Weed competition in maize (Zea mays L.) as a function of the timing of hand-hoeing weed control in the southern Guinea savanna zone of Nigeria

2012 ◽  
Vol 60 (3) ◽  
pp. 257-264 ◽  
Author(s):  
F. Takim

Field studies were conducted in 2010 and 2011 at the Teaching and Research Farm of the University of Ilorin, Nigeria (9°29′ N, 4°35′ E) to evaluate the effect of early weed competition on the growth and yield of maize. The experiment was designed as a randomized complete block (RCBD) with a split-plot arrangement and three replications. The main plots consisted of three weed control treatments included weedy (no herbicide), grass weeds (pre-emergence atrazine) and broadleaf weeds (pre-emergence metolachlor), while the sub-plots consisted of six durations of weed infestation (3, 4, 5, 6, 7 and 8 weeks after emergence). The pre-emergence herbicides had a greater effect on weed density and weed dry weight. Weed seedling emergence and weed dry weight increased significantly with an increase in the duration of weed interference. The grasses and broadleaf weeds had a similar influence on the growth and grain yield of maize. Three to five weeks of weed interference gave similar grain yields, which were significantly higher than those obtained in plots that had 6-8 weeks of weed interference. These results suggest that the maize crop must be kept free of weeds for 6-8 weeks after the application of pre-emergence herbicide to minimize weed-crop competition and harvest a good grain yield.

2021 ◽  
Vol 27 (1) ◽  
pp. 51-66
Author(s):  
Haseeb Ahmad

An experiment entitled: Maize yield as affected by methods of tillage and weed control methods was conducted at Agronomy Research Farms, The University of Agriculture Peshawar during summer 2016. The study was conducted in randomized complete block design (RCBD) with split plot arrangement having four replications. Tillage practices 1) Chisel plough + rotavator 2) Mouldboard plough + rotavator 3) Cultivator + rotavator and 4) Rotavator were assigned to main plots. Weed management practices included 1) Control, 2) Hoeing 15 days after sowing 3) Hoeing 15 and 30 days after sowing 4) Hoeing 15, 30 and 45 days after sowing, and 4) Herbicide (nicosulfuron) were kept into the subplots. The results revealed that chisel plough + rotavator has significantly reduced weeds m-2 (122, 101 and 125 weeds m-2), weeds fresh weight (19.73 g m-2, 116.35 g m-2 and 252.56 g m-2) and weeds dry weight (6.83 g m-2, 38.69 g m-2 and 80.61 g m-2) at 30, 45 and 60 days after sowing, respectively. The operation of chisel plough + rotavator has produced tallest plants (221.22 cm) with maximum grain rows ear-1 (16), grain yield (3586 kg ha-1) and shelling percentage (78.14%). Among weed control methods, hoeing 15, 30 and 45 days after sowing revealed maximum plant height (226.41 cm), grain rows ear-1 (16), grain yield (3604 kg ha-1) and shelling percentage (79.11%). All weed control methods have showed significant reduction in weeds m-2, weeds fresh weight and weeds dry weight. Interaction was also found significant for weeds m-2 at 60 DAS and grain yield of maize. Lowest weeds (56 weeds m-2) at 60 DAS and highest grain yield (4569 kg ha-1) was recorded when seedbed was prepared with chisel plough + rotavator with 3 hoeings (hoeing 15, 30 and 45 days after sowing). It is concluded that treatment of chisel plough + rotavator and hoeing 15, 30 and 45 days after sowing has significantly produced maximum grain yield of maize crop.


