Maize Seed Production

Credits: Infonet-Biovision

Varieties of maize 
(c) Keith Weller, USDA
Maize seed untreated with chemicals
(c) A.A.Seif, icipe

Introduction

Maize has for many years been the crop against which food security is measured in Kenya. However, when it comes to seed supply, farmers are often at the mercy of large seed companies and may not always be able to get the kind of seed they want. In many maize producing areas farmers have kept and multiplied old maize varieties, which over time have become better adapted to their climatic zones, better able to withstand extreme weather conditions and at least provide them with a yield when hybrids fail.

Also Kenya Agricultural and Livestock Research Organization (KALRO) has maintained some of the old open pollinated varieties for their research and developed new ones especially for dryland areas, where the seed companies do not have much to offer. The following is a listing of best practices for maintaining and developing the best type of maize seed for particular areas. Farmers interested in maintaining their own seed supply can possibly find inspiration here.

A healthy maize cob
(c) A.A. Seif, icipe

Production of own maize seed by smallholder farmers

Own maize seed can only be produced from varieties which are not hybrids. Hybrid varieties are made by planting two varieties in the same field, allowing only the male parent to produce pollen, and harvesting the seed only from the female parent. This is controlled crossing of two different parents. The offspring (the hybrid) will perform better than the average of the parents or even better than each of the parents. Generally hybrid maize varieties are denoted by letter “H”. Some examples of hybrid maize varieties in Kenya include: “H 614”, “H 626”, “KH 600-15A”, “H 516”, “KH 500-21A”, “Pwani Hybrid 1” and “Pwani Hybrid 4”.However if you try to plant the seeds from the cobs of these hybrids, your plants will not have the characteristics of the mother plants and also the yields would be different.Non-hybrid (open pollinated) varieties are produced by allowing maize plants to pollinate freely, and seed can be harvested from all healthy plants. Some examples of open pollinated maize varieties in Kenya: “Coast Composite”, “Katumani Composite B”, “DLC1”, “Kikuyu” (a landrace which is popular in the Central Province of Kenya). A landrace is a variety developed by farmers under influence of their farming system and their physical environment (soils and weather). Landraces are characterised by high genetic variation

Maize seed ‘KCB’ treated with seed dressants (fungicide plus insecticide)
(c) A.A. Seif, icipe

How to produce on-farm own seed from non-hybrid (open pollinated) maize varieties

Sources of seed

If you want to start your own seed multiplication programme as an income generating activity,

buy seed which is certified for example in Kenya, by the Kenya Plant Health Inspectorate Service (KEPHIS). In other countries in the region, check on certifying institutions. In Kenya, ensure that you consult KEPHIS, extension officers of Ministry of Agriculture or the nearest Kenya Agricultural and Livestock Research Organization (KALRO) centre on the required procedures and regulations for seed production and sale in Kenya.If you want to produce seed for your own use (and sharing with neighbours), you can source seed from your existing maize crop in your farm provided it is not a hybrid maize crop. Or if in Kenya, you can visit your nearest KALRO field station and see if they can supply an initial small amount of seeds of a suitable open pollinated variety for your area. Plant this local seed variety and select the best cobs in your field according to the following principles:

Basic procedure in producing own seeds:

1.) Select healthy looking maize plants, and particularly, those not infected with seed-borne diseases (head smut, downy mildew, southern leaf blight, Stewart’s wilt).

2.) Look for good closure of cobs to ensure good bird. resistance, and protection from infection of cob diseases.

3.) Choose cobs of good size with well filled seeds.

  • Off-type plants: should be removed/discarded all off-type plants before flowering.
  • The selected plants should have well filled cobs not damaged by birds or attacked by insect pests (e.g. stalk borers) and not infected with ear rots.
  • The cobs must be matured and dry at picking. Sufficiently dry seed cracks when bitten. For planting, take seeds from the middle and bottom of the cob.
  • If there is another maize crop of different variety next to your field or near it (less than 300 metres), select plants in central part of your field and / or farthest from the neighbouring maize crop.
  • In organic farming it is not allowed to treat the seeds with a fungicide and also repels insects and provides a starter nutrition for the seeds in areas where soils are deficient in Copper. 200 g of copper compound /50 kg seed maize will be sufficient. If you are growing organic maize, consult your Organic Certification Body.

