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Domestication Reshaped The Genetic Basis Of Inbreeding Depression In A Maize Landrace Compared To Its Wild Relative, Teosinte, Luis Fernando Samayoa, Bode A. Olukolu, Chin Jian Yang, Qiuyue Chen, Markus G. Stetter, Alessandra M. York, Jose De Jesus Sanchez-Gonzalez, Jeffrey C. Glaubitz, Peter J. Bradbury, Maria Cinta Romay, Qi Sun, Jinliang Yang, Jeffrey Ross-Ibarra, Edward S. Buckler, John F. Doebley, James B. Holland

Department of Agronomy and Horticulture: Faculty Publications

Inbreeding depression is the reduction in fitness and vigor resulting from mating of close relatives observed in many plant and animal species. The extent to which the genetic load of mutations contributing to inbreeding depression is due to large-effect mutations versus variants with very small individual effects is unknown and may be affected by population history. We compared the effects of outcrossing and self-fertilization on 18 traits in a landrace population of maize, which underwent a population bottleneck during domestication, and a neighboring population of its wild relative teosinte. Inbreeding depression was greater in maize than teosinte for 15 of …

Principal Component Analysis In Paspalum Germplasm Characterization, A. Regitano Neto, L. A. R. Batista

IGC Proceedings (1977-2023)

In a survey, through principal component analyses, for the most representative descriptors to be used in Paspalum germplasm characterization, 16 agronomic traits, 16 reproductive traits and 21 vegetative traits were evaluated in 32 accessions comprising Paspalum plicatulum (19) and Paspalum compressifolium (13) from the institutional germplasm collection. ANOVA for agronomic descriptors showed significant differences among accessions, except for percentage of dry matter in winter (DMW) which was not significant. Principal component analyses allowed reduction of 69%, 69% and 62%, respectively, in the initial number of descriptors, and the election of the most important for agronomic traits: DMYS, DMYW, RGS, CPPW …

Production And Quality Of Paspalum Forage In State Of São Paulo, L. A. R. Batista, A. Regitano Neto, Rodolfo Godoy

IGC Proceedings (1977-2023)

Biomass produced by accessions of 26 species, belonging to 12 botanical groups of the genus Paspalum, collected in the south and central regions of Brazil, were evaluated during the first year of establishment for quantitative characteristics: production of dry biomass (DMY), percentage of dry matter (PDM) and regrowth score and qualitative traits: concentration of neutral detergent fiber (NDF), “in vitro” dry matter digestibility (IVDMD) and crude protein percentage in dry matter (CPPDM) -, in the central area of the state of São Paulo, in a completely randomized block design with two replications. The largest averages of DMY were obtained …

Study Of The Diversity Of Soil Animals Community In The Songnen Plain Grassland Of China, Xiuqin Yin, Tingcheng Zhu

IGC Proceedings (1977-2023)

This paper dealt with the diversity in eight habitat soil animals communities in Songnen plain grassland. The results showed the better habitat condition the higher diversity index of soil animals, and vice-versa. The diversity of soil animals communities correlated positively with soil organic matter, total nitrogen, and negatively with soil pH; there was a poor correlation with soil water content and total soil phosphorus. The diversity of soil animals communities decreased with increasing depth of soil layer and has surface-collection.

Evaluating Varieties Of Alfalfa And Tall Fescue For Tolerance To Over-Grazing By Cattle, Robert F. Spitaleri, Jimmy C. Henning, Charles T. Dougherty, Garry D. Lacefield, B. T. Larson

IGC Proceedings (1977-2023)

Cultivars of alfalfa (Medicago sativa L.) and tall fescue (Festuca arundinacea Schreb.) were seeded in small (1.5 m x 4.6 m) plots and harvested for estimating yield the following spring. Plots were then grazed by cattle continuously for the remainder of the season so as to keep stand heights at 7.5 cm or less. This procedure was repeated for one or two more grazing seasons, depending on stand survival. Stands were visually rated for stand in the fall and spring. Marked differences in grazing tolerance were observed among alfalfa cultivars, following closely the commercial designations as grazing-type or …

