The influence of cultural factors and mildew on yield of winter barley

1980 ◽  
Vol 94 (2) ◽  
pp. 389-397 ◽  
Author(s):  
A. Bainbridge ◽  
M. E. Finney ◽  
J. F. Jenkyn

SummaryIn experiments on winter barley in 1975–6 and 1977–8 early or late sowing, full or half seed rate, nitrogen applied in March or April and tridemorph spray applied in autumn, early spring and late spring were assessed factorially in all combinations for their effects on mildew development, crop growth and grain yield.Date of sowing had the biggest effect on yield. Early-sown crops (24 September 1975, 6 October 1977) greatly out-yielded the late-sown; by 79·8% in the first year and 53·9% in the second. Late sowing (6 November 1975, 2 November 1977) approximately halved plant emergence. Although late-sown plants developed more tillers, more grains per ear and larger grain this failed to compensate for the thinner stand.Sowing at half seed rate did not decrease yield when compared with the crop sown at the full seed rate on the same date. In contemporaneous crops extra tillering and larger ears generally compensated for fewer plants.The effect of date of applying N was variable. April N gave the best yield in the early· and late-sown crops in 1975–6 and in the late-sown crop in 1977–8. However, in the early-sown crop in the second year March N was best. Number of ears was increased in early-sown crops by March N but date of N application had no influence on number of ears in late-sown crops or on the number of grains per ear in any crop.The winter of 1975–6 was mild and mildew developed on both early· and late-sown crops throughout their growth.Single tridemorph sprays applied in autumn (14 November) to the early-sown crop or winter (25 February) to the late-sown crop or early spring (9 April) to both crops gave significant yield increases of 6·3–7·6%. Applying two sprays, one in autumn or winter plus one in early spring gave an increase equal to the sum of each applied separately. A late spring spray (14 May) had no significant effect on yield. The 1977–8 winter was colder and although mildew was moderate on the early-sown crop in autumn it was almost absent from this experiment after winter. Spraying failed to increase yield significantly.

Author(s):  
G.W. Sheath ◽  
R.W. Webby ◽  
W.J. Pengelly

Comparisons of controlling late spring to early summer pasture growth on either easy or steep contoured land with either a fast rotation or continuous grazing policy were made in self-contained farmlets for two years. Pasture control was maintained over more land by controlling steep land first and with continuous grazing. Animal performances (ewes, steers) were generally similar for the mid-November to early January treatment period, and subsequently until May shearing. In the first year better animal performances occurred in "steep control" farmlets during winter and early spring, but this was less evident in the second year. Priority control of steep land during late spring-early summer is recommended because of likely longer-term benefits in pasture composition,density and production. Quick rotation grazing through the period provides a better ability to recognise and manage pasture quantities and should be adopted if summer droughts are anticipated. For well fenced properties in summer-wet areas and with integrated stock grazing, continuous grazing during late spring-early summer may be equally suitable. Keywords: hill country, grazing management, pasture control


1995 ◽  
Vol 124 (3) ◽  
pp. 343-350
Author(s):  
D. L. Easson

SUMMARYOmitting or changing various inputs to winter wheat, cv. Norman, were studied over the 1985/86, 1986/87 and 1987/88 crop years in Northern Ireland. Control plots received chemical inputs as commonly applied to intensively managed wheat, including herbicide, two broad spectrum fungicides and chlormequat and yielded 7·5, 9·3 and 6·3 t/ha in 1986, 1987 and 1988 respectively. Other treatments included no herbicide, no chlormequat, no late fungicide, no fungicide, no sprays, half seed rate, late sowing and late sowing with no sprays. Later sowing decreased take-all in 1986 and increased yield. All other treatments either reduced yield or had no effect. Omitting fungicide gave consistent and large decreases in yield by depressing the 1000-grain weight but the importance of early and late applications varied between years. The yield reductions from omitting fungicide were generally larger than those reported elsewhere. Lodging occurred in all years but chlormequat reduced it only in 1988 and gave a yield increase only in 1986, although the number of grains/ear was increased in all years. There was no evidence of any interactions between different pesticide inputs or with seed rate or sowing date.