2000 ◽  
Vol 53 ◽  
pp. 269-272 ◽  
Author(s):  
T.K. James ◽  
A. Rahman ◽  
J. Mellsop

The effect of early weed competition was determined for a maize (Zea mays) crop grown in Waikato Maize was established in three different environments viz weedy (no herbicide) grass weeds (preemergence atrazine) and broadleaf weeds (preemergence metolachlor) Surviving weeds were controlled with postemergence nicosulfuron (60 g/ha) after different periods of competition and the plots kept weed free for the remainder of the trial Weeds left completely uncontrolled for 4 weeks after emergence significantly reduced crop yields When a preemergence herbicide was used surviving weeds began to reduce maize yields after about 6 weeks with grasses having greater effect than broadleaf weeds The actual period before the weeds started affecting crop growth and yield appeared to be related to the time taken by the weeds to achieve complete ground cover


2020 ◽  
Vol 27 (2) ◽  
pp. 491-498
Author(s):  
Salman Ali ◽  
Muhammad Arif ◽  
Mehran Ali ◽  
Muhammad Afzaal ◽  
Gohar Saeed ◽  
...  

Weeds pose a significant threat to successful crop production. To meet the increasing future food demand, sustainable and efficient weed control remains a cornerstone practice. Usage of high doses of herbicides for killing weeds has created several ecological and environmental problems which cannot be overlooked. Therefore, other weed control practices and techniques should be adopted to minimize weed-crop competition and increase the growth and productivity of crop, instead of chemicals. An experiment was established at Agronomy Research Farm, the University of Agriculture Peshawar to evaluate the effects of biochar and organic-inorganic P sources on density, fresh and dry weight of weeds in maize during 2016. Experiment was executed using randomized complete block design and treatments included biochar (0 and 10 tonnes ha-1) and three sources of P; FYM, PM and one DAP. Phosphorus at the rate of 100 kg ha-1 was applied in such a way that each plot received 50, 75 and 100% P from PM or FYM and the rest from DAP. Biochar and P sources significantly affected density, fresh and dry weight of weeds at 25 and 50 days after sowing of crop. 10 tonnes ha-1 biochar reduced weed density and fresh and dry weight of weeds at both intervals i.e. 25 and 50 days after sowing. Similarly, lower weed density, weed fresh and dry weight with addition of PM or FYM and DAP in 50:50 ratios. Sole FYM and PM resulted in higher weed density and weeds fresh and dry biomass. It is concluded that 10 tons ha-1 biochar and P application 50% from FYM or PM and 50% from DAP improved maize growth and reduced weed competition.


2013 ◽  
Vol 30 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Samaneh Vafaei ◽  
Jamshid Razmjoo ◽  
Hassan Karimmojeni

Abstract This study explores the effects of the pre-emergence herbicides alachlor (1680; 2400 g ha-1) and trifluralin (720; 1200 g ha-1), the post-emergence herbicides bentazone (360; 480 g ha-1) and haloxyfop (250; 375 g ha-1) and their combinations, along with the effect of seed hydro-priming on weed control, growth and yield of sesame (Sesamum indicum L.). Hydropriming reduced the interval from planting to seedling establishment, increased the seedling dry weight and the crop grain yield. Based on grain yield, 720 g ha-1 trifluralin followed by 250+720 g ha-1 holoxyfob + trifluralin, 250 +1680 g ha-1 holoxyfob + alachlor, 2400 g ha-1 alachlor, and 1680 g ha-1 alachlor, all combined with priming, were the best treatments. The results showed that proper combination of pre- and post-emergence herbicides along with seed priming could be used to control the weeds in the sesame and obtain seed yield comparable with weed-free conditions


