WORKSHOP ON MLN DIAGNOSTICS AND

MANAGEMENT IN AFRICACURRENT PHYTOSANITARY POLICIES TO CONTROL THE INCIDENCE AND

SPREAD OF MAIZE LETHAL NECOSIS DISEASE (MLND) IN AFRICA (NIGERIA)

BY

DR. P. O. OJO

DG, NASC-NIGERIA

INTRODUCTION

• Maize or corn is a cereal crop that is grown widely throughout the world in a range of agro-ecological environments. About 50 species of maize exist and are of different colours, textures, shapes and sizes. White, yellow and red are the common types. Maize is rich in vitamin A, C and E, carbohydrates and essential minerals and contain 9% protein. They are also rich in dietary fibre and calories which are good sources of energy. Maize is a good source of food for man, livestock and raw material for industry.

• Worldwide productions of maize is 785 million tons with United State producing 42% and Africa 6.5% the largest which is nearly 8 million tons is from Nigeria.

INTRODUCTION CONT’D

• Maize is affected by various pests and diseases, among which is stem borers, which is capable of causing 20-40% losses during cultivation, downy mildew, rust, leaf blight, stalk and ear rots, leaf spot, maize streak virus. Others are ear borers, army worms, cut worms, grain moth, beetle, weevils, grain borers, root worms, white grubs and striga.

• Maize lethal necrosis disease (MLND)/maize mosaic virus disease (MMVD) is a serious disease of maize which was first noticed in Kenya in 2011 and now found in many East African Countries where maize is grown. This disease affects varieties of maize with visible symptoms of chloroticmottling of the leaves, severe stunting and necrosis often leading to plant death. Losses of up to 100% has been reported in Kenya and Tanzania.

INTRODUCTION CONT’D

• Causative Agent: MLND is caused by a mixed infection between Maize Chlorotic Mottle Virus (MCMV) and potyviruses infecting maize. In some cases it is caused by synergy between Sugarcane Mosaic Virus (SCMV) and Maize Chlorotic Mottle Virus (MCMV). This is always severe.• No outbreak of the disease has been reported in Nigeria• Non-the-less, crop pest and disease prevention and control

measures are always adopted through legislatures, policies, regulations and cultural practices.

CURRENT PHYTOSANITARY POLICIES

1. LEGAL FRAMEWORK

National Agricultural Seed Act 72 of 1992 that established the National Agricultural Seed Council.

Plant Import Control Act of 1959 as amended in 1970.

National Biosafety Act of 2015

National Phytosanitary Regulations enforced by the Nigerian Agricultural Quarantine Service.

The New National Agricultural Policy.

Nigeria is a signatory to International Plant Protection Convention (IPPC) treaty for international cooperation in plant protection.

CURRENT PHYTOSANITARY POLICIES

2. IMPORT RESTRICTION

No seed/planting material is allowed into the country without an approved permit. Plant import permit is granted to importer before importation of seed.

Importers are not allowed to bring seeds from countries affected by diseases.

At instances of proposed import of seed or planting material from endemic country, pre-shipment sampling and testing of the crop seed is carried out before import.

Usually approval is only given for importation of seed for research and development purposes and not for commercial purpose.

Only limited quantity of seeds are allowed which is usually pegged at 5 Kg per variety except on special cases.

The imported seeds are mainly planted at research stations for proper monitoring and evaluation before taking to the farmer’s field when found satisfactory.

CURRENT POLICIES CONT’D

3. QUARANTINE SERVICES

Port Inspections are carried out to track seeds/ planting materials coming into the country.

Imported seeds are screened/ quarantined at the port of entry and tested for seed health status before release to the importer.

Cordon off disease infected fields and destruction

4. CHEMICAL CONTROL MEASURES

Seeds meant for sales should be treated with appropriated fungicide.

Pesticide to be used should be targeted towards the virus vector for effectiveness.

CURRENT POLICIES CONT’D

5. CULTURAL METHOD

The use of good crop rotation system to break the disease/ vector cycle has been found to be effective.

All affected fields above threshold level are recommended for destruction.

Adjacent fields should be regularly monitored.

Adoption of appropriate planting period have been found to be effective in the control of some pests and diseases.

CURRENT POLICIES CONT’D

6. SURVEILLANCE

Monitoring of possible entry points of diseases exotic to the country is a strategy employed to prevent introduction of new disease.

International Airports, Seaports and Land boarders are manned by Quarantine Officers who carry out inspection of all seeds/ planting materials as well as other agricultural products imported to the country to ensure such materials are pests and diseases free.

The pattern of spread of disease offers clue for intensification of surveillance at certain locations in the country.

CURRENT POLICIES CONT’D

7. CERTIFICATION

Certification is two-fold:

1. That carried out by the NAQS for the purpose of issuance of phytosanitarycertificate, and

2. That carried out by the NASC for quality assurance of seeds/ planting materials with due diligence towards ensuring compliance with minimum field and seed standards for quality seed production.

I. ECOWAS harmonized seed rules and regulations has made certification compulsory for all classes of seed.

II. NASC, Nigeria adopts ECOWAS standards in her certification scheme.

CURRENT POLICIES CONT’D

8. NATIONAL BREEDING PROGRAMME

Plant breeding is an effective tool for adapting to new challenges of biotic and abiotic stresses in agriculture.

Breeding for diseases resistance/ tolerance is a priority in the national breeding programme for controlling emerging diseases.

Plant Breeders shall continually develop new varieties of pest and disease resistant crop varieties to reduce losses in agricultural production.

CURRENT POLICIES CONT’D

9. COLLABORATION WITH OTHER COUNTRIES

Cross boarder pest and diseases are better controlled in collaboration with other countries which is a policy trust in tackling plant diseases in Nigeria.

Neighbouring countries are engaged in surveillance, information sharing, awareness campaigns to contain eminent disease outbreaks.

CONCLUSION

• It is established that MLND is transmitted by seed among other means of transmission and the use of clean, healthy maize seed for propagation will keep uninfected ecologies free of the disease.

• Efforts should therefore be made to step up phytosanitary measures to prevent entry of the disease to regions that are free.

• Increase surveillance, restrict movement of seeds from endemic areas, share information and step up collaboration among African countries to contain the spread of the disease.