Download or read book Effects of Three Herbicides on Yields of Five Cultivars of Winter Wheat Triticum Aestivum L Em Thell written by Amor Yahyaoui and published by . This book was released on 1980 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt: With the development of new selective herbicides and the frequent change in commercial wheat cultivars, information is needed as to the possible interaction between cultivars and herbicides. The responses of five genotypically diverse wheat cultivars (Bezostaya, Daws, Maris Hobbit, Stephens and Yamhill) to diuron [3-(3,4-dichloropheny1)-1,1- dimethylurea], diclofop methyl 2-[4-(2,4-dichlorophenoxy)phenoxy] propanoate and 2,4-D (2,4-dichlorophenoxy acetic acid) herbicides were compared under field and greenhouse conditions during the 1979-80 growing season. Grain yield was considered as a measure of herbicide injury when compared to the control plots for each cultivar. Effect on components of yield, plant height and grain protein content also were investigated. Differences in yield performance and related agronomic characters could be attributed to specific herbicides, designated rates and growth stages at the time of application. The lower (1.4 kg/ha) rate of diuron, diclofop and 2,4-D reduced yields less than the higher rate (2.8 kg/ha). Diuron and diclofop applied at the earlier (three to to five leaf) growth stage caused greater yield reductions than when applied at the later (five to six tiller) growth stage. Differential yield responses were found among and within the five winter wheat cultivars. The higher rate of diuron (2.8 kg/ha) caused the most injury in all of the cultivars tested. Major injury from diclofop occurred on the cultivar Maris Hobbit with minor effects on the other four cultivars. The primary reduction in yield from application of 2,4-D was to the cultivar Bezostaya. Among the five wheat cultivars tested in this experiment, Daws was the most tolerant to the three herbicides tested. Among the yield components (number of spikes per unit area, kernels per spike and 1000 kernel weight), number of kernels per spike accounted for most of the variation in yield. The data showed a direct relationship between kernel number and grain yield. Grain protein percentage of Daws, Maris Hobbit, Stephens and Yamhill significantly increased at the higher rate of diuron; whereas a similar increase was noted only in Bezostaya at the lower rate of 2,4-D. These increases in protein were associated with significant decreases in yield. Yield reductions due to herbicide treatments were generally lower than those due to weed competition. Reductions in yield and corresponding changes in the other agronomic characteristics observed in this experiment were the result of concentrations which are higher than those normally used in spraying wheat for weed control. This high chemical dosage was chosen for each herbicide to assure a greater differential response among and within the wheat cultivars. It also provided information for the plant breeder as to which cultivars had higher levels of tolerance. Such information is important when making hybrid combinations for the development of future varieties if higher levels of tolerance to specific herbicides are required.

Download or read book O S U Theses and Dissertations 1978 1982 written by Oregon State University and published by . This book was released on 1983 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Compensating Effects and Gene Action Estimates for the Components of Grain Yield in Winter Wheat Triticum Aestivum L Em Thell written by Michel Abi-Antoun and published by . This book was released on 1977 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt: Five winter wheat cultivars and their diallel crosses were evaluated for plant height, harvest index, deading-maturity duration, the components of yield, (spikes per plant, spikelets per spike, kernel weight and kernels per spikelet)and total plant yield. Two diverse locations, Moro, a dryland site (250 mm annually) located in central Oregon and the Hyslop Agronomy Farm, a high rainfall site (over 1000 mm annually) located in the Willamette Valley, were utilized for one and two cropping seasons, respectively. Three rates of seeding were used as main plots in a split-plot design that was replicated four times. A modified blend method of seeding was used to simulate solid seeding conditions. Experimental seeds were planted 30.5 centimeters apart within the row over a filler cultivar in equally spaced (30.5 centimeters) rows. The data were analyzed by analysis of variance, Griffing's diallel analysis (Method 4, Model 1), correlation, path-coefficient analysis and by parent progeny regression. The correlation between grain yield, its components, harvest index, maturity-duration and plant height was dependent on the particula. r environment of the test. The re waspoorcorrelationbetween yield, tiller number and seed size under all the conditions of these studies. Negative associations between the components of yield indicated the sequential compensatory behavior of these characters under all environments. It would be very hard to select for large grain and short stature wheat because of the positive correlation between plant height and seed size within this population. The low correlations of yield with tiller number and seed size were mainly caused by indirect negative effects through one or more of the other yield components. Harvest index, maturity-duration and plant height had very small direct or indirect influences on grain yield. It was concluded that maximum yield would be obtained from a plant type which produces enough tillers to cover a particular unit of field area with large, fertile spikes, having medium to large kernels and semi-dwarf stature. No significant differences existed between parents and single crosses in the expression of the yield components. Nevertheless, hybrids outyielded their parents in grain yield and demonstrated that heterosis for complex traits was a consequence of multiplicative relationships among the components of these traits. Significant interactions between the genotypes and locations, seeding rates and years were observed in the expression of all characters studied. These interactions indicated that using data from non-competitive conditions to assess performance under competitive conditions could not be justified. Also, limiting the number of testing sites may lead to unsound generalizations and erroneous recommendations regarding gene action estimates of yield and the components of grain yield and three associated characters. Under non-competitive conditions, estimates of the additive type of gene action were more significant and contributed larger effects than the non-additive type for all traits. As competition increased at higher seeding rates, the effects of specific combining ability became more important in the expression of yield, number of spikes, spikelets per spike, and plant height. Heritability estimates confirmed these results except for yield. Of the agronomic characters, harvest index, maturity-duration and plant height, only harvest index showed some promise as a selection criterion under noncompetitive conditions. A breeding procedure utilizing the component approach consisted of selecting early generations under spaced planting with emphasis on avoiding extreme values in any of the components of yield. The balanced combinations of the components of yield should be tested under solid seeding conditions.