2014 ◽  
Vol 3 (3) ◽  
pp. 126-138
Author(s):  
Tamiru Hirpa

Field studies conducted to determine the effects of intercrop row arrangements and staggered intercropping of haricot bean (Phaseolus vulgaris L.) on the performances of maize (Zea mays L.) crop at Hallaba and Taba areas in 2013 cropping season, southern Ethiopia, revealed that there were significant effects of cropping patterns and staggered interseeding of the legume component on growth and yield components of maize crop. Significant interaction of row arrangement × intercropping time of haricot bean was observed with respect to leaf area index (LAI) of the maize crop. Increasing trends of LAI of maize crop were observed as interseeding of haricot bean was delayed for 3 weeks after maize (WAM) that stabilized during the 6 WAM interseeding time. Maize stover production was significantly high at 1:2 row ratio and delaying of the undersowing haricot bean in the already established maize crop for 6 weeks, 10.94 tha-1 and 11.39 t ha-1, respectively. Maize grain yield showed a significant variation with respect to the staggered sowing of haricot bean, whereby the highest (3.99 t ha-1) being recorded when haricot bean intercropping was delayed for 21 days after maize planting. The data of this study revealed that the larger maize plant canopy providing larger photosynthetic area, attained when haricot bean interseeding was delayed, probably resulted in higher grain yield of maize. DOI: http://dx.doi.org/10.3126/ije.v3i3.11072 International Journal of Environment Vol.3(3) 2014: 126-138


Author(s):  
Mainpal Singh ◽  
Rakesh Kumar ◽  
Satish Kumar ◽  
Virender Kumar

Field studies were conducted during 2008-09 and 2009-10 at Hisar, India to assess the effect of weed competition on crop growth and yield of field pea. Weed density increased up to 60 days and then decreased at later stages of crop growth. Seed yield of field pea was decreased by 50% when weeds were allowed to compete for the entire season. The critical period for weed control was 21-63 days in year 1 and 20-70 days in year 2 to achieve 95% of weed-free yield. It is therefore concluded that, to minimize yield loss due to weed competition in field pea, weed control measures should be targeted to avoid weed competition between 20-70 days after sowing.


2017 ◽  
Vol 35 (0) ◽  
Author(s):  
J. IQBAL ◽  
H.A. RAUF ◽  
A.N. SHAH ◽  
B. SHAHZAD ◽  
M.A Bukhari

ABSTRACT Selection of tree species under agroforestry systems is crucial to sustain the productivity of a crop. In present study, allelopathic effects of the leaf litters of 5 trees named Rose wood (Dalbergia sissoo), Guava (Pisidium guajava), Eucalyptus (Eucalyptus camaldulensis), Sacred fig (Ficus religiosa) and Jaman (Syzygium cumini) species on wheat growth and yield was examined. Leaf litter of each tress species was mixed in soil with two doses @ 100 and 200 g of leaves of each species per pot. Higher shoot length, shoot dry weight, number of spikelets per spike and biological yield were recorded in 200 g sun dried Jaman (Syzygium cumini) leaves. Total number of tillers per plant and number of ears per plant were higher under the application of Eucalyptus camaldulensis leaves (200 g sun dried) as compared to other treatments. Spike length, grain yield per pot, number of grains per pot and harvest index were maximum in 200 g sun-dried Sacred fig (Ficu sreligiosa) leaves. Majority of the parameters were promoted at lower doses of leaves per pot, however, at higher doses they started inhibiting the growth and grain yield of wheat.


1978 ◽  
Vol 91 (1) ◽  
pp. 31-45 ◽  
Author(s):  
I. Pearman ◽  
S. M. Thomas ◽  
G. N. Thorne

