scholarly journals Ear development and formation of grain yield in winter wheat.

1980 ◽  
Vol 28 (3) ◽  
pp. 156-163 ◽  
Author(s):  
A. Darwinkel

The pattern of grain production of a winter wheat crop and the effect of plant density and time of tiller emergence on grain yield/ear were studied. At harvest, ear size and ear components were ascertained and were discussed in relation to ear growth and ear development during the prefloral and postfloral growing period. Detailed information was obtained on the productivity of ear-bearing tillers and their contribution to final grain yield. Shoot productivity decreased in denser crops; ears were smaller because spikelet differentiation, grain set and grain filling were inadequate. The date that the tiller emerged largely determined its subsequent grain yield. With later tiller initiation and emergence fewer ears were produced. Moreover, these ears were smaller because spikelet initiation, spikelet differentiation, grain set and grain filling were reduced. At low and moderate plant densities, the grain yield of the early-emerged tillers only slightly lagged behind that of main shoots and max. grain yield could be achieved at moderate plant densities. It was concluded that in cereal farming, high and stable grain yields are aims to be achieved. These can be best achieved by having moderate plant densities and applying correct treatments for good crop growth. (Abstract retrieved from CAB Abstracts by CABI’s permission)

1978 ◽  
Vol 26 (4) ◽  
pp. 383-398 ◽  
Author(s):  
A. Darwinkel

The effect of plant density on the growth and productivity of the various ear-bearing stems of winter wheat was studied in detail to obtain information on the pattern of grain production of crops grown under field conditions. Strong compensation effects were measured: a 160-fold increase in plant density (5-800 plants/m2) finally resulted in a 3-fold increase in grain yield (282 to 850 g DM/m2). Max. grain yield was achieved at 100 plants/m2, which corresponded to 430 ears/m2 and to about 19 000 grains/m2. At higher plant densities more ears and more grains were produced, but grain yield remained constant. Tillering/plant was largely favoured by low plant densities because these allowed tiller formation to continue for a longer period and a greater proportion of tillers produced ears. However, at higher plant densities more tillers/unit area were formed and, despite a higher mortality, more ears were produced. The productivity of individual ears, from main stems as well as from tillers, decreased with increasing plant density and with later emergence of shoots. In the range from 5 to 800 plants/m2 grain yield/ear decreased from 2.40 to 1.14 g DM. At 800 plants/m2 nearly all ears originated from main stems, but with decreasing plant density tillers contributed increasingly to the number of ears. At 5 plants/m2, there were 23 ears/plant and grain yield/ear ranged from 4.20 (main stem) to 1.86 g DM (late-formed stems). Grain number/ear was reduced at higher densities and on younger stems, because there were fewer fertile spikelets and fewer grains in these spikelets. At the low density of 5 plants/m2, plants developed solitarily and grain yield/ear was determined by the number of grains/ear as well as by grain wt. Above 400 ears/m2, in this experiment reached at 100 plants/m2 and more, grain yield/ear depended solely on grain number, because the wt. of grains of the various stems were similar. The harvest index showed a max. of about 44% at a moderate plant density; at this density nearly max. grain yield was achieved. At low plant densities the harvest index decreased from 45% in main stems to about 36% in late-formed stems. However, no differences in harvest index existed between the various ear-bearing stems if the number of ears exceeded 400/m2. (Abstract retrieved from CAB Abstracts by CABI’s permission)


2018 ◽  
Vol 98 (6) ◽  
pp. 1357-1364 ◽  
Author(s):  
David C. Hooker ◽  
Nader Soltani ◽  
Peter H. Sikkema

