Soil weed seedbank dynamic and allelopathic potential of Tithonia diversifolia (Hemsl)

The phenomenon of allelopathy is receiving increased attention as a possible alternative weed control method that is environment-friendly when compared with the use of herbicides with a wide range of toxic side effects which pose potential hazards to the environment. This study was designed to estimate the distribution of weed seeds in Tithonia diversifolia dominated fields and to evaluate the effect of leaf, stem and root extracts of T. diversifolia on the emergence of weed seeds in a southern Guinea savanna agro-ecology of Nigeria. To achieve the stated objectives, soil samples were taken from T. diversifolia dominated field and enumerated using direct seedling germination method. The phytosociological survey and growth parameters of T. diversifolia were assessed with the aid of permanently fixed quadrats measuring 0.5 m x 0.5 m placed at 1 m interval between quadrats during the rainy seasons (May– November, 2014 and 2015). The aqueous extracts of the leaf, stem, root and whole plant of T. diversifolia were prepared and applied to soil samples taken from different arable fields. The results of the study shows that 23 weed species belonging to 19 genera and 12 families were enumerated in the seedbank and 65 % of emerged weed seedlings were found between 0-10 cm soil depth. Digitaria gayana contributed (21.90 - 24.45 %), Brachiaria lata (17.07 – 19.24 %) while T. diversifolia (8.53 – 11.58 %). The similarity between the composition of the seedbank and that of the established vegetation was 24.42. The aqueous extract of the whole plant of T. diversifolia was found to have suppressed the emergence of 80.29 % weed seedlings, stems extract 79.57 %, leaves extract 74.35 % while the root extract suppresses 55.95 %. This study indicates that T. diversifolia has the potential to interrupt emergence of most weed species. It can further be used as a tool to formulate new eco-friendly bio-herbicides to control weeds in agro-ecosystems.Keywords: Allelopathy, Aqueous extracts, Seedbank, Tithonia diversifolia, Weed emergenc

Impact of Tillage Operation on the Fruit Yield of six Exotic Tomato Varieties on an Alfisol in the Southern Guinea Savanna of Nigeria

Three separate field experiments were conducted at the Teaching and Research Farm, University of Ilorin, Nigeria on an alfisol with low inherent fertility status to study the effect of two conventional tillage methods on yield of tomato (Lycopersicon esculentum) during 2006 normal and 2007 irrigation growing seasons. The conventional tillage treatments (Ridge: tractor ploughed, harrowed and ridged and Flat: tractor ploughed and harrowed) were used to assess the response of the varieties to four N-Fertilizer regimes (0, 30, 60 and 90 Kg N/ha), two different growing seasons (rainfed versus irrigation) and two moisture regimes (normal watering versus post-anthesis moisture deficit) respectively. Tomato yields were significantly influenced by tillage methods with planting on the flat producing a significantly higher fruit yield than planting on the ridge except under moisture deficient condition. Roma (check variety) significantly yielded higher than other varieties under both N-Fertilizer regimes and growing seasons while Periondonta was superior for fruit yield under moisture regime. Keywords: Tillage system, fruit yield, N-Fertilizer rate, Moisture regime

Impact of Plant Population and Weed Control Methods on the Growth, Yield and Economic Potential of Sugarcane (Saccharum officinarum L.) Cultivation

<div><p>ABSTRACT: Sugarcane industries are faced with the challenges of reduced cane yield due to inability to ascertain an appropriate sugarcane planting density. Field trials were conducted at Bacita, southern Guinea savanna of Nigeria to examine appropriate planting density and weed control method that can minimize weed infestation in sugarcane field and give an optimum cane yield to improve the economic status of the sugarcane farming community. The experiment was established as a randomized complete block design in a split-plot arrangement with three replications. The main plot constituted four planting populations (43,200, 64,800, 86,400 and 108,800) plants ha-1 while the sub-plot consisted of six weed control practices (weedy check, pre-emergence application of terbuthylazine at 2.0 kg a.i. ha-1 + three supplementary hoe weeding (SHW), post emergence application of ametryn at 3.0 kg a.i. ha-1 + two SHW., post emergence application of dicamba at 0.5 kg a.i. ha-1 + two SHW., pre emergence application of terbuthylazine at 2.0 kg a.i. ha-1 + post emergence application of 2.4-D at 3.0 kg a.e. ha-1 and monthly hoe weeding). The study revealed that fifteen weed species were encountered as the most prevalent weed species in sugarcane ecology. Plant population of 108,800 plants ha-1 had the lowest weed seedlings population with highest cane yield (216.03 tons ha-1), production efficiency of 9.20% and benefit cost ratio of US$9.86 on every US$ 1 spent. This study concludes that, the adoption of 86,400-108,800 plants ha-1 of sugarcane and pre emergence application of terbuthylazine at 2.0 kg a.i. ha-1 + three SHW (for small scale growers) or pre emergence application of Terbuthylazine at 2.0 kg a.i. ha-1 + post emergence application of 2.4-D at 3.0 kg a.e. ha-1 for the commercial estates will minimize weed infestation and make sugarcane cultivation a profitable venture.</p></div

Effects of crude extracts of Aspergillus fumigatus and Penicillium citrinum on the biomass of Eleusine indica (L.) Gaertn