The Role Of Cattle Dung In Seed Dispersal Of Major Species In A Zoysia Japonica Pasture In Japan, K. Shimoda, S. Sakanoue

IGC Proceedings (1977-2023)

To evaluate the role of cattle dung in seed dispersal of major species in Zoysia japonica pasture in Japan, we investigated the species composition and density of seeds in cattle dung by means of a germination test. Of 20 major species which had a mean coverage of more than 0.1%, 90% were detected as seeds in cattle dung. In addition, the species composition and density of seeds in cattle dung differed among three sampling seasons. Seeds of the six most prevalent species in terms of coverage were detected from cattle dung during the growing season. Hence, we conclude that it …

Identification Of Candidate Genes And Genomic Regions Associated With Adult Plant Resistance To Stripe Rust In Spring Wheat, Amira M. I. Mourad, Mohamed A. Abou-Zeid, Shamseldeen Eltaher, P. Stephen Baenziger, Andreas Börner

Department of Agronomy and Horticulture: Faculty Publications

Wheat stripe rust (caused by Puccinia striiformis f. sp. tritici) is a major disease that damages wheat plants and affects wheat yield all over the world. In recent years, stripe rust became a major problem that affects wheat yield in Egypt. New races appeared and caused breakdowns in the resistant genotypes. To improve resistance in the Egyptian genotypes, new sources of resistance are urgently needed. In the recent research, a set of 95 wheat genotypes collected from 19 countries, including Egypt, were evaluated for their resistance against the Egyptian race(s) of stripe rust under field conditions in the two …

Biodiversity And Spatial Heterogeneity In Semi-Natural Grasslands In A Mountain Area In Slovakia, Masae Shiyomi, N. Gáborèík, H. Koizumi, A. Javorkova, E. Uhliarova, O. Jezikova

IGC Proceedings (1977-2023)

The spatial pattern of vegetation in the following 3 semi-natural grasslands in Banska Bystrica, Slovakia, was observed in August, 1998: (1) a grassland sown with improved herbage plants after plowing in 1991, (2) a grassland oversown with improved herbage plants in 1991, and (3) a natural grassland without any treatment at the time of establishment. A new method of measuring vegetation was adopted: in each grassland, 50 quadrats 50 cm × 50 cm, composed of 4 smaller cells 25 cm × 25 cm, were set up, and all the species in each cell were recorded. The sown grassland displayed the …

Optimum Area Of Semi-Natural Grassland To Maintain Maximum Butterfly And Avian Species Richness In Japan, A. Shoji, K. Kohyama, H. Sasaki

IGC Proceedings (1977-2023)

To evaluate the optimum area of semi-natural grassland to maintain maximum butterfly and avian species richness in Japan, digitalized grid data of butterfly and avian distribution, as well as vegetation distribution, throughout the country were used. After obtaining logistic regression models explaining the probabilities of occurrence of each species with semi-natural grassland area and latitude as variables, the optimum value was calculated. The expected maximum species richness of butterflies in the country was the highest in the case of about 40 square kilometers of semi-natural grassland per 100 square kilometers, though the value varied somewhat with latitude. The expected maximum …

Managing Grassy Woodlands: Balancing Production And Conservation Of Resources, John G. Mcivor, Neil D. Macleod, S. Mcintyre

IGC Proceedings (1977-2023)

Eastern Australian eucalypt woodlands are important agricultural areas that have been widely modified during two centuries of European-style use. Despite this they contain important natural resources including significant biodiversity. Long term sustainability of production depends on maintaining resources and management must be for both production and conservation. A research program on four properties in south east Queensland showed the properties were in generally good condition although all had some problems, and has highlighted a number of significant costs and barriers to adopting a more balanced approach to production and conservation.