2021 ◽  
pp. 1-17
Author(s):  
Leo Roth ◽  
José Luiz C. S. Dias ◽  
Christopher Evans ◽  
Kevin Rohling ◽  
Mark Renz

Garlic mustard [Alliaria petiolata (M. Bieb.) Cavara & Grande] is a biennial invasive plant commonly found in the northeastern and midwestern United States. Although it is not recommended to apply herbicides after flowering, land managers frequently desire to conduct management during this timing. We applied glyphosate and triclopyr (3% v/v and 1% v/v using 31.8% and 39.8% acid equivalent formulations, respectively) postemergence to established, second-year A. petiolata populations at three locations when petals were dehiscing, and evaluated control, seed production and seed viability. Postemergence glyphosate applications at this timing provided 100% control of A. petiolata by 4 weeks after treatment at all locations whereas triclopyr efficacy was variable, providing 38-62% control. Seed production was only reduced at one location, with similar results regardless of treatment. Percent seed viability was also reduced, and when combined with reductions in seed production, we found a 71-99% reduction in number of viable seed produced plant-1 regardless of treatment. While applications did not eliminate viable seed production, our findings indicate that glyphosate and triclopyr applied while petals were dehiscing is a viable alternative to cutting or hand-pulling at this timing as it substantially decreased viable A. petiolata seed production. Management Implications Postemergence glyphosate and triclopyr applications in the early spring to rosettes are standard treatments used to manage A. petiolata. However, weather and other priorities limit the window for management, forcing field practitioners to utilize more labor-intensive methods such as hand-pulling. It is not known how late in the development of A. petiolata these herbicides can be applied to prevent viable seed production. Since prevention of soil seedbank replenishment is a key management factor for effective long-term control of biennial invasive species, we hypothesized late spring foliar herbicide applications to second year A. petiolata plants when flower petals were dehiscing could be an effective management tool if seed production or viability is eliminated. Our study indicated that glyphosate applications at this timing provided 100% control of A. petiolata plants by 4 weeks after treatment at all locations, whereas triclopyr efficacy was inconsistent. Although both glyphosate and triclopyr decreased viable seed production to nearly zero at one of our three study locations, the same treatments produced significant amounts of viable seed at the other two locations. Our findings suggest late spring glyphosate and triclopyr applications should not be recommended over early spring applications to rosettes for A. petiolata management, as our late spring application timing did not prevent viable seed production, and may require multiple years of implementation to eradicate populations. Nonetheless, this application timing holds value in areas devoid of desirable understory vegetation compared to no management practices or mechanical management options including hand-pulling when fruit are present, as overall viable seed production was reduced to similar levels as these treatments.


2000 ◽  
Vol 45 (6) ◽  
pp. 1265-1273 ◽  
Author(s):  
Claude Belzile ◽  
Sophia C. Johannessen ◽  
Michel Gosselin ◽  
Serge Demers ◽  
William L. Miller
Keyword(s):  

2010 ◽  
Vol 24 (1) ◽  
pp. 11-19 ◽  
Author(s):  
Vince M. Davis ◽  
Greg R. Kruger ◽  
Bryan G. Young ◽  
William G. Johnson