In a pot experiment, two fungal strains namely Aspergillus fumigatus and Penicillium citrinum were evaluated for their herbicidal properties on the biomass of Eleusine indica using the biomass reduction method. Crude extracts of Aspergillus fumigatus and Penicillium citrinum made up of 10 treatments at three levels each with positive and negative controls in three replications in a Completely Randomised Block Design was adopted. Infections were evident within 48 hours after the application of the various treatments. At 1, 3, 5 and 7 days after application of the treatments, the percentage biomass yields and biomass reductions of E. indica were determined. The data collected were subjected to analysis of variance and the means separated using Duncan Multiple Range Test. The percentage reductions in biomass yields (88.46% and 35.61%) of Eleusine indica especially at the highest inocula concentration (1010 spores/ml) of the crude extracts showed significant differences (p≤ 0.001). The results indicate that both crude extracts possess the potentials for herbicidal control of Eleusine indica with evidence that the concentrated crude extracts of Aspergilus fumigatus had the greatest impact on its biomass yields. Therefore, it is recommended that further work be carried out on the purification of both crude extracts to confirm the effective biological metabolites accountable for their herbicidal properties and also evaluate these herbicidal properties on other weed species adopting different time and methods of application.Keywords: Fungal strains, Herbicidal properties, Biological metabolites, Concentrated crude extracts, Biomass yields and Biomass reduction

Effect of maize sweet potato intercrop over sole cropping system on weed infestation

A field experiment was conducted at the Teaching and Research Farm of Landmark University, Omu-Aran, Kwara State, during the 2018 cropping season. located at latitude 80 9’ 0 N and longitude 50 6’ 0 E of the southern Guinea savannah zone of Nigeria. The experiment was laid as a randomized complete block design with a split-plot arrangement and 3 replications. The main plots were 2 trial sites (Site A and B), sub-plots consisted of intercropping pattern : T1: 2 seeds of maize + 1 vine of sweet potato, T2: 2 seeds of maize / 2 vines of Sweet potato, T3: 2 seeds of maize + 3 vines of sweet potato; T4: sole maize and T5: Sole Sweet Potato. Data collected on weed were estimated using a quadrat (25cm x 25cm) placed randomly at 5 positions within each sub plot at 3, 6, 9 and 12 WAP. All data collected were analyzed with analysis of variance (ANOVA) at P<0.05. Results showed that there was better grain yield of 1.89 t/ha intercrop of maize – sweet potato at ratio 2 : 2 of seeds / hill to vines / stand with better weed suppression and optimum tuber yield of 1.72 t/ha. Actual yield loss in the study was very high in the cropping system 2 seed of maize + 3 vine of sweet potato with -0.85 and in maize weed suppression percentage (%), 2 seed of maize +1 vine of sweet potato highly suppressed weed with 98.2% at 6 weeks after planting (WAP) and it showed 48% weed suppression in 2 seed of maize + 3 vine of sweet potato at 9 weeks after planting (WAP). Sweet potato weed suppression showed highest weed suppression of 37.2% at 3 weeks after planting (WAP) in 2 seed of maize + 2 vines of sweet potato. The highest competitive ratio occur in the cropping system 2 seed of maize + 1vine of sweet potato with 4.06 value. Maize showed the highest lnd equivalent value of 0.79 better than sweet potato and both maize and sweet potato combined had the highest land coverage in 2 seed of maize and 2 vines of sweet potato with 1.19 value. It is concluded from the study that the cropping system of 2 seed of maize + 1 vine of sweet potato gave the high response to weed suppression

Evaluation of maize-soybean intercropping systems and fertilizer rates on maize grain yield using competitive indices

Field trials were conducted in savanna ecologies of Nigeria during the 2015 and 2016 seasons using maize (PVA8) and soybean (TGX 1448-2E) intercropping systems with different fertilizer rates to evaluate the yield of maize and assess the best intercropping system for resource management. Single plant stands and two plants/stand and 2 arrangements of rows (one row on a ridge and two rows on a ridge) were used to impose maize plant densities evaluated in strip inter-crop with soybean. The trial was factorial, laid out in a randomized complete block design and replicated three times. Thus, 8 maize-soybean strip cropping systems and application of 3 NPK rates were evaluated at Saki-Oyo, Ilorin, and Nasarawa (southern Guinea savanna), Kaduna in the northern Guinea savanna, Funtua (Katsina) and Gusau (Zamfara) located within Sudan savanna ecologies of Nigeria. Data on yields and yield components were collected. The intercropping systems were assessed using existing intercropping indices such as Land Equivalent Ratio (LER), Relative Crowding Coefficient (K), Aggressivity (A), Competitive Ratio (CR), Actual Yield Loss (AYL), Intercropping Advantage (IA) and Monetary Advantage Index (MAI). The result showed that Nasarawa and Kaduna were most ideal locations for maize production in the Nigeria savannas. The highest grain yield of 4.04 tons/ha maize and 1.36 tons/ha soybean were obtained from seeding 1 plant/stand in 2-rows per ridge x 4 ridges of maize alternated with 2 rows of soybean with the application of NPK at 100:50:50. The LER was 1.11, AYL (1.10) and MAI (208) gave a profit of ₦312,102.00 (US$990.80) ha-1 with a benefit-cost ratio of 2.38 and production efficiency of 29.56%. The study concluded that, seeding 80% maize and 20% soybean per ha will lead to sustainable maize crop production with limited use of fertilizer. It can be adopted by the farmers in Nigeria savannas as a relatively profitable intercropping system. Keywords: Maize production, Ideal location, Fertilizer rate, Competitive indices, Savanna ecologies, Nigeri