DEFOLIATION EFFECTS ON BIOMASS YIELD COMPONENTS OF WINTER WHEAT

1990 ◽  
Vol 70 (4) ◽  
pp. 1191-1194 ◽  
Author(s):  
S. H. SHARROW

Short duration, high intensity grazing is often used to maximize production of grazed forage crops. Relatively little information is currently available for this practice on dual purpose cereal crops such as wheat. Components of soft white winter wheat biomass yield were studied during the 1979 and 1980 crop years near Corvallis, Oregon. Treatments were a factorial arrangement of two defoliation times (mid-April and mid-May) and three defoliation intensities (undefoliated and clipped to either an 8-cm or 4-cm stubble). All defoliation regimes reduced grain yields compared to undefoliated controls. However, biomass yields of 8-cm vs. 4-cm treatments were similar within defoliation dates. Grain yields primarily reflected the most recent defoliation event, suggesting that plant phenological stage and/or the length of the regrowth period following defoliation was more important than the intensity of the defoliation event in determining plant yield.Key words: Short duration grazing, grazing wheat

Author(s):  
Georgiy Gulyuk ◽  
Aleksey Ivanov ◽  
Yuri Yanko

Current situation and agricultural management on the non-black earth area of Russia arebeing gradually worsen by the negative natural factors such as a significant increase of weather based climatic abnormal risks, deterioration of agro-meliorative conditions of agricultural lands because of colonization by tree and shrubbery vegetation and secondary bog formation, hidden degradation of soil fertility. When combined with functional loss of ameliorative complex and meliorative systems amortization, regional agriculture adaptation possibilities were rapidly limited. Production shortfall due no abnormal weather conditions for particular field crops was 19…48% during last five years, level of business realization of bioclimatic potential on a field was decreased by 7…12%.The complete realization of regional agricultural adaptive potential to weather based climatic changes and limitation of greenhouse gases emissions is possible on a basis of regeneration ofalll functions and aspects of ameliorative complex management. Toward this goal the coordinated actions of federal and regional management of Agricultural Complex, Scientific and Educational institutions, project foundations and managers are needed in a relation to human resources, scientific and regulatory supply. Any incomplete treatment in these fields inherent in visual negative consequences for food security and social economic development of rural areas of non-black earth zones not only at the current historical moment, but in a future also. Fundamental influence of solving of these problems deserves to scientific supply of innovative ameliorative complex, renewal of which should be based on principals of resources and energy preservation, nature management, computerization and digitalization management. During a long term research it was established that increase of average vegetation period temperature by lоСhas increased productivity of winter wheat, barley and summer wheat in average on 0,7 tons per ha, winter wheat and oat on 0,4 tons per ha, potatoes – 8,2 tons per ha, edible roots-6,4 tons per ha, cabbage 9,8 tons per ha, dry basis of herbage of multi and one age grasses–0,5 and 0,7 tons per ha. Increase of СО2 Concentration from 0,35 to 0,45% during last twenty years contributed into grow of yield in regional agriculture which can be estimated as 0,3 tons per ha per measure; searching remedy for agroclimatical risks decreasing production became drainage and irrigation systems (decrease 3…5 times);new method of reclamation of abandoned areas with transformation of biomass of tree and shrubbery vegetation into biochar makes it possible to decrease СО2 emissions up to times and get an adverse balance of СО2;secondary reclamation of lands covered by trees and shrubbery on area of 22ha used for vegetables and area of 37ha used for forage crops could supply a farmer with work and revenue sufficient for maintenance of one child what is on the major facts of population declaim in rural areas.


2000 ◽  
Vol 48 (2) ◽  
pp. 191-195
Author(s):  
C. Kondora ◽  
M. Szabó ◽  
A. Máté ◽  
G. Szabó

Owing to the significant differences in the adaptability of state-registered varieties, those which can adapt well to the local conditions should be given preference. There are several high-yielding varieties available in Hungary with excellent agronomic properties, good adaptability and satisfactory baking quality. This study was conducted to analyse the adaptability of 34 state-registered winter wheat varieties tested in the small plot trials of the National Institute for Agricultural Quality Control (NIAQC) at 5–9 locations between 1994 and 1997 based on their gluten quantity and farinographic index. For the comparison of the varieties the evaluation method of Eberhart and Russell (1966) was applied as modified by Bedő and Balla (1977). The qualitative stability and adaptability values of the varieties differ from the adaptability and stability values calculated from the grain yields. Some winter wheat varieties have good qualitative adaptability and stability, while others have special adaptability and poor qualitative stability, but the majority of the varieties do not belong to these groups.


