Integrated Pest Management for Brassica Production in East Africa A Guidebook A.A. Seif and Brigitte Nyambo Integrated Pest Management for Brassica Production in East Africa A Guidebook A.A. Seif and Brigitte Nyambo Produced by International Centre of Insect Physiology and Ecology (ICIPE) P. O. Box 30772-00100, Nairobi – Kenya Tel.: + 254 (0)20 8561680-4/8502501 Fax: + 254 (0)20 85560110/8503360 Email: [email protected] www.icipe.org Funded by International Fund for Agricultural Development (IFAD) Via Paolo di Dono, 44 00142 Rome, Italy www.ifad.org DISCLAIMER Where specific pesticides have been mentioned in the text these are generally given as examples and should not be regarded as exclusive of others. Furthermore, mention of certain pesticides does not imply any preference or advantage over similar compounds not mentioned by name. Since some countries have restrictions on the use of certain pesticides, check local regulations before purchase or use. While every effort has been made to ensure the accuracy of the information in this booklet at the time of printing, the authors accept no responsibility for any damage that may arise as a consequence of using information in this guide. Integrated Pest Management for Brassica Production in East Africa: A Guidebook A.A. Seif1 and Brigitte Nyambo2 1Plant Pathologist, ICIPE; e-mail: [email protected] 2Entomologist and IPM Specialist, ICIPE; e-mail: [email protected] ISBN:978-9966-063-00-7 © 2013 International Centre of Insect Physiology and Ecology (ICIPE) Editorial consultants: SciTech Publishers (Kenya) Ltd. Page layout and cover design: Conrad Mudibo, Ecomedia Ltd. Printed by: Signal Press Ltd, P.O. Box 12714-00400 Nairobi, Kenya. Photographs by ICIPE unless otherwise stated. Non-ICIPE photos are individually acknowledged in the text. Acknowledgment Financial support for the production of this manual was provided by an IFAD grant to ICIPE under the programme “Scaling-up Biological Control of the Diamondback Moth on Crucifers in East Africa to Other African Countries”. Table of Contents IntrodUCTION ................................................................................................ 1 Cabbage ProdUCTION ................................................................................... 3 Ecological requirements ................................................................................. 3 Varieties .......................................................................................................... 3 Hybrid varieties ..................................................................................... 3 Open pollinated varieties ....................................................................... 6 Land preparation and management ................................................................ 7 Nursery management ...................................................................................... 7 Manure and fertilizer requirements ................................................................. 7 Intercropping ................................................................................................. 7 Nutrient deficiencies ....................................................................................... 8 Nitrogen deficiency............................................................................... 8 Phosphorous deficiency ......................................................................... 8 Potassium deficiency .............................................................................. 10 Boron deficiency ................................................................................... 10 Molybdenum deficiency ........................................................................ 10 Calcium deficiency ................................................................................ 10 Harvesting ..................................................................................................... 11 Integrated PEST Management FOR BRASSICAS ................................ 13 Crop scouting ................................................................................................. 13 Problem recognition ....................................................................................... 15 Record keeping ............................................................................................... 15 Decision-making to optimize production Management of insect pests and diseases ......................................................... 16 Biological control................................................................................... 16 Mechanical control ................................................................................ 17 Use of plant resistance ........................................................................... 17 Cultural methods ................................................................................... 18 Pesticides ............................................................................................... 19 Natural enemies as biological control agents ................................................... 21 Predators................................................................................................ 21 Other predators .................................................................................... 25 Parasitoids ............................................................................................. 26 Pathogens ............................................................................................. 27 IPM options for brassicas ................................................................................ 27 IPM for brassica production in East Africa | V MAJOR INSECT Pests OF BRASSICAS ........................................................... 34 Diamondback moth ....................................................................................... 34 Aphids ........................................................................................................... 36 Mealy cabbage aphid ............................................................................. 37 False cabbage aphid ............................................................................... 38 Green peach aphid ................................................................................. 38 Cabbage webworm ......................................................................................... 39 Bagrada bug .................................................................................................... 41 Cabbage sawfly ............................................................................................... 42 Cabbage moth ....................................................................................... 43 Cutworms ....................................................................................................... 44 Cabbage looper ............................................................................................... 45 Leafminers ...................................................................................................... 46 Whiteflies ...................................................................................................... 47 Thrips ............................................................................................................. 50 MAJOR DISEASES OF BRASSICAS ..................................................................... 52 Damping-off diseases ...................................................................................... 52 Black rot ........................................................................................................ 53 Soft rot .......................................................................................................... 54 Alternaria leaf spot ......................................................................................... 55 Black leg ......................................................................................................... 56 Clubroot ........................................................................................................ 57 Cottony rot (white mould) ............................................................................ 59 Downy mildew .............................................................................................. 60 Ring spots ...................................................................................................... 61 Powdery mildew ............................................................................................ 62 Wirestem ........................................................................................................ 63 Yellows wilt .................................................................................................... 64 White blister rust ............................................................................................ 65 Mosaic viruses ................................................................................................. 66 Turnip mosaic virus ........................................................................................ 66 Cauliflower mosaic virus ........................................................................ 67 Turnip mosaic virus ............................................................................... 66 Cauliflower mosaic virus ........................................................................ 67 Glossary .............................................................................................................