Exploring the influence of calcium sources (calcium ammonium nitrate [CAN] and lime) on groundnut (Arachis hypogaea L.) growth and yield in Rwanda

An experiment was conducted in Huye district, Southern Province of Rwanda, during the 2023-2024 seasons, using a randomized complete block design with seven treatments replicated three times. The study aimed to investigate the impact of different calcium sources on the growth and yield components of groundnut (Arachis hypogaea L). The treatments included T0-N17 P17 K17 at 300 kg ha-1, T1- N17 P17 K17  at 300 + CAN at 100 kg ha-1, T2- N17 P17 K17  at 300 + CAN at 200 kg ha-1, T3- N17 P17 K17  at 300  + CAN at 300 kg ha-1, T4 - N17 P17 K17  at 300  + CAN at 400 kg ha-1, T5- N17 P17 K17  at 300  + Lime at 500 kg basal ha-1, T6- N17 P17 K17  at 300  + Lime at 250 kg basal ha-1 +  CAN at 100 kg ha-1. The application of calcium ammonium nitrate (CAN) at 200 kg ha-1 yielded significant increases in groundnut growth and yield parameters. Specifically, at 14 weeks, mean plant height increased by 29%, the number of branches by 33%, the number of pegs by 78%, and the number of nodules by 138%. Moreover, seed weight, shelling percentage, and 100-seed weight increased by 141, 37, and 18%, respectively, compared to the control treatment. Based on these findings, the research recommends applying NPK (17:17:17) at 300 kg ha-1 and CAN at 200 kg ha-1 for optimal groundnut production in Rwanda. Key words: Calcium ammonium nitrate, lime, groundnuts.