Horseweed (Conyza canadensis) is a common weed in no-till crop production systems. It is problematic because of the frequent occurrence of biotypes resistant to glyphosate and acetolactate synthase (ALS)-inhibiting herbicides and its ability to complete its life cycle as a winter or summer annual weed. Tactics to control horseweed while controlling other winter annual weeds routinely fail; herbicide application timing and spring emergence patterns of horseweed may be responsible. The objectives of this experiment were to (1) determine the influence of fall and spring herbicides with and without soil residual horseweed activity on spring-emerging glyphosate-resistant (GR) horseweed density and (2) evaluate the efficacy and persistence of saflufenacil on GR horseweed. Field studies were conducted in southern Indiana and Illinois from fall 2006 to summer 2007 and repeated in 2007 to 2008. Six preplant herbicide treatments were applied at four application timings: early fall, late fall, early spring, and late spring. Horseweed plants were counted every 2 wk following the first spring application until the first week of July. Horseweed almost exclusively emerged in the spring at both locations. Spring horseweed emergence was higher when 2,4-D + glyphosate was fall-applied and controlled other winter annual weeds. With fall-applied 2,4-D + glyphosate, over 90% of the peak horseweed density was observed before April 25. In contrast, only 25% of the peak horseweed density was observed in the untreated check by April 25. Starting from the initiation of horseweed emergence in late March, chlorimuron + tribenuron applied early fall or early spring, and spring-applied saflufenacil at 100 g ai/ha provided greater than 90% horseweed control for 12 wk. Early spring–applied saflufenacil at 50 g ai/ha provided 8 wk of greater than 90% residual control, and early spring–applied simazine provided 6 wk of greater than 90% control. When applied in late spring, saflufenacil was the only herbicide treatment that reduced horseweed densities by greater than 90% compared to 2,4-D + glyphosate. We concluded from this research that fall applications of nonresidual herbicides can increase the rate and density of spring emerging horseweed. In addition, spring-applied saflufenacil provides no-till producers with a new preplant herbicide for foliar and residual control of glyphosate- and ALS-resistant horseweed.


Author(s):  
Г. М. Козелець

Наведено результати досліджень впливу норми висіву і ширини міжрядь на продуктивність коріандру за підзимового та ранньовесняного строків сівби.Встановлено, що кращим строком сівби для коріандру є підзимовий, за якого врожайність плодів становила 1,21 т/га, що більше порівняно із ранньовесняним на 0,30 т/га, або 24,7 %. Для коріандру в умовах північного Степу оптимальною є норма висіву 2,0–2,5 млн сх. нас. на 1 га, яка забезпечила урожайність 1,14–1,15 т/га. Сівба з шириною міжрядь 0,45 м сприяла отриманню врожайності 1,09 т/га, що більше ніж при 0,15 м на 0,06 т/га, або 8,0 %. Вищий рівень врожаю (1,39 т/га) отримано за підзимового строку сівби з шириною міжрядь 0,45 м та нормою висіву 2,0 млн сх. нас. на 1 га. The results of investigations of the effect of seed rate and row spacing on the productivity of coriander on the podzim and early spring yields are given.It was established that the best seeding period for coriander is the podzimovy, in which the fruit yield was 1.21 t / ha, which is more compared to the early spring by 0.30 t / ha, or 24.7%. For a coriander in the conditions of the northern steppe, the seeding rate of 2.0-2.5 million cu is optimal. us. per 1 hectare, which yields 1.14-1.15 t / ha. A seam with a width of 0.45 m row spacings contributed to yielding 1.09 t / ha, which is more than 0.15 m at 0.06 t / ha, or 8.0%. The highest level of harvest (1.39 t / ha) was obtained for the podium seeding period with a width of rows of 0.45 m and a seeding rate of 2.0 million growing seeds per 1 hectare.


Author(s):  
A. Ouji ◽  
S. Chekali ◽  
M. Rouaissi

Background: In Tunisia, faba bean (Vicia faba L.) is the first major food legume. The development of faba bean production is facing several biotic constraints. Faba bean Ascochyta blight caused by Ascochyta fabae is one of the most destructive diseases of faba bean and can cause significant yield loss under favorable conditions. As only incomplete resistance ABL varieties are available, some agronomic practices should be applied to control and reduce Ascochyta blight incidence wherever possible. Therefore, this work was undertaken to evaluate the effect of spacing row and seed rate on ABL severity, growth and yield of faba bean. Methods: A split-plot design with three replications was adopted to carry out this study during 2018 and 2019 cropping seasons. ‘Bachaar’ faba bean variety was sown at 40 and 60 cm row spacing and at three seed rates (100, 140 and 200 kg ha-1). ABL severity was assessed visually on a 0-9 scale and agro-morphological traits were measured. Analysis of variance was used to analyze the data. Correlations between agronomic traits, row spacing, seed rate and ABL severity were investigated. Result: Results showed that seed rate has a larger effect on yield than row spacing. In both cropping seasons, the highest grain yield was recorded in 60 cm row spacing and 140 kg ha-1 seed rate treatment. So, this treatment is recommended for obtaining high yield of faba bean. Most of the variation in disease severity was associated with seed rate (r=0.62). The highest ABL score severity was noted at 200 kg ha-1 rate. Over both years, wide row spacing and low seed rate reduced ABL severity. In this study, the small amounts of ABL disease (which reached a score of 5.3 and 4.7 in 2018 and 2019, respectively) had little or no effect on yield.


