with emphasis on the following six 
(6) key areas: 
 
a.  Farm location; 
b.  Farm en vironment; 
c.  Farm structure and facility maintenance;  
d. Farming practices (land preparation, seed material, pesticide and fertilizer 
application, pes ts and disease  management, weed management, water 
management, harvesting practices and post-harvesting practices); 
e.   Worker’s health and safety; and 
f.    Farm management (farm records, traceab ility, staff training). 
 
 Considering the increasing incidence of  food-borne illnesses  and incidence of 
aflatoxicosis  in  swine,  poultry  and  other  animals,  the  GAP  Corn  is  primarily  aimed 
at p roviding safe and  high quality corn to cons umers and feed millers/processors. The 
focus  is to reduce risk of pesticide and aflatoxin contamination. Additional ben efits of the 
program are workers health, safety and welfare and environmental su stainability. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 PHILIPPINE NATIONAL STANDARDS  PNS/BAFS 20:20xx  
Code of Good Agricultural Practices (GAP) for Corn  
 
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 SECTION I – FARM LOCATION 
 
1.1    The  produc tion  area  and  adjoining  sites  or  farms  shou ld  be  evaluated  for  its
 suitability for agricultural land use.  Obtain a history of prior land use (e.g., sanitary
 landfill, cemetery, etc.) in order to identify poss ible potential hazards spec ifically
 chemical (heavy metals) and  physical haza rds (broken glass, p lastics, etc). 
 
1.2    Provide correspond ing p reventive or mitigating measu res to the potential hazards 
          identified. 
 
 
 
SECTION II – FARM  ENVIRONMENT 
 
The production area, post harvest and storage areas shou ld be kept clean and tidy at all 
times. F ield sanitation practices shou ld always be observed . 
 
2.1  Soil and  soil nutrients  
 
2.1.1  Prior to land preparation, soil samples shou ld be analyzed for pH, nutrient status
 for appropriate fertilizer recomm endation and soil characteristics. Soil analysis
 shou ld be done e very 2 years and carried-out by  an accredited laboratory. 
 
2.1.2  Where applicable, soil mapping may be established  to plan crop rotation and/or
 produc tion programs. 
 
2.2  Water  
 
2.2.1  Identify the location of water sources and if poss ible, water shou ld be made 
available throughout the corn production cycle.  
 
SECTION III – FARM STRUCTURE  AND  FACILITY MAINTENANCE 
 
3.1 Farm structures such  as warehouse and stock pile area  for the corn produc e, storeroom 
for fertilizer, pes ticide  and  other  farm  supp lies  and  materials  including  protection  
shed  of  farm machineries shou ld be appropriately des igned for  the intended  purpose.  
Each of these  shou ld be cons tructed in a considerable distance from one another to 
minimize contamination. 
 
3.2 All farm structures, facilities and equipment  should always  be kept clean and in good 
condition for optimal operations.    
 
3.3 Sewage, waste disposal  and drainage system should  be appropriately located and 
constructed to minimize the risk of contaminating the production a rea and water 
supp ly with che mical ha zards such  as pesticides and heavy metals. 
 PHILIPPINE NATIONAL STANDARDS  PNS/BAFS 20:20xx  
Code of Good Agricultural Practices (GAP) for Corn  
 
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 3.4 Irrigation system shou ld be  maintained to provide effective delivery of water. Remove 
litters, wastes and weeds  in the water ways and dispose  them properly to prevent 
blockage.  
 
3.5 Farm code should be displayed in the production area.  
 
3.6 Medicine kit should be readily available in the farm.  
 
SECTION IV: FARMING PRACTICES  
 
4.1 Pre-harvest practices  
4.1.1  Land  preparation   
Proper  land preparation shou ld be observed to ensu re healthy and uniform plant 
growth and provide advance  effective and efficient weed control measures. 
 
4.1.2 Planting and  seed  materials  
 
4.1.2.1 Use quality seed  materials. Use high-yielding varieties or hybrids that are
 adap table to the locality and approved by National Seed Industry Counc il (NSIC).  
4.1.2.2  Record the sources of seed materials including product  identity (i.e., company
 name, lot number, variety, germination percentage, da te tested). 
 
4.1.2.3  Follow the appropriate planting distance  and seeding rate as recomm ended. 
 
 
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 corn production and  
postha rvest hand ling shou ld comply with the regulations set by the Fertilizer and Pesticide 
Authority (FPA) as follows: 
 
4.1.3.1 Only trained/certified pesticide applicators are allowed to carry out pesticide
 application in the farm. 
 
4.1.3.2  Use registered pes ticides and ag rochemicals   acco rding   to the manufacturer’s 
recommendation. 
 
4.1.3.3  Storage area should be properly labeled, well ventilated and locked. Warning signs
 should be displayed. Pesticides and agrochemicals shou ld be stored properly and
 clearly labeled. 
 