Species Segregation And Functional Groups In The Hill Country Of New Zealand, I. López, I. Valentine, D. Hedderley, M. G. Lambert

IGC Proceedings (1977-2023)

In the hill country of New Zealand, the soil-sward relationship on hill microrelief was studied. Three categories of slope or microsites were distinguished: low, medium and high. The hypothesis was that soil variables of neighbouring microsites differ, and because of this, there is a segregation of species or functional groups of species between the microsites. Soil features, botanical composition and total annual yield were measured in the slope categories in two similar paddocks; one of which had received long-term phosphorus fertilisation and a non-fertilised paddock. ANOVA, cluster analysis and canonical variate analysis were performed on the data. Unsaturated hydraulic conductivity, …

Influence Of Grassland Management And Grazing By Different Farm Animals On Animal Performance And Flora Alterations, W. Jentsch, H.-D. Matthes, A. Admasu, H. Möhring

IGC Proceedings (1977-2023)

The objectives of this study were to test the possibilities of using different farm animals for landscape care on extensive pasture, taking into account their particular performance, and to analyse alterations of the flora in consequence of grazing by different animals and various pasture management. Salers had the highest (836g/d) and Galloways (584g/d) the lowest live weight gain as compared with the other breeds (771g/d). Lambs had higher live weight when grazing together with cattle and horses (mixed grazing) than under one species grazing. The number of legume increased and that of grass decreased. Following 3 years the grazing animals …

Animal Production From Tropical Pastures Renovated By Subsoiling And Fertilization In The Cerrados Of Brazil, Valéria P. B. Euclides, Manuel C. M. Macedo, M. P. Oliveira

IGC Proceedings (1977-2023)

A grazing trial was conducted, to study the effects of fertilization on the maintenance of the productivity of four tropical grasses. The paddocks were subsoiled, and dived into halves: one (LF1) received 400 kg/ha of a fertilizer formula 0-20-20.and the other (LF2) 800 kg/ha of the same fertilizers, in January 1995. Annually, 50 kg/ha of N was applied. The productivity on LF2 pastures was greater than that on FL1 pastures, averaging 520 and 410 kg of liveweight gain/ha/year. A double strategy should be followed to sustain animal production in the savanna: maintain soil P over a critical value of 3.0 …

Performance Of Nellore Cattle Under Two Grazing Management Systems, L. De A. Corrêa, Maurício M. De Alencar, Rogério T. Barbosa, P. F. Barbosa, Geraldo M. Da Cruz, I. U. Packer, C. A. Cordeiro

IGC Proceedings (1977-2023)

The objective of this study was to evaluate the effects of grazing intensification on birth weight (BW), weaning weight (WW, standartized to 205 days), average daily gain from birth to weaning (ADG), and gestation length (GL) of calves, cow weight at calving (CWC) and at weaning (CWW), cow condition score at calving (CCC) and at weaning (CCW), and BW/CWC (BWR), WW/CWC (WWRC) and WW/CWW (WWRW) ratios. One hundred and sixty eight Nellore calves born in 1998 and 1999, out of dams maintained in two grazing management systems were evaluated: an extensive 1.0 animal unity (AU). ha^-1 system on unfertilized …

Orchardgrass Pastures For Early-Weaned Beef Calves, J. C. Waller, H. A. Fribourg, C. Dixon, A. E. Fisher, B. V. Conger

IGC Proceedings (1977-2023)

Orchardgrass (Dactylis glomerata) grown alone or with ladino white (Trifolium repens) and red (T. pratense) clovers, provides a high quality March to June pasture. However, many beef producers have their cows calving in January-March, thus producing offspring that are too young to utilize spring forage well. As an alternative, some producers have their cows bred so that calves are born in autumn (September-November). By spring, these calves are old enough to consume pasture forage. The few earlier studies on early weaning of fall-born calves consist of drylot feeding of high quality hay or concentrates. …

Relationships Among College-Level Science Course Enrollment, Environmental Perception, And Pro-Environmental Attitude: Evidence From The Us General Social Survey, Mazbahul G. Ahamad, Fahian Tanin

Department of Agronomy and Horticulture: Faculty Publications

Understanding pro-environmental attitudes is critical to encouraging pollution-minimizing behaviors. Therefore, identifying associated factors is essential for understanding different types of pro-environmental attitudes. We aimed to investigate the associations among individuals’ college-level science course enrollment and their perceptions of the level of spending to improve and protect the environment, as well as their pro-environmental attitudes. We used nationwide population-based cross-sectional survey data from 2,348 individuals obtained from the General Social Survey in the United States. An ordered logistic model was used to examine the associations among college-level science course enrollment, environmental perception, and pro-environmental attitude. We found that science course enrollment …