Download or read book American Doctoral Dissertations written by and published by . This book was released on 1987 with total page 532 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book O S U Theses and Dissertations 1970 1977 written by Oregon State University and published by . This book was released on 1980 with total page 138 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Effect of Winter Wheat Triticum Aestivum Cultivars on Weed Control in Ecofallow Corn Zea Mays written by Robert E. Ramsel and published by . This book was released on 1984 with total page 50 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Agronomy Abstracts written by and published by . This book was released on 1991 with total page 898 pages. Available in PDF, EPUB and Kindle. Book excerpt: Includes abstracts of the annual meetings of the American Society of Agronomy; Soil Science Society of America; Crop Science Society of America ( - of its Agronomic Education Division).

Download or read book Differential Tolerance of Spring Wheat Cultivars to Difenzoquat 1 2 dimethyl 3 5 diphenyl 1H pyrazolium Methyl Sulfate a New Wild Oat Herbicide written by Kiflu Bedane and published by . This book was released on 1976 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Comprehensive Dissertation Index written by and published by . This book was released on 1984 with total page 1086 pages. Available in PDF, EPUB and Kindle. Book excerpt: Vols. for 1973- include the following subject areas: Biological sciences, Agriculture, Chemistry, Environmental sciences, Health sciences, Engineering, Mathematics and statistics, Earth sciences, Physics, Education, Psychology, Sociology, Anthropology, History, Law & political science, Business & economics, Geography & regional planning, Language & literature, Fine arts, Library & information science, Mass communications, Music, Philosophy and Religion.

