GOOD AGRICULTURAL PRACTICES FOR MAIZE PRODUCTION

GOOD AGRICULTURAL PRACTICES FOR MAIZE PRODUCTION

Pre-planting activities

Pre-planting activities determine the success of establishment of maize field and future of yield quality and quantity. It is critical that a farmer is acquainted with these activities before planting if he/her is to benefit from the enterprise.  

Site selection

• Check with previous and present usage of the production area and the adjoining sites or history of prior land use. The land should be under rotation to reduce pests and disease attacks and nutrient depletion.
• Planting on restricted area should not be allowed and follow government regulation.
• Access of farm and wild animals to the site and to water sources used in primary production.  
• Potential for contaminating maize areas from leaking, leaching or overflowing of polluted surface waters.
• Environmental impact assessment, if available.
• Remedial action should be taken if significant risk is identified and actions taken should be monitored and noted.
• Site used for production should comply with country regulations, such as limited planting of crops on wetlands.
• Farm planning and layout should be done.
• Maize farms may be established as an intercrop to existing legume farms, in existing agro-forestry systems.
• Maize farm should be established in open land areas or intercropped with low crops. Areas with shade trees should be avoided as they will shelter the crop and reduce yields.
• The site should have well drained fertile sandy loam soils with PH of 5.5-6.5.
• The soil should have a good water holding capacity, free from soil erosion and flooding risks and trees.

Soils and substrates

• Soil should be tested and analysed for the presence of heavy metals before planting for new establishment. If ever heavy metals will be detected from harvested maize plant, soil should be analysed and appropriate remedial action should be done
• Cultivation practices that lead to soil degradation should be avoided. The farmers should use techniques to prevent soil erosion if the land is slopy.
• Cultivation practices that improve soil structure and fertility should be done. The farmer should use natural techniques to maintain and optimize soil fertility and structure. Disease-free organic waste, such as pruned branches and leaf litter, are left in the field or used for composting.

Land Preparation

• Prepare land thoroughly and ensure that soils are well loosened and leveled to allow even germination and increase germinability. Well prepared land allows good root development, reduces weed and pests, provides adequate moisture and temperature and thus far improving the yield potential of the plant.
• Avoid bad practices such as indiscriminate cutting down of trees and uncontrolled burning of forests to clear land. This can lead to loss of soil fertility, soil erosion and contribute to environmental degradation.

Seed selection

• Seed varieties have a different yield potentials and benefits therefore, a farmer should select quality certified seeds which are high yielding, early maturing, pests and disease tolerant and drought resistant.
• The seeds should be dressed seeds to avoid damages commonly associated with early crop development stages.
• The seed should be uniform.
• The seeds should have high germination rate > 85%.
• The seed should be well dried to 13% moisture content.
• The seed should be 98% pure (all seeds are of the same variety).
• The seed should be clean (not mixed with foreign matter like stones or dirt, or other seeds).
• The seed should be undamaged, broken, shrivelled, mouldy, or insect damaged, not rotten or discoloured faded.
• All non-conformity should not exceed 2%.
• The seeds should be selected from accredited sources.

Commonly cultivated improved varieties in Uganda

Germinability Test

Maize seeds loose viability when not handled well during processing and storage. Quality seeds tend to be expensive but, will give high crop yields. It is therefore important that you assure the seed germination before planting. The germination test is simple and easy to conduct.

• Take samples of seeds from different parts of the bag and mix them thoroughly
• Count out 100 whole soybean seeds and place them on one half of cotton cloth.
• Soak the seeds for twenty-four hours
• Wrap the soaked seeds in a moist cotton cloth or paper towel
• Position the moist wrapped cotton cloth upright so that roots will grow downwards while shoots grow upwards.
• Keep the rolled cotton cloth in a warm place (between 23° and 30°C).
• Count the first germinated seeds after three days by opening the cloth
• Fold and roll back into a tube.
• Repeat counting after another three to four days, germination time for maize is between 5 – 10 days.

