Wild radish (Raphanus raphanistrum) interference in wheat

Weed Science ◽  
2006 ◽  
Vol 54 (4) ◽  
pp. 749-756 ◽  
Author(s):  
Seyed V. Eslami ◽  
Gurjeet S. Gill ◽  
Bill Bellotti ◽  
Glenn McDonald

Wild radish is a major weed of field crops in southern Australia. The effects of various densities of wild radish and wheat on the growth and reproductive output of each other were investigated in field studies in 2003 and 2004. The experiments were established as a factorial combination of wheat (0, 100, 200, and 400 plants m−2) and wild radish (0, 15, 30, and 60 plants m−2) densities. The effect of wild radish density on wheat yield loss and wild radish seed production were described with a rectangular hyperbola model. The presence of wild radish in wheat reduced aboveground dry matter, leaf-area index (LAI), and grain yield of wheat, and the magnitude of this reduction was dependent on weed density. Increasing the density of wheat substantially reduced the adverse effects of wild radish on wheat. As crop density increased, wild radish dry matter, LAI, and seed production per unit area decreased. The maximum seed production of wild radish was achieved at its highest density (60 plants m−2), and was 43,300 and 61,200 seeds m−2for the first and second year, respectively. The results indicated that higher densities of wheat were able to suppress seed production of this weed species. From a practical viewpoint, this study shows that increased wheat density in the range of 200 to 400 wheat plants m−2can reduce wild radish seed production and also give some reduction in crop yield loss, and could be an important component of an integrated weed management program.

2019 ◽  
Vol 37 ◽  
Author(s):  
L.C. TAVARES ◽  
E.S. LEMES ◽  
Q. RUCHEL ◽  
N.R. WESTENDORFF ◽  
D. AGOSTINETTO

ABSTRACT: Weed competition limits wheat yield by reducing the availability of essential resources for its growth and development. In this sense, this study aimed to estimate the economic threshold level (ETL) of wild radish (Raphanus raphanistrum) in competition with wheat cultivars. Treatments were arranged in a factorial scheme. The factor wheat cultivar consisted of early (BRS 328), medium (BRS 177), and late (BRS Umbu) cycles and the factor wild radish population ranged from 0 to 564 plants m-2 (10 populations) for the cultivar BRS 328, 0 to 472 plants m-2 for the cultivar BRS 177 (11 populations), and 0 to 724 plants m-2 for the cultivar BRS Umbu (10 populations). The early-cycle BRS 328 presented a higher competitive ability when compared to the medium-cycle BRS 177 and late-cycle BRS Umbu. Yield losses of wheat grains due to wild radish interference can be satisfactorily estimated by the rectangular hyperbola model using the variables plant population, shoot dry matter, soil cover, and leaf area of the weed. ETL values varied as a function of the cultivar cycle, being higher for the cultivar BRS 328 (early) > BRS 177 (medium) > BRS Umbu (late). Wild radish is competitive in wheat crop, requiring at least 1.6 plants m-2 for control to be justified.


2009 ◽  
Vol 60 (7) ◽  
pp. 667 ◽  
Author(s):  
Michael J. Walsh ◽  
Stephen B. Powles

Crop-topping, the practice of applying non-selective herbicides at crop maturity, has proved to be an effective management technique in preventing the input of seed into the seedbank for some annual weed species of southern Australian crop production systems. However, the efficacy of this practice on the dominant broad-leaf weed of these systems, wild radish, is not well understood. These studies investigated the effect of crop-topping and swathing on the viable seed production of wild radish. Crop-topping with either glyphosate or sprayseed (paraquat 135 g/L + diquat 115 g/L) can provide large reductions of 80–90% in viable seed production of wild radish plants present in crops at the end of the growing season. However, the efficacy of this practice was found to be highly variable and therefore, cannot be relied upon to consistently produce these large reductions in seed numbers. Similarly, swathing also produced large reductions in viable seed production but results from this practice were even less consistent than crop-topping treatments. For all treatments, early application timings of growth stage 6.5 or earlier, were optimum for targeting wild radish seed production. However, these treatment timings also resulted in large crop yield losses of ~30%. To preserve at least 90% of crop yield, crop-topping and swathing treatments need to be delayed until wild radish growth stage 8.5, with expected reductions in seed numbers of up to 70%. However, in high-density infestations the need to preserve grain yield will be less important than preventing substantial inputs of wild radish seed into the seedbank.