Seed plot system

Site selection

Choose a field as uniform as possible (not lying on a slope) and typical of the environment particularly the soil type. The field should not have been under maize the previous season. This would avoid the problem of volunteers especially if the previous maize crop was a different variety. It will prevent cross-pollination. Volunteers are plants that grow from seed spilled the previous season. Therefore, crop rotation with unrelated crops is recommended. Maize rotated with legumes is a good combination. If rotating is not possible, use the field for the same maize variety intercropped with a legume.

Isolation

To prevent your seed crop being pollinated by a neighbour’s crop or by a different variety on your own farm, keep a distance of 300 metres from any maize likely to flower at the same time. A difference of around 4 weeks in planting time also provides enough protection. If a source of outside pollen is suspected to have contaminated the crop, only the central part and / or the part farthest removed from the source of contamination should be harvested for seed.

Soil

There are no special requirements for seed crops over and above those for normal grain maize.

Planting time

Choose a planting time that will ensure dry weather at harvest.

Plant population

Follow the recommended spacing for your location (consult extension officers of the Ministry of Agriculture or in Kenya the nearest Kenya Agricultural and Livestock Research Organisation (KALRO).

Fertilisation

Fertilise as for normal grain maize. Use the recommended fertilisation rates for your conditions (consult extension officers of the Ministry of Agriculture or in Kenya the nearest KALRO centre). Guard against over-application of nitrogen. This leads to excess vegetative growth (stalks and leaves) at the expense of flowering, and produces in general weaker plants with less vigorous seeds. The best method is to apply nitrogen in at least 2 instalments, one at or shortly after planting, and the second halfway between planting and flowering. On the other hand, phosphorus and potassium are more important than in normal grain crops, because they stimulate flowering and the production of more and hardier seeds.

Insect pest and disease control

Consult extension officers of the Ministry of Agriculture or in Kenya the nearest KALRO centre for advice on the recommended seed dressing products. If you are growing organic maize, consult your Certification Body . Inspect your seed field at least once per week for insect pests and diseases. If stalk borers are a problem, consult extension officers of the Ministry of Agriculture or in Kenya the nearest KALRO centre for advice on effective chemical control. Better still adopt the “push and pull” method.
Plants infected with downy mildew, smuts, southern leaf blight, Stewart’s wilt and streak virus should be pulled out and destroyed by burning.

Harvesting and storage

Harvest the seed when it is matured. Maturity is reached when a “black layer” is seen in the seed after taking a seed off the cob, removing the bits of fibrous and papery tissue at its point of attachment to the cob. The crop can be harvested at this point and will yield very good quality, but only if properly dried. If you rely on field drying, you must plan your planting time so that harvesting can take place in the dry season. Drying will have to be done on the cob, before threshing, since threshing is not possible at high moisture content. Newly harvested cobs can be protected against weevils by dusting them with diatomite powder before storage. Dust threshed grains again with diatomite powder before long term storage to make sure they are not destroyed before next planting season. Maize seed can also be kept very well on the cob. Small quantities of cobs can be bundled and hung indoors. Smoke from fireplaces keeps insects away. Large quantities need to be kept in a raised crib or granary. Maize seed stores well at a moisture content of 12-13 %. You can judge seed moisture content by biting the seed. If they crack, rather than cut, they are dry enough for storage. Stored seed can be protected from insects by chemicals (consult extension officers of the Ministry of Agriculture or in Kenya the nearest KALRO centre) or by mixing with ashes or dried leaves (e.g. eucalyptus, lantana or neem) that repel insects.  Seed should never be stored in direct contact with the floor or walls. The stack should be on a wooden pallet or platform made from poles. Ensure the storage environment is dry, cool and clean.

Information Source Links

  • Almekinders, C. and N. Louwaars (1999). Farmers’ seed production. IT Publications, London. ISBN: 1853394661
  • Harry van den Burg (2004). Small-scale seed production. Agrodok 37, Agromisa/CTA, Wageningen, the Netherlands. ISBN: 90-77073-43-4. Agromisa website: www.agromisa.org
  • Hayma, J (1995). Storage of tropical products. Agrodok 31, Agromisa/CTA, Wageningen, the Netherlands. ISBN: 90-72746-63-5. Agromisa website: www.agromisa.org

Maize ladybird beetle

(Epilachna similes)

Credits:Biovision-Infonet

Damage by plant-feeding maize ladybird beetle (Epilachna similes) on maize leaf. Note close-up of beetle (inset).
(c) A. M. Varela, icipe

The adult is oval in shape, about 6 mm in length and reddish brown in colour with black spots on the wing covers. The body is covered with short, light coloured hairs. The larvae are 7-9 mm in length, soft and covered with dark coloured spines. They pupate on leaves. Both larvae and adults of the maize ladybird beetle feed on leaves, scrapping them, usually on the underside, leaving the upper epidermis intact. This beetle will cause much damage only when present in large numbers. It also attacks cereals such as wheat and sorghum.

