Small grain screenings in wheat: interactions of cultivars with season, site, and management practices

2004 ◽  
Vol 55 (7) ◽  
pp. 797 ◽  
Author(s):  
D. L. Sharma ◽  
W. K. Anderson

Small grains that pass through a 2-mm slotted screen (sievings or screenings) are one of the most important causes of price dockages of wheat in Australia because grain size variation greatly affects flour yield and commercial value. The aims of this study were to examine the effects of season, time of sowing, plant population, and applied nitrogen, and their interactions with cultivars, on small grain screenings. Twenty-one field experiments involving 16 new cultivars and elite crossbreds, and various management variables, were conducted in the medium (annual rainfall 325–450 mm) and low (annual rainfall <325 mm) rainfall zones of the Northern Agricultural Region of Western Australia over 3 diverse cropping seasons (1999–2001). Rainfall events towards the end of the season were critical to the level of screenings. Screenings were higher in season 2000 with terminal drought stress, but were low in 2001 despite severe drought stress during early growth. Delayed seeding caused higher screenings in 1999 (average rainfall with even distribution) and in 2000 (terminal drought) but not consistently in 2001 when early drought stress restricted tillering and spike size thereby constraining the yield level. Strong varietal and time of sowing interactions were evident but the relationship between maturity group and the level of screenings was not consistent. Rather, the ability of cultivars to adjust yield components was more important; 82% of the total variance in small grain screenings was accounted for by a regression model based on variety-specific kernel weight, post-heading rainfall (from about 2 weeks before anthesis), and location factors. The effect of increasing plant population on screenings was mostly negative, with some minor exceptions for a few cultivars in the low-rainfall zone. As applied nitrogen was increased, screenings generally increased and cultivar influenced this trend more than rainfall zone. It is postulated that for a cultivar to be unaffected by applied nitrogen, it should have inherently higher grain weight as well as high stability of grain weight across nitrogen levels. Applied nitrogen had a significant effect on screenings only at higher plant populations. In experiments where the level of screenings exceeded 5%, the yield components that were significantly associated with screenings, in order of relative importance, were grain weight > grain number/area > grain number/head > grain yield. Cultivars differed in production of screenings in response to plant population, nitrogen fertiliser and sowing time. Harrismith was the most sensitive cultivar and Wyalkatchem was overall the most tolerant cultivar. Delayed seeding had the least effect on the screenings of cultivars Westonia, Carnamah, and Wyalkatchem. Carnamah was the most stable cultivar against higher levels of applied nitrogen, whereas Westonia required high plant numbers to contain screenings. It is concluded that cultivars can be classified according to specific sensitivities, and appropriate management practices may be suggested to growers.

2021 ◽  
Vol 22 (4) ◽  
pp. 2053
Author(s):  
Judit Bányai ◽  
Marco Maccaferri ◽  
László Láng ◽  
Marianna Mayer ◽  
Viola Tóth ◽  
...  

A detailed study was made of changes in the plant development, morphology, physiology and yield biology of near-isogenic lines of spring durum wheat sown in the field with different plant densities in two consecutive years (2013–2014). An analysis was made of the drought tolerance of isogenic lines selected for yield QTLs (QYld.idw-2B and QYld.idw-3B), and the presence of QTL effects was examined in spring sowings. Comparisons were made of the traits of the isogenic pairs QYld.idw-3B++ and QYld.idw-3B−− both within and between the pairs. Changes in the polyamine content, antioxidant enzyme activity, chlorophyll content of the flag leaf and the normalized difference vegetation index (NDVI) of the plot were monitored in response to drought stress, and the relationship between these components and the yield was analyzed. In the case of moderate stress, differences between the NIL++ and NIL−− pairs appeared in the early dough stage, indicating that the QYld.idw-3B++ QTL region was able to maintain photosynthetic activity for a longer period, resulting in greater grain number and grain weight at the end of the growing period. The chlorophyll content of the flag leaf in phenophases Z77 and Z83 was significantly correlated with the grain number and grain weight of the main spike. The grain yield was greatly influenced by the treatment, while the genotype had a significant effect on the thousand-kernel weight and on the grain number and grain weight of the main spike. When the lines were compared in the non-irrigated treatment, significantly more grains and significantly higher grain weight were observed in the main spike in NIL++ lines, confirming the theory that the higher yields of the QYld.idw-3B++ lines when sown in spring and exposed to drought stress could be attributed to the positive effect of the “Kofa” QTL on chromosome 3B.


