scholarly journals WEED COMPETITION WITH SOYBEAN IN NO-TILLAGE AGROFORESTRY AND SOLE-CROP SYSTEMS IN SUBTROPICAL BRAZIL

2017 ◽  
Vol 35 (0) ◽  
Author(s):  
L. DEISS ◽  
A. MORAES ◽  
A. PELISSARI ◽  
A.J. FRANZLUEBBERS ◽  
F.S. NETO ◽  
...  

ABSTRACT Weed competition on soybean (Glycine max) growth and yield was expected to be different when managed in an agroforestry system as compared with sole-cropping without trees. Therefore agronomic practices to control weeds might need to be modified in agroforestry systems. We analyzed weed competition effects on soybean growth, grain yield, and yield components at different distances from 4year-old eucalyptus (Eucalyptus benthamii) in an alley cropping system, as well as in a sole-crop system in southern Brazil. Above-ground soybean biomass was collected throughout the growing season and a logistic function was used to model crop growth. Weed above-ground biomass sampled during the soybean cycle, and grain yield and yield components at the end of the growing season were evaluated using regression analysis across positions between tree lines, and results compared to those without influence of trees. Soybean yield components were mostly reduced between tree lines compared with sole-cropping without trees. Soybean growth and yield within the eucalyptus agroforestry system was not affected by weed competition. However, weeds reduced soybean growth and yield in sole-cropping without trees. Reduction in soybean yield in the agroforestry system was rather caused by competition from trees. Therefore, tree interference may limit both weed and soybean growth potential.

2014 ◽  
Vol 6 (4) ◽  
pp. 166 ◽  
Author(s):  
B. M. Sani ◽  
I. U. Abubakar ◽  
A. M. Falaki ◽  
H. Mani ◽  
M. M. Jaliya

An experiment was conducted to assess the yield and yield components of QPM genotypes to plant population under irrigated conditions in a semi arid ecology of Northern Nigeria. Field trials were conducted at the Irrigation Research Station, Institute for Agricultural Research, Kadawa (11° 39'N, 08° 20'E) and 500 m above sea level) during dry seasons 2007, 2008 and 2009 to study the effect of (Zea mays L.) genotypes (TZE-W Pop X 1368, EV-DT W99 STR and DMR-ESRW), four plant population (33333, 44444, 55555 and 66666 plants ha-1) and three irrigation scheduling (40, 60 and 80 centibars soil moisture tension) on the growth and yield of quality protein maize. A split plot design was used with combinations of genotypes and irrigation regimes assigned to the main plot and plant population assigned to the sub-plot. The treatments were replicated three times. The study revealed that genotype EV-DT W99 STR had significantly higher weight of ears per plant, cob length, cob diameter, number of rows per cob, 100 grain weight, grain yield, shelling percentage and harvest index than the other two genotypes used in the trial. Irrigating at 40 and 60 centibars significantly increased weight of ears per plant, while delayed irrigation significantly depressed total dry matter production. Based on the results obtained in this study, it can be concluded that the use of genotype EV-DT W99 STR, at 60 centibars irrigation scheduling and population of 55,555 plants ha-1 had resulted in good agro-physiological characters of QPM at Kadawa.


1985 ◽  
Vol 21 (2) ◽  
pp. 135-144 ◽  
Author(s):  
F. O. Olasantan

SUMMARYThe effects of intercropping, mulching and staking on growth and yield of three tomato varieties were evaluated in four field trials in 1982 and 1983. Fruit yields of the improved varieties were significantly reduced by intercropping with okra but the yield of a local variety was unaffected. Though the yield of okra when grown with tomato varieties was less than that of a sole crop, the combined yield of the two crops in mixtures was more than the means of the species in monoculture. Relative Yield Totals (RYT) increased to maxima of about 1.42 and 1.39 when the local variety was grown with okra in 1982 and 1983 trials, respectively. Mulching and staking significantly increased vegetative growth, yield and yield components of the tomato plants. Mulched plants grew taller and had more branches and a greater number and weight of fruits than staked plants. Improved varieties responded better to mulching and staking than the local variety. Growing improved varieties of tomato in sole stands with proper mulching and staking is therefore recommended.


