Effects of delaying chemical fallowing in pasture rotations on pasture quality and wheat yield in the Victorian Wimmera

1989 ◽  
Vol 29 (1) ◽  
pp. 69 ◽  
Author(s):  
GJ O'Leary ◽  
RM Binns ◽  
TR Lewis
Keyword(s):  
Dry Matter ◽  
Yield Loss ◽  
Wheat Yield ◽  
Growth Period ◽  
Poor Quality ◽  
Yield Losses ◽  
The Third ◽  
Pasture Quality ◽  
Chemical Fallow ◽  
Conservation Method

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.

Estimating yield losses in wheat resulting from infestation by doublegee (Emex australis)

1974 ◽  
Vol 14 (70) ◽  
pp. 656 ◽  
Author(s):  
DJ Gilbey
Keyword(s):  
Crop Yield ◽  
Field Trial ◽  
Yield Loss ◽  
Wheat Yield ◽  
Yield Reduction ◽  
Yield Losses ◽  
Seedling Mortality ◽  
Emex Australis ◽  
Percentage Yield

The effect of doublegee (Emex australis) density on wheat yield was studied in a field trial. Percentage yield reduction (y) was related to doublegee plants m-2 at 1 week (x1) and 8 weeks (x2) after seeding thus: y = 10.3 + 0.24 x1 r = 0.78*** y = 5.6 + 0.44 x2 r = 0.86*** showing that estimates of doublegee density could be used for forecasting crop yield losses before it is too late to spray. No further yield loss occurred when x1 was greater than 120 plants metre-2. Doublegee seedling mortality that occurred during the seven weeks between plant counts was strongly related to the initial counts (x1) thus: r = 0.88***.

Commercial generations of Brassica napus cause greater yield loss in Triticum aestivum, than volunteer B. napus generations

2010 ◽  
Vol 90 (5) ◽  
pp. 777-783 ◽  
Author(s):  
N J Seerey ◽  
S J Shirtliffe
Keyword(s):  
Triticum Aestivum ◽  
Brassica Napus ◽  
Generational Differences ◽  
Yield Loss ◽  
Plant Density ◽  
Wheat Yield ◽  
Yield Losses ◽  
Large Area ◽  
Seedling Mortality ◽  
Brassica Napus L

Volunteer canola (Brassica napus L.) has become a common weed in producer fields, due to the large area cropped, and inherent harvest losses. Commonly grown B. napus varieties which segregate in subsequent generations to create volunteers with unknown competitive capabilities are developed by hybrid genetics. The objective of this study was to evaluate the effect of volunteer B. napus variety and generation on competition yield loss in hard red spring wheat (Triticum aestivum L.). Two hybrid and one open-pollinated B. napus varieties with three consecutive generations produced from each variety were grown at varying densities in a wheat stand over 5 site-years. Yield loss depended on the density of B. napus in relation to total plant density. Generational differences in B. napus seedlings resulted in differences in wheat yield losses. Brassica napus densities at maturity provided a more robust model of wheat yield loss, as there were differences in wheat yield losses due to the interaction of generation and variety of B. napus. Commercial seed generations were the most competitive plants, while volunteer generations were less competitive. The amount of yield loss caused by volunteer B. napus was highly variable. The availability of low-priced herbicides, and the competitive ability of volunteer B. napus may allow for economic thresholds concerning weed control to be surpassed at low densities of volunteer B. napus populations. Key words: Competition, hybrid, open-pollinated, volunteer weed, seedling mortality, mature density, seedling density, feral

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
Keyword(s):  
Seed Production ◽  
Dry Matter ◽  
Yield Loss ◽  
Wheat Yield ◽  
Integrated Weed Management ◽  
Wild Radish ◽  
Raphanus Raphanistrum ◽  
Area Index ◽  
Crop Density ◽  
Radish Seed

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.

scholarly journals Winter Wheat Response to Preplant Applications of Aminocyclopyrachlor