2010 ◽  
Vol 61 (6) ◽  
pp. 503 ◽  
Author(s):  
K. G. Pembleton ◽  
D. J. Donaghy ◽  
J. J. Volenec ◽  
R. S. Smith ◽  
R. P. Rawnsley

Understanding which component has the greatest influence on yield is vital when managing lucerne (Medicago sativa) crops to maximise the production of high-quality forage. However, both yield components and plant morphology are affected by interactions between environment conditions and plant genetics. Field experiments across three environments (dryland at Cambridge: 500 mm annual rainfall, brown sodosol soil type; dryland at Elliott: 1200 mm annual rainfall, red ferrosol soil type; and irrigated at Elliott) in Tasmania, Australia were undertaken to investigate the yield, yield components and plant morphology of four lucerne cultivars; DuPuits, Grasslands Kaituna, SARDI 7 and SARDI 10 under cutting. The effect of cultivar on dry matter (DM) yield was different in each environment, with Grasslands Kaituna achieving the highest yield (P < 0.05) in dryland environments, while no difference in DM yield among cultivars (P > 0.05) occurred under irrigation. Stepwise linear regression consistently confirmed mass per shoot as the yield component with the greatest influence on DM yield for all cultivars and environments. Shoot density also had an influence on DM yield in two of the three environments. DuPuits had the highest leaf : stem ratio in all three environments and slower morphological development in two of the environments. Management practices across all environments and cultivars should aim to increase mass per shoot to maximise yield. Of the cultivars examined Grasslands Kaituna is the most appropriate for dryland conditions in Tasmania, while all cultivars examined were suited to production under irrigation.


2009 ◽  
Vol 195 (6) ◽  
pp. 427-441 ◽  
Author(s):  
N. H. Samarah ◽  
A. M. Alqudah ◽  
J. A. Amayreh ◽  
G. M. McAndrews

2021 ◽  
Vol 49 (4) ◽  
pp. 12003
Author(s):  
Ali RAHBARI ◽  
Jafar MASOUD SINAKI ◽  
Ali DAMAVANDI ◽  
Shahram REZVAN

Castor bean is considered as an important non-edible oilseed crop and source of castor oil, which has many applications ranging from cosmetics to the biofuels industry. Humic acid (HA) results from organic matter decomposition and is beneficial to plant growth and development. In the present study, a two-year experiment was conducted in Damghan, Iran, to study the physiological responses of castor bean to foliar application of zinc nano-chelate (Zn-nano) and HA under drought stress. The drought stress was used as the main treatment in three levels: normal irrigation as control, irrigation up to 75 BBCH scale (Biologische Bundesantalt, Bundessortenamt und Chemische Industrie) (mild stress), and irrigation up to 65 BBCH (severe stress). Foliar application of HA in three levels (non-application, application of the recommended rate and two times more than the recommended rate), as well as Zn-nano fertilizer in two levels (application at 1.5 part per thousand (ppt) and non-application) as subplots. The drought stress, HA, and Zn-nano fertilizer could significantly affect the number of capsules, the number of seeds, 100-seed weight, seed yield, oil yield, protein percentage and yield, activities of catalase (CAT), superoxide dismutase (SOD), and peroxidase (POD), and chlorophyll a (Chl a), chlorophyll b (Chl b), and total chlorophyll (total Chl) contents. In addition, severe drought stress resulted in reducing the number of capsules (33.9%), the number of seeds (32.7%), 100-grain weight (16.0%), as well as seed (43.0%), oil (59.3%), and protein (29.9%) yield. Based on the results, the highest yield components, oil and protein contents, and photosynthetic pigments were achieved in the foliar application of HA (recommended rate) and Zn-nano fertilizers under normal irrigation during the second year. Further, the foliar application of Zn-nano fertilizer led to a decrease in the activities of CAT, SOD, and POD enzymes. According to partial regression analysis, the recommended rate of HA application the changed the nature of relationships governing the characteristics, especially under drought stress conditions. Finally, the foliar application of HA (recommended rate) and Zn-nano fertilizers could create an excellent resistance to drought stress in castor under dry and semi-arid climate conditions by improving yield and yield components and physiological traits.