The maize ladybird beetle rarely causes serious defoliation and therefore control is usually not necessary.

What to do:

  • In case of severe attack spray neem products. Weekly applications of simple neem products have given control of Epilachna beetles in other crops such as cucurbits.

Bean Common Mosaic Virus

Common mosaic virus on beans
(c) A.A. Seif, icipe

Symptoms of bean common mosaic virus (BCMV) are cupping and twisting of leaves with a light and dark green mosaic pattern. The dark green tissue is often bubbled and/or in bands next to the veins. Affected plants produce smaller, curled pods with a greasy appearance, and yields are reduced. The virus is seed borne. It can be transmitted by several aphid species.What to do:

  • Use certified and disease-free seeds
  • Plant resistant varieties (e.g. French bean variety ‘Paulista’)
  • Control attacks of aphids
  • Remove infected plants from the field

Maize aphid or corn leaf aphid

(Rhopalosiphum maidis)

Credits: Biovision-Infonet

Aphids on maize
(c) Clemson University, Bugwood.org
The maize aphid (Rhopalosiphum maidis). Apterous individualson leaf of maize
The maize aphid Rhopalosiphum maidis. Colony on leaf of maize

It is dark green to bluish-green in colour with black cornicles. Particularly during dry/periods the colonies appear on the inflorescences and young leaves. Feeding by this aphid causes yellow mottling, but this damage is seldom of economic importance. Their role as vector of the sugarcane virus, maize dwarf mosaic virus and maize leaf-fleck virus makes them a pest of considerable importance. This aphid usually attacks maize plants at the end of the mid-whorl stage. Aphid colonies may completely cover emerging tassels, and the surrounding leaves, preventing pollen release. In severe outbreaks the ear shoot is also infested, and seed set may be affected.

What to do:

  • Conserve natural enemies. Aphids have a wide range of natural enemies, which normally keep them under control.

Angoumois grain moth

(Sitotroga cerealella)

Credits:Biovision-infonet

Angumois grain moth on maize. The moth is small, pale brown, 5-7 mm long with wings folded, wingspan 1-1.6 cm
(c) Clemson University

The larvae of the Angoumois grain moth penetrate and feed inside maize grain. This insect may also infest the crop in the field prior to harvest. The moths are small (nearly 1 cm long) yellowish or straw-coloured, a have a fringe along the posterior margins of the wings. They can be observed flying around infested stores.

Female moths lay eggs at night. Eggs are laid singly or in clumps on the outside of cereal grains, in cracks, grooves or holes made by other insects. Eggs are initially white turning red near hatching. The larvae are whitish. The larvae prepare a round exit hole for the moth, leaving the outer seed wall only partially cut as a flap over the hole, resembling a trap door. The adult pushes its way out through this “window” leaving the trap door hinged to the grain. Infested grains can be recognised by the presence of these small windows. The adult lifespan may be up to 15 days, and 1 female can lay over 100 eggs.

What to do:

  • Practise store hygiene. All residual pockets of infestation should be cleaned out at the end of the storage season. This is important to minimise re-infestation of the new crop.
  • Store old and new lots separately.
  • Do not leave maize in the field after drying, this increases the chances of infestation.
  • Whenever possible separate stores from fields. The grain moths are good flyers and adults from infested stores often infest growing maize in the field.
  • Keep the temperature and humidity as low as possible. There are indications that storing grain in a dry place can reduce infestation.
  • Prevent pest entry by sealing the store (windows, doors, ventilation facilities) with insect-proof gauze. Hermetic storage at low humidity gives good levels of control. In Malawi, plastering stores with mud to reduce water uptake was found to be effective (Golob and Muwalo, 1984, CABI, 2000).
  • Periodically inspect and remove any infested maize.

Larger grain borer and the grain weevils

(Prostephanus truncatus) (Sitophylus spp.)