4.1.3.4  Disposal  of pe sticides and agrochemical containers and  residues should be done  
acco rding to instructions included  on the manufacturer’s label or  in acco rdance  with 
the FPA regulation.  Empty pesticide container shou ld not be  recycled for o ther usage. 
 PHILIPPINE NATIONAL STANDARDS  PNS/BAFS 20:20xx  
Code of Good Agricultural Practices (GAP) for Corn  
 
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 4.1.3.5 Records of purchas e, application and disposal  of the pesticides and
 agroche micals must be  kept (log records, procedu res, or instruction manua l). 
 
4.1.3.6  Spraying e quipment s hould be regularly maintained to ensu re that the equipment
 operates at its optimum cond ition so that right application rates are delivered
 and unnecessa ry leakage is avoided.  
 
4.1.3.7  Withholding periods or pre-harvest intervals shou ld be strictly obse rved. 
 
4.1.3.8  Farm  personnel  involved  in  the  use  of  pesticide  and  agrochemicals  shou ld 
 wear app ropriate protective clothing and safety gadgets. 
 
4.1.4  Fertilizer management 
 
4.1.4.1  Use on ly fully deco mposed o rganic materials.  Raw and/or slightly deco mposed
 animal manure shou ld be confined in a designated area for treatment. 
 
4.1.4.2  Use only the registered comm ercial fertilizers. Observe appropriate method and
 time of  application of the recomm ended c ombination and amount of fertilizers
 based  on the result of soil ana lysis. 
 
4.1.4.3  Seed  inocu lant  may  be  used  to  supp lement  part  of  the  co rn  plant  nutrient
 requirement. 
 
4.1.4.4  Fertilizers  shou ld  be  stored  separately with partition  from  pesticides  in  a  clean  
and dry  area (preferably slightly elevated above ground  on pallets). 
 
4.1.4.5  Storage area of fertilizers shou ld be isolated from corn drying and storage areas to
 prevent contamination due to leach ing, runoff or wind drift.  
4.1.4.6  A complete set of records of fertilizers and fertilizer preparation shou ld 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. 
 
4.1.5 Insect  pest  and  disease management  
 
4.1.5.1  A pest  and disease  management program should be put in place taking into 
 account  historical d ata, trends  and current cond itions.  
 
4.1.5.2  Practice Integrated Pest Management (IPM) to control the incidence  of crop
 pests. 
 
4.1.5.3  Practice  crop  rotation  to  minimize  built-up  of  insect  pests  and  diseases.  The
 continuous  planting of the same plant spec ies within a piece of land leads to the
 build-up of insect  pests and diseas es. 
 
 
 
 
 PHILIPPINE NATIONAL STANDARDS  PNS/BAFS 20:20xx  
Code of Good Agricultural Practices (GAP) for Corn  
 
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 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 corn plant against weeds.  
 
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 susc eptible to aflatoxin 
contamination. 
 
4.1.8  Other cultural manag ement practices  
 
4.1.8.1 If detopp ing of corn plants is to be practiced,  this shou ld be done  after physiological 
maturity has been  attained. 
 
4.1.8.2 Follow the other recommended  cultural practices of corn including the
 maintenance of the recommended  row and plant spac ing to avoid overcrowding. 
 
4.1.8.3 Conduct  regular monitoring at all crop stages to provide measu res to problems
  that may arise. 
4.2  Harvesting practices  
 
4.2.1 Harvest corn at full maturity as recommended. Use c lean mats, screens and /or other 
suitable unde rlays to prevent corn ears from direct contact to so il or foreign matter. 
Harvesting shou ld be completed in the sho rtest time poss ible especially du ring the 
rainy season.  
 
4.2.2 Before using machines for harvesting and postha rvest operations,  ensu re that all the    
equipment to be used  are functional, clean, and well-maintained.  
 
4.2.3 Sort-out and discard corn ears that show visible signs and symptoms of insect or 
microbial da mage. 
 
4.3 Post harvesting practices   
 
4.3.1 Hauling and  piling  
 
Haul newly harvested corn ears imm ediately after harvest. Hauling facilities to be used  
for collecting and transpo rting the harvested corn from the farm should be clean and 
dry. 
 
4.3.2  Shelling  
 
4.3.2.1 Before shelling, dry the corn ears to at least  21 % moisture content (MC). This is 
 the optimum MC that will bring about less damage to corn kernels during shelling. 
 