Planta ◽  
2021 ◽  
Vol 253 (4) ◽  
Author(s):  
Malick Ndiaye ◽  
Bertrand Muller ◽  
Komla Kyky Ganyo ◽  
Aliou Guissé ◽  
Ndiaga Cissé ◽  
...  

2015 ◽  
Vol 66 (4) ◽  
pp. 308 ◽  
Author(s):  
Alison. J. Frischke ◽  
James R. Hunt ◽  
Dannielle K. McMillan ◽  
Claire J. Browne

In the Mallee region of north-western Victoria, Australia, there is very little grazing of crops that are intended for grain production. The success of dual-purpose crops in other regions in south-eastern Australia with higher and more evenly distributed rainfall has driven interest in assessing the performance of dual-purpose cereals in the region. Five experiments were established in five consecutive years (2009–13) in the southern Mallee to measure the forage production and grain yield and quality response in wheat and barley to grazing by sheep or mechanical defoliation. The first three experiments focused on spring cultivars sown from late April to June, and the last two on winter cultivars planted from late February to early March. Cereal crops provided early and nutritious feed for livestock, with earlier sowing increasing the amount of dry matter available for winter grazing, and barley consistently produced more dry matter at the time of grazing or defoliation than wheat. However, the grain-production response of cereals to grazing or defoliation was variable and unpredictable. Effects on yield varied from –0.7 to +0.6 t/ha, with most site × year × cultivar combinations neutral (23) or negative (14), and few positive (2). Changes in grain protein were generally consistent with yield dilution effects. Defoliation increased the percentage of screenings (grains passing a 2-mm sieve) in three of five experiments. Given the risk of reduced grain yield and quality found in this study, and the importance of grain income in determining farm profitability in the region, it is unlikely that dual-purpose use of current cereal cultivars will become widespread under existing grazing management guidelines for dual-purpose crops (i.e. that cereal crops can be safely grazed once anchored, until Zadoks growth stage Z30, without grain yield penalty). It was demonstrated that early-sown winter wheat cultivars could produce more dry matter for grazing (0.4–0.5 t/ha) than later sown spring wheat and barley cultivars popular in the region (0.03–0.21 t/ha), and development of regionally adapted winter cultivars may facilitate adoption of dual-purpose cereals on mixed farms.


2015 ◽  
Vol 5 (1) ◽  
pp. 24
Author(s):  
J. M. Finnan ◽  
J. I. Burke ◽  
T. M. Thomas

<p>A four year experiment was conducted at a site in the south-east of Ireland in which medium and high input conventional winter wheat production systems were compared to no input and low input systems in which winter wheat was direct drilled into an understory of white clover. Whole crop and grain yields from all systems were strongly related to external input levels, yields from bicropped treatments were poor. Nitrogen uptake and grain yields from the conventional treatments declined during the course of the study whereas nitrogen uptake and yields from bicropped treatments were more stable. Fertiliser N application significantly depressed biological production efficiency and altered biomass partitioning. The proportion of biomass partitioned to the stem decreased with fertiliser N, differences between treatments persisted until final harvest. Although the clover sward was still present in the fourth year, this component of the bicrop was gradually replaced by weeds as the experiment progressed in spite of several attempts to control weeds. It is suggested that further research is needed to identify a clover management strategy which ensures the persistence of the white clover sward and allows it to enrich soil fertility in such a way as to be of benefit to the accompanying wheat crop.</p>


2017 ◽  
Vol 155 (9) ◽  
pp. 1394-1406 ◽  
Author(s):  
X. M. MAO ◽  
W. W. ZHONG ◽  
X. Y. WANG ◽  
X. B. ZHOU

SUMMARYThe production of winter wheat (Triticum aestivum L.) is affected by crop population structures and field microclimates. This 3-year study assessed the effect of different precision planting patterns and irrigation conditions on relative humidity (RH), air and soil temperature within the canopy, intercepted photosynthetically active radiation (iPAR), evapotranspiration (ET), water productivity (WP) and grain yields. Field experiments were conducted from 2011 to 2014 on a two-factor split-plot design with three replicates. The experiments involved three precision planting patterns (single row, alternating single and twin rows [hereafter ‘single–twin’] and twin row) and three irrigation treatments (0 mm (I0), 90 mm (I90) and 180 mm (I180)). Planting patterns and irrigation treatments exerted a significant effect on RH, air and soil temperature, iPAR, ET, WP and grain yield. The lowest RH and iPAR levels were detected in the single row pattern. When the irrigation treatment was identical, the highest soil and air temperatures were detected in the single row pattern, followed by the single–twin row and twin row patterns. Compared with the single row, the single–twin and twin row patterns increased ET by 0·3 and 1·4, WP by 4·7 and 5·7% and yields by 6·0 and 7·9%, respectively. Compared with I0, the I90 and I180 irrigation treatments increased ET by 0·3 and 1·4%, and WP by 4·7 and 5·7%, respectively. The grain yields of the twin row pattern were 5·8 and 1·7% higher than those of the single row and single–twin row patterns, respectively. Compared with I0, I90 increased yield by 19·3%. The twin row pattern improved crop structure and farmland microclimate by increasing RH and iPAR, and reducing soil and air temperatures, thus increasing grain yield. These results indicated that a twin row pattern effectively improved grain yield at I0. On the basis of iPAR, WP and grain yield, it was concluded that a twin row pattern combined with an I90 irrigation treatment provided optimal cropping conditions for the North China plain.


