Abstract
Maize lethal necrosis (MLN), maize streak virus (MSV), grey leaf spot (GLS) and turcicum leaf blight (TLB) are among the major diseases affecting maize grain yields in sub-Saharan Africa. Crop models allow researchers to estimate the impact of pest damage on yield under different management and environments. The CERES-Maize model distributed with DSSAT v4.7 has the capability to simulate the impact of major diseases on maize crop growth and yield. The purpose of this study was to develop and test a method to simulate the impact of MLN on maize growth and yield. A field experiment consisting of 17 maize hybrids with different levels of MLN tolerance was planted under MLN virus-inoculated and non-inoculated conditions in 2016 and 2018 at the MLN Screening Facility in Naivasha, Kenya. Time series disease progress scores were recorded and translated into daily damage, including leaf necrosis and death, as inputs in the crop model. The model genetic coefficients were calibrated for each hybrid using the 2016 non-inoculated treatment and evaluated using the 2016 and 2018 inoculated treatments. Overall, the model performed well in simulating the impact of MLN damage on maize grain yield. The model gave an R2 of 0.97 for simulated vs. observed yield for the calibration dataset and an R2 of 0.92 for the evaluation dataset. The simulation techniques developed in this study can be potentially used for other major diseases of maize. The key to simulating other diseases is to develop the appropriate relationship between disease severity scores, percent leaf chlorosis and dead leaf area.
Highlights
The spread of transboundary diseases and insect-pests has increased significantly in recent years, threatening the food security and livelihoods of several million smallholders, especially in sub-SaharanAfrica
Maize lethal necrosis (MLN) is caused by the co-infection of maize plants with a combination of maize chlorotic mottle virus (MCMV; genus Machlomovirus, family Tombusviridae) [4], and any one of several viruses from the family Potyviridae, such as sugarcane mosaic virus (SCMV), maize dwarf mosaic virus (MDMV) or wheat streak mosaic virus (WSMV)
The area under the disease progress curve (AUDPC) ranged from a low of 136 for hybrid CKMLN150072 to a high of 422 for the MLN-susceptible hybrid check, PHB3253
Summary
Maize lethal necrosis (MLN) has emerged as a major threat to maize producers in eastern. The disease was reported in Kenya in 2011, and subsequently reported in several eastern Africa countries from 2012 to 2014 [1,2,3]. MLN is caused by the co-infection of maize plants with a combination of maize chlorotic mottle virus (MCMV; genus Machlomovirus, family Tombusviridae) [4], and any one of several viruses from the family Potyviridae, such as sugarcane mosaic virus (SCMV), maize dwarf mosaic virus (MDMV) or wheat streak mosaic virus (WSMV). MCMV was reported for the first time in eastern Africa in 2012, while SCMV has been prevalent worldwide for many decades.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
