خيارات البحث
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Studies on weed seeds and their intensity in winter wheat production in Erzurum and its provinces
1996
Zengin, H. (Ataturk Univ., Faculty of Agriculture, Erzurum (Turkey). Div. of Plant Protection)
In this study weed seeds and their level of infestation in winter wheat production from Erzurum were determined by number and weight. Of the weeds in winter wheat product, 99 species and genera were identified. On average 7.73 % and 2.45 % weed seeds were found to be mixed in winter wheat production by number and weight respectively. If uncleaned production was used as seed material 37443 weed seeds on average would be carried to the field
اظهر المزيد [+] اقل [-]Influence of molluscicides on arthropod predators on winter wheat agrocoenosis
1996
Tuubel, E. (Estonian Agricultural Univ., Tartu (Estonia). Inst. of Plant Protection)
The influence of molluscicides (Mesurol, Larbate) on the number of predators - Carabidae, Staphylinidae and Araneidae was investigated in winter wheat agrocoenosis in Southern Sweden. The indirect influence of molluscicide application on predators' populations was established. Different predator groups were affected differently. In the treated plots the number of Carabidae and Araneidae was two times smaller compared to untreated plots. Of Carabidae specimens 15 general were found. The most common were Agonum, Trechus and Bembidion. The two first groups occurred in smaller numbers in treated plots. The indirect influence of molluscicide Larbate compared to Mesurol was more harmful to predators
اظهر المزيد [+] اقل [-]Electrophoretic characterization of spring spelt wheat gliadins النص الكامل
1996
Abdel-Aal, E.S.M. | Salama, D.A. | Hucl, Pierre | Sosulski, F.W. | Cao, W.
Gliadin compositions of 95 spring spelts, 5 winter spelts, and Neepawa Hard Red Spring (HRS) wheat were evaluated by acid-polyacrylamide gel electrophoresis (A-PAGE). Five spring spelts grown in three environments over 2 years were compared to the HRS cultivar Katepwa using A-PAGE and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SD-PAGE). On the basis of the scoring of 13 bands, the spring and winter spelts diverged widely from Neepawa HRS wheat. None or the spring spelts evaluated had a gliadin protein profile identical to that of commercially available winter spelt. Spring and winter spelts were differentiated from Katepwa MRS wheat based on omega-gliadin composition, in which common wheat was characterized by the presence of a slow-moving omega-gliadin and a strong-staining fast-moving omega-gliadin. Common wheat and spring spelt accessions SK0505, SK0283, and RL5407 (black-hulled spelts) had a distinct strong band in the gamma-gliadin region with MW of about 64K which was absent in winter spelts and the spring spelts SK0021 and PGR8801 (white-hulled spelts). The molecular weights of gliadin proteins were in the range of 34K-75K.
اظهر المزيد [+] اقل [-]Changes infestation of winter wheat cultivated in rotation with cereals share increase
1996
Derylo, S. | Szymankiewicz, K. (Akademia Rolnicza, Lublin (Poland). Katedra Ogolnej Uprawy Roli i Roslin)
The paper presents the results of experiments on the influence of crop rotation with differentiated cereals share (50, 75 and 100% cereals) and the crop cultivated there, on the qualitative and quantitative changes in winter wheat infestation. A significant increase of infestation indices i.e. amount and mass of weeds as well as the intensification of occurrence of a dominant species Apera spica-venti in a winter wheat canopy was recorded as a result of increase of cereals share. Although, the catch crops decreased the winter wheat infestation, they did not eliminate completely the unfavourable effects of an improper sequence of plants
اظهر المزيد [+] اقل [-]Investigation on health of winter wheat after different forecrops
1996
Plaskowska, E.
In 1989-91 investigations were performed on winter wheat of "Jawa" cultivar grown after the forecrops: spring barley, field bean and red clover. To learn the communities of fungi of the wheat culture habitat, the method of washing was used. Differentiation in the specific and quantitative composition of the fungi communities explored was influenced by the habitat developed by crop rotation as well as by atmospheric conditions. The best forecrop for winter wheat from the health point of view was field bean and the worst was spring barley. The greatest danger from foot-rot complex to winter wheat, irrespective of crop rotation, were Fusarium avanaceum and Fusarium culmorum
اظهر المزيد [+] اقل [-]Effect of winter wheat continual growing on yield structure
1996
Macuhova, K. (Vyskumny Ustav Rastlinnej Vyroby, Piestany (Slovakia))
Chain Diking Effects on Runoff and Winter Wheat Production النص الكامل
1996
Wiedemann, Harold T. | Clark, Lewis E.