4.3.2.2 Use clean,  dry and properly calibrated mechan ical she ller for efficient sh elling. PHILIPPINE NATIONAL STANDARDS  PNS/BAFS 20:20xx  
Code of Good Agricultural Practices (GAP) for Corn  
 
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4.3.2.3 Use clean and dry containers of the shelled corn. 
 
 4.3.4 Drying  
 
4.3.4.1 Immediate drying of the corn grains to reduce  the MC after harvest shou ld be
 done by a ny available means,  to minimize if not avoid grain deterioration, mold
  and fungi attack and  pest infestation. 
 
4.3.4.2 If immediate drying is not poss ible, temporarily store the corn ears in cribs or
 any structure with good ventilation. 
 
4.3.4.3 As much as poss ible, immediately dry the shelled corn to 13 to 14 % MC. Ensure
  that corn has been  dried uniformly to this MC. 
 
4.3.4.4 Use clean suitable containers for the dried corn grains. 
 
4.3.5 Transport  
 
4.3.5.1 The corn shou ld be moved to a suitable storage or processing area as soon
 as poss ible after drying. 
 
4.3.5.2 Avoid grain moisture accumulation during transp ort by us ing an appropriate
 covering for the container. Corn grains to be transported shou ld be properly
 stacked inside the transp ort vehicle and covered with any protection against
 moisture and pests. 
 
  4.3.6 Storage  
 
The storage containers, warehouse  or silos should be properly designed and shou ld be  
able to meet the following minimum requirements such as: 
 
4.3.6.1  p revent re-wetting of dry corn grains; 
4.3.6.2  p revent entry of insec ts,  birds and rodents; and  
4.3.6.3  p rovide good ventilation to the stored corn. 
4.3.6.4 Maintain the recommended moisture content (13 to 14%) of the corn grain 
during storage to minimize aflatoxin contamination. 
   4.3.6.5  During storage, follow the first-in first-out (FIFO) principle. 
 
SECTION V: WORKER’S HEALTH AND SAFETY  
 
5.1 Farm  workers  and/or  personnel  who  will  be  involved  in  produc tion  and post 
produc tion activities should wear appropriate clothing and protective gadgets. 
 
5.2 Farm  workers  shou ld  be  trained  and  shou ld  follow  the  recomm ended  personal  
      hygienic and sanitary practices. 
 
 
 
 PHILIPPINE NATIONAL STANDARDS  PNS/BAFS 20:20xx  
Code of Good Agricultural Practices (GAP) for Corn  
 
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   SECTION VI: FARM MANAGEMENT  
 
6.1 Farm records  
 
6.1.1 Identify or designate an in-charge to deal  with matters assoc iated with GAP Corn
 certification. 
 
6.1.2 All farm records must be upda ted as required under the GAP Corn certification. (See
 attached proforma record system)  
 
6.1.3  Updated records must be kept for up to two years. New farm applying for
 certification must have at least  3 months of farm records which shou ld be presen ted
 during aud it. 
 
6.1.4 Copies  of  laboratory  analysis  and  certificates  that  verify  compliance  with  the 
Department of Agriculture’s regulations must be filed. 
 
6.2 Traceability  
 
6.2.1 Each package/bulk packed produce  leaving the farm must be traceab le (i.e
 tagged with GAP Corn Certification Number or farms name, date of harvest) to
 farm/sources. 
 
6.2.2  Records of lot or b atch numbers must be  maintained for all produce leaving the
 farm. 
 
6.3 S taff training   
 
6.3.1  Records of personnel a nd/or farm workers shou ld be maintained.  
 
6.3.2  Staff training records must be maintained and should be available during audit .PNS/BAFPS 20:2008  
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 References                                                                                               
 
The following referenced docu ments are indispensable for the app lication of this 
docu ment. For  dated references, only the edition cited applies.   For  unda ted references,  
the latest ed ition of the referenced  docu ment (including any amendments) applies: 
 
A Flora of Manila. E.D. Merill. 1984.  
 
ASEA N GAP.  2006.  Good Agricultural  Practices  for  Production  of  Fresh  Fruit  and 
Vegetables in the ASEA N Region. J akarta: ASEAN Secretariat. 28 pp. 
 
Codex  Alimentarius Comm ission. Code of Practice for the Prevention and Reduc tion 
of Aflatoxin Contamination in Peanu ts. 
 
DA-BAFPS. 2004. Philippine National Standa rds in Corn. PNS /BAFPS10:2004. DA. 
2005. Code of Good Agricultural Practices for F ruits and Vegetable Farming. 
Det Norske Veritas Italia.   International Certification Processes:  Specific Regulations for 
the Certification of Good Agricultural Practices According to the EUREP GAP Scheme. 
 
Food  and Agriculture Organization.   2003.   Development of a Good Agricultural 
Practice Approach.  Rome.