2011 ◽  
Vol 25 (1) ◽  
pp. 51-57 ◽  
Author(s):  
Andrew R. Kniss ◽  
Drew J. Lyon
Keyword(s):  
Winter Wheat ◽  
Yield Loss ◽  
Wheat Yield ◽  
Field Studies ◽  
Wheat Crop ◽  
Yield Losses ◽  
Fallow Period ◽  
Winter Wheat Yield ◽  
Winter Wheat Crop ◽  
Preceding Winter

Field studies were conducted in Wyoming and Nebraska in 2007 through 2009 to evaluate winter wheat response to aminocyclopyrachlor. Aminocyclopyrachlor was applied at rates between 15 and 120 g ai ha−1 6, 4, and 2 mo before winter wheat planting (MBP). Redroot pigweed control was 90% with aminocyclopyrachlor rates of 111 and 50 g ha−1 when applied 4 or 2 MBP. Aminocyclopyrachlor at 37 g ha−1 controlled Russian thistle 90% when applied 6 MBP. At Sidney, NE, winter wheat yield loss was > 10% at all aminocyclopyrachlor rates when applied 2 or 4 MBP, and at all rates > 15 g ha−1 when applied 6 MBP. At Lingle, WY, > 40% winter wheat yield loss was observed at all rates when averaged over application timings. Although the maturing wheat plants looked normal, few seed were produced in the aminocyclopyrachlor treatments, and therefore preharvest wheat injury ratings of only 5% corresponded to yield losses ranging from 23 to 90%, depending on location. The high potential for winter wheat crop injury will almost certainly preclude the use of aminocyclopyrachlor in the fallow period immediately preceding winter wheat.

scholarly journals Estimating and Analyzing the Spatiotemporal Characteristics of Crop Yield Loss in Response to Drought in the Koshi River Basin, Nepal

2021 ◽  
Author(s):  
Nirmal Mani Dahal ◽  
Donghong XIONG ◽  
Nilhari Neupane ◽  
Su Zhang ◽  
Yong Yuan ◽  
...  
Keyword(s):  
River Basin ◽  
Crop Yield ◽  
Agricultural Sector ◽  
Yield Loss ◽  
Interpolation Method ◽  
Wheat Yield ◽  
High Yield ◽  
Yield Losses ◽  
Koshi River Basin ◽  
Crop Yield Loss

Abstract The quantitative assessment of crop yield loss in response to drought is crucial in the development of the agricultural sector to improve the productivity. This study estimated and analyzed the spatiotemporal patterns of crop yield loss in response to drought using the Lagrange interpolation method, wavelet analysis, and sequential Mann-Kendall test in the mountain, hill, and Terai (low-land) regions of Nepal's Koshi River Basin from 1987 to 2016. According to the findings, average crop yield loss was common after 2000, with the Terai, hill, and mountain experiencing the greatest loss in maize, rice, and wheat, respectively. Average annual rice and wheat yield losses rate were highest in the mountains, while maize yield losses were highest in the Terai. There was an abrupt change in wheat yield loss in the mountain, with significant increasing trend. In the hill, significant increment in maize and wheat yield loss, and decrement in rice yield loss, were observed. Between 1987 and 2016, periodic variations of maize, rice, and wheat revealed significant yield loss after 2000. The characteristics of the first and second key periods for crop yield loss demonstrated variation period which predicted that crop yield loss would either enter high yield loss or low yield loss period shortly after 2016. The findings of the study provide a detailed intervention in assessing crop yield loss at the river basin level and can provide an important pathway for developing a crop yield loss mitigation plan in the agricultural sector to achieve self-reliance and sustainable agricultural productivity.

scholarly journals Wheat Yield Loss in a Two Species Competition with Emex australis and Emex spinosa

2016 ◽  
Vol 34 (1) ◽  
pp. 35-46 ◽  
Author(s):  
M.M. JAVAID ◽  
A. TANVEER ◽  
H.H. ALI ◽  
M.A. SHAHID ◽  
R.M. BALAL ◽  
...  
Keyword(s):  
Yield Components ◽  
Field Experiments ◽  
Yield Loss ◽  
Maximum Yield ◽  
Wheat Yield ◽  
Growth And Yield ◽  
Wheat Crop ◽  
Yield Losses ◽  
Weed Species ◽  
Emex Australis

