WEED DRY MATTER PRODUCTION AND RELATIVE IMPORTANCE VALUE OF WEEDS AS AFFECTED BY AGE OF PEPPER SEEDLINGS AND DIFFERENT WEED INTERFERENCE PERIODS IN PEPPER

The field trials were conducted at the Teaching and Research Farm Federal University of
Agriculture, Abeokuta, Ogun State, Nigeria in the early and late wet seasons of 2012. The
objective of the study was to evaluate the influence of weed interference period and age of pepper seedlings on weed dry matter production and relative importance value (RIV) of weed species in pepper. Two ages of pepper seedlings at transplant as the main plot and six weed interference periods as sub-plot treatments were accommodated in a split-plots arrangement of a randomized complete block design with three replications. Data were collected on weed dry matter production and those collected on weed species composition were used to compute RIV. Results showed that weed dry matter production and number of weed species reduced with weed-free period, while up to 80% reduction in weed dry matter production was observed on plot kept weed free for 12 weeks after planting (WAP) of pepper. There were also, 13 and 17 weed species present in the early and late wet seasons, respectively, while only Tridaxprocumbens had RIV greater than 5 % irrespective of age of pepper seedling and weed interference period in both seasons. Our findings reveal that either of the two ages of pepper seedlings at transplant can be adopted in its cultivation while pepper plot should be kept weed free for 12 WAP to reduce weed dry matter production.