2001 ◽  
Vol 33 ◽  
pp. 225-229 ◽  
Author(s):  
R.W. Lindsay

AbstractThe RADARSAT geophysical processor system (RGPS) uses sequential synthetic aperture radar images of Arctic sea ice taken every 3 days to track a large set of Lagrangian points over the winter and spring seasons. The points are the vertices of cells, which are initially square and 10 km on a side, and the changes in the area of these cells due to opening and closing of the ice are used to estimate the fractional area of a set of first-year ice categories. The thickness of each category is estimated by the RGPS from an empirical relationship between ice thickness and the freezing degree-days since the formation of the ice. With a parameterization of the albedo based on the ice thickness, the albedo may be estimated from the first-year ice distribution. We compute the albedo for the first spring processed by the RGPS, the early spring of 1997. The data include most of the Beaufort and Chukchi Seas. We find that the mean albedo is 0.79 with a standard deviation of 0.04, with lower albedo values near the edge of the perennial ice zone. The biggest source of error is likely the assumed rate of snow accumulation on new ice.


Parasitology ◽  
1991 ◽  
Vol 102 (1) ◽  
pp. 147-155 ◽  
Author(s):  
D. Rh. Thomas

SUMMARYNatural populations of 3rd-stage Nematodirus battus larvae were present on pastures in North Wales throughout the year; highest numbers were present in late spring, with smaller peaks occurring in autumn. Inter-site variation was observed in the timing and magnitude of these peaks. Hatching on experimental plots occurred 2 months to 2 years following deposition of eggs. Intraspecific and inter-site variation occurred in the timing, and inter-site variation occurred in the magnitude, of the mass hatch on upland and lowland experimental plots. Arrested 4th-stage N. battus were recovered from Welsh Mountain lambs. Percentage arrest and number of arrested worms was greatest during winter and early spring. The prevalence and intensity of N. battus infection in 1-, 2- and 3-year-old Welsh Mountain ewes was low. The plasticity exhibited in the parasite's life-history is discussed in relation to potential changes in the epidemiology of nematodiriasis.


2020 ◽  
Vol 71 (2) ◽  
pp. 171
Author(s):  
Marco Mariotti ◽  
Marco Macchia ◽  
Domenico Cerri ◽  
Domenico Gatta ◽  
Iduna Arduini ◽  
...  

Cultivation of buckwheat (Fagopyrum esculentum Moench) under Mediterranean photothermal conditions could affect synthesis of the flavonoid rutin and its partitioning within the plant, thus affecting the nutraceutical value of plant products. We examined rutin concentration and yield in the forage and the grain of common buckwheat grown under Mediterranean field conditions, in response to sowing time, irrigation, growth stage at harvest, and variety. The highest rutin concentration and yield in the forage were obtained with late spring sowing, thanks to greater accumulation of solar radiation and higher efficiency of rutin synthesis per photothermal unit. Water supply promoted a more efficient use of light resources for both biomass accumulation and rutin synthesis. Rainfed conditions reduced biomass accumulation to a greater extent than rutin synthesis. Rutin concentration was highest in leaves, followed by inflorescences, stems and achenes, and in all plant parts it decreased with plant age. In the grain, rutin concentration was highest with late spring sowing, and rutin yield was highest with early spring sowing. Correlation analyses suggest that rutin synthesis proceeds from the leaves to the other plant parts. Our research demonstrates that buckwheat can be cultivated in Mediterranean regions as a source of rutin for medicine and for food and feed supplementation.


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