If about 10 seeds (10%) have failed to germinate (90% germination) then use the recommended seed rate

If germination is below 90% but above 85%, increase the seeds per acre at planting following calculation below:

Recommended seed rate = 10 kg per acre

Percentage germination = 85%

Adjusted seed rate = (100÷85) x 10kg = 12kg

The new seed rate will be 12 kg per acre.

If germination percentage is below 85% reject the seed and report back to the stockiest, extension worker or the seed company (supply) immediately after the test.

Planting

Planting of maize improved/certified seeds should be done as early as possible. In Uganda, recommended planting dates for maize include; March for areas along Lake Victoria, Eastern Uganda and Mid-western, End of March for Southern part of Uganda, and Month of July for Northern region. Farmers should plant maize at onset of stable rains.

During planting, a farmer should observe the following;

• Proper spacing of 75 cm by 25 cm or 37 cm by 35 cm to attain optimal plant population. A farmer needs about 25kg for hectare and 10kg for an acre.
• The soil should have adequate moisture content of least 30-40 cm deep.
• Ensure the seeds are placed at the depth of 2-3 cm for moist soils and 2-5cm for drier soils.
• Ensure that seeds are not in contact with DAP. The seeds should be sown after DAP has been placed in the hole and covered with light soil.  
• Use planting string to maintain correct spacing between plants.
• Sow 2 seeds per hole to allow removal of a weaker plants.
• In case a planter is to be used; planting should be done at least when the soil is a little drier (25cm).
• Records of the source of planting seeds should be maintained.
• Planting materials for intercropping should be the recommended legume crop and variety.
• Planting materials should be the recommended variety by government.

Crop Field Management practices

Weeding

• Effective weed control is essential to prevent the adverse effect of weeds on crop and for achieving high maize yields.
• First weeding should be done at 2-3 weeks after planting while second weeding should be done in the 5-6 week after planting.
• Weeding by hand pulling and mechanical weeders should be encouraged.
• In case chemical use, the registered chemical should be used by trained worker (more details under Pesticide synthetic and Biopesticide section).

Fertilizer and soil additives

• Fertilizer and soil additives must be registered and recommended to minimize the risk of contamination. Raw manure or human waste must not be used for cultivation.
• Fertilizer and soil additives should be recorded. Records, including origin and composition of organic fertilizers, date, frequency, and location of application, should be kept. Analysis for heavy metals should likewise be conducted.
• Farmers should practice effective use of farm wastes, particularly pod husks, by shredding them as base material in making compost or organic fertilizer. Farm wastes may include diseased pods or parts of the plants in the cacao farm. However, it is critical to make sure that these wastes are properly composted whereby organisms or pathogens are destroyed during the composting process.
• Equipment used to apply fertilizers and additives should be maintained and kept in the proper storage area
• Used and unused fertilizers and soil additives should be stored securely, out of reach of children, and away from tools and food products
• Farmers and agricultural workers should be trained on proper handling and application
• Fertilizer application must follow recommended requirements and methods and should comply with regulations

Irrigation water

• Source of water should be derived from sustainable sources, free from biological and chemical contamination and be analysed at least once a year.
• Corrective actions should be made to prevent or minimize contamination from livestock, sewage treatment and human habitation.
• The producer should allow a strip of native vegetation (at least 5 meters wide) or guard plants to grow along water streams and sources to control erosion, filter out agrochemicals and protect the wildlife habitat. Irrigation should be based on cacao requirements and environmental impact.
• Farm workers should be trained on proper irrigation.

Pest Management

Integrated Pest Management (IPM) system must be in place.

