Weed Flora of a Maize/Cassava Intercrop under Integrated Weed Management in an Ecological Zone of Southern Guinea Savanna of Nigeria

Weed flora of different management techniques under different cropping systems have been reported but no sufficient information on weed flora of integrated weed control method in maize/cassava intercrop in southern Guinea savanna of Nigeria. This study assessed the weed flora and relative frequencies of weeds in a maize/cassava intercrop under integrated weed management involving two pre-emergence herbicides (Primextra and Galex, each at 2.5 kg/ha alone or with one or two supplementary hoe-weeding, at 6 weeks after planting (WAP) or 6 and 12 WAP, a hoe-weeded check (hoeing at 3, 6 and 12 WAP) and a weedy control. A total of 41 weed species belonging to 35 genera and 19 families comprising of Poaceae, Euphorbiaceae, Asteraceae, Rubiaceae, Cyperaceae among others were encountered in the experimental plots during 2002 and 2004 cropping seasons. The very abundant weed species included Paspalum obiculare Forst, Digitaria horizontalis Willd and Brachiaria deflexa (Schumach) while those with moderate abundance were Bulbistylis arbotiva (Steudel), Cleome viscosa L., Croton lobatus L., Dactylocternium aegyptium (L) P. Beauv., Tridax procunbens L. and Vernonia galamensis (Cass.) Less. The remaining weed species had rare abundance. The relative frequency of the weed species was generally reduced under all the weed control treatments except Paspalum obiculare whose relative frequency was consistently high in all the assessment periods under all the weed control treatments

Djelovanje isteka roka pendimetalina (Stomp) na klijanje i razvoj mlade biljke manga (Mangifera indica)

Effect of expired herbicide on seed germination and seedling development of Mango (Mangifera indica) was investigated using Pendimethalin herbicides that have expired for 7, 5 and 1 years respectively. Two concentrations 100 and 150ml/l of each of the expired herbicides were used as the treatment concentrations for the investigation. Mango germination was delayed in all the herbicide treatments but not in the control treatment. Germination rate was consistently higher in the control treatment than in all the herbicide treatments except the herbicide that expired in 2011.There were no herbicide injuries nor growth retardation on Mango seedlings except slight stem distortion and reduced leaf size at the early emergence stage.Djelovanje isteklog roka herbicida na klijanje sjemena i razvoj biljke manga (Mangifera indica) istraživano je primjenom herbicida pendimetalin čiji je rok istekao 7, 5 i 1 godinu. Dvije koncentracije od 100 i 150 ml/l svakoga od spomenutih herbicida primijenjene su kao koncentracije tretmana u istraživanju. Klijanje manga zakasnilo je u svim tretmanima herbicida osim u kontrolnom tretmanu. Stopa klijanja bila je stalno viša u kontrolnom tretmanu nego u tretmanima s herbicidom osim u tretmanu s herbicidom kojemu je rok istekao 2011. Nije bilo oštećenja zbog herbicida niti zaostatka u rastu biljaka manga osim neznatnog nakrivljenja stabljika i smanjenja veličine listova na ranom stadiju klijanja

Effect of Different Concentrations of Imazaquin on Performance of Soybean (Glycine max).

An experiment was conducted in order to examine the effect of different concentrations of Imazaquin applied as both pre and post emergence treatments on soybean plants. Soybean variety TGX 17402X was used in this experiment. Results obtained revealed that efficacy of Imazaquin varies according to concentration and time of application. Adequate weed control was achieved in all the concentrations of Imazaquin with the best in concentration 0.375 kg a i./ha applied as pre emergence and all the concentrations applied as post emergence at 4 WAP (Weeks after planting) ,0.250 and 0.375 kg a i./ha at 12 WAP. Stem height was best at higher concentration of 0.375 kg, a i./ha (45.00cm) at 8WAP while at 12 WAP, pre emergence concentration 0.250 kg. a i./ha and post emergence 0.375kg.ai./ha also produced best stem heights of 67.00 and 68.00cm respectively. Leaf number was highest in the control experiment with 50 leaves at 8 WAP followed by post emergence concentration of 0.375 and 0.250 kg.a i./ha with 46.00 and 45.00 which were not statistically significant. However, the control, pre emergence treatments of concentrations 0.125 and 0.375 kg. a i./ha, and the post emergence concentration of 0.375 kg. a i./ha were significantly higher than the rest at 9 WAP (61,60,58 and 57 respectively). At 12WAP, concentrations of 0.125 and 0.250kg. a i./ha at post and pre emergence application produced significantly higher number of leaves than the remaining treatments. Weed emergence was significantly higher in the control experiment at 4, 8, 9 and 12WAP

Nitrogen and weed management in transplanted tomato in the Nigerian forest-savanna transition zone

