Field observations in Nigeria indicate the inhibitory ...
and rolling due to mechanical impedance by gravels. Plant height was 19, 21, 17, 15 and 13 cm for gravel percentage of 0, 10, 25, 50 and 75 respectively. Plant height was not related to inter-gravel bulk density. Also the fresh and dry shoot weights were significantly affected by gravel concentration (Table 1) and inter-gravel density.