Randomized Complete Block Design

Maize (Zea mays) is one of the most important cereal crop worldwide. It contains starch, proteins, fibers, oils, and sugars. It plays a significant role in human and livestock nutrition. Nitrogen (N) is essential for crop growth and yield. The most common sources of nitrogen are NPK and urea. However, consistent usage of these inorganic fertilizers can have adverse effects on the soil which includes soil acidification, reduced soil microorganisms, alteration of soil PH, which in turn can affect the soil fertility. This has made it essential to utilize organic fertilizers like plant residues, which can improve soil fertility without causing damage to the soil. Chromolaena odorata (L.) shows promise in boosting plant nutrient levels as mulch. Hence, this study is aimed to assess the agronomic performance of maize fertilized with C. odorata. The trial was conducted at the Faculty of Agriculture Teaching and Research Farm, University of Benin, Benin City, Nigeria. The experiment was laid out in a Randomized Complete Block Design (RCBD) replicated four times. The treatment involved the use of four rates of freshly cut C. odorata leaf residues (0, 1, 3, 5 kg m-2). The variables studied were plant height, cob yield, grain yield and stover yield. Maize plant height and cob, grain and stover yields increased with increase in the levels of C. odorata plant residues (0-5 kg m-2). Based on the present
study, C. odorata residues has potential for use as a mulch in improving maize yield and soil quality.

This research was conducted with sole aim of investigating the effect of crude oil on the group, morphology and plant based compound of Eichornia crassipes. Samples of the macrophyte were obtained from Ologbo pond in Edo State and transported to the Department of Plant Biology and Biotechnology, where they were used for the experiment conducted in the screen house. The experimental treatments consisted of 0 (control), 0.2, 0.4, 0.6 and 0.8 % v/v. Using a randomized complete block design (RCBD) and three replicates per treatments, the plants were exposed to the treatments for 8 days. E. crassipes samples grown in crude oil showed significant decrease (p<0.01) in all morphological parameters observed. When compared with the control. Wilting, chlorosis and necrosis were observed in some of the plants treated with 0.8 % v/v and 0.6 % v/v.
The plants showed remarkable increase in the accumulation of heavy metals with concentration being more in the roots than in the shoots. Observations obtained in this study revealed that crude oil impact macrophyte parameters at higher concentration levels. The study has shown that E. crassipes can be employed as a tool for biomonitoring of crude oil in fresh water habitats. The study further suggests the need for more intensive research to fully understand the impacts of crude oil pollution on aquatic plants.