scholarly journals Chlormequat chloride and ethephon affect growth and yield formation of conventional, naked and dwarf oat

2001 ◽  
Vol 10 (3) ◽  
pp. 165-174 ◽  
Author(s):  
P. PELTONEN-SAINIO ◽  
A. RAJALA

Department of Plant Production, PO Box 27, FIN-00014 University of Helsinki, Finland. Current address: MTT Agrifood Research Finland, Plant Production Research, FIN-31600 Jokioinen, Finland. e-mail: [email protected] Plant growth regulators (PGRs) are not usually applied to oat (Avena sativa L.) crops. This study was designed to test whether the antigibberellin chlormequat chloride (CCC) and ethylene-releasing ethephon sprayed on to oat foliage represent potential agents for manipulation of yield formation under northern growing conditions. Effects of these PGRs on yield components and tiller growth and productivity were examined in detail. This study included a long-strawed landrace, a modern standard height cultivar, two naked (A. sativa ssp. nuda L.) and two dwarf oats. Field experiments were conducted at Viikki Experimental Farm, University of Helsinki, in 1995 and 1996. Chlormequat chloride was sprayed at the two-node stage and ethephon when the flag leaf ligule was just visible on the main shoot. Various traits characterizing growth and yield formation were assessed. Chlormequat chloride increased grain yield by 0% to 13% depending on cultivar and year, while ethephon most often decreased it by up to 17%. No lodging occurred and the recorded increase in grain yield of CCC treated plants was not therefore due to prevention of lodging. However, CCC treatment resulted in more panicles per square meter and in 1995 tillers contributed more to grain yield. Ethephon treated plants had less grains per main shoot panicle, lower panicle filling rate (PFR) and parallel decreased harvest index (HI). Stem elongation of dwarf oat was enhanced by CCC, in contrast to that of conventional and naked cultivars.;

2002 ◽  
Vol 11 (3) ◽  
pp. 233-244 ◽  
Author(s):  
A. RAJALA ◽  
P. PELTONEN-SAINIO

Plant growth regulators (PGRs) are commonly used in commercial farming to control lodging in cereals. PGRs have been shown to alter yield formation and plant stand structure, other than the straw length. To study their potential in Northern growing conditions PGRs and their application time impacts on plant stand structure and yield formation in tall and short statured cultivars of barley, oat, and wheat were studied in the field. Crop stands were sprayed with the gibberellin biosynthesis inhibitors CCC [chlormequat chloride CCC], Moddus [Trinexapac-ethyl TE], or with ethylene-releasing Cerone [ethephon ETH] at the recommended times or at an earlier growth stage. CCC applied at Zadoks growth scale (ZGS) 13-14 increased and ETH applied at ZGS 39-40 reduced grain yield of oat by 370 kg ha-1 and 270 kg ha-1, respectively. In wheat, CCC applied at ZGS 31-32 reduced grain yield by 480 kg ha-1. This yield reduction was associated with lower grain yield production by the main head and particularly lower single grain weight. In barley cv. Kymppi, ETH and TE treatments promoted yield formation, whereas in cv. Saana they tended to reduce yield. Early applied PGRs reduced stem height at 14 days after treatment irrespective of species or stem stature, but at maturity no constant PGR effect was noted. Excluding the stem length, PGRs did not modify plant stand structure or yield formation markedly.


2008 ◽  
Vol 13 (1-2) ◽  
pp. 170 ◽  
Author(s):  
P. MÄKELÄ ◽  
S. MUURINEN ◽  
P. PELTONEN-SAINIO

The Finnish growing season is particularly short, with an intensive growth period, unfavourable rainfall distribution and frequently occurring fluctuations in climate that affect crop growth and yield formation. A three-year study was conducted in the field to determine the contribution of alterations in canopy structure, tillering and stem elongation among dwarf (D), semidwarf (SD) and tall (T) oat (Avena sativa L.) lines to yield formation. Yield components, leaf characteristics and straw traits were measured from six oat lines (D lines Pal and Grane, SD lines Hja 76416 and Salo, and T lines Veli and Jalostettu maatiainen) separately on the main shoot and tillers. Results indicated that long leaf area duration and high leaf area index were associated with increased grain yield probably due to more persistent and active assimilation. Also, higher number of leaves increased the grain yield. Higher peduncle, straw and node weights associating with increased grain yield may result from more abundant assimilate reserves; however, the longer the straw and peduncle, the lower the grain yield, which may result from increased lodging of SD and T lines. The traits contributing most to the grain yield varied greatly from year to year. It is concluded that no single dominant trait determined grain yield, since yield is a product of several different traits. SD lines seemed to be most promising for further breeding programs on the basis of their growth pattern and yielding ability.;