Agriculture ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 579
Author(s):  
Gustavo Castilho Beruski ◽  
Luis Miguel Schiebelbein ◽  
André Belmont Pereira

The potential yield of annual crops is affected by management practices and water and energy availabilities throughout the crop season. The current work aimed to assess the effects of plant population, planting dates and soil covering on yield components of maize. Field experiments were carried out during the 2014–2015 and 2015–2016 growing seasons at areas grown with oat straw, voluntary plants and bare soil, considering five plant populations (40,000, 60,000, 80,000, 100,000 and 120,000 plants ha−1) and three sowing dates (15 September, 30 October and 15 December) for the hybrid P30F53YH in Ponta Grossa, State of Paraná, Brazil. Non-impacts of soil covering or plant population on plant height at the flowering phenological stage were observed. Significant effects of soil covering on yield components and final yield responses throughout the 2014–2015 season were detected. An influence of plant populations on yield components was evidenced, suggesting that, from 80,000 plants ha−1, the P30F53YH hybrid performs a compensatory effect among assessed yield components in such a way as to not compromise productivity insofar as the plant population increases up to 120,000 plants ha−1. It was noticed, a positive trend of yield components and crop final yield as a function of plant density increments.


Author(s):  
Maryam Rahimi Jahangirlou ◽  
Gholam Abbas Akbari ◽  
Iraj Alahdadi ◽  
Saeid Soufizadeh ◽  
Uttam Kumar ◽  
...  

AbstractIn semi-arid regions, selecting cultivars and planning management practices are critical issues for improving yields and reducing risks of maize cultivation in the short summer cropping season. This study aimed to assess the responses of grain yield (GY) and important phenotypic characteristics of maize cultivars from different maturity groups under various irrigation regimes, planting dates, and nitrogen rates, in a 2-year experiment. According to the clusters identified in the loading plot, stover yield, radiation use efficiency (RUE), height, leaf greenness index, stem weight, and ear size during flowering (VT/R1) were strongly correlated with GY, yield components and harvest index. Based on analysis of variance, more irrigation or N, or their interaction often increased GY, rows ear−1, grains row−1 and hundred-grain weight. Late planting decreased GY of KSC704 (late maturity cultivar). KSC260 (early maturity cultivar) had greater flexibility in planting time, required less days for maturity, and had less water consumption. The findings highlight the physiological basis of the relationship between the different phenotypic characteristics and how they affect GY and its components. They were in line with the established theories that higher RUE, biomass and sink activity (e.g. grain weight and numbers, and larger ear size) are associated with better genetic gains to produce high GY. Although the results were not consistent between years, findings suggested the good performance of recently released early maturity cultivars for use during the summer growing season.