The farmer should perform good cultural and landscape management options recommended practices to control particularly FAW including:

• Using “Push-Pull” companion cropping strategy, farmers protect maize crops from pest damage by intercropping them with pest-repellent (“push”) plant species (e.g., Desmodium spp.), surrounded by a border pest-attractive trap (“pull”) plant species [usually grasses such as napier grass (Pennisetum purpureum Schumach.) or Brachiaria spp. intercropping maize with certain types of crops to attract and repel insects, can be used. Apart from that, landscape management can also be used.
• Grow corn in early monsoon or as soon as the water recedes from submerged areas as FAW infestation can get worse on late sowing crops.
• Apply enough fertilizer to have a healthy crop so that to stand the pest attack.
• Intercrop the main crop, maize, with some other crops, for example, pigeon pea, cassava, sweet potato, sweet pea, beans, pumpkin or green manure crops row by row.
• No tillage, retaining crop residues and crop rotation can encourage the development of beneficial i9nsects (spiders, beetles, ants, beneficial fungi and bacteria) and these biocontrol agents will help control FAW. FAW cannot be controlled by burning crop residues as commonly practiced for the control of other insect pests.
• Grow sunn hemp, lablab bean and some other pulses in free space to get more natural enemies, repelling the pest, less oviposition and less infestation of FAW.
• Grow a variety of crops at the boundary/periphery of maize fields for biodiversification. This practice will also enhance the abundance of natural enemies to control FAW.
• Grow large tree like neem or other bushy type at the boundary of main crop, maize. Natural enemies and birds will come and feed on the pest, FAW.
• The effect of intercropping maize with certain legumes (green gram, soybean, cow pea) on the infestation of fall armyworm should be tested.
• Intercropping with pigeon pea and Gliricidia should be tested in certain areas.
• The push-pull strategy using Desmodium as repellent or pushing the pest away crop and napier grass as a pull crop should be confirmed with field trial before giving recommendations to the maize growers.

In a situation where Chemical controls are to be farmers should consider an integrated approach with preventive measures together with biological treatments if available. Thresholds for application of control measures may vary according to the area but is usually considered when: egg masses are present on 5 percent of the plants or 25 percent of the plant shows damage symptoms and live larvae are still present. Treatments must be applied before larvae burrow deep into the whorl or enters ear of the mature plants.

• The efficacy of chemical insecticides commonly used across the country should be tested in the field in different locations.
• Their impact on non-target organisms (natural enemies and beneficial insects) should be explored at the same time.
• The use of biopesticides and botanical pesticides should be encouraged.
• Training should be given to the farmers for efficient use of chemical pesticides and also to reduce the health hazards of human beings.
• The use of PPE should be encouraged whenever pesticides are applied.

Pesticides – Synthetic and Bio-Pesticides

• Farm owners and workers must follow recommended application procedures stated in the product ‘s label.
• Chemicals must be purchased from authorized dealers; based on recommendations from EAC member state authorities and included in the list of allowed and regulated chemicals by the government.
• Withholding periods for the interval between chemical application and harvest should be followed.
• Unused chemicals should be stored properly until next use or disposal; empty chemical containers should be kept secured until disposal.
• A record of chemicals obtained should be kept, detailing chemical name, supplier of chemical, date, and quantity obtained, and expiry or manufacture date.
• Farm owners and farm workers should be trained to a level appropriate to their area of responsibility for chemical application.
• Crop protection measures should be appropriate for the control of pests and diseases and be based on recommendations from member state authorities.
• Integrated Pest Management systems and non-chemical products should be used as much as possible to minimize the use of synthetic agrochemicals
• A rotation strategy for chemical application and other crop protection measures should be used to avoid pest resistance and pest resurgence.
• Re-entry requirement should be followed.
• Equipment used for chemical application should be properly cleaned and securely stored.
• Medical facilities and first aid measures should be available to treat farm workers contaminated/intoxicated with chemicals
• Workers handling and applying chemicals and entering newly sprayed sites should be equipped with protective clothing and equipment.
• Protected clothing should be cleaned and stored separately from crop protection products.
• Chemical application in areas of public access should be marked with warning signs.

Table: Recommended pesticides to manage FAW

Harvesting and Postharvest Practices

Harvesting

• Harvest the maize grains when it has dried and achieved full physiological maturity. A mature maize shows the following signs; brown stalk and sheath, drooping ears depending on a variety, hard grains with floury texture when bitten, a black layer at kernel tip and moisture content of 18-24 per cent.
• Immature maize should not be harvested. Immature maize imposes challenges during drying and cause huge loses to farmers.
• Apply appropriate harvesting methods. Avoid dropping the maize directly on the ground.
• Harvest maize on time. Early and late harvesting may increase the chances of grain contamination.
• Maize damaged by termites and found on the ground should not be harvested or mixed with clean maize.
• Containers for harvesting should be stored properly.  
• Harvesters should be properly trained before harvesting.

