A positive allelopathic effect of corn cockle, Agrostemma githago, on wheat, Triticum aestivum

1992 ◽  
Vol 70 (9) ◽  
pp. 1916-1918 ◽  
Author(s):  
Bodil Søgaard ◽  
Hans Doll

The effect of corn cockle on wheat was studied during germination and on adult plants in a growth chamber. Seedling length of wheat germinated together with corn cockle for 5 days increased 13%. Wheat growing together with corn cockle in pots to maturity had a statistically significant higher wheat biomass and grain production than wheat growing alone. However, two other experiments with adult plants harvested before wheat maturity showed no effect of corn cockle on wheat production per pot. Within the pots the presence of corn cockle influenced wheat in all three experiments. Wheat plants growing at the same position as a corn cockle plant were 20 to 50% larger than wheat plants standing alone. Key words: growth stimulation, allelopathy, competition, interference.

1990 ◽  
Vol 68 (7) ◽  
pp. 1597-1601 ◽  
Author(s):  
John S. Taylor ◽  
Munjeet K. Bhalla ◽  
J. Mason Robertson ◽  
Lu J. Piening

During overwintering in a northern climate, winter wheat goes through a hardening process, followed by dehardening in late winter – early spring. This sequence of events may be partially controlled by changes in endogenous hormone levels. Crowns and leaf tissue from field grown winter wheat (Triticum aestivum L. cv. Norstar) seeded at the beginning of September were collected and freeze-dried at monthly intervals during the winters of 1985–1986 and 1986–1987. Material was also sampled and freeze-dried from seedlings grown in a growth chamber under hardening conditions (21 °C for 2 weeks plus 3 °C for 6 weeks) or nonhardening conditions (3 weeks at 21 °C). The tissues were analysed for cytokinins and abscisic acid. Cytokinin levels, measured with the soybean hypocotyl section assay, declined from October onwards and then rose to a peak in late winter (January and February, winter 1986–1987; February and March, winter 1985–1986), subsequently declining again. Abscisic acid, quantitated as the methyl ester by gas chromatography with an electron capture detector, increased in level from October to December, then decreased to a relatively low level between January and March. Hardened seedlings from the growth chamber contained significantly higher abscisic acid levels and significantly lower cytokinin levels than did the nonhardened seedlings. Key words: abscisic acid, cytokinins, hardening, Triticum aestivum, winter wheat.


2015 ◽  
Vol 33 (1) ◽  
pp. 93-101 ◽  
Author(s):  
N.M. CORREIA ◽  
L.T. ACRA ◽  
G. BALIEIRO

This study aimed to control different populations of Digitaria insularisby glyphosate herbicide, isolated and mixed, besides the combination of methods (chemical and mechanical) to manage resistant adult plants. Three experiments were conducted, one in pots which were maintained under non-controlled conditions and two under field conditions. In the experiment in pots, twelve populations of D. insularis were sprayed with isolated glyphosate (1.44 and 2.16 kg a.e. ha-1) and mixed (1.44 and 2.16 kg a.e. ha-1) with quizalofop-p tefuryl (0.12 kg i.a. ha-1). The treatment of 1.44 kg a.e. ha-1 of glyphosate plus 0.12 kg a.i. ha-1 of quizalofop was sufficient for adequate control (>95%) of all populations. Population 11 (area of grain production in Itumbiara, GO) was considered sensitive to glyphosate. Others populations were moderately sensitive or tolerant to the herbicide. In the field, the plants of D. insularis of one of the experiments were mowed and, in the other, there were not. Eight treatments with herbicides [isolated glyphosate (1.44 and 2.16 kg a.e. ha-1) and mixed (1.44 and 2.16 kg a.e. ha-1) with quizalofop-p-tefuryl at 0.12 kg a.i. ha-1), clethodim at 0.108 kg a.i. ha-1) or nicosulfuron at 0.06 kg a.i. ha-1)] were assessed, in combination with or without sequential application of the standard treatment, sprayed 15 days after the first application. The combination of the mechanic control with the application of glyphosate (2.16 and 1.44 kg a.e. ha-1) plus quizalofop-p-tefuryl (0.12 kg a.i. ha-1) or clethodim (0.108 kg a.i. ha-1), associated to the sequential application, was the most effective strategy for the management of adult plants of resistant D. insularis.


2016 ◽  
Vol 6 (3) ◽  
pp. 95-100
Author(s):  
Nadi Awwad Al Harbi

The aim of the present study was to investigate the potentials for utilization of Artemisia herba-alba and Anthemis arvensis shoot aqueous extract at different concentrations (1%, 3%, and 5%) to suppress the germination and growth of Panicum turgidum and Portulaca oleracea (weeds of crop fields) in Petri dish experiment. Results indicated that the degree of inhibition on seed germination and growth of the recipient species was largely dependent on the concentration of A. herba-alba and A.arvensis shoot aqueous extract. The aqueous extract of A.herba-alba showed the highest allelopathic effect on the germination of the seeds of P. turgidum, (10%,10% and 0%) while the effect of A. arvensis shoot aqueous extract was greater on the germination of the seeds P. oleracea (40%,0% and 0%). Percentage germination of the two selected crop species Triticum aestivum and Hordeum vulgare also de-creased as the A.herba-alba and A.arvensis shoot aqueous extract concentra-tion increased from 1% to 5% (90%,80% and 70%),(40%,40% and 20%). But the inhibition percentage was largely less than that of weed species. The results also showed that H.vulgare was more sensitive than T. aestivum and responds more strongly to the increase of concentration of A. herba-alba shoot aqueous extract . Results also showed that the radicle length of almost all tested species was more sensitive to allelochemicals from A.herba-alba and A.arvensis shoot aqueous extract than plumule length. Therefore, A. herba-alba and A. arvensis shoot aqueous extract may offer promises for their usefulness as a tool for weed management.