The major factor limiting crop production in the Texas Rolling Plains is water,and better methods of conserving soil water in dryland wheat production are needed. Chain diking is a novel method of forming basins on flat-tilled land to impound and conserve water received from precipitation. The objective of this research was to determine the influence of chain diking on dryland winter wheat (Triticum aestivum L.) yield and on runoff during the growing season. The study site, in northwest Texas, has an annual mean rainfall of 632 mm and a cropping season average of 444 mm. Following September drill-seeding of wheat, plots were chain diked or not diked. All other cultural practices were the same for all plots. Exit flumes and automatic recording devices were installed to measure runoff from each plot during the growing season. Grain was harvested in June. Diking reduced runoff an average of 40% (P = 0.02), which amounted 1.0 ha-cm over three crop years, compared with tillage without diking. The increase in wheat grain yield from dikingw as not significant over four crop years (P = 0.75). When analyzed by year, diking increased yields 11%(277 kg ha⁻¹; P = 0.02) in 1989, when cropping-season rainfall was 22% below average.The probability of receiving rainfall below average by more than 20% during the cropping year is 30%, based on 88-yr records at this test site. Diking following planting apparently will be valuable less than 30% of the time, although other applications for chain diking are possible. Contribution of the Texas Agric. Exp. Stn.
اظهر المزيد [+] اقل [-]Comparison of Interseeded Legumes and Small Grains for Cover Crop Establishment in Cotton النص الكامل
1996
Keeling, J Wayne | Matches, Arthur G. | Brown, C Philip | Karnezos, T Peter
Wind erosion of soil is a potential problem in unprotected cotton (Gossypium hirsutum L.) fields on the Southern High Plains of Texas during winter and early spring. Our objective was to determine which winter annual forage legumes and small grains may be successfully established by fall Intel-seeding into standing cotton. Thirteen plantings were made over 6 yr at three locations. Both cotton and the interseeded forages were grown under rainfed conditions. The forages were winter wheat (Triticum aestivum L. emend. Thell.), rye (Secale cereale L.), Austrian winter pea [Pisum sativum subsp. pisum var. arvense (L.) Poir.], hairy vetch (Vicia villosa Roth), subterranean clover (Trifolium subterraneum L.; 5 cultivars), rose clover (Trif. hirtum All.; 3 cultivars), crimson clover (Trif. incarnatum L.; 2 cultivars), red clover (Trif. pratense L.), berseem clover (Trif. alexandrinum L.), and barrel medic (Medicago truncatula Gaertn.; 2 cultivars). Successful stands of wheat, rye, winter pea, and hairy vetch were obtained in 69% of the plantings, but in only 53% for the other forages. Establishment of the small-seeded legumes (clovers and medics), which must be planted at a shallow depth, seemed to be governed by the timing of effective rainfall events after seeding. Establishment of the larger-seeded wheat, rye, winter pea, and vetch was less dependent on timely rainfall after planting. Of these winter annuals, wheat and rye were the most dependable in producing a soil cover.
اظهر المزيد [+] اقل [-]Life-cycle and further evidence of distribution of the Russian wheat aphid (Diuraphis noxia) in the Czech Republic
1996
Stary, P. (Akademie Ved, Ceske Budejovice (Czech Republic). Entomologicky Ustav)
The Russian wheat aphid, Diuraphis noxia, was for the first time detected in the Czech Republic in June 1995 and is distributed at least throughout southern Moravia. The samples demonstrated the presence of sexual (oviparous females) as well as parthenogenetic (alate adults) progeny on winter barley (but not on winter wheat) in the target area.
اظهر المزيد [+] اقل [-]Farming systems and conservation needs in the Northwest Wheat Region
1996
Papendick, R.I.
The Northwest Wheat Region is a contiguous belt of 3.3 million ha in Idaho, Oregon and Washington. Its climate varies from subhumid (< 650 mm annual precipitation) to semiarid (<350 mm), with more than 60% of the annual occurring during the winter. Winter wheat yields range from a high of 8 t/ha in the wetter zones to a low of 1.5 t/ha in the drier zones. Winter wheat is grown in rotation with spring cereals and pulses where annual precipitation exceeds 450 mm; winter wheat-fallow prevails where annual precipitation is less than 330 mm. Tillage practices are designed to maximize infiltration and retention of water through soil surface and crop residue management. Because of the combination of winter precipitation, steep topography, and winter wheat cropping, much of the region is subject to a severe water erosion hazard, accentuated by freeze-thaw cycles that increase surface runoff and weaken the sod structure. Wind erosion is a major problem in the drier zones, where cover is less and sods are higher in sand. Residue management, primarily through reduced tillage and no-till systems, is the first defense against both wind and water erosion, but yields often are higher with conventional intensive tillage. Factors that limit yields with conservation farming include weed and disease problems and the lack of suitable tillage and seeding equipment strategies must shift from relying on traditional tillage methods to development of complete no-till systems. Spring cropping as a replacement for winter wheat also needs to be investigated. In some cases, tillage for water conservation must be made compatible with tillage for erosion control.
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