Download or read book Response of Wheat Triticum Aestivum L Cultivars and Downy Brome Bromus Tectorum L to Metribuzin and Ethyl Metribuzin written by Muhammad Munir and published by . This book was released on 1988 with total page 412 pages. Available in PDF, EPUB and Kindle. Book excerpt: Downy brome (Bromus tectorum. L.), a serious grass weed in eastern Oregon can be partially controlled in wheat by metribuzin [4-amino-6-tertbutyl- 3-(methylthio)-as triazin -5(4H)-one]. However, cultivars of many crops Lave been reported to differ in their level of tolerance to metribuzin. This lack of tolerance has led to the investigation of other compounds, such as the ethylthio analog of metribuzin [4-amino-6-tert-butyI-3-(ethylthio)-as-triazin- 5(4H)-on], for selective control of downy brome in wheat. Greenhouse and growth chamber experiments on wheat, growing in soil or nutrient solution showed that: 1) GR50 values for Stephens, Hill 81, Yanahill, and Malcolm in soil were 0.41, 0.23, 0.25, and 0.44 kg/ha, respectively, for metribuzin and 1.89, 1.29, 1.37, and 1.97 kg/ha, respectively, for ethyl metribuzin; 2) GR50 values for these cultivars in nutrient solution were 3.26, 1.17, 1.32, and 3.87 uM, respectively, for metribuzin and 12.69, 7.20, 7.19, and 13.41 uM, respectively, for ethyl metribuzin; 3) Uptake of both herbicides.; by wheat was through the roots; 4) Cultivars did not show any differences in herbicide absorption from the nutrient solution. Therefore, differences in varietal tolerance may be are due to biochemical or physiological reasons, but are not due to differences in herbicide uptake. Increased growth at lower concentrations of these herbicides was observed in all cultivars studied. Metribuzin was five times more active than ethyl metribuzin. Both of these herbicides can be applied as an early postemergence treatment at the 3 leaf stage of wheat for effective control of downy brome. Yield components of the four cultivars were measured in response to metribuzin and ethyl metribuzin at two ecologically different sites. The susceptible cultivars (Hill 81 and Yamhill) showed greater injury in the lighter soils with high pH and lower organic matter content. Visual estimates of crop injury were generally higher than the actual reduction in final yield. Crop injury ratings up to 25% generally did not show a significant reduction in final grain yield. A positive correlation between protein content and concentration of these herbicides was noted. A study on the joint action of these two herbicides in the field and greenhouse showed that the combination of the two, increased the control of downy brome at lower rates. Their combined action was studied by using Colby's method and isobole method of Tammes. The reaction was calculated as additive. Downy brome was 8, 5, 5, and 9 times more sensitive to metribuzin and 6, 4, 4, and 6, times more sensitive to ethyl metribuzin than were the cultivars Stephens, Hill 81, Yamhill, and Malcolm, respectively. The use of these two herbicides to control downy brome in the cultivars Hill 81 and Yamhill should be avoided unless careful attention is given to soil properties and environmental conditions.

Download or read book Yield Loss Assessment in Nonprotected Winter Wheat Varieties Triticum Aestivum L Em Thell written by Miguel Alfonso Camacho Casas and published by . This book was released on 1985 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt: The effects of some soil- and foliar-borne biotic factors on grain yield and the components of yield were evaluated using five winter wheat varieties sown at two dates. Within each planting date, varieties were grown under four different combinations of two soil treatments (fumigation and nonfumigation) and two foliar treatments (fungicide protection and nonprotection). The conditions created by fumigation induced a luxuriant growth and subsequent lodging of all varieties especially in the first date of planting. This prevented an accurate assessment to be made on the influence of biotic soil factors on grain yield. Despite the larger number of fertile spikes observed for all varieties when sown in fumigated plots, grain yield, grain weight of ten spikes, harvest index, and weight of 300 kernels were reduced as a result of lodging. The comparison between protected and nonprotected plots revealed that foliar diseases were important in causing grain yield reductions. Development of foliar diseases was accelerated in nonprotected, fumigated plots due to the lodging. This was also accompanied by a greater reduction in grain yield and the components of yield. Date of planting did influence the time of expression of foliar diseases as a consequence of lodging and the more luxuriant growth which created a more favorable microclimate for the pathogen. Also, field proximity between dates of planting may have increased the inoculum pressure in the second planting date resulting in greater yield reduction.

