Abstract

Application of three levels of nitrogen as urea (0, 60 and 120 kg/ha), phosphorus as single super phosphate (SSP) (0, 72 and 144 kg/ha) and potassium as muriate of potash (MOP) (0, 24 and 48 kg/ha) fertilizers on inflorescence blight of cashew caused by Lasiodiplodia theobromae and yield of cashew were studied on acid sand soils of Ochaja, Nigeria in 2000 and 2001. Results showed that single application of SSP at 144 kg/ha significantly reduced infection and slightly increased yield during the second year. Combination of urea at 120 kg/ha with MOP at 48 kg/ha gave the highest yield of 3.53 kg/tree and lowest disease infection (90 inflorescence panicles infected) for the first year, while NPK fertilizer when applied as urea at 60 kg/ha, SSP at 144 Kg/ha and MOP at 24 kg/ha gave the highest yield for the second year and significantly reduced the disease infection (125 inflorescence panicles infected). Appropriate management of NPK fertilizers leading to a reduction in infection of inflorescence blight and increase in yield is an additional tool for minimizing the use of pesticides on cashew.

Key words: Anacardium occidentale, cashew, fertilizer, inflorescence blight, yield.