Synchrony of flowering between canola and wild radish (Raphanus raphanistrum)

Weed Science ◽  
2004 ◽  
Vol 52 (6) ◽  
pp. 905-912 ◽  
Author(s):  
Marie-Josée Simard ◽  
Anne Légère
Keyword(s):  
Flowering Time ◽  
Field Experiments ◽  
Plant Density ◽  
Wheat Crop ◽  
Transgenic Crop ◽  
Wild Radish ◽  
Raphanus Raphanistrum ◽  
Planting Dates ◽  
Essential Requirement ◽  
Flowering Periods

Many conditions need to be satisfied for gene flow to occur between a transgenic crop and its weedy relatives. Flowering overlap is one essential requirement for hybrid formation. Hybridization can occur between canola and its wild relative, wild radish. We studied the effects of wild radish plant density and date of emergence, canola (glyphosate resistant) planting dates, presence of other weeds, and presence of a wheat crop on the synchrony of flowering between wild radish and canola (as a crop and volunteer). Four field experiments were conducted from 2000 to 2002 in St-David de Lévis, Québec. Flowering periods of wild radish emerging after glyphosate application overlapped with early-, intermediate-, and late-seeded canola 14, 26, and 55%, respectively, of the total flowering time. Flowering periods of early-emerging wild radish and canola volunteers in uncropped treatments overlapped from mid-June until the end of July, ranging from 26 to 81% of the total flowering time. Flowering periods of wild radish and canola volunteers emerging synchronously on May 30 or June 5 as weeds in wheat overlapped 88 and 42%, respectively, of their total flowering time. For later emergence dates, few flowers or seeds were produced by both species because of wheat competition. Wild radish density in canola and wild radish and canola volunteer densities in wheat did not affect the mean flowering dates of wild radish or canola. Increasing wild radish density in uncropped plots (pure or weedy stands) hastened wild radish flowering. Our results show that if hybridization is to happen, it will be most likely with uncontrolled early-emerging weeds in crops or on roadsides, field margins, and uncultivated areas, stressing the need to control the early flush of weeds, weedy relatives, and crop volunteers in noncrop areas.

scholarly journals Criteria for Decision Making and Economic Threshold Level for Wild Radish in Wheat Crop

2019 ◽  
Vol 37 ◽  
Author(s):  
L.C. TAVARES ◽  
E.S. LEMES ◽  
Q. RUCHEL ◽  
N.R. WESTENDORFF ◽  
D. AGOSTINETTO
Keyword(s):  
Dry Matter ◽  
Competitive Ability ◽  
Soil Cover ◽  
Wheat Cultivar ◽  
Wheat Yield ◽  
Threshold Level ◽  
Wheat Crop ◽  
Wild Radish ◽  
Raphanus Raphanistrum ◽  
Economic Threshold

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.

scholarly journals Experimental and simulated wheat data from across a temperature gradient along the River Nile in Egypt

2020 ◽  
Vol 6 ◽  
pp. 19-20
Author(s):  
Ahmed Mohammed Saad Kheir ◽  
Aly Abdelaal ◽  
Gerrit Hoogenboom ◽  
Senthold Asseng
Keyword(s):  
Temperature Gradient ◽  
Field Experiments ◽  
Plant Density ◽  
Surface Wind ◽  
Kernel Weight ◽  
Dew Point ◽  
Weather Data ◽  
River Nile ◽  
Planting Dates ◽  
Daily Weather Data

The dataset includes detailed field experiments from four locations across a temperature gradient along the River Nile. The data covering four contrasting environments from North (low temperature) to South (high temperature), includes Sakha (North delta, lower Egypt), Menofya (Middle delta), Benisuef (Middle Egypt) and Aswan (upper Egypt). Measurements included plant density, aboveground biomass, anthesis and maturity dates, grain yield, grains m-2, kernel weight and N content in grains as well as daily weather data (solar radiation, maximum and minimum temperature, precipitation, surface wind, relative humidity, dew point and vapor pressure) and soil characteristics and crop management. Wheat was sown under full irrigation and fertilization with two planting dates. Simulations include three DSSAT-Wheat models (CERES, NWHEAT and CROPSIM).

