In Brazil, 46.5% of more than 5 million agricultural establishments have producers aged 55 or older who have important needs in their interaction with technology, considering physical, cognitive and generational aspects that impact their use of it. This paper evaluated mobile information systems, analyzing their inclusivity of older people and the impact of usage problems. The case study was conducted by a detailed inspection of 86 empirically derived interface guidelines focused on older people on a set of publicly available agricultural apps used in Brazil. The results revealed 304 guideline violations, with critical issues that jeopardize the interaction of older people with mobile information systems for agricultural businesses, such as support for sensory losses, lack of voice input, and lack of documentation and contact information. The study discusses the impact of usability issues on agricultural businesses owned by older people in Brazil. The paper contributes a consolidation of design recommendations for more inclusive agricultural apps for older adults in the Brazilian agricultural sector.