Genome ◽  
1987 ◽  
Vol 29 (4) ◽  
pp. 627-629 ◽  
Author(s):  
George Fedak ◽  
K. C. Armstrong ◽  
R. J. Handyside

Plants of Triticum aestivum cv. Chinese Spring were regenerated from 30 calli obtained from suspension cultures. All four plants showed abnormal meiotic chromosome behaviour relative to the control. The average meiotic configuration over all plants was 1.55 I + 18.16 II + 0.30 III + 0.82 IV. In addition, an isochromosome was frequently observed in cells of all plants, which was indicative of centromeric breaks. Key words: culture (suspension), wheat, chromosome instability.


1998 ◽  
Vol 12 (2) ◽  
pp. 286-292 ◽  
Author(s):  
Case Medlin ◽  
Thomas F. Peeper ◽  
James H. Stiegler ◽  
John B. Solie

Experiments were conducted near Duke and Forgan, OK, on land enrolled in the Conservation Reserve program (CRP) that had been seeded to Old World bluestem (OWB) to evaluate tillage systems for returning CRP grassland to winter wheat production. Glyphosate controlled OWB 72% or less in no-till (NT) wheat. Disk tillage (DT) and moldboard plow tillage (MPT) for wheat seedbed preparation controlled OWB 87 and 99%, respectively, at Forgan and 96 and 100%, respectively, at Duke. At Forgan, OWB control in NT was higher when glyphosate was applied in July than when applied in May. Soil water content to a depth of 120 cm at planting was as high in DT and MPT without herbicide as in NT with 1,680 g ae/ha glyphosate. Within NT and MPT, glyphosate did not consistently increase soil water content compared to the respective nontreated checks. In DT, soil water content to a depth of 120 cm was greater following glyphosate at 1,680 g/ ha than without glyphosate. Wheat density was greater in DT and MPT than in NT. Compared to the NT no herbicide treatment, tillage tripled wheat yields. Wheat yields were often greater where glyphosate was applied before tillage. No-till wheat production immediately after CPR in Oklahoma without prior destruction of accumulated OWB residue does not appear feasible.


Genome ◽  
1996 ◽  
Vol 39 (2) ◽  
pp. 272-276 ◽  
Author(s):  
B. Friebe ◽  
E. D. Badaeva ◽  
B. S. Gill ◽  
N. A. Tuleen

C-banded karyotypes of a complete set of 14 Triticum peregrinum whole chromosome addition lines and 25 telosomic addition lines are reported. The added T. peregrinum chromosomes were not structurally rearranged compared with the corresponding chromosomes of the donor accession. Comprehensive karyotypic analysis confirmed Triticum umbellulatum as the donor species of the Uv genome and identified Triticum longissimum as the donor species of the Sv genome of T. peregrinum. Neither the Uv nor Sv genome chromosomes of the T. peregrinum accession showed large modifications when compared with the ancestral U and S1 genomes. Key words : Triticum aestivum, Triticum peregrinum, Triticum umbellulatum, Triticum longissimum, chromosome addition lines, C-banding.


1991 ◽  
Vol 69 (11) ◽  
pp. 2574-2577 ◽  
Author(s):  
Hari B. Krishnan ◽  
Jerry A. White ◽  
Steven G. Pueppke

Antibodies raised against gliadins, the alcohol-soluble proteins of wheat (Triticum aestivum L.) seeds, were used to localize gliadins within the lumen of the endoplasmic reticulum. Endosperm cells at 20 days after anthesis contain extensive rough endoplasmic reticulum that is fragmented and dilated. The dilated endoplasmic reticulum encloses aggregates of proteinaceous material that reacts strongly with gliadin-specific antibodies. Key words: gliadins, immunocytochemistry, protein A – gold, rough endoplasmic reticulum, wheat.


1990 ◽  
Vol 68 (10) ◽  
pp. 2119-2126
Author(s):  
J. Charon ◽  
E. Vindt-Balguerie ◽  
J. Launay

An ontogenic study of the primary resin ducts was carried out from the embryo to the 2-month-old seedlings stage in Pinus pinaster Ait. and revealed two separate systems, the hypocotyl-radicular ducts and the epicotylar ducts. In the first system, each one of the resin ducts, which are numerically equal to the protoxylem strands of the radicle, is formed by vertical juxtaposition of two canals initiated partly in the hypocotyl and in the radicle. This system is closed at the level of the cotyledonary node. The second system consists of the anastomosis of the resin ducts initiated in the base of euphylls. This system is closed at the level of the base of the epicotyl and is not correlated with the first one. The primary resin ducts are formed on a schizolysigenous pattern. In the epicotylar bud, the schizogenous and lysigenous processes are described and they occur over a long distance. This schizolysigenous process of primary resin ducts is compared in young and adult plants. Key words: resin duct, ontogenesis, schizogeny, lysigeny, seedling, Pinus pinaster.


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