Credits:Biovision-infonet

Adult beetles of Maize weevil (Sitophilus zeamais) in maize. Adult emergence holes with irregular edges are apparent some weeks after the initial attack.
(c) University of Georgia Archives, University of Georgia, Bugwood.org
Larger grain borer (Prostephanus truncatus). The adult beetle is 3-4.5 mm long.
(c) NRI/MAFF. Reproduced from the Crop Protection Compendium, 2004 Edition. (c) CAB International, Wallingford, UK, 2004
The maize weevil (Sitophilus zeamais) adult. It is possible to confuse the maize weevil with other storage insect pests such as the larger grain borer – LGB (Prostephanus truncatus). The end of the body of the maize weevil is more rounded than that of the LGB.
(c) USDA, ARS (Public Domain

They attack stored maize grains. Both the adults and the larvae (grubs) of these beetles feed in the grains. Adults come from infested cobs in the field or from an infested maize store and lay eggs in the grains. They attack maize both in the field and after harvest. Attacked maize grains lose all their contents and are not fit to eat. These pests become a serious problem in short time if no control measures are applied. The larger grain borer also attacks dried cassava roots and even the wooden structures of the stores.

What to do:

  • Conserve natural enemies. An imported predatory beetle Teretrius (formerly Teretriosomanigrensis has been released in several African countries in an attempt to control the larger grain borer.

Information Source Links

Credits: Biovision-Infonet

  • AIC, Kenya (2002). Field Crops Technical Handbook.
  • Agroecology Research Group. Corn-bean-squash intercrop in Mexico. www.ag-transition.org
  • Asean IPM Knowledge Network Management. Management of corn plant hoppers in the Philippines.
  • Borgemeister, C., Holst, N., Hodges, R. J. (2003). Biological control and other pest management options fo larger grain borer Prostephanus truncatus. In Biological Control in IPM Systems in Africa. Neuenschwander, P., Borgemeister, C and Langewald. J. (Editors). CABI Publishing in association with the ACP-EU Technical Centre for Agricultural and Rural Cooperation (CTA) and the Swiss Agency for Development and Cooperation (SDC). pp. 311-328. ISBN: 0-85199-639-6.
  • CAB International (2005). Crop Protection Compendium, 2005 Edition. Wallingford, UK www.cabi.org
  • Dlib Magazine 2002 Vol 8 Number 5 www.anu.edu.au
  • FADINAP. Integrated plant nutrition systems. www.eldis.org
  • FAOSTAT, 2017 www.faostat.org
  • Frescho seeds www.freshcoseeds.co.ke
  • Herren, H., Pickett, J. (2000). Kenya: Vuta-sukuma (Push-pull) pest management in smallholder systems. ICIPE annual reports.
  • ICIPE (2003). Development of biocontrol-based management of Helicoverpa armigera in eastern and southern Africa. 2000-2003 ICIPE Scientific Report. International Center for Insect Physiology and Entomology, Nairobi, Kenya. www.push-pull.net
  • ICIPE. Implementation of habitat management strategies for the control of the stemborers and striga in maize-based farming systems in Eastern Africa and mechanisms of striga suppression by Desmodium sp. www.push-pull.net
  • Intergrated management of the Fall Armyworm in maize. A guide for Farmer Field Schools in Africa, FAO 2018. www.fao.org
  • IITA. www.iita.org
  • Kranz, J., Schumutterer, H., Koch, W. (1977). Diseases, pests and weeds in tropical crops. Verlag Paul Parey. ISBN: 3-489-68626-8.
  • Le Pelley, R. H. (1959). Agricultural insects of East Africa. East African High Commission. Nairobi, Kenya.
  • Ministry of Agriculture 2006: Economic Review of Agriculture
  • Nutrition Data www.nutritiondata.com.
  • OISAT: Organisation for Non-Chemical Pest Management in the Tropics www.oisat.org
  • Ortega, A. O. (1987). Insect pests of maize. A guide for field identification. Mexico, D. F.: CIMMYT. ISBN 968-6127-07-0
  • Songa J.M., Overholt W.A., Mueke J.M., Okello R.O., (2002). Farmers’ perceptions of aspects of maize production systems and pests in semi-arid eastern Kenya: factors influencing occurrence and control of stem borers. International Journal of Pest Management, 48 (1):1-11.
  • Terry, P. J. and Michieka, R. W. (1987). Common weeds of Africa. Food and Agriculture Organization of the United Nations (FAO). ISBN 92-5-002426-6.
  • CIMMYT Maize Program (2004). Maize diseases: A guide for field identification. 4th edition. Mexico, D. F: CIMMYT. ISBN 970-648-109-5
  • The Organic Farmer Magazine 
  • Western seed company www.westernseedcompany.com
  • WISARD PROJECT INFORMATION (2001). Biology and management of termites and white grubs in smallholder cropping systems.
  • Youdeowei, A. (2002). Integrated pest management practices for the production of cereal and pulses. Ministry of Agriculture (MOFA) Plant Protection and Regulatory Services Directorate (PPRSD), Ghana, and the German Development Cooperation (GTZ). ISBN: 9988-0-1086-9.

