Regulatory Measures for Maize Lethal Necrosis Disease (MLND) Management in Kenya

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1 Regulatory Measures for Maize Lethal Necrosis Disease (MLND) Management in Kenya James Onsando (PhD) Managing Director Kenya Plant Health Inspectorate Service (KEPHIS)

2 Operations at KEPHIS Phytosanitary inspections Seed field inspections Evaluation of new plant varieties Seed germination and purity testing Screening for plant pest and disease Soil, water and agrochemical analysis

3 Maize Maize is the leading staple food crop in Kenya and in consumed largely as whole meal or occasionally as whole grain as well as in mixtures with other food crops and in porridge. The crop is grown in all parts of the country.

4 Distribution and spread of MNLD between 2011 and 2014 Farmers noted unfamiliar symptoms in June 2011 in Bomet, Naivasha, Narok. Disease is now widespread in Chepalungu, Sotik, Transmara, Bureti, Nakuru, Konoin, South Narok, Mathira East, Imenti South Districts and Nyeri. Incidence in the field % Area affected over 80% crop loss has been incurred

5 The Maize Lethal Necrotic Disease It is a combination of sugarcane mosaic virus and maize chloritic mottle virus. It is a very high r value disease. It has never been reported in Kenya and so it is yet to be included in our maize import documents. For maize seed business to grow in Kenya and the region, this disease must be controlled.

6 Disease Epidemiology It can be introduced into a maize growing region through introduction of an infected plant or seed (Crop Protection Compendium). It is seed transmitted but the incidence is low (Crop Protection Compendium and Plant Disease December 2011). The main transmission route is insect vector (thrips and beetles). The virus can stay in the soil and in the insect vector when the crop is absent making management difficult.

7 What is a seed borne disease? The seed can be surface sterilized and still transmit disease. This means the disease pathogen is systemic and transmittable.

8 Low incidence of seed transmission o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o

9 Disease level Disease Progression Vector assisted Disease level Disease level 1 0 Year 1 Year 2 Year 3 Year 4

10 Symptoms The disease affects a wide range of varieties Symptoms occur on all stages of the crop From four leaf stage up to maturity Symptoms are found on the cobs too Planting young plants next to an older affected crop encouraged disease spread which made disease more severe Combination of symptoms are seen.

11 Symptoms contd.. Viral like mottling, flecking, streaking, mosaic and leaf roll. Fungal symptoms also noted included chlorosis, necrosis with leaf reddening, discoloration of internodes, brownish white mould growth on rotting cobs. Ear bracts dry when the rest of plant is green Partial grain or no grain filling All plants may die giving blighted appearance Transmission: vectors such as thrips, aphids etc.

12 Maize chlorotic mottle virus (MCMV)

13 Symptoms of the maize disease

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15 Symptoms contd..

16 Symptoms contd..

17 Symptoms contd..

18 Drying young maize crop

19 Drying maize

20 Symptoms contd..

21 KEPHIS Activities in relation to MLND Disease surveillance Laboratory diagnostics of MLN - For local and imported seed as well as post control testing of maize seed - Has laboratory capacity to test MLND Centralized regulation of maize seed imports Seed Certification process Training and sensitization of stakeholders 21

22 KEPHIS Laboratory Diagnostics on MLND Capacity Building on MLND diagnostics done at FERA-UK; January 2013 Focused on Real-Time PCR assays for seed testing A seed testing protocol developed KEPHIS adopted the protocol Currently involved in routine testing of MCMV and SCMV for advisory services and seed certification ( local and imported seeds) 22

23 Laboratory diagnostics Diagnostics equipment in the molecular lab and analysts doing nucleic acids extraction 23

24 Centralized regulation of maize seed/grain imports All Requests to import maize seed are controlled at KEPHIS- HQ Karen. Also imports of maize grain has been centralized Maize seed importers required to send a representative sample to KEPHIS for MLN Screening prior to importation. 24

25 Seed import/export regulation Only registered seed merchants are allowed to import/export seed An SR14 form is filled to notify kephis for the intention to import or export seed. A plant import permit is issued for the importation. Seed can also be imported by researchers for experimental purposes 25

26 Actions contd Seed crops to be planted in fields with no history of the disease. Scouting to map out most affected and disease free areas to assist in chosing sites for seed production. Pre-shipment sampling and testing of maize seed before importation into Kenya. Affected seed crops to be converted to grain use.

27 Actions contd Seed from affected fields not to be transported to Trans- Nzoia. Breeders/Seed companies encouraged to develop resistant/tolerant varieties. Screening of all maize varieties under NPT for MLN tolerance. This is a collaborative effort with CIMMYT.

28 Import regulation and phytosanitary measures Due to the threats of introducing new strains of MCMV, seed samples are delivered to Kephis Plant health labs for screening for the two viruses. A plant Import permit is issued for importation once the lot is declared to be free from the viruses. The imported seed is subjected to seed testing in the Seed testing lab In Kephis, Lanet. 28

29 Actions contd Ensure Seed treatment with systemic insecticides and fungicides to control the vector and opportunistic fungi for the first 6-8 weeks. (Imidachloprid e.g. Gaucho, Thiamethoxam e.g. Cruiser, Cabendazim, Maxim XL. Farmers encouraged to continue spraying after 8 leaf stage to limit population of the vector.

30 Actions contd Tolerant varieties to be fast-tracked for release. One moderately tolerant variety (WE1101) has been released and seed may be available in the current season. WE1101 CIMMYT/KARI have established a screening facility in Naivasha.

31 Disease Management Crop rotation greatly reduces the incidence of (MCMV) in first year maize even in susceptible hybrids Avoid bringing in planting material from unknown sources Do not plant recycled seed but plant only certified treated seeds Avoid bringing in maize from affected areas Use manure and fertilizer to boost plant vigor

32 THANK YOU 32