Time of Emergence Affects Survival and Development of Wild Radish (Raphanus raphanistrum) in South Carolina

Weed Science ◽  
2010 ◽  
Vol 58 (4) ◽  
pp. 402-407 ◽  
Author(s):  
Jason K. Norsworthy ◽  
Mayank S. Malik ◽  
Melissa B. Riley ◽  
William Bridges
Keyword(s):  
South Carolina ◽  
Life Cycle ◽  
Biomass Production ◽  
Field Experiments ◽  
Seedling Emergence ◽  
Wild Radish ◽  
Raphanus Raphanistrum ◽  
Minimal Growth ◽  
Survival And Development ◽  
Developmental Phases

Field experiments were conducted from 2004 through 2006 at Pendleton and Clemson, SC, to determine the influence of seasonal emergence of wild radish on phenological development, survival, and seed and biomass production in a noncompetitive environment. The duration of four developmental phases, emergence to bolting, bolting to flowering, flowering to silique production, and silique production to maturity, were recorded following wild radish sowing at monthly intervals from October 2004 through September 2006. Seedling emergence occurred 2 to 4 wk after sowing. Mortality of seedlings that emerged from December through March was greater than that of seedlings that emerged in all other months. Wild radish that emerged from April through August completed its life cycle by summer or early autumn. Wild radish that emerged from September through November was able to survive the winter and complete its life cycle the following spring. The developmental phases most affected by time of emergence were emergence to bolting and bolting to flowering. The duration of emergence to bolting ranged from 249 to 479 growing degree days (GDD), and bolting to flowering from 270 to 373 GDD, depending on the month of emergence. The total life cycle of wild radish varied from a low of 1,267 GDD following June emergence to 1,503 GDD following November emergence. Multiple regression analysis revealed that emergence to bolting and silique production to maturity phases were dependent on accumulated heat units and photoperiod. Seed and biomass production were influenced by month of emergence. An average of 1,470 seeds plant−1was produced when emergence occurred in July and 10,170 seeds plant−1when emergence occurred in November. Plants that emerged in autumn exhibited minimal growth during the winter months, but conditions were conducive for growth in mid-March and April, with biomass production of 809 g plant−1at silique production.

The Adaptive Value of Flowering Time in Wild Radish (Raphanus raphanistrum)

Weed Science ◽  
2021 ◽  
pp. 1-26
Author(s):  
Ci Sun ◽  
Michael B. Ashworth ◽  
Ken Flower ◽  
Martin M. Vila-Aiub ◽  
Roberto Lujan Rocha ◽  
...  
Keyword(s):  
Flowering Time ◽  
Weed Management ◽  
Cropping Systems ◽  
Early Flowering ◽  
Management Technique ◽  
Wild Radish ◽  
Raphanus Raphanistrum ◽  
Weed Species ◽  
Ecological Fitness ◽  
Cutting Height

Abstract Harvest weed seed control (HWSC) is a weed management technique that intercepts and destroys weed seeds before they replenish the soil weed seedbank and can be used to control herbicide-resistant weeds in global cropping systems. Wild radish (Raphanus raphanistrum L.) is a problematic, globally distributed weed species that is considered highly susceptible to HWSC as it retains much of its seed on the plant during grain harvest. However, previous studies have demonstrated that R. raphanistrum is capable of adapting its life cycle, in particular flowering time; to allow individuals more time to mature and potentially shed seeds before harvest, thereby evading HWSC interception. This study compared the vegetative growth plus physiological and ecological fitness of an early flowering R. raphanistrum biotype with an unselected genetically related biotype to determine if physiological costs of early flowering exist, when in competition with wheat (Triticum aestivum L.). Early flowering time adaptation in R. raphanistrum did not change the relative growth rate or competitive ability of R. raphanistrum. However, the height of first flower was reduced in the early flowering time-selected population, indicating that this population would retain more pods below the typical harvest cutting height (15 cm) used in HWSC. The presence of wheat competition (160 – 200 plants m-2) increased flowering height in the early flowering time-selected population, which would likely increase the susceptibility of early flowering R. raphanistrum plants to HWSC. Overall, early-flowering adaption in R. raphanistrum is a possible strategy to escape being captured by the HWSC; however, increasing crop competition is likely to be an effective strategy to maintain the effectiveness of HWSC.

scholarly journals INFLUENCE OF MOISTURE AVAILABILITY ON HELIANTHUS ANNUUS L. YIELD IN DRY CONDITIONS OF THE CRIMEAN PENINSULA

2020 ◽  
Vol 4 (24) ◽  
pp. 81-89
Author(s):  
E.V. Kostenkova ◽  
◽  
A.S. Bushnev ◽  
Keyword(s):  
Field Experiments ◽  
Plant Density ◽  
Precipitation Amount ◽  
Limiting Factor ◽  
Planting Dates ◽  
Crimean Peninsula ◽  
Hydrothermal Coefficient ◽  
Moisture Availability ◽  
Selyaninov Hydrothermal Coefficient ◽  
The Crimean Peninsula

