Evaluation Of The Available Cross-Border Phytosanitary Measures For The Control Of Maize Pests In Malawi

Abstract

Pests cause significant losses in maize worldwide and are barriers to the achievement of global food security. Cross-border agricultural trade is ranked as a major factor that places maize at risk as it creates pathways for the spread of different maize pests. This study, was therefore, carried out to determine the common pests affecting maize and the available phytosanitary measures for the management of maize pests across the borders of Malawi. A survey was conducted in 2018 to determine phytosanitary measures and phytosanitary capacity at border points, major towns, regulatory and research institutions in Malawi. Data collection points included manned points between Tanzania, Zambia and Mozambique. The major cities covered were Mzuzu, Lilongwe and Blantyre while the institutions included government regulatory organizations and private organizations that work in the phytosanitary systems. The information obtained comprised of phytosanitary activities, trade patterns on maize, staffing in relation to plant health, capacity and available facilities within the organizations. Most of the training courses (63%) that were offered in phytosanitary disciplines were attended by the government organizations. Major Phytosanitary activities were done by the Malawi National Plant Protection Organization and maize under importation was inspected more than those in transit and exportation. Majority (67%) of the imported maize originated from Mozambique, Tanzania and Zambia. The phytosanitary facilities in Malawi are not well equipped. Larger grain borer (Prostephunus truncatus) and common maize weevil (Sitophilus zeamais) were the most common insect pests contaminating maize while flour beetle (Tribolium castaneum) and grain moth (Sitotroga cerealella) were the least. There were no significant differences in the population of insect pests before incubation in all the surveyed districts. xiv However, there was a significant difference after incubation for the larger grain borer and common maize weevil. The largest number (1.5) of insect pest infestation for larger grain borer was reported in Karonga and the least was in Mzuzu. Largest (3.7) infestation for maize weevil was reported in Nkhatabay whilst the least was in Lilongwe district. There were significant differences in the total number of damaged kernels before and after incubation. The greatest damage (2.9) on unincubated kernels was observed in Blantyre while the least was observed in Mulanje. However, after incubation, the highest (5.5) kernel damage was observed in Karonga whilst the least was observed in Mulanje. Common fungal pathogens isolated from the kernels were Fusarium (70%), Aspergillus (29%) and Penicillium (1%). The highest percentage of kernel infection with Fusarium was in Dedza and Lilongwe whilst for Aspergillus were in Mzuzu. The Aspergillus spp isolated were A. niger (29%), A. flavus (22%) and A. parasiticus (5%) while the Fusarium spp isolated was Fusarium verticilloides. The study reveals that Malawi faces a lot of challenges in the implementation of phytosanitary measures in the management of maize pests. Therefore, there is need for the government to initiate programes to enhance plant health system for example capacity building, improve facilities and inspection practices and increase funding in the phytosanitary system. Key words: cross-border trade, maize pests, phytosanitary measures, phytosanitary capacity