Weed infestation and inherent low soil fertility are among primary reasons for low yields of tomato in Nigeria. Field trials were carried out during the wet season of 2015 and 2016 to evaluate yield response of tomato to nitrogen (N) application and weed control methods in the forest-savanna transition zone of Abeokuta, Nigeria. Positive relationship exists between growth of weed species and increase in N application. Across the years of study, increase in N up to 90 kg/ha increased weed density by 11–25%, however, the increased N gave the transplanted tomato competitive advantage and thus enhanced weed smothering. Pre-transplant application of butachlor (50% w/v) or probaben® (metolachlor 20% w/v+prometryn 20% w/v) each at 2.0 kg a.i/ha followed by supplementary hoe weeding at 6 weeks after transplanting (WAT) significantly reduced weed density by at least 15% and increased fruit yield of tomato by at least 32%, compared to use of the pre-transplant herbicides alone, across both years of study. The greatest tomato fruit yield of 12.2 t/ha was obtained with pre-transplant application of butachlor at 2.0 kg a.i/ha followed by supplementary hoe weeding at 6 WAT, averaged for both years. In general, this study suggests that increased application of N up to 90 kg/ha, and complementary weed control by pre-transplant herbicide and hoe weeding at 6 WAT would improve yield of tomato in the forestsavanna transition zone of Nigeria

Effects of Petroleum Products on the Chlorophyll Accumulation in Barbula lambarenensis

The effects of petroleum products: Petroleum Motor Spirit (petrol, PMS), Automobile Gas Oil (diesel. AGO), Dual Purpose Kero (kerosene, DPK), were investigated on the chlorophyll accumulation in Barbula lambarenensis. This plant with its substrates were collected from its natural populations, taken to the screen house and divided into ten regimes widely separated. Each of these regimes was irrigated with borehole water for two weeks, thrice a week to bring about hydration. The three petroleum products were separately diluted with borehole water in 1:1 ratio to give 50% concentrations. Moreover, 100% of these products were also used .The 50% concentrations were separately used to irrigate the first three regimes, A, B and C for 20 weeks .The D, E and F regimes were irrigated with 100% kerosene, petrol and diesel respectively for the 2 weeks and later with borehole water for twenty weeks while the G regime was irrigated with borehole water (Control). Irrigations were done thrice a week. Samples of B. lambarenensis were collected fortnightly for chlorophyll extraction and the chlorophyll a, b and total chlorophyll content determined with the aid of spectrophotometer .It was observed that the 50% treated moss plants had greater chlorophyll a, b and total chlorophyll than the control but their concentrations were statistically the same. The 100% treatment gave greater chlorophyll a content than the control, PMS treatment had greater chlorophyll b than the control but the reverse were for DPK and AGO treated moss plant. However, all these values were the same statistically. The same results were found for the total chlorophyll except that the DPK, AGO and Control treatments had the same value statistically while DPK, Control and PMS treatments were the same statistically. The 50% treatments had worse effects than the 100% followed by borehole water treatments. Furthermore, the two concentrations had the same effects on the chlorophyll contents but DPK and AGO had significantly greater chlorophyll b concentrations in 50% treated regimes than 100% treatments at 5% level of significance. Petroleum products damaged the chlorophyll apparatus of the plant making the treated to produce greater chlorophyll contents than the Control

INFLUENCE OF INTER-ROW SPACING AND WEED CONTROL METHODS IN GROUNDNUT (Arachis hypogeal (L.)

Weed competition has been identified as one of the major obstacles in crop production. The produc-tion of groundnut is limited by high weed infestation resulting in yield losses ranging from 50 - 80% in Nigeria. Hence, the need to evaluate integrated weed control in its production. Field trials were there-fore conducted at the Teaching and Research Farm of the Federal University of Agriculture, Abeokuta (7o 20’ N, 30 23’ E) to evaluate the influence of inter-row spacing and weed control methods on growth and yield of groundnut during the wet seasons in 2009 and 2010. The experiment was a Randomised Complete Design (RCBD) laid out in a split plot with three replications. The main plot treatment con-sisted of three inter-row spacings of 60 cm, 75 cm and 90 cm while the subplots included five weed control treatments of commercial formulation of metolachlor plus promethyne mixture (codal) at 1.0 kg a.i/ha, codal at 1.0 kg a.i./ha followed by supplementary hoe weeding at 6 weeks after sowing (WAS), codal at 2 kg a.i./ha, hoe weeding at 3, 6 and 9 WAS and a weedy check. Inter-row spacings of 60 cm and 75 cm reduced weed growth with consequent higher yields compared to the inter-row spacings of 90 cm in the early season of 2009. Application of codal at 1.0 kg a.i./ha followed by supplementary hoe weeding at 6 WAS combined with 60cm inter-row spacing gave effective weed control and higher groundnut pod yield than hoe-weeded control in both years of experimentation

