Due to the incessant application of synthetic herbicides in the agricultural system coupled with a rapid increase in herbicide-resistant weed species across the globe, much attention has been focused on alternative weed management, including allelopathy, which is eco-friendly and reduces reliance on synthetic herbicides. The effect of Sida cordifolia root and leaf ethyl acetate extract was evaluated under field conditions to determine its effects on growth, physiological response, stomatal index and density, and biochemical activity on weed species (Panicum maximum, Panicum repens, and Andropogon gayanus), as well as its effects on soil micronutrients. S. cordifolia root and leaf were collected from the wild in Nigeria and prepared into powder, which was dissolved to obtain the following concentrations 10, 20, 40, 60, and 80%, and distilled water served as the control. The percentage inhibition seems to be correlated with different growth indices as proven by an increase in malondialdehyde (MDA) content, reactive oxygen species (ROS), glutathione transferase (GST), and peroxidase (POD). Physiological growth indices such as plant height, leaf area, number of leaves, dry weight, stomatal density, and stomatal index were inhibited in both weed species while biochemical parameters such as Chlorophyll a, b, total chlorophyll and chlorophyll stability index were slightly reduced, increase in MDA, GST, ROS and POD were also noticed. In general, Andropogon gayanus showed a high inhibition rate compared to tomato. It is therefore recommended that concentrations of the Sida cordifolia extracts be increased to have a robust effect on the physiological processes of the weed species.

This study investigates the influence of Arbuscular Mycorrhizal Fungi (AMF) on the growth of Crotallaria retusa and Senna occidentalis under three phosphorus levels (low, medium, and high). Conducted in the experimental garden of Ahmadu Bello University Zaria, the soil samples were collected from a degraded site at the Institute of Agricultural Research, sieved, and sterilized. Perforated buckets were filled with sterilized soil, and the trench method was employed for AMF application. Three phosphorus levels were tested, and seeds of C. retusa and S. occidentalis were planted in individual buckets. Daily watering and observations were carried out for twelve weeks, measuring seedling height, leaf length, width, and number of leaves. The results indicate that high phosphorus concentration (12g/bucket) constrains the growth of C. retusa, while medium concentration (6g/bucket) enhances shoot length, branches, and leaves. AMF inoculation significantly improves growth attributes, but reduced growth in C. retusa under high phosphorus suggests potential incompatibility between phosphorus and AMF. At week 6, medium phosphorus (6g/bucket) resulted in more leaves (122.17±37.61) than low and high levels. Lowest growth occurred at low phosphorus (0g/bucket). Arbuscular mycorrhizal fungi improved overall growth, but high phosphorus hindered C. retusa growth due to potential incompatibility with AMF. Overall, the study highlights the complex interplay between AMF, phosphorus levels, and plant growth, offering insights into optimizing conditions for the cultivation of C. retusa and S. occidentalis.

The response of phytoplankton population dynamics to changes in densities of Nymphaea lotus L. and Polygonum limbatum Meisn. was studied in an artificial pond in Zaria, Nigeria, from June to November 2007. Antagonistic effects of these macrophytes on Netrium sp., Staurastrum sp., Ulothrix sp., Marssionella sp. and Closterium sp. were collinear and clearly separated from other environmental effects. Dermatophyton sp., Cyanoderma sp. and Pernia sp. were sensitive to high densities of both macrophytes, and were closely positively associated with DO and pH. Qualitative analysis confirmed the presence of glycosides, anthraquinone, saponins, steroids, triterpenes, flavonoids and alkaloids in N. lotus and P. limbatum. Fourier transform infra-red analysis peaks were recorded, confirming the presence of these allelochemical groups in both species. The observed variations in phytoplankton community structure and dynamics were closely linked to the presence of these macrophytes as well as to environmental conditions in the pond.