1996 ◽  
Vol 36 (4) ◽  
pp. 437 ◽  
Author(s):  
GR Code ◽  
TW Donaldson

The effect of different cultivation and sowing methods on wild radish (Raphanus raphanistrum L.) density in 4 successive wheat crops was measured in an experiment in north-eastern Victoria. The number of seasons taken for populations to decline below an estimated threshold for economic spraying of wild radish (5-10 plants/m2) was examined. Two herbicide applications in each crop in all but one treatment prevented or significantly reduced wild radish seed production during the experiment. Wheat sown after mouldboard ploughing (MBP) in the first season contained wild radish at 42 plants/m2, before spraying. Densities were significantly higher (P<0.05) when wheat was direct drilled (96 plants/m2), or sown after cultivation to 80 mm (116 plants/m2) or to 50 mm (202 plants/m2). MBP in the first season followed by cultivation to 80 mm or direct drilling in subsequent seasons resulted in wild radish populations below the threshold for economic spraying in the second crop. Cultivation to 80 mm before sowing in the first 2 years, followed by direct drilling in subsequent years resulted in a wild radish population of 6.9 plants/m2 in the third crop. This density was within the range estimated as the threshold for economic spraying. Wild radish densities on treatments cultivated to 50 or 80 mm before sowing, or direct drilled each year, had declined to within or below the threshold for economic spraying by the fourth crop.


2004 ◽  
Vol 18 (3) ◽  
pp. 509-520 ◽  
Author(s):  
Johnathon D. Holman ◽  
Alvin J. Bussan ◽  
Bruce D. Maxwell ◽  
Perry R. Miller ◽  
James A. Mickelson

Integrated weed management practices, such as crop rotation and increased seeding rates, potentially improve weed management. Yet, few studies compare competitive interactions of weeds with different crops. This research quantified the impact of Persian darnel on spring wheat, canola, and sunflower yield across different seeding rates. Increasing crop density increased yield when Persian darnel affected crop yield early in physiological development. Crop yield loss was estimated to reach 83, 70, and 57% for spring wheat, canola, and sunflower, respectively, at high Persian darnel densities. Persian darnel reduced spring wheat yield by limiting the number of tillers per plant and seed per tiller; reduced canola yield by limiting the number of branches per plant, pods per branch, and seed per pod; and reduced sunflower yield by limiting the number of seed per plant. Persian darnel affected crop growth early in physiological development, indicating that interspecific interference occurred early in the growing season. Cultural and resource management aimed at reducing Persian darnel impact on resource availability and crop yield components will reduce Persian darnel impact on crop yield.


Weed Science ◽  
1997 ◽  
Vol 45 (2) ◽  
pp. 276-282 ◽  
Author(s):  
Aca C. Bosnic ◽  
Clarence J. Swanton

Barnyardgrass is a serious weed problem in cornfields in Ontario. Field experiments were conducted at two locations in 1994 and 1995 to determine the influence of emergence time and barnyardgrass density on corn yield loss, leaf area at 50% silking, and barnyardgrass seed production. Selected barnyardgrass densities up to 200 plants m−1were established within 12.5 cm on either side of the corn row. Barnyardgrass seeds were planted concurrently with corn and at the 3- to 5- or 1- to 2-leaf stage of corn growth in 1994 and 1995, respectively. Barnyardgrass density and seedling emergence relative to corn influenced the magnitude of corn yield loss. Maximum corn grain yield loss ranged from 26 to 35% for early emerging barnyardgrass, and less than 6% yield loss occurred from barnyardgrass seedlings emerging later than the 4-leaf stage of corn growth. Changes in corn leaf area index at 50% silking reflected the level of barnyardgrass competition in corn. Maximum leaf area reduction ranged from 21 to 23%. Barnyardgrass seed production varied with time of seedling emergence and density. Ten barnyardgrass plants emerging up to the 3-leaf stage of corn growth produced 14,400 to 34,600 seeds m−2compared to only 1,200 to 2,800 seeds m−2from plants emerging after the 4-leaf corn stage. The results of this study are essential in the development of an integrated weed management strategy for corn.


1989 ◽  
Vol 29 (1) ◽  
pp. 69 ◽  
Author(s):  
GJ O'Leary ◽  
RM Binns ◽  
TR Lewis

The effects of delaying chemical fallowing in a pasture rotation on pasture quality and subsequent wheat yield were investigated at sites near Minyip and Charlton, Victoria, in 1983 and 1984. Three chemical fallows were commenced at different times and were compared with a conventionally cultivated fallow. The earliest chemical fallow was established, together with a conventional fallow, at the end of winter. The second chemical fallow commenced towards the end of the rapid spring growth period in mid-October (early hayfreezing), and the third in mid- November (late hayfreezing) on a grass-dominant pasture. The pasture in spring ranged from 51 to 72% digestible dry matter (DDM) but the quality declined to 42-50% DDM by the end of the fallow treatments in autumn at each site in both years. Weathering of the pasture over summer reduced it to roughage. In contrast to a conventional fallow, early hayfreezing of pasture reduced the yield of subsequent wheat crops at Minyip by 14% in 1984 and 26% in 1985. Late hayfreezing caused losses of around 35% in each year at Minyip. At Charlton yield losses were much lower with only 14% loss observed from late hayfreezing in 1985. Because the feed produced by hayfreezing was of very poor quality, hayfreezing cannot be recommended as a viable fodder conservation method as it could not adequately compensate for any yield loss.