Satintail

(Imperata cylindrica)

Credits: Biovision-Infonet

Satintail leaves close-up. Identification: The whitish midribs are often off-centre.
(c) Chris Evans, The University of Georgia
Imperata cylindrica (L.) P. Beauv, also known as Satin Tail is a perennial grass with extensively scaly underground rhizome
(c) Ahmad Fuad Morad, 2011

In south-western Nigeria, satintail is a major weed reducing maize yields. The rhizomes of this weed often reduce the efficacy of farmers’ weed control practice (slashing followed by 2-4 times of additional weeding) and contribute to high yield losses.

What to do:

  • Slash satintail at regular intervals, followed by handweeding
  • Remove rhizhomes through deep tillage. In field trials grain yield was 62% less than in fields where rhizomes had been removed from soil before sowing maize.
  • Plant cover crop such as Mucuna to smoother the weed

Purple witchweed

(Striga spp.)

Credits: Biovision-Infonet

Striga (Striga hermonthica) weeds in maize field.
(c) Courtesy EcoPort: David C. Nowell

The parasitic weeds Striga spp. known as witchweeds, are important pests of maize, particularly in drier areas. The weeds grow on the roots of maize affecting development of maize plants. The young weeds tap the roots of maize plant and draw water and nutrients. A single weed plant produces many thousands of tiny seeds that survive in the soil for long periods. A heavy infestation can cause complete yield loss.

Striga weeds infest 40% of the arable land in the savannah region, causing annual crop losses of 7 to 13 billion dollars. Around the Lake Victoria basin infestation by Striga hermonthica causes 30 to 100% loss in maize yield. Striga infestation is associated with increased cropping intensity and declining soil fertility. Witchweed infestation has resulted in the abandonment of much arable land by farmers in Africa. The problem is more serious in areas with low soil fertility and rainfall.

None of these methods described will, alone, provide complete control and without complete control there is the certainty that surviving plants will mature and replenish the soil seed bank. Therefore, integration of one or more methods is essential for any substantial reduction of the problem. Furthermore, such integrated treatments will almost certainly need to be repeated over a number of years for long-term control.

What to do:

  • Weed regularly. This is the conventional method for striga control, but is time-consuming and labour-intensive.
  • Rotate maize with trap crops. Some plants, such as such as sunflower, pulses and cotton, stimulate the germination of striga seeds, but also inhibit post-germination growth of the weed. Thus, although the seeds germinate, striga cannot develop successfully in these roots.
  • Intercrop maize with Desmodium or other legumes. Desmodium have been shown to be more effective in reducing striga when interplanted with maize in the field than other legumes such as cowpea, soybean and sun hemp. Desmodium progressively reduces the number of striga seeds in the soil.
  • Use resistant/tolerant varieties. Some maize varieties show partial resistance, such as “Katumani” in Kenya.

Couch grass or Bermuda grass

(Cynodon dactylon)

Credits: Biovision-Infonet

Couch grass (Cynodon dactylon) flower
(c) Charles T. Bryson, USDA ARS
Couch grass (Cynodon dactylon) is a perennial grass, with underground rhizomes and on the ground runners.
(c) Charles T. Bryson, USDA ARS

It is a spreading perennial grass with vigorous mat-forming stolons. It reproduces and spreads mostly by means of rhizomes but also propagates by seed. This grass is considered as one of the most important weeds in the world. It is present in virtually every tropical and subtropical country and in virtually every crop in those countries. Couch grass and other species of Cynodon are common in East Africa, and some species are occasionally troublesome as a weed of arable land and perennial crops.

Couch grass is reported in Ghana as a problem in crops such as eggplant, okra, onion, peppers and tomato.What to do:

  • Where couch grass is a problem, control it before planting maize, as it will not be possible to grow a profitable maize crop in a couch dominated field.
  • Harrow with a tooth harrow during the dry season in order to uproot the rhizomes and letting them dry completely on top of the soil. If possible, collect and burn dry rhizomes. Burning them will increase the success of couch control.The same tooth harrow can be used to sweep the dry rhizomes together in bands on the field which can then be burned on site or collected and used for fuel elsewhere (farmer experience).
  • Introduce shade producing cover crops, within a crop rotational system.