The germination and growth of seedlings of Adansonia digitata were investigated at the Biological garden of ABU Zaria, Nigeria (07o38′ and 11o11′N) at different planting depths and soil types. The seeds were planted at different planting depths of 1.0 cm, 2.0 cm, 4.0 cm and 6.0 cm in nursery bags and kept in a screen house and watered regularly. Results shows that as the planting depth increased, there was an increase in percentage germination, seedling height, number of leaves produced and leaf area index. The case was reverse in terms of percentage survival as increased planting depth resulted in a decrease survival. Number of days before emergence increased with increased planting depth. The highest percentage germination was recorded in sandy soil (75 %), followed by humus soil (32.7 %) while clay soil had no germination. The highest number of days before emergence was recorded in humus soil. Sandy soil had seedlings that produced leaves with Leaf Area Index (LAI) of 18.04 cm2, Humus 9.24 cm2 and loamy soil 7.26 cm2. All seedlings from all soil types produced between 8-15 leaves. Germinated seedlings from clay soil did not survive 60 days post planting. Significant correlation values were observed between planting depth and seedling height, number of days before emergence, number of leaves produced and seedling survival. Both the depth of planting and soil type affected seed germination and seedling performance of Adansonia digitata. Keywords: Planting depth, soil type, seed, germination, seedling, Adansonia digitata

Mode of germination and seedling characteristics of four Savanna palm trees; Borassus aethiopum, Hyphaene thebaica, Phoenix reclinata and Raphia sudanica were studied. In the course of their germination, the radicle was found to be cotyledonary in nature, and it carried the undeveloped plumule below ground before its further development. This is called cryptogeal germination which occurred in two stages: (i) preparatory germination and (ii) germination proper. Bigger seedlings were produced by larger seeds. Pinnate and palmate leaf arrangements with parallel venation were also found among these palms. Keywords: Palm trees, germination, seedling, characteristics, Savanna, Nigeria

Experiments were carried out to determine the effect of seed mass and cotyledon removal on the germination and growth of African fluted pumpkin (Telfaria occidentalis, Hook. F.). The seeds of pumpkin were divided into 3 weight classes A (13.10-13.05 g), B (11.10-11.05 g), C (8.60-8.55 g) and planted in a 1:1 mixture of soil and sawdust, and the following parameters observed: germination rate, seedling height, number of leaves produced, leaf area index, fresh and dry weight of seedlings. Except for leaf area index, it was found that the seeds with the highest weight showed superiority over the seeds of the other weight classes based on the results of Analysis of variance (ANOVA) at P> 0.05. The removal of one and two cotyledons had adverse effect on the seedling growth. The plants with their two cotyledons removed both before and after first foliage leaves emergence showed the least seedling growth. The seed mass was strongly positively correlated with the observed parameters. These results show that seedlings originating from large seeds can better endure loss of cotyledons and aerial biomass and are thus better adapted to withstand cotyledon damage due to soil fauna and other deteriorating factors in the early stage of life. Key words: Seed mass, Cotyledon removal, Telfaria occidentalis, Fluted Pumpkin, Germination, Growth

AbstractPlant height, number of leaves, diameter and fresh weight of the bulbs, and the dry weights of the component plant parts of 3 onion cvs were measured weekly, starting 40 days after transplanting, up to maturity. Red Kano had singificantly more leaves, greater leaf area, larger bulbs and fresh and dry weights than Eclipsel Bermuda and Texas Grano.Net Assimilation Rate (NAR), Relative Growth Rate (RGR), and Relative Leaf Growth Rate (RLGR) were generally high in the early stages of growth in all cvs and declined with plant age. Red Kano had much higher values than the other two. Crop Growth Rate (CGR) of tops was positive in the early stages of plant growth in all the cvs but decreased to negative values towards maturity which was due to a decrease in the dry weight of the leaf blades caused by decrease in leaf number. Red Kano and Texas Grano showed positive values throughout the experimental period. The higher CGR for the bulbs as compared to the blades was due to large quantities of carbohydrates which were translocated to the bulbs. Leaf Area Ratio (LAR) was constant in Red Kano, due to proportionate increase in leaf blade area and weight.Results of all the growth characteristics showed that Red Kano was superior to the other cvs in attaining a larger bulb size due to large number of leaves and longer growing season, resulting in the translocation of more carbohydrates to the bulbs.