1983 ◽  
Vol 55 (4) ◽  
pp. 333-344
Author(s):  
Reijo Karjalainen ◽  
Aino Laitinen ◽  
Tapio Juuti

Data from two experiments was analysed in order to determine the effects of Septoria nodorum Berk. on the yield of spring wheat. In the first experiment the cultivar Hankkija’s Taava was artificially inoculated with low spore concentration suspensions of S. nodorum. The resulting disease reduced grain yield by 10%, 1000-grain weight by 14%, and hectorlitre weight by 5.7 %. An examination of the ears from the main stems revealed that the pathogen induced a reduction in all yield components but especially in grain number/ear and grain weight. In the second experiment a total of 28 cultivars or lines were studied and the correlation between grain yield/ear and disease severity was found to be negative but low. No consistent trend among the correlations was seen and some susceptible cultivars suffered only slightly from the disease while other fairly resistant cultivars showed great losses. The results are discussed in relation to compensatory mechanisms and potential disease tolerance in wheat.


Author(s):  
Gustavo Castilho Beruski ◽  
Luis Miguel Schiebelbein ◽  
André Belmont Pereira

The potential yield of annual crops is affected by management practices and water and energy availabilities throughout the crop season. The current work aimed to assess the effects of plant population and soil covering on yield components of maize. Field experiments were carried out during 2014-15 and 2015-16 growing seasons at areas grown with oat straw, voluntary plants and bare soil, considering five different plant populations (40,000, 60,000, 80,000, 100,000 and 120,000 plants ha-1) and three sowing dates (15 Sep., 30 Oct., 15 Dec.) for the hybrid P30F53YH in Ponta Grossa, State of Parana, Brazil. Non-impacts of soil covering or plant population on plant height at the flowering phenological stage were observed. Significant effects of soil covering on crop physiological and yield components responses throughout the 2014-15 season were detected. Influence of plant populations on yield components was evidenced, suggesting that from 80,000 plants ha-1 the P30F53YH hybrid performs a compensatory effect among assessed yield components in such a way as to not compromise productivity insofar as plant population increases up to 120,000 plants ha-1. It was noticed a positive trend of yield components and crop final yield as a function of plant density increments.


Euphytica ◽  
2011 ◽  
Vol 186 (1) ◽  
pp. 127-138 ◽  
Author(s):  
Khalil Zaynali Nezhad ◽  
W. E. Weber ◽  
M. S. Röder ◽  
S. Sharma ◽  
U. Lohwasser ◽  
...  

2021 ◽  
Author(s):  
Xinjun Zhang ◽  
Wenting Liu ◽  
Yaci Lv ◽  
Tianliang Li ◽  
Jianzhao Tang ◽  
...  

Abstract Revealing the effects of drought stress during the critical period on the photosynthetic characteristics and production performance of naked oats could provide theoretical basis for optimizing the water managements and selecting the drought resistance cultivars. In this study, a potted experiment consisting of four water levels was conducted, to investigate the response of photosynthesis, chlorophyll fluorescence, biomass, yield and yield components of to drought stress during 12-15 days before heading at a typical site in Zhangjiakou. Results showed that the initial chlorophyll fluorescence rate (Fo) increased by 9.03-50.92% under drought stress, while the maximum fluorescence rate (Fm) and photochemical efficiency (Fv/Fm) decreased by 8.49-19.73% and 10.37-24.12%. Moreover drought stress decreased the photosynthetic rate (Pn), transpiration rate (Tr), stomatal conductance (Gs). The CO2 concentration (Ci) decreased under light drought stress, while increased under moderate and severe drought stress. Drought stress during critical periods also had significant impacts on oat yield and yield components. Oat yields decreased by 9.5-12.7%, 16.8-27.0% and 44.1-47.7% under light, moderate and sever drought stress, respectively. The yield components such as grains per spike, 1000-grain weight were decreased by 1.7-12.5%, 8.3-24.3%, 32.7-34.2% and 5.7-8.6%, 12.7-14.5%, 16.8-19.1% under light, moderate and severe drought stress, respectively. But the Spike numbers were not signifigantly different between different treatments. Our study explored the impacts of drought stress on the photosynthetic characteristics and production performance of naked oats, which had significance for enhancing the production efficiency for oat under drought stress.


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