Advances of groundnut breeding and seed systems in TanzaniaOMpondaauthorEMonyoauthorPOkoriauthorGroundnut (Arachis hypogeal L.) is an important oilseed crop, mainly grown by smallholder farmers on 839,631 ha in four agro-ecological zones (Lake, central, western and southern) of Tanzania. The average yield is 965kg/ha with a national production of 810,000 tons. The major production constraints are foliar diseases (rosette, early leaf spot, late leaf spot, and rust), drought, aflatoxin contamination, and low soil fertility. This paper explores the advances made in a breeding program to solve these challenges. The genotype by environment interaction with linkage to good agronomic practices, using effective selection molecular tools, was used and significant achievements were recorded. Eight improved varieties were released with support from ICRISAT-led programs. The newly-released varieties command high-yielding ability (1800-2500 kg/ha), and tolerance to rosette disease and drought, and are highly preferred by farmers and market. The improved varieties increased yields and productivity at the farm level and groundnut production from 400,000- 810000 tons over the last 10 years. Effective seed delivery to smallholder farmers did not automatically follow. The Tropical Legumes Project, through NARI, designed rural seed fairs which are used to create awareness, increase accessibility, and create working contacts among community seed producers. Other seed delivery models tested and used include: farmer research groups, demonstrations, field days, community seed production, radio and TV events, political figures’ engagement and multi-stakeholder engagements. These models have raised awareness, increased demand of improved seed, and enhanced smallholder seed supply at affordable price with a significant number of beneficiaries reached (1,600,000 farmers)Plant BreedingTanzaniaGroundnutSeed Systems2017-02Conference or Workshop Item