Eggplant Integrated Pest Management AN ECOLOGICAL GUIDE

___________________________________________________________________________________Major Agronomic PracticesPotting seedlings versus flatfield beds, an experience from Lao PDR:In a study in Lao PDR, cabbage seedlings that were raised in polybags were found to recoverquicker after transplanting. Compared to traditionally raised seedlings, polybag seedlingssuffered less from transplanting shock (less root injury) and they were generally stronger andmore resistant against pests and diseases. In addition, they could be harvested 7 to 10 daysearlier (pers. comm. A. Westendorp, 2000).Related exercises from CABI Bioscience/FAO Vegetable IPM Exercise Manual:2-B.1. Farmers’ practices and problems during the nursery phase2-B.2. Design and testing of good nurseries2-B.3. Use of clean soil: subsoil versus topsoil2-B.4. Use of clean soil: solarization of the seed bed2-B.5. Use of clean soil: topsoil burning2-B.6. Use of clean soil: steam sterilization2-B.7. Broadcasting versus potting2-B.8. Fertilizing seed beds2-B.9. Roofing and screening of seed beds2-B.10. Mulching of seed beds2-B.11. Overhead or flood irrigation of seed beds2-B.12. Length of raising period2-B.13. Transplanting methods3.11 Field preparation3.11.1 Working the soilTillage or ploughing is carried out to prepare goodplant beds. When turning the soil, insects that live orpupate in the soil may come to the surface and areeither dried out by the sun or may be eaten by birds.Ploughing can also control weeds and pests thatremain in plant left-overs in the soil. Ploughinghowever, also disturbs the micro-organisms in thesoil and this may reduce soil fertility. To maintain andimprove soil fertility, it is important to apply organicmaterials such as compost every year.Sustainable soil practices are focused on using lesstillage and more organic materials, such as greenmanure or mulch, to increase biological activity in thesoil. Less tillage is possible where enough mulchcovers the soil. See sections 3.8.3.2 and 3.8.3.4,and box below on conservation tillage.Ploughing may expose insects and pupae in the soil topredators like birds and to the drying force of the sun.Left-overs from a previous crop should be carefully removed and destroyed as it may still containdiseases and pests which can spread into the new crop. These left-overs can be used for compostingwhich, if properly done, will get rid of pathogens.When drainage of the field is problematic, or when crops are grown during the rainy season, it isadvisable to prepare raised beds for growing the crop and dig trenches between the beds for drainage.This is also a good practice when problems with soil-borne diseases can be expected: most pathogensneed water to spread and if there is an excess of water all the time, they can easily spread in the field.Excess water in the soil, or even water-logging, results in weak plants which are more susceptible todiseases and pests and give a lower yield.37Eggplant Ecological Guide