Response of castor (<i>Ricinus communis</i> L.) to organic fertilizer application and sowing date in the humid tropics

Abstract

There is limited information on the appropriate agronomic practices for castor in the humid tropics. This study evaluated the effects of organic fertilizer (OF) and sowing date (SD) on the agronomic performance of castor during late cropping season (June − Dec.) of 2021 and 2022 at the Institute of Food Security, Environmental Resources and Agricultural Research, Abeokuta, Nigeria. Two factors: OF − control and organic fertilizer (main plot) and SD − eight sowing dates (SD1-SD8 i.e. , from June 18 to August 5) at 7-day intervals (sub plot) were laid in a split-plot arrangement fitted into Randomized Complete Block Design in three replicates. Data were collected on agronomic traits of castor. Organic fertilizer significantly ( P &lt; 0.05) expedited days to flowering and increased height to primary raceme in 2021. SD had significant ( P &lt; 0.05) effect on days of flowering, seed yield, and yield attributes of castor. Castor sown at SD1 and SD2 in 2022 produced high seed yield of 773.7 and 799.1 kg/ha higher by 498.8% and 503.0% than SD8 yield of 129.2 kg/ha. It is concluded that for optimum castor seed production, sowing should be done from June 18 to latest July 2 with or without organic fertilizer in the humid tropics.