A Tillage Study In kenya Coffee. The Long Term Effects of Tillage Practices Upon Yield and Growth of Coffee

Abstract

A fifteen-year tillage experiment in Arabic. coffee grown on a red volcanic latosol has shown that weed growth during wet seasons consistently lowers the mean annual yield by between one-quarter and one-third; it also reduces the proportion of large beans. These losses can be mitigated by mowing the weeds or adding cattle manure. No relationship has been detected between the trial results and rainfall, but the yield response to weeding was strongly, although irregularly, affected by the stage of recovery from the cyclic removal of the bearing stems of the coffee. Initially, higher yields were obtained from clean weeding with forked hand-hoes than from the use of tractor-mounted ploughs or disks, but during the final five years these differences disappeared. A tractormounted rotary hoe was developed during these studies which is superior to the forked hand-hoe, provided its use is associated with routine grass mulching.