WEED SPECIES COMPOSITION AND DIVERSITY OF PADDY FIELD IN USUR, YOBE STATE, NIGERIA

The present study investigates the weed species composition and diversity of paddy field in Usur, Yobe State, Nigeria. Random vegetation surveys were used to conduct the study in June to October, 2020. A quadrat measuring 1m x 1m randomly placed in the weeds infested area within the study site. Plants observed were photographed, geo-referenced collected and prepared as herbarium specimens. Standard key, manuals and checklists were utilized for plant identification and organized using angiosperm plant phylogeny (APG) classification system. Component features in the study were; scientific and family names, common English names, Hausa names, life cycle, native/exotic species, life form and mode of propagation. A total of (72) species distributed within (16) families and (50) genera were inventoried, native (47) and exotic (25) species. The density populated species was (Cyperus rotundus). Highly frequently species was (Cyperus rotundus). Species with highest importance value index (IVI) was (Cyperus rotundus). Simpson’s index of diversity value was 0.371 and Shannon Weigner index value was 1.0. The differences in the diversity indices are an indication of alteration in water quality probably due to anthropogenic activities; pollution and weeds control method. The results obtained from the research will be significant for understanding the distribution, diversity and control of paddy weeds. It was evident from the study that ecosystem in the area is less balanced.