A study was conducted at six field sites near Exeter and Ridgetown, ON, over a 3 yr period (2014, 2015, and 2016) to determine the effect of ammonium thiosulphate (ATS), various fungicides (azoxystrobin/propiconazole, trifloxystrobin/prothioconazole, or pyraclostrobin/metconazole), and various herbicides (bromoxynil/MCPA, thifensulfuron/tribenuron + MCPA, pyrasulfotole/bromoxynil, or 2,4-D/dichlorprop) applied alone and in tank-mix combinations on winter wheat crop injury and grain yield. The treatments were applied using Hypro ULD120-02 flat-fan nozzles around Zadoks growth stage 30. The herbicides and fungicides caused <0.6% leaf injury when ATS was not added to the tank-mix. When averaged across fungicides in ATS tank-mixes, leaf injury 1 wk after treatment application was 3.5% to 3.7% with thifensulfuron/tribenuron and dichlorprop-P/2,4-D herbicides and 5.1% to 5.8% injury with bromoxynil/MCPA and thifensulfuron/tribenuron herbicides. On the three field sites with the highest leaf injury, a fungicide–ATS tank-mix increased injury to 4.5% averaged across fungicides and to 4.3% with a herbicide–ATS tank-mix averaged across herbicides. Three-way tank-mixes of herbicide–fungicide–ATS caused the highest injury (7.1%). Despite significant crop injury 1 WAA with some tank-mixes, there was no evidence that grain yields were adversely affected. This study shows that the co-application of a three-way tank-mix of ATS with fungicides (azoxystrobin/propiconazole, trifloxystrobin/prothioconazole, or pyraclostrobin/metconazole) and herbicides (bromoxynil/MCPA, thifensulfuron/tribenuron + MCPA, pyrasulfotole/bromoxynil, or dichlorprop-P/2,4-D) has the potential to cause considerable injury in winter wheat under some environmental conditions in Ontario, but the effect seems transient, with no grain yield reductions detected.


2001 ◽  
Vol 136 (1) ◽  
pp. 1-14 ◽  
Author(s):  
J. F. JENKYN ◽  
D. G. CHRISTIAN ◽  
E. T. G. BACON ◽  
R. J. GUTTERIDGE ◽  
A. D. TODD

Three experiments on winter wheat, each lasting 5 years and on different soil types, were used to test the effects of incorporating different amounts of straw, mainly to determine the importance of achieving uniform distribution to avoid adverse effects on grain yield. Decreases in crop growth and/or grain yield as a consequence of incorporating straw were detected in the first year. The decreases were much larger in one experiment where straw was imported and applied to soil that had been fallowed for 12 months before sowing the wheat than in the other two where the straw was incorporated following the harvest of a winter wheat crop. In the subsequent 4 years, incorporating up to 20 t straw/ha had no significant effects on grain yield but there were some significant effects on concentrations and uptakes of N, P and K, especially on the heavier textured soils. The effects on crop growth and yield that were detected in the first year on each site are tentatively attributed to decreases in available N representing that which was required to support the decomposition of the incorporated straw. The relative lack of significant effects in subsequent years seems to imply that a significant proportion of this N was remineralized relatively quickly, and thus available to support the decomposition of the straw that was incorporated in the second year and, after further recycling, in the years after that. Eyespot, caused by the fungus Pseudocercosporella herpotrichoides, was decreased by incorporating straw but there were few significant effects on other diseases. The results provide a generally reassuring message for farmers in suggesting that on most, if not all, soils there is little cause for concern about the consequences of incorporating even large amounts of wheat straw before sowing a further crop of winter wheat.


2007 ◽  
Vol 99 (2) ◽  
pp. 549-555 ◽  
Author(s):  
Anatoliy G. Kravchenko ◽  
Kurt D. Thelen

2017 ◽  
Vol 30 (3) ◽  
pp. 670-678 ◽  
Author(s):  
ROGÉRIO PERES SORATTO ◽  
TIAGO ARANDA CATUCHI ◽  
EMERSON DE FREITAS CORDOVA DE SOUZA ◽  
JADER LUIS NANTES GARCIA

ABSTRACT The objective of this work was to evaluate the effect of plant densities and sidedressed nitrogen (N) rates on nutrition and productive performance of the common bean cultivars IPR 139 and Pérola. For each cultivar, a randomized complete block experimental design was used in a split-plot arrangement, with three replicates. Plots consisted of three plant densities (5, 7, and 9 plants ha-1) and subplots of five N rates (0, 30, 60, 120, and 180 kg ha-1). Aboveground dry matter, leaf macro- and micronutrient concentrations, yield components, grain yield, and protein concentration in grains were evaluated. Lower plant densities (5 and 7 plants m-1) increased aboveground dry matter production and the number of pods per plant and did not reduce grain yield. In the absence of N fertilization, reduction of plant density decreased N concentration in common bean leaves. Nitrogen fertilization linearly increased dry matter and leaf N concentration, mainly at lower plant densities. Regardless of plant density, the N supply linearly increased grain yield of cultivars IPR 139 and Pérola by 17.3 and 52.2%, respectively.


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