The Crimean Peninsula is located in the dry zone. In the steppe Crimea, which is the driest part of the peninsula, the major limiting factor for crop productivity is the natural moisture supply of plants. The purpose of the research was to establish the relationships between hydrometeorological factors (moisture reserves in the soil before sowing, precipitation amount and Selyaninov hydrothermal coefficient during the growing season) and sunflower yield depending on planting dates (I, II, III decade of April) and plant density (30, 40, 50, 60, 70 thousand units per hectare). The studies were carried out on the trial fields of the Research Institute of Agriculture of Crimea (village of Klepinino) in 2017–2019 using hybrid of ultra-early sunflower ‘Avangard’. The laying of field experiments, accounting, analyzes and statistical processing of data were carried out according to the methods of field research and methodology of field agricultural experiments with oil crops. A strong correlation was observed: 1) between yield and precipitation amount in May (r = 0.977) and moisture reserves before sowing (r = 0.978), planting dates – the first decade of April; 2) between precipitation amount in May (r = 0.932) and moisture reserves before sowing (r = 0.977–0.978), sunflower was sown in the second decade of April; 3) moisture before sowing (r = 0.892), crop planted in the third decade of April. A close positive relationship (r = 0.853–0.972) was observed at the optimal plant density for the region (40 thousand units/ha) between the amount of precipitation in April–May, moisture reserves in the soil before sowing and yield of sunflower. This indicates a high value of moisture availability during this period in the crop yield formation. In denser crops (50–70 thousand units/ha), the closest relationship is observed between the yield and the amount of precipitation in May. This makes the latter primary and decisive in the cultivation of crops with such a density since the competition for moisture increases with an increase in the number of plants per unit area. The closest relationship between the Selyaninov hydrothermal coefficient and sunflower yield was observed in April and May (r = 0.833–0.967) when plants grow more intensively and require sufficient moisture.

Narbon bean (Vicia narbonensis) agronomy in south-western Australia

2006 ◽  
Vol 46 (10) ◽  
pp. 1355
Author(s):  
M. Seymour
Keyword(s):  
Western Australia ◽  
Field Experiments ◽  
Plant Density ◽  
Cropping Systems ◽  
Sowing Date ◽  
Wheat Crop ◽  
Yield Increase ◽  
Vicia Narbonensis ◽  
Application Rates ◽  
Wide Range

Narbon bean (Vicia narbonensis L.) shows promise as a fodder, green manure and grain crop in south-western Australia. This study examines the effect of time of sowing (2 experiments), plant density (3 experiments) and reaction to herbicides (4 experiments on tolerance to herbicides and 1 experiment on removing narbon bean from a wheat crop) in 10 separate field experiments sown at 4 locations in the mallee region of Western Australia from 1998 to 2001. Narbon bean was found to be unresponsive to changes in sowing date with yield maintained until the first week of June. The optimum plant density (90% of fitted maximum) for seed yield was found to be 31 plants/m2, equivalent to sowing rates in the range of 75–100 kg/ha. A wide range of herbicides applied either before sowing or immediately after sowing and before emergence had no significant effect on grain yield. These included simazine (750 g a.i./ha), cyanazine (1.25 kg a.i./ha) and diuron (500 g a.i./ha), which were applied immediately before sowing, and imazethapyr (29 g a.i./ha), which was applied after sowing, before emergence. Diflufenican (75 g a.i./ha) was found to be the only available option for post-emergence control of broadleaf weeds. The use of the non-selective herbicides glyphosate (450 g a.i./L) and Sprayseed 250 (paraquat 135 g a.i./L and diquat 115 g a.i./L) as post-emergence herbicides was found to be unpredictable at a range of application rates. Results ranged from a yield loss of 47% to a yield increase of 23%. In an experiment to test a range of herbicides for the selective control of narbon bean within a wheat crop, numerous herbicides were found to effectively remove volunteer narbon bean indicating that narbon bean is unlikely to become a weed in most cereal cropping systems.

Wild Radish (Raphanus raphanistrum) Control in Soft Red Winter Wheat (Triticum aestivum)

Weed Science ◽  
1989 ◽  
Vol 37 (1) ◽  
pp. 112-116 ◽  
Author(s):  
Jill Schroeder
Keyword(s):  
Winter Wheat ◽  
Field Experiments ◽  
Forage Yield ◽  
Wild Radish ◽  
Wheat Grain ◽  
Raphanus Raphanistrum ◽  
Soft Red Winter Wheat ◽  
Tiller Stage ◽  
The Difference ◽  
Red Winter Wheat