2015 ◽  
Vol 16 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Genna M. Gaunce ◽  
William W. Bockus

Barley yellow dwarf (BYD) is one of the most important wheat diseases in the state of Kansas. Despite the development of cultivars with improved resistance to BYD, little is known about the impact that this resistance has on yield loss from the disease. The intent of this research was to estimate yield loss in winter wheat cultivars in Kansas due to BYD and quantify the reduction in losses associated with resistant cultivars. During seven years, BYD incidence was visually assessed on numerous winter wheat cultivars in replicated field nurseries. When grain yields were regressed against BYD incidence scores, negative linear relationships significantly fit the data for each year and for the combined dataset covering all seven years. The models showed that, depending upon the year, 19–48% (average 33%) of the relative yields was explained by BYD incidence. For the combined dataset, 29% of the relative yield was explained by BYD incidence. The models indicated that cultivars showing the highest disease incidence that year had 25–86% (average 49%) lower yield than a hypothetical cultivar that showed zero incidence. Using the models, the moderate level of resistance in the cultivar Everest was calculated to reduce yield loss from BYD by about 73%. Therefore, utilizing visual BYD symptom evaluations in Kansas coupled with grain yields is useful to estimate yield loss from the disease. Accepted for publication 1 December 2014. Published 9 January 2015.


1996 ◽  
Vol 47 (5) ◽  
pp. 817 ◽  
Author(s):  
GJ Murtagh ◽  
GR Smith

Changes in the concentration, composition, and yield of oil in coppice growth of tea tree (Melaleuca alternzfolia) were assessed when plants were harvested in different months. Oil concentrations in leaves were lower when plants were harvested in July-September than in other months, but biomass yields were higher. Consequently, there was no consistent effect of harvest month on oil yield. Oil yield varied as much between the same month in different years, as between months within a year. The oil concentration in one harvest was positively related to the biomass yield at the previous harvest of the same plants, suggesting that a carryover of energy reserves contributed to oil production. The oil concentration was also positively related to the mean air temperatures over the 3 months before harvest. The proportion of the economically significant compounds in oil, terpinen-4-01 and 1,8-cineole, was not affected by either the month of harvest or regrowth cycle, but other compounds did change. There was a significant loss of monoterpene olefins from oil which was present at high concentrations.


2018 ◽  
Vol 64 (No. 4) ◽  
pp. 156-163
Author(s):  
Wang Dapeng ◽  
Zheng Liang ◽  
Gu Songdong ◽  
Shi Yuefeng ◽  
Liang Long ◽  
...  

Excessive nitrogen (N) and water input, which are threatening the sustainability of conventional agriculture in the North China Plain (NCP), can lead to serious leaching of nitrate-N (NO<sub>3</sub><sup>–</sup>-N). This study evaluates grain yield, N and water consumption, NO<sub>3</sub><sup>–</sup>-N accumulation and leaching in conventional and two optimized winter wheat-summer maize double-cropping systems and an organic alfalfa-winter wheat cropping system. The results showed that compared to the conventional cropping system, the optimized systems could reduce N, water consumption and NO<sub>3</sub><sup>–</sup>-N leaching by 33, 35 and 67–74%, respectively, while producing nearly identical grain yields. In optimized systems, soil NO<sub>3</sub><sup>–</sup>-N accumulation within the root zone was about 80 kg N/ha most of the time. In the organic system, N input, water consumption and NO<sub>3</sub><sup>–</sup>-N leaching was reduced even more (by 71, 43 and 92%, respectively, compared to the conventional system). However, grain yield also declined by 46%. In the organic system, NO<sub>3</sub><sup>–</sup>-N accumulation within the root zone was generally less than 30 kg N/ha. The optimized systems showed a considerable potential to reduce N and water consumption and NO<sub>3</sub><sup>–</sup>-N leaching while maintaining high grain yields, and thus should be considered for sustainable agricultural development in the NCP.  


Sign in / Sign up

Export Citation Format

Share Document