SummaryEight amounts of nitrogen ranging from 0 to 210 kg N/ha were applied to two tall and one semi-dwarf variety of winter wheat in the spring of 1975 and 1976. The tall varieties were Cappelle-Desprez and Maris Huntsman; the semi-dwarf variety was Maris Fundin in 1975 and Hobbit in 1976. Interactions between varieties and nitrogen were few and small compared with the main effects. All varieties produced their maximum grain yields with 180 kg N/ha. The yield of the semi-dwarf varieties, but not the others, decreased slightly with more nitrogen.Cappelle-Desprez yielded less grain than the other varieties in both years. In 1975 the yields of Maris Fundin and Maris Huntsman were similar and in 1976 Hobbit yielded more than Maris Huntsman. The varieties had similar numbers of ears at maturity and similar patterns of tillering. The semi-dwarf varieties had most grains per spikelet, and hence grains per ear, and Cappelle-Desprez had least. The semi-dwarf varieties had the smallest grains. The semi-dwarf varieties had less straw than the other varieties and hence the largest ratios of grain to total above-ground dry weight. The decrease in dry weight of stem and leaves between anthesis and maturity was similar for all varieties. In 1975 the efficiency of the top two leaves plus top internode in producing grain was the same for all varieties, but in 1976 Hobbit was more efficient than the other two. There were some small differences between varieties in nutrient uptake that were not related to differences in growth. Maris Fundin tended to have a greater phosphorus and potassium content than the tall varieties. Hobbit contained slightly less nitrogen than the tall varieties at maturity, and had a smaller concentration of nitrogen in the grain.Applying 210 kg N/ha doubled grain yield in 1975. Applying nitrogen resulted in a largeincrease in number of ears and a small increase in number of grains per ear due to the development of more fertile spikelets per ear. Nitrogen decreased dry weight per grain, especially of the semi-dwarf varieties. With extra nitrogen, straw dry weight at maturity, shoot dry weight atanthesis and leaf area were all increased relatively more than grain yield, and stems lost moredry weight between anthesis and maturity than without nitrogen. The year 1976 was exceptionallydry and nitrogen had only small effects in that it affected neither straw dry weight nor numberof ears but slightly increased grain yield by increasing the number of spikelets and number of grains per spikelet. It also increased leaf area proportionately to grain yield. In 1975 nitrogen increased evaporation of water from the crop before anthesis but decreased it after anthesis, even though it continued to increase the extraction of water from below 90 cm.


2012 ◽  
Vol 4 (3) ◽  
pp. 70-75 ◽  
Author(s):  
Hossein GHAMARI ◽  
Goudarz AHMADVAND

Dry bean is one of the most important pulse crops in Iran. Field study was conducted in 2011 to evaluate effects of weed competition from a natural flora on growth and yield of dry bean (Phaseolus vulgaris L.). The treatments consisted of weed infestation and weed removal periods (10, 20, 30, 40 and 50 days) after crop emergence. Control plots kept weed-infested and weed-free throughout growing season. To assess the weed competition effect on crop characteristics, Richards, Gompertz and logistic equations were fitted to the data. The most abundant weed species were Chenopodium album and Amaranthus retroflexus. Increase in duration of weed interference decreased the stem height of dry bean. At the end of the growing season, dry bean was 20 cm taller in season-long weed-free treatment compared to the season-long weed-infested treatment. As the number of days of weed interference increased, a declining trend of LAI and number of pods was observed. The minimum number of pods was obtained in season-long weed-infested treatment (5.01 pods/plant). Weed interference during the whole growing season, caused a 60% reduction in yield. Considering 5% and 10% acceptable yield lost, the critical period of weed competition was determined from 20 to 68 and 23 to 55 days after planting (DAE), respectively.


2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Alexandra M. Knight ◽  
Wesley J. Everman ◽  
David L. Jordan ◽  
Ronnie W. Heiniger ◽  
T. Jot Smyth

Adequate fertility combined with effective weed management is important in maximizing corn (Zea mays L.) grain yield. Corn uptake of nitrogen (N) is dependent upon many factors including weed species and density and the rate and formulation of applied N fertilizer. Understanding interactions among corn, applied N, and weeds is important in developing management strategies. Field studies were conducted in North Carolina to compare corn and weed responses to urea ammonium nitrate (UAN), sulfur-coated urea (SCU), and composted poultry litter (CPL) when a mixture of Palmer amaranth (Amaranthus palmeri S. Wats.) and large crabgrass (Digitaria sanguinalis L.) was removed with herbicides at heights of 8 or 16 cm. These respective removal timings corresponded with 22 and 28 days after corn planting or V2 and V3 stages of growth, respectively. Differences in N content in above-ground biomass of corn were noted early in the season due to weed interference but did not translate into differences in corn grain yield. Interactions of N source and N rate were noted for corn grain yield but these factors did not interact with timing of weed control. These results underscore that timely implementation of control tactics regardless of N fertility management is important to protect corn grain yield.


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