Field experiments were conducted at two locations in Georgia to evaluate wild radish control and soft red winter wheat tolerance of herbicides applied February 1 (one- to five-tiller stage) or March 1 (three- to seven-tiller stage). Bromoxynil controlled wild radish with no wheat grain or forage yield reductions in any experiment. Thiameturon controlled wild radish when applied at rates >0.02 kg/ha on March 1. Metribuzin, dimethylamine salt of 2,4-D, and dimethylamine salt of MCPA provided late-season control of wild radish. February 1 treatments of metribuzin reduced wheat stands at Plains. The difference was attributed to environmental conditions, wheat tiller number at application, and possibly to differences in soil fertility at planting. Metribuzin, thiameturon, dimethylamine salt of dicamba, MCPA, and 2,4-D reduced wheat forage yield at Tifton. Dicamba did not control wild radish and reduced grain yield when applied at a rate of 0.3 kg ai/ha on March 1.

Variable crop plant establishment contributes to differences in competitiveness with wild oat among cereal varieties

2005 ◽  
Vol 85 (4) ◽  
pp. 771-776 ◽  
Author(s):  
John T. O’Donovan ◽  
Robert E. Blackshaw ◽  
K. Neil Harker ◽  
George W. Clayton ◽  
Ross McKenzie
Keyword(s):  
Spring Wheat ◽  
Field Experiments ◽  
Plant Density ◽  
Crop Plant ◽  
Wheat Crop ◽  
Wild Oat ◽  
Seeding Rate ◽  
Hordeum Vulgare L ◽  
Wheat Varieties ◽  
Crop Density

Field experiments were conducted at three locations in Alberta to determine the relative competitiveness with wild oat (Avena fatua L.) of three hard red spring (HRS) and three Canada prairie spring (CPS) wheat (Triticum aestivum L.) varieties and a semidwarf hull-less barley (Hordeum vulgare L.) (Falcon), and normal height general purpose barley (AC Lacombe). Crop variety significantly affected crop yield loss, wild oat shoot dry weight and wild oat seed yield (competitive indicators). AC Lacombe barley was consistently more competitive than Falcon barley or any of the wheat varieties, while the HRS wheat varieties were mainly more competitive than the CPS varieties. Falcon barley was generally similar in competitiveness to the CPS wheat varieties. Differences among varieties in crop plant density at establishment correlated significantly with the competitive indicators suggesting that this factor contributed to the differences in competitiveness among the varieties. Crop density tended to be higher with the more competitive AC Lacombe barley and HRS wheat varieties than with the less competitive Falcon barley and CPS wheat varieties. Variety and seeding rate did not interact significantly but intentionally increasing the seeding rate improved the competitiveness of all varieties. Key words: Hard red spring wheat, Canada prairie spring wheat, crop seeding rate, hull-less barley, semi-dwarf wheat and barley

Nitrogen Demand of Cut Chrysanthemums in Relation to Shoot Height and Planting Date

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 523c-523
Author(s):  
Siegfried Zerche
Keyword(s):  
Dry Matter ◽  
Plant Density ◽  
Plant Biomass ◽  
N Uptake ◽  
Planting Date ◽  
Dry Matter Accumulation ◽  
Planting Dates ◽  
Shoot Height ◽  
Climate Conditions ◽  
Growing Period

Refined nutrient delivery systems are important for environmentally friendly production of cut flowers in both soil and hydroponic culture. They have to be closely orientated at the actual nutrient demand. To solve current problems, express analysis and nutrient uptake models have been developed in horticulture. However, the necessity of relatively laborious analysis or estimation of model input parameters have prevented their commercial use up to now. For this reason, we studied relationships between easily determinable parameters of plant biomass structure as shoot height, plant density and dry matter production as well as amount of nitrogen removal of hydroponically grown year-round cut chrysanthemums. In four experiments (planting dates 5.11.91; 25.3.92; 4.1.93; 1.7.93) with cultivar `Puma white' and a fixed plant density of 64 m2, shoots were harvested every 14 days from planting until flowering, with dry matter, internal N concentration and shoot height being measured. For each planting date, N uptake (y) was closely (r2 = 0.94; 0.93; 0.84; 0.93, respectively) related to shoot height (x) at the time of cutting and could be characterized by the equation y = a * × b. In the soilless cultivation system, dry matter concentrations of N remained constant over the whole growing period, indicating non-limiting nitrogen supply. In agreement with constant internal N concentrations, N uptake was linearly related (r2 = 0.94 to 0.99) to dry matter accumulation. It is concluded that shoot height is a useful parameter to include in a simple model of N uptake. However, in consideration of fluctuating greenhouse climate conditions needs more sophisticated approaches including processes such as water uptake and photosynthetically active radiation.

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