Increasing cassava root yield on farmers’ fields in Nigeria through appropriate weed management

Open Access Article; Published online: 08 Sep 2021Weed competition is the major biological stress affecting cassava production in smallholder farms in West and Central Africa, where yields are low compared with those in Asia and Latin America. Options for improved weed management are crucial in increasing productivity. Selected pre- and post-emergence herbicides, integrated with appropriate tillage and plant spacing, were tested in 96 sites in four locations in Nigeria, 24 in 2016 and 72 in 2017. Trials were split plots with six pre-emergence herbicides and no post-emergence treatment as main plots. Subplot treatments were four post-emergence herbicides, weeding with a motorized rotary weeder, short- and long-handled hoes, and no post-emergence weed control, i.e., regardless of pre-emergence treatments. Indaziflam-based treatments, irrespective of post-emergence treatment, and flumioxazin + pyroxasulfone applied pre-emergence followed by one weeding with a long-handled hoe provided >80% control of major broadleaf and grass weeds. Compared with herbicide use, farmer control practices (53%) were not efficient in controlling weeds. The highest root yield was produced where (1) s-metolachlor was combined with atrazine, and one weeding with a long-handled hoe or clethodim with lactofen, and (2) indaziflam + isoxaflutole was combined with glyphosate. An increase in root yield from 3.41 to 14.2 t ha-1 and from 3.0 to 11.99 t ha-1 was obtained where herbicides were used compared with farmers’ practice and manual hoe weeding. Our results showed that integrating good agronomic practices with safe and effective use of appropriate herbicides can result in root yield >20 t ha−1. i.e., twice the national average root yield of 8–12 t ha−1, with >50% net profit. The use of appropriate herbicides can reduce the amount of manual labor required and improve livelihoods, specifically for women and children. Smallholder cassava farmers would require continuous training on the safe use and handling of herbicides to improve efficiency and prevent adverse effects on humans and the environment

Djelovanje isteka roka pendimetalina (Stomp) na klijanje i razvoj mlade biljke manga (Mangifera indica)

Effect of expired herbicide on seed germination and seedling development of Mango (Mangifera indica) was investigated using Pendimethalin herbicides that have expired for 7, 5 and 1 years respectively. Two concentrations 100 and 150ml/l of each of the expired herbicides were used as the treatment concentrations for the investigation. Mango germination was delayed in all the herbicide treatments but not in the control treatment. Germination rate was consistently higher in the control treatment than in all the herbicide treatments except the herbicide that expired in 2011.There were no herbicide injuries nor growth retardation on Mango seedlings except slight stem distortion and reduced leaf size at the early emergence stage.Djelovanje isteklog roka herbicida na klijanje sjemena i razvoj biljke manga (Mangifera indica) istraživano je primjenom herbicida pendimetalin čiji je rok istekao 7, 5 i 1 godinu. Dvije koncentracije od 100 i 150 ml/l svakoga od spomenutih herbicida primijenjene su kao koncentracije tretmana u istraživanju. Klijanje manga zakasnilo je u svim tretmanima herbicida osim u kontrolnom tretmanu. Stopa klijanja bila je stalno viša u kontrolnom tretmanu nego u tretmanima s herbicidom osim u tretmanu s herbicidom kojemu je rok istekao 2011. Nije bilo oštećenja zbog herbicida niti zaostatka u rastu biljaka manga osim neznatnog nakrivljenja stabljika i smanjenja veličine listova na ranom stadiju klijanja

Nitrogen and weed management in transplanted tomato in the Nigerian forest-savanna transition zone

Weed infestation and inherent low soil fertility are among primary reasons for low yields of tomato in Nigeria. Field trials were carried out during the wet season of 2015 and 2016 to evaluate yield response of tomato to nitrogen (N) application and weed control methods in the forest-savanna transition zone of Abeokuta, Nigeria. Positive relationship exists between growth of weed species and increase in N application. Across the years of study, increase in N up to 90 kg/ha increased weed density by 11–25%, however, the increased N gave the transplanted tomato competitive advantage and thus enhanced weed smothering. Pre-transplant application of butachlor (50% w/v) or probaben® (metolachlor 20% w/v+prometryn 20% w/v) each at 2.0 kg a.i/ha followed by supplementary hoe weeding at 6 weeks after transplanting (WAT) significantly reduced weed density by at least 15% and increased fruit yield of tomato by at least 32%, compared to use of the pre-transplant herbicides alone, across both years of study. The greatest tomato fruit yield of 12.2 t/ha was obtained with pre-transplant application of butachlor at 2.0 kg a.i/ha followed by supplementary hoe weeding at 6 WAT, averaged for both years. In general, this study suggests that increased application of N up to 90 kg/ha, and complementary weed control by pre-transplant herbicide and hoe weeding at 6 WAT would improve yield of tomato in the forestsavanna transition zone of Nigeria