2002 ◽  
Vol 11 (2) ◽  
pp. 153-161 ◽  
Author(s):  
P. PELTONEN-SAINIO ◽  
A. RAJALA ◽  
S. MUURINEN

Aspects of crop physiology and agronomy of spring rye were evaluated at Viikki Experimental Farm, University of Helsinki in 1996-1998 to get baseline information on its potential as a novel cereal crop in southern Finland.The German spring rye cultivar Ovid was fertilized with 80 kg N ha-1. Seeding rates were 300,500 and 700 viable seeds m-2. Chlormequat chloride (CCC)was sprayed at the two-node stage of the main shoot and its effects on lodging and yield formation were studied. Various traits were assessed that characterised tiller and main shoot growth and productivity, growth duration and plant stand structure.Spring rye responded differently over years and among CCC treatments. CCC increased grain yield by about 200 kg ha -1 compared with the control.Spring rye has long straw (130-140 cm)and tended to lodge under heavy rainfall.Thus,grain yield was maximum (ca. 5200 kg ha -1 in 1997)when rainfall was minimum.Partly because high seeding rates enhanced lodging,no seeding rate effects on grain yield were recorded.At 300 seeds m-2, yield formation of both main shoot and tillers was enhanced to compensate for the reduced number of main shoots m-2. Ripening was not delayed at low seeding rates.Grain and hectolitre weights were not affected by seeding rate. Thus,spring rye is a potential crop for Finland if low seeding rates are used.;


2019 ◽  
Vol 70 (1) ◽  
pp. 55 ◽  
Author(s):  
Mark S. McLean ◽  
Grant J. Hollaway

Net form of net blotch (NFNB), caused by Pyrenophora teres f. teres, is a major foliar disease of barley (Hordeum vulgare L.) worldwide that can cause grain yield and quality loss in susceptible varieties. Seed- and foliar-applied fungicides were evaluated in six field experiments infected with NFNB during 5 years, for suppression of NFNB severity and protection of grain yield and quality. Suppression of NFNB severity varied between treatments and experiments. Grain yield and quality improvements were recorded in two experiments. Foliar fungicide applications at stem elongation (Zadoks growth stage Z31) and flag leaf emergence (Z39) or ear emergence (Z55) significantly reduced NFNB severity, increased grain yield by up to 23%, and improved grain-quality measurements of retention, screenings and weight. The seed-applied fungicide fluxapyroxad provided significant reductions in NFNB severity, improvements in grain yield of up to 20%, and improved grain quality. Where NFNB was severe, none of the seed or foliar fungicide application strategies provided complete control of NFNB, indicating that more than two applications were necessary when conditions were favourable for disease development in susceptible varieties.


2020 ◽  
Author(s):  
Nikolaos-Christos Vavlas ◽  
Toby Waine ◽  
Jeroen Meersmans ◽  
Goetz Richter

<p>Synthetic Aperture Radar (SAR) is sensitive to the surface structure as well as dielectric properties, so can be used to quantify the canopy characteristics and surface moisture. High temporal frequency SAR backscatter data are useful in terms of quantifying crop phenological development, growth and yield formation. The aim of this research is to identify the growth dynamics of winter wheat from SAR at field scale, validated using farm sites with different productivity between two years (2018-2019). We identify and explore the parameters which characterize crop performance from SAR temporal curves and use these to improve and automate the monitoring of wheat fields. Our novel methodology includes the extraction of crop indicators using the VH/VV ratio temporal curve from Sentinel-1. Sigmoid curve fitting is used to simulate the VH/VV response and the extracted parameters are related to the field development. The results show that specific indicators, such as the duration of the high vegetation (stem elongation to dough development) as well as the timing of the booting stage of wheat significantly correlate with the final yield. Other indicators can provide information about the canopy characteristics of wheat (e.g. above ground biomass and plant water content). The combination of selected indicators can provide a more robust analysis of the fields. These results demonstrate the potential of SAR to remotely quantify yield without using any management data from the farm.</p>


