Farmers' Knowledge, Compliance with Post-Harvest Handling Standard Operating Procedures and State-Level Variation in Sweet Potato Production in North-Western Nigeria

Abstract

Post-harvest losses remain a major constraint on food security and farm incomes in Nigeria, where a substantial share of harvested sweet potato is lost between the field and the market through careless harvesting, inadequate curing, poor storage and unsuitable transportation. This study examined farmers' knowledge of recommended post-harvest handling practices, assessed their level of compliance with Standard Operating Procedures (SOPs), estimated the magnitude of post-harvest losses, and compared compliance between Kano and Jigawa states. A cross-sectional survey design was adopted and a multistage sampling procedure was used to administer structured questionnaires to sweet potato farmers in ten local government areas, yielding 418 valid responses (210 in Kano and 208 in Jigawa). Data were analysed using descriptive statistics, a weighted compliance index and an independent samples t-test supported by Cohen's d and Levene's test. Farmers possessed a moderate but uneven level of knowledge, strongest in the experience-based harvesting and curing components and weakest for refrigerated transport and technically demanding storage practices. The overall weighted compliance index was 50.22%, indicating that only about half of the recommended procedures were being implemented; compliance was highest for harvesting (57.58%) and lowest for transportation (31.44%), and 52.9% of farmers reached the 50% compliance threshold. Mean post-harvest loss was 37.50% of output, valued at approximately NGN 89.3 million, with harvesting and storage accounting for the largest absolute losses. Compliance was significantly higher in Kano (53.85%) than in Jigawa (46.45%) (t = 5.648, df = 416, p < 0.001; Cohen's d = 0.552). Targeted, demonstration-based extension emphasising transportation and storage, and more intensive support for Jigawa, are recommended.