Download or read book Response of Winter Wheat Triticum Aestivum L Em Thell to Nitrogen and Chloride Fertilization in the Presence of Take all Root Rot Gaeumannomyces Graminis Var Tritici Walker written by Mohamed El Hadi Maatougui and published by . This book was released on 1984 with total page 202 pages. Available in PDF, EPUB and Kindle. Book excerpt: Response from nitrogen and chloride fertilization was measured in field experiments on winter wheat (Triticum aestivum L. Em. Thell. var. 'Stephens' and 'Yamhill') grown in western Oregon in an environment with a range of susceptibility to take-all root rot (Gaumannomyces graminis var. tritici Walker). Cropping sequences and expected disease severity considered in the study were: first year wheat after clover (low risk of severe take-all root rot: Nixon I experiment), second year wheat with high disease infection in the previous crop (high risk of severe take-all root rot: Keyt II experiment), second year wheat with low disease infection in the previous crop (moderate risk of severe take-all root rot: Nixon II and Coon experiment), third year wheat (high risk of severe take-all root rot: Jones experiment), fifth year wheat (high risk of severe take-all root rot: Keyt II experiment), and eighteenth year wheat (take-all decline established: the pathogen is present in the soil but does not cause damage, Evers experiment). Nitrogen treatments were applied at 0, 67, 134, and 202 kg/ha in all experiments where wheat followed wheat and at 0, 45, 90, and 134 kg/ha in the experiment where wheat followed clover. Chloride treatments were applied at 0, 45, and 90 kg/ha in all experiments and a rate of 134 kg C1/ha was also used on the Jones experiment. Nitrogen was predominantly supplied from urea while ammonium chloride supplied chloride and ammonium sulfate supplied the crop requirement for sulfur (about 20 kg/ha). Fertilizers were top-dressed in split application with chloride and sulfur containing fertilizers applied first (February) and urea applied later (March) in all experiments but those conducted in the Nixon farm where a single fertilizer was applied in March. Crop response was measured through the effects of N and c1 treatments on dry matter production, plant nitrogen content, plant nitrogen uptake and plant percent nitrogen recovery, as well as grain yield, yield components, grain nitrogen content, grain protein content, grain nitrogen uptake, and grain percent nitrogen recovery. The results of the study strongly indicated that take-all root rot was only a problem in the Jones, Keyt I, and Keyt II experiments and was most severe in third year wheat (Jones experiment). This also was the only experiment with significant (p = 0.05) response from rates of 202 kg N/ha. Nitrogen fertilization was the main factor that greatly influenced the levels of the variables studied while chloride fertilization generally did not have a significant (p = 0.05) influence. 134 kg N/ha was generally the rate accounting for the best levels of each variable studied in all experiments except in the Jones experiment as precised earlier. Crop response was also affected by a relatively long 'dry' period (April 20th to June 20th), particularly in the experiment where take-all root rot was a problem. Levels of the variables studied accounted for by the optimum rates of N were consistently higher in the experiments where take-all root rot was not a problem than where it was a problem by the following amounts: dry matter yields-17%, plant nitrogen contents-18%, plant nitrogen uptake levels-30%, plant nitrogen recoveries-28%, grain yields-22%, grain nitrogen contents-only 4%, grain protein contents-only 2%, grain nitrogen uptake levels-26%, grain nitrogen recoveries-18%, and spikes/m2-24%.

Download or read book Pesticides Documentation Bulletin written by and published by . This book was released on 1969 with total page 636 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Effect of Timing and Rate of Metribuzin on Wheat and Barley Cultivars and on Italian Ryegrass written by Nedret Durutan and published by . This book was released on 1975 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt: A field study was conducted in 1973 and 1974 to determine optimum timing of metribuzin (4-amino-6-tert-butyl-3(methylthio) as - tria.zine-5(4H)one) on winter wheat (Triticum aestivum L. 'Hyslop') for control of Italian ryegrass (Lolium multiflorum Lam.). Herbicide treatments were applied at 5 different stages of growth of winter wheat. Metribuzin at 0.56 kg/ha applied in December at the three to four tiller stage gave the best combination of high wheat yields and excellent ryegrass control. Preemergence and early postemergence treatments caused more wheat injury than later applidations. Poor ryegrass control was obtained from April treatments. The objective of the greenhouse experiments was to compare the responses of wheat and barley cultivars to metribuzin. Experiments were conducted either in the greenhouse or in growth chambers. Wheat cultivars were Hyslop, McDermid, Wanser, Paha, and Yamhill. Kamiak and Hudson were the barley cultivars. Metribuzin was applied at the two-leaf stage at rates ranging from 0.11 kg/ha to 1.68 kg /ha. Within barley cultivars, Kamiak tended to be more tolerant to metribuzin than Hudson. The relative sensitivity of the five wheat cultivars varied between experiments but three of the cultivars, Paha, Wanser, and Yamhill tended to be less susceptible than Hyslop and McDermid. Under the conditions of higher light intensity and higher temperature, barley cultivars were found to be significantly less susceptible to metribuzin injury than wheat cultivars.

Download or read book Agrindex written by and published by . This book was released on 1995 with total page 1390 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Bibliography of Agriculture written by and published by . This book was released on 1990 with total page 1120 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Periodicum Biologorum written by and published by . This book was released on 1996 with total page 584 pages. Available in PDF, EPUB and Kindle. Book excerpt: