Effects of NPK Fertilizer Rates and Plant Population on Foliar Diseases, Insect Damage and Yield of Groundnut

摘要

Groundnut ( Arachis hypogeae L.) is a well know oil-seed crop grown as food for man and feed for animals. It is mostly grown in the savannah region with little cultivation in the forest south. A two season experiments was conducted in 2003 and 2004 respectively, to determine the effects of NPK fertilizer rates and plant population on foliar diseases, insect damage and yield of groundnut. Analysis of variance indicated that NPK fertilizer rates significantly influence foliar disease development with leafspot disease ( Cercospora arachidicola Hori) (4.618, 4.326) being highest, followed by rust (3.214, 3.013), with seedling blight (2.90; 3.015) being lowest in 2003 and 2004, respectively. 0 kg ha ^-1 (control) recorded highest in all these foliar diseases investigated, when 130 kg ha ^-1 recorded lowest development of these foliar diseases. Plant population was significant in these foliar diseases. 1,000,000 plants per hectare, recorded highest foliar diseases development when 250, 000 plants ha ^-1 had the lowest in all the seasons investigated. Interaction of NPK and plant population was significant on leafspot disease (3.86, 2.70), rust (2.55, 2.00) and seedling blight (1.76, 1.85) in 2003 and 2004 respectively. 0kg ha ^-1 recorded lowest seed yield , but highest insect damage while 130 kg ha ^-1 had highest seed yield (tons ha ^-1 ) (3.56, 3.23) but lowest insect damage (3.28, 2.96) in 2003 and 2004 respectively. Also foliar diseases development increased with plant age.