Postharvest Practices 

Transportation

• Vehicle for farm implements should be checked for contamination and should be kept clean at all times.
• Vehicle used for handling soil, animal manures, chemical fertilizers and pesticides should be appropriately cleaned prior to delivering.

Drying

• Always dry the maize on tarpaulins, canvas, plastic sheets, raised bed, solar dryer. Avoid drying of cobbed maize and shelled maize on the ground to prevent exposure to spoilage by fungi during storage.
• Monitor the moisture content of maize regularly and ensure maize attains 12-13 percent moisture content. Higher moisture levels favour the growth of fungi and make the maize crop more susceptible to aflatoxin contamination if the maize was already colonized by aflatoxigenic mould species.
• Prevent the grain from rain, chicken, rats or other animals that contaminate the grains. Drying maize in the cribs is much better.
• Maintain layer of at least 2-3 cm thick and turn the maize regularly to speed up drying and allow even drying. Avoid stepping on the maize during turning process to avoid contamination.

Shelling/Threshing

• Properly calibrated shellers should be used to ensure quality of maize.
• Always ensure that shellers are well calibrated before shelling of maize.
• Avoid improper shelling methods such as beating and uncalibrated shellers that can cause damage, wound or break maize grains and exposure to microbial attack and contamination. Fungal hyphae easily penetrate the broken grains.
• Shell the maize on to tarpaulins.

Cleaning

• Clean the grain to remove foreign material and non-conforming grains from the normal ones by winnowing and sieving.

Sorting

• Sort the maize grains to remove damaged, discolored and mouldy grains.

Packaging

• Package the grains in food grade hermetic bags, plastic silos, or plastic silos. 
• Ensure that the packaging material are thoroughly cleaned and free from any contaminants.

Storage

• Store only properly dried shelled maize grain. Improperly dried maize placed in the bags leads to the buildup of the humidity that germination of fungal spore and contamination.
• Store maize on raised platform or pile on the pallets and 30cm away from the wall.
• Ensure the storage house is well ventilated to allow cooling of the temperatures inside the stores.
• Keep the store free from animals, insect pests, hazardous chemicals and on other products.
• Regularly check the store for signs of water leakage, the floor for cracks and crevices, for signs of damage on bags (rodent or insect) spillage of grain on the floor, presence of live insects and signs of contamination.
• Always inspect the surrounding environment to ensure hygiene.
• Carry out quality control checks on a regular schedule.
• Fumigate to control infestation of storage insects. Use a licensed professional fumigator.
• Ensure FIFO (first in first out) rule when handling stock in storage.
• In case of cobbed maize, store in the cribs and shell when there is assured market.

Processing

• Use of good quality, well maintained and well calibrated equipment.
• Use of approved packaging materials that are not easily torn.

Waste and energy efficiency

• A waste management plan should be followed
• Proper waste disposal should be done in designated locations, follow recommended segregation, reuse and recycling.

Biodiversity

• Farming activities should comply with member state regulations, covering protected plant and animal species to ensure that protected species are not endangered
• Conservation of biodiversity and wildlife by enhancing the habitats and increase agricultural biodiversity.

Record keeping

Record forms and documents shall be updated as follows:

• Record showing planting site, date of planting, date of harvesting, quantity of harvested bean weight and selling places for the benefit of productivity improvement and traceability.
• Source of planting materials
• Record on sources of acquired production inputs, such as pesticides and fertilizers by indicating the details on dates, quantity, name of the fertilizers.
• Stack cards (The stack card fixed to a bag stack, used to keep a tally of the number and weight of bags of grain either added or removed from the stack).
• Received stock ledger book
• Outgoing stock ledger book
• Quality control records
• Cleaning records
• Fumigation records