Emex australis and E. spinosa are significant weed species in wheat and other crops. Information on the extent of competition of the Emex species will be helpful to access yield losses in wheat. Field experiments were conducted to quantify the interference of tested weed densities each as single or mixture of both at 1:1 on their growth and yield, wheat yield components and wheat grain yield losses in two consecutive years. Dry weight of both weed species increased from 3-6 g m-2 with every additional plant of weed, whereas seed number and weight per plant decreased with increasing density of either weed. Both weed species caused considerable decrease in yield components like spike bearing tillers, number of grains per spike, 1000-grain weight of wheat with increasing density population of the weeds. Based on non-linear hyperbolic regression model equation, maximum yield loss at asymptotic weed density was estimated to be 44 and 62% with E. australis, 56 and 70% with E. spinosa and 63 and 72% with mixture of both species at 1:1 during both year of study, respectively. It was concluded that E. spinosa has more competition effects on wheat crop as compared to E. australis.

scholarly journals Yield Losses Associated with Virus-Infected Garlic Plants During Five Successive Years

Plant Disease ◽  
2003 ◽  
Vol 87 (12) ◽  
pp. 1411-1415 ◽  
Author(s):  
Vilma C. Conci ◽  
Ana Canavelli ◽  
P. Lunello ◽  
J. Di Rienzo ◽  
S. F. Nome ◽  
...  
Keyword(s):  
Virus Infection ◽  
Yield Loss ◽  
Yield Losses ◽  
The Third ◽  
Production Values ◽  
Gradual Loss ◽  
Crop Cycle

Virus-free garlic plants, when planted in the field, are quickly infected by viruses, but it is not known to what extent this affects the yield over successive crop cycles. The yield loss curve was studied for these plants during 5 years of tests in the field. Highly significant differences were detected in the weight and perimeter of bulbs in relation to the years of exposure to virus infection. An increase was observed in yield compared with chronically diseased plants of between 66 and 216% in weight and 13 and 37% in perimeter of bulbs in the first crop cycle and 49% in weight and 16% in perimeter in the fifth year. These results showed a gradual loss in yield until the third year, and subsequently the production values remained steady for the fourth and fifth years of testing but were still higher than those reached by chronically diseased plants.

scholarly journals THE EFFECT OF A PLANT GROWTH REGULATOR (MEFLUIDIDE) ON PASTURE GROWTH AND MILK PRODUCTION

1985 ◽  
pp. 83-87
Author(s):  
I.M. Brookes ◽  
C.W. Holmes
Keyword(s):  
Growth Rates ◽  
Plant Growth Regulator ◽  
Dry Matter ◽  
Milk Protein ◽  
Nutritive Value ◽  
Grazing Pressure ◽  
Subsequent Growth ◽  
The Third ◽  
Pasture Quality ◽  
Clover Pasture

Nine paddocks (0.85 hectares each) of ryegrass-white clover pasture were divided in half and one half of each paddock sprayed,with 0.15 kg ai mefluidide per hectare in mid-October. All paddocks were grazed 7-9 days after spraying and then rested for a further 14-20 days. A 7 week grazing trial using 8 pairs of idential twin cows was then conducted. All cows received an equal herbage allowance of 40 kg dry matter per head daily. Equal areas were offered to each treatment group and extra cows used to adjust the grazing pressure where necessary. Mefluidide depressed pasture growth rates by 29% for 3-4 weeks after spraying. Subsequent growth rates did not differ significantly between sprayed (S) and unsprayed (U) pastures. Pasture quality was similar for both treatments in the second round of grazing (late November and early December), but in the third round (mid-December) sprayed pastures were more leafy, less stemmy, had higher N concentrations and were more digestible than unsprayed. This was not reflected as differences in the yields of milk, milkfat or milk protein between treatments. The net effect of spraying with mefluidide was therefore to decrease the carrying capacity of the sprayed area used in the grazing trials by 76 cow days compared with the equivalent unsprayed area. This would have resulted in the production of approximately 59 kg less milkfat from 2.5 ha over a 7 week period. Keywords: Mefluidide, Embark 2-V , pasture growth, pasture quality, milk yield, dairy cows, milkfat, nutritive value.

