Abstract

Common bean is commonly grown by smallholder farmers under quite diverse farming systems and it is for both food security and income generation. The impact of plant density is important to bean growers for yield optimization and the inadequate source of phosphorus leads to low productivity due to its significant in growth and development. This study focused on determining optimal spacing of different bush bean varieties for enhancing productivity in relation to application rates of P-fertilizers. A field experiment was conducted at Selian Agricultural Research Institute during short and long rain cropping seasons of 2016/2017 and 2017/2018 respectively. Treatments comprised of three bush bean varieties (Lyamungu 90, JESCA and KATB1), three spacing options 50 cm x 20 cm; 40 cm x 20 cm and 30 cm x 20 cm and four levels of P-fertilizers of 0 kg ha-1; 20 kg ha-1; 40 kg ha-1 and 60 kg ha-1 replicated three times in randomized complete block factorial design. Both treatments and their interaction showed significant differences (p ≤ 0.05). The combination for spacing of 30 cm x 20 cm with planting density of 333,333 plants ha-1 and P-fertilizer rate of 60 kg ha-1 with productivity of 2580 kg ha-1 enhanced bean productivity compared to commonly used combinations with productivity of < 600 kg ha-1.

Key words: Productivity, interactions, food security, plant density and yield responses.