2014 ◽  
Vol 94 (5) ◽  
pp. 891-903 ◽  
Author(s):  
M. R. Fernandez ◽  
W. E. May ◽  
S. Chalmers ◽  
M. E. Savard ◽  
A. K. Singh

Fernandez, M. R., May, W. E., Chalmers, S., Savard, M. E. and Singh, A. K. 2014. Are early foliar fungicide applications on durum wheat grown in southeast Saskatchewan beneficial in increasing grain productivity? Can. J. Plant. Sci. 94: 891–903. Producers have expressed interest in applying fungicides early in the development of durum wheat to reduce disease severity and increase grain yield. To address this issue, a field trial was conducted in southeast Saskatchewan (2004–2006) to determine the impacts of single and double foliar fungicide (tebuconazole) applications at various growth stages on leaf spotting, Fusarium head blight/Fusarium-damaged kernels, deoxynivalenol concentration, dark kernel discolouration, and grain traits of durum wheat. In most cases, application at stem elongation was not effective in reducing Fusarium diseases, or improving yield and grain characteristics. Application at flag leaf emergence was more effective, but for the most part, application at anthesis resulted in the most consistent reduction in disease levels, and improvement in test weight. Double fungicide applications (stem elongation or flag leaf emergence, and anthesis) were not more effective in disease control than a single application at anthesis. Grain yield did not differ significantly among any of the treatments. In contrast to Fusarium diseases and leaf spotting, fungicide applications at stem elongation and/or flag leaf emergence resulted in increased kernel weight and percentage dark kernel discolouration, which was significant in 2005 (10.53–10.60% total kernel discolouration in the stem and flag leaf treatments vs. 6.13% for the untreated control). In one or more years, kernel weight was negatively associated with Fusarium disease variables and leaf spotting, but positively associated with kernel discolouration. We conclude that under variable environmental conditions in Saskatchewan, early preventative fungicide use on durum wheat should not be recommended as a strategy to improve productivity, and might even result in increases in dark kernel discolouration and grain downgrading.


1980 ◽  
Vol 31 (4) ◽  
pp. 637 ◽  
Author(s):  
EE Whingwiri ◽  
DR Kemp

Wheat plants in an irrigated field crop were fertilized with 0 (N0), 3 (N3), 10 (N10) or 30 (N30) kg nitrogen ha-1 week-1 for 10 weeks, commencing 12 days after sowing, till the flag leaf reached maturity. Nitrogen significantly increased tiller numbers, dry matter and grain yields per plant. Maximum plant size resulted from the N30 treatment, but maximum grain yields per plant from the N10 treatment. Total spikelet numbers increased with increasing nitrogen supply up to the N30 treatment, and this was due to increased rates of spikelet primordia production. Nitrogen treatments had almost no effect on the duration of spikelet primordium formation. Only two ear-bearing tillers were produced in the N10 and N30 treatments, and none in the others. Tiller apices had a similar, or in the case of the second tiller of N30 plants a 29% higher, rate of spikelet primordia formation to that of the associated main shoot, and all apices formed terminal spikelets at a similar time. The second tiller did not initiate primordia production until 25% of final spikelet numbers were present on the main shoot apex. The higher grain yield per plant in the N10 than in the N30 treatment was due largely to more grains per fertile spikelet on the tillers of N10 plants. It was speculated that the poorer performance of tillers on N30 plants was due to mutual shading of shoots and/or poorer nitrogen nutrition of the tiller apices owing to the method of nitrogen application. It was concluded that nitrogen supply affected grain yield per ear more by influencing the ability of florets to set grain than by varying spikelet number.