2004 ◽  
Vol 44 (12) ◽  
pp. 1195 ◽  
Author(s):  
M. Monjardino ◽  
D. J. Pannell ◽  
S. B. Powles

Most cropping farms in Western Australia must deal with the management of herbicide-resistant populations of weeds such as annual ryegrass (Lolium rigidum) and wild radish (Raphanus raphanistrum). Farmers are approaching the problem of herbicide resistance by adopting integrated weed management systems, which allow weed control with a range of different techniques. These systems include non-herbicide methods ranging from delayed seeding and high crop seeding rates to the use of non-cropping phases in the rotation. In this paper, the Multi-species RIM (resistance and integrated management) model was used to investigate the value of including non-cropping phases in the crop rotation. Non-crop options investigated here were haying and green manuring. Despite them providing excellent weed control, it was found that inclusion of these non-cropping phases did not increase returns, except in cases of extreme weed numbers and high levels of herbicide resistance.


2004 ◽  
Vol 55 (4) ◽  
pp. 461 ◽  
Author(s):  
Heping Zhang ◽  
Neil C. Turner ◽  
Michael L. Poole

The yields of wheat and canola in 2 successive years with and without the development of a perched watertable were compared in the high rainfall zone of south-western Australia. In 2001, no perched watertable was observed and wheat and canola yields were close to their estimated potentials. In 2002, a perched watertable developed at less than 30 cm below the soil surface for more than 8 days and at less than 50 cm below the soil surface for at least 30 days at the tillering stage of wheat and at the rosette stage of canola. The air-filled porosity of the soil fell below the critical value of 10% at 10 and 30 cm depth for about 40 days. This reduced the maximum leaf area index of canola by 46% and of wheat by 30%, and reduced the shoot dry matter of wheat at flowering by 27% and by 40% at podding in canola compared with those in 2001. The growth of the wheat roots was constrained at depths from 50-90 cm from the soil surface in 2002 compared with 2001. However, the roots of canola and wheat were able to grow to at least 1.4 m in both 2001 and 2002. In both years, a much higher proportion (>10%) of roots was present in the clay subsoil compared with previous reports in south-western Australia and enabled the crops to utilise a greater amount of water from the clay subsoil. The wheat yield in 2002 was 37% lower than in 2001 and well below the potential, largely as a result of a reduced tiller number per plant and ears per unit area. Despite the greater reduction in dry matter in canola than in wheat in 2002, the seed yield of canola was 17% higher in 2002 than in 2001. Canola, an indeterminate crop, was able to respond to the late rain that occurred in 2002 compared with 2001 and produced a significantly higher seed number per unit area. In 2002, grain size in wheat was 25% larger than in 2001, but this increase was insufficient to compensate for the yield loss resulting from the fewer ears per unit area. It is concluded that early transient perched watertable induced subsurface waterlogging, and that the subsurface waterlogging can be a major constraint to crop growth in the high rainfall region of southwestern Australia, and that reducing waterlogging could be a key to achieving higher crop production.


2004 ◽  
Vol 44 (3) ◽  
pp. 265 ◽  
Author(s):  
M. Monjardino ◽  
D. J. Pannell ◽  
S. B. Powles

Most cropping farms in Western Australia must deal with the management of herbicide-resistant populations of weeds such as annual ryegrass (Lolium rigidum Gaudin) and wild radish (Raphanus raphanistrum�L.). Farmers are approaching the problem of herbicide resistance by adopting integrated weed management systems, which allow weed control with a range of different techniques. One important question in the design of such systems is whether and when the benefits of including pasture in rotation with crops exceed the costs. In this paper, the multi-species resistance and integrated management model was used to investigate the value of including pasture phases in the crop rotation. The most promising of the systems examined appears to be so-called 'phase farming', involving occasional 3-year phases of pasture rather than shorter, more frequent and regular pasture phases. This approach was competitive with the best continuous cropping rotation in a number of scenarios, particularly where herbicide resistance was at high levels.


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