Round-leaved Mallow (Malva pusilla) Growth and Interference in Spring Wheat (Triticum aestivum) and Flax (Linum usitatissimum)

Weed Science ◽  
1992 ◽  
Vol 40 (3) ◽  
pp. 448-454 ◽  
Author(s):  
Lyle F. Friesen ◽  
Kenneth P. Nickel ◽  
Ian N. Morrison
Keyword(s):  
Triticum Aestivum ◽  
Spring Wheat ◽  
Linum Usitatissimum ◽  
Dry Matter ◽  
Wheat Yield ◽  
Logistic Function ◽  
Wheat Crop ◽  
Regression Equations ◽  
Yield Losses ◽  
Active Radiation

Round-leaved mallow interference in spring wheat and flax was investigated under field conditions in southern Manitoba. Additionally, the growth of mallow alone and in a wheat crop was compared. In six of seven trials, wheat yield losses due to mallow interference were not significant. In a seventh trial, where mallow densities of up to 237 plants m−2were recorded, wheat yields were reduced up to 15%. In contrast, significant flax yield losses occurred in each of three trials where maximum mallow densities ranged from 21 to 52 plants m−2. From the regression equations it was calculated that 20 mallow plants m−2caused flax yield losses of 33, 9, and 10% in 1987, 1988, and 1989, respectively. Periodic sampling of mallow plants growing alone and in wheat, and regression analysis of these data using a logistic function as a biological model of plant growth indicated that mallow growth was severely suppressed by wheat By the eighth week after emergence, the lamina area and shoot dry matter of mallow plants growing in wheat was less than 3% of plants growing alone. Similarly, in wheat, mallow produced less than 1% of the seed produced by plants growing alone. This extreme suppression of mallow growth corresponded with an 80 to 90% decrease in photosynthetically active radiation penetrating the wheat canopy for approximately six continuous weeks, beginning 4 wk after crop emergence.

scholarly journals Production and quality of meadow associations in forest hunting grounds in Serbia

2009 ◽  
Vol 25 (3-4) ◽  
pp. 251-260 ◽  
Author(s):  
Z. Tomic ◽  
Z. Nesic ◽  
D. Vilotic ◽  
D. Gacic ◽  
M. Zujovic
Keyword(s):  
Dry Matter ◽  
Poor Quality ◽  
Breeding Ground ◽  
Crude Fibre ◽  
The Third ◽  
Plant Associations ◽  
As Species ◽  
Location Association

Determination of meadow associations was done on three locations: enclosed section of the hunting ground 'Posavsko loviste Karakusa' (Forest holding Sremska Mitrovica), enclosed breeding ground i.e. area 'Miloseva voda' (Sokolovica) and enclosed breeding ground 'Lomnicka reka' (Veliki Jastrebac). Phytocenological records were used to determine number and cover, and in samples the presence of plant species was determined and based on this analysis to which plant associations they belong. In determined associations the share in percentages of grass and leguminous species of high, medium and poor quality was determined, as well as species of other families, conditionally useful, bad, worthless, harmful and slightly poisonous. On the first location the following associations were established: Agrostio-Juncetum effusi Cinc. 1959., Trifolio-Agrostietum stoloniferae LJ. Mark. 1973., Agrostietum vulgaris Z. Pavl. 1955. sensu lato. On the second location, on both meadows, the association Festuco-Agrostietum Horv. (1952) 1982. em Trinajest. 1972. was established, whereas on the third location, association Agrostio-Festucetum vallesiacae Gajic 1961 was established. In investigated associations, the production of green mass and dry matter was established, as well as main parameters of the quality of grass mass (crude proteins, crude fibre, crude lipids, NFE and mineral matters). .

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