This policy guidance note is part of a series developed to support governments and their development partners in creating a policy and institutional environment to achieve sustainable food security and nutrition and meet SDG2. This note focuses on crops and varieties, the foundation of agriculture and food production, and outlines policies and actions needed to ensure that farmers have access to quality seeds and planting materials of well-adapted and preferred crop varieties. Good quality seeds and plant materials, of crop varieties which have desirable traits bred into them do not just happen; they have to be developed. This policy guidance note shows how this development depends on a continuum of activities to manage plant genetic resources for food and agriculture (PGRFA), from the conservation of plant genetic diversity, to the effective use of this diversity in breeding productive and nutritious crop varieties, to the delivery of seeds and planting materials to farmers. This note presents practical steps that governments may take in articulating policies and activities, drawing heavily from the Second Global Plan of Action for PGRFA, an internationally agreed framework for the conservation and sustainable use of PGRFA. This note helps policymakers to understand the potential of PGRFA to improve food security and nutrition, and to recognise this in their policies.