Occurrence, Distribution and Alternative Host of Tomato (solanum Lycopersicum) Yellow Leaf Curl Virus in Sokoto State

ABSTRACT A survey was conducted to document the incidence, severity, distribution and alternative host of TYLCV in Wamakko, Gwadabawa and Kware. Molecular diagnostics were employed to confirm the presence of the virus. Symptoms such as stunting, chlorosis, necrosis, and leaf curling were observed in infected tomato plants. The highest percentage of infection was recorded in Kware having (25%), while the lowest incidence was recorded (8%) in Wamakko. Disease severity ranged from (5.8%) to (17%), with the highest infection recorded in Kware and the lowest in Wamakko (5.8%). Distribution of this virus ranged from (8.5%) in Wamakko, the highest record was observed in Kware having (18.5%). A total of 48 symptomatic and asymptomatic plant samples were collected and analyzed across six locations. In addition, eighteen weed species from thirteen botanical families were tested for TYLCV presence. Molecular analysis confirmed several weed species, including Euphorbia hirta, Phyllanthus urinaria, Chenopodium album, and Amaranthus retroflexus, as alternative virus hosts. These weeds play a crucial role in harboring and spreading the virus in tomato fields. The study highlights the significant threat TYLCV poses to tomato production in Sokoto State due to its high prevalence and the presence of multiple weed hosts. Questionnaire administered revealed that mixed and sole cropping patterns dominate the region, with inconsistent field hygiene and widespread reliance on local seed varieties. These factors contribute significantly to the spread of TYLCV. It is recommended that farmers adopt best agricultural practices such as regular weeding, crop rotation, and using resistant tomato varieties. Further research should focus on sequencing and phylogenetic for better understanding and effective management of the virus.