2013 ◽  
Vol 59 (No. 10) ◽  
pp. 472-477 ◽  
Author(s):  
B. Roitner-Schobesberger ◽  
Kaul H-P

Amaranth is a promising C4-crop. However, for a wider spread of the crop a better understanding of factors that are influencing yield formation is crucial for optimizing the plant phenotype and enhancing yield. The present study wanted to clarify the effects of assimilate sources and sinks on yield formation by artificially altering source or sink size. Field experiments were conducted in Eastern Austria during three years with three genotypes, applying source-sink manipulation treatments at mid flowering (control, 50% of inflorescence removed, 50% or 100% of leaves removed). At maturity we measured shoot, inflorescence and grain dry matter, thousand kernel mass and number of seeds per plant. An average grain yield level of about 3.5 t/ha dry matter on control plots indicated favorable growth conditions for amaranth in general. The removal of all leaves had a strong detrimental effect on all parameters, but severity of yield reduction due to defoliation differed between genotypes, ranging from –49% to –73%. Contrastingly, 50% flower reduction did not have any significant effects. Also with 50% defoliation no significant yield reduction was observed. We conclude that source strength of amaranth during flowering is more yield limiting than its sink capacity.


2017 ◽  
Vol 2 (1) ◽  
pp. 58-69
Author(s):  
Armara Macimiliam Galwab ◽  
Prof. Peter Kamau

Purpose: The purpose of this study was to determine the interaction effects between  water harvesting techniques and spacing on grain yield and above ground biomass of cowpea.Methodology: A randomized complete block design was used. Field experiments were conducted. The study was conducted at Agriculture demonstration farm (Dakabaricha) and Yayo’s farm(Nagayo) and a private farm Demo farm. There were 18 treatment combinations consisting of three water harvesting techniques and two intra-row spacing.Results: The use of tied ridges (W3/S2) as the first and open ridges (W2/S1) as the second efficient techniques of water harvesting for this specific condition (Arid and semi-arid). In line with the above ground biomass, tied ridges with a spacing of 60 x 20cm planting could be safely recommended as the first and effective type of water harvesting techniques for use as a means of soil and water conservation for rain-fed cowpea under the prevailing conditions. The results of the study also showed that water harvesting techniques had a significant effect on the growth and yield of cowpea (Katumani K80).Unique  Contribution to Theory, Practice and Policy: Farmers are encourage to give more emphasis to water harvesting techniques in situ and drought tolerant crops (DTC) which are high yielding in order to bost the economic of the resource poor residence in the area through capacity building. An assessment of adaptation of more cowpea genotypes at different environments across years is recommended. The investigation provided sufficiently evidence to continue with further studies. 


2020 ◽  
Author(s):  
Rayehe Mirkhani ◽  
Mehdi Shorafa ◽  
Mohammad Zaman

<p>Among the essential plant nutrients, nitrogen (N) is the most needed. Farmer apply N fertilizer, predominantly urea to meet crop N demand. However, a greater proportion of the applied urea-N is not being used by plants and lost to the atmosphere as ammonia or greenhouse gases. Therefore, it is necessary to enhance N use efficiency (NUE) of applied urea by minimizing such losses, which has environmental and economic implications. Nitrification inhibitor, such as nitrapyrin (NP), has the most potential to minimise N losses and enhance crop yield. Similarly, plant hormones, such as GA3, has the potential to reduce abiotic stress and improve plant growth and yield.   <br>A field experiment was established on an arable site at University of Tehran, Karaj to determine the effect of urea applied with Nitrapyrin and GA3 on wheat yield in 2018-2019. Karaj has a Mediterranean climate with annual precipitation of 265 mm. A randomized complete block design in five replications was used in this study. Treatments were: T1 (control treatment - without urea), T2 (farmers practice - 138 kg N/ha), and T3 (best practice - 138 kg N/ha+NP+GA3). Urea was applied in three split applications (46 kg N/ha) at growth stage (GS 21) or tillering, (GS 32) or stem elongation, and (GS 40) or booting. GA3 in T3 treatment, was applied only at stem elongation stage. <br>The crop yield data showed that, urea applied with NP and GA3 had a significant (p ≤ 0.01) effect on grain yield, biological yield, number of grains, 1000-grain weight and % Harvest Index (%HI) compared to other treatments. Urea applied with NP and GA3 increased grain yield (10.30 t ha-1) by 13.9% and 46.1% compared to farmer practices (9.04 t ha-1) and control treatment (7.05 t ha-1). These results suggest that co-application of urea with NP and GA3 has the potential to enhance wheat yield in semi-arid area of Iran.</p>


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