2010 ◽  
Vol 58 (1) ◽  
pp. 65-72
Author(s):  
D. Jug ◽  
M. Sabo ◽  
I. Jug ◽  
B. Stipešević ◽  
M. Stošić

Eight different tillage systems were compared in soybean production on one experimental field (chernozem) located in the Baranya region of Croatia over a 4-year period (2001/2002, 2002/2003, 2003/2004, 2004/2005). The dry conditions experienced in 2003 exacerbated the effects of NT and CWNS on the soybean yield. The most stable grain yield was obtained using CSNW and CSDW in all four experimental years. DH, CH and CWDS did not result in any significant reduction in crop yield compared to CT. There was no clear trend regarding the applied tillage systems and grain yield components. The greatest effects on soybean yield and yield components were due to climatic conditions. Different tillage systems had a significant effect on the soybean grain yield and yield components in the four experimental years. The largest differences in stem height were determined between CSNW and NT. The number of pods per plant, the hectolitre mass and the grain yield were significantly lower under NT than under the other tillage systems. The number of fertile nodes of soybean and the number of branches per plant in the experimental years had approximately the same values for all the tillage systems. To sum up, the results achieved with DH, CH, CSDW, CWDS and CSNW were on par with each other and slightly better than CT, and these systems could represent adequate replacements for conventional tillage. No tillage could not be considered as the most favourable for soybean growing.


Weed Science ◽  
2020 ◽  
pp. 1-10
Author(s):  
Muhammad Javaid Akhter ◽  
Per Kudsk ◽  
Solvejg Kopp Mathiassen ◽  
Bo Melander

Abstract Field experiments were conducted in the growing seasons of 2017 to 2018 and 2018 to 2019 to evaluate the competitive effects of rattail fescue [Vulpia myuros (L.) C.C. Gmel.] in winter wheat (Triticum aestivum L.) and to assess whether delayed crop sowing and increased crop density influence the emergence, competitiveness, and fecundity of V. myuros. Cumulative emergence showed the potential of V. myuros to emerge rapidly and under a wide range of climatic conditions with no effect of crop density and variable effects of sowing time between the two experiments. Grain yield and yield components were negatively affected by increasing V. myuros density. The relationship between grain yield and V. myuros density was not influenced by sowing time or by crop density, but crop–weed competition was strongly influenced by growing conditions. Due to very different weather conditions, grain yield reductions were lower in the growing season of 2017 to 2018 than in 2018 to 2019, with maximum grain yield losses of 22% and 50% in the two growing seasons, respectively. The yield components, number of crop ears per square meter, and 1,000-kernel weight were affected almost equally, reflecting that V. myuros’s competition with winter wheat occurred both early and late in the growing season. Seed production of V. myuros was suppressed by delaying sowing and increasing crop density. The impacts of delayed sowing and increasing crop density on seed production of V. myuros highlight the potential of these cultural weed control tactics in the long-term management programs of this species.


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 14 (3) ◽  
pp. 239-244 ◽  
Author(s):  
W. Godfrey-Sam-Aggrey

SUMMARYEffects of plant population on mean yield and yield components of 2-year sole cassava crops were studied on Njala upland soils of Sierra Leone in two experiments. Increasing plant population of multi-shoot Cocoa cassava over 7000/ha decreased all the parameters studied except top/root weight ratio, which increased. The observed effects were attributed to competition for environmental resources, since area of land/plant unit decreased as plant population increased. The relations between plant populations and yields of fresh root and cortex dry matter were asymptotic, indicating that the respective yields were products of the vegetative phase of cropping.


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.


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