Management Of Meadow Fescue Pasture For High-Producing Dairy Cows In Northern Japan, K. Sudo, K. Ochiai, T. Ikeda

IGC Proceedings (1977-2023)

The objective of this study was to establish an intensive grazing system of meadow fescue (Festuca elatior L.) pasture for high-producing dairy cows in some areas of Japan where soil freezes in winter. Plant succession of meadow fescue pastures that had been grazed at different plant heights and milk production from cows grazed on meadow fescue pasture compared to that from cows grazed on perennial ryegrass pasture were surveyed over a five year period. Succession of meadow fescue pasture depended on the management of plant height before grazing use. Milk production from cows grazed on meadow fescue pasture was …

Leaf Blade Selection By Sheep In Kleingrass (Panicum Coloratum L.) Pastures With Different Deferment Periods, P. Sierra, M. S. Cid, M. A. Brizuela, C. M. Ferri

IGC Proceedings (1977-2023)

The winter use of standing dead biomass produced by warm season grasses during the previous growing season may be an alternative to grazing systems in the semi-arid Pampean Region of Argentina. This study evaluated: 1) the effect of different deferment periods on the leaf blade percentage and quality of ‘kleingrass’ (Panicum coloratum L.), a warm season specie recently introduced to that region, and 2) whether rams grazing the vegetation accumulated during these different periods are able to select leaf blades to maintain the quality of their diets. It was generated three treatments by deferment of the forage produced after …

Microhistological Estimation Of Leaf Blade Percentage In Diets From Monoespecific Pastures, P. Sierra, M. S. Cid, M. A. Brizuela, C. M. Ferri

IGC Proceedings (1977-2023)

Although a decrease in the leaf-stem ratio affects the nutritive value of pastures, herbivores can reinforce selection for leaf blades to maintain the quality of their diets. This study evaluated whether the percentage of fragments with furrows in blades could be used to estimate the relative intake of this part of the leaves by herbivores grazing monoespecific pastures. It was worked with vegetation of kleingrass (Panicum coloratum L.) from paddocks with three deferment periods. Blade samples, and different plant part mixtures hand compounded were in vitro digested. The digestion residues were microhistological analyzed determining the number of fragment with …

Evaluation Of Kentucky Bluegrass (Poa Pratensis L.) For Creating Sustainable Grazing Swards In Hokkaido, T. Saigusa, S. Tejima, Y. Ogawa, S. Takahashi

IGC Proceedings (1977-2023)

Kentucky bluegrass (Poa pratensis L.) is generally considered to be a weed in the meadows of Hokkaido. However, a revaluation of this species should be undertaken in terms of its useful characteristics for labor-saving management on farms in marginal areas. The performance of steers (Holstein-Friesian) and botanical composition of Kentucky bluegrass swards were investigated under the stocking methods of set and rotational grazing and compared with timothy (Phleum pratense L.) swards. Kentucky bluegrass was stable over the grazing season under both methods, although timothy decreased rapidly. The average daily gain of steers raised on Kentucky bluegrass swards was …

Cold Conditioned: Discovery Of Novel Alleles For Low-Temperature Tolerance In The Vavilov Barley Collection, Ahmad H. Sallam, Kevin P. Smith, Gongshe Hu, Jamie Sherman, Peter Stephen Baeziger, Jochum Wiersma, Carl Duley, Eric J. Stockinger, Mark E. Sorrells, Tamas Szinyei, Igor G. Loskutov, Olga N. Kovaleva, Jed Eberly, Brian J. Steffenson

Department of Agronomy and Horticulture: Faculty Publications

Climate changes leading to higher summer temperatures can adversely affect cool season crops like spring barley. In the Upper Midwest region of the United States, one option for escaping this stress factor is to plant winter or facultative type cultivars in the autumn and then harvest in early summer before the onset of high-temperature stress. However, the major challenge in breeding such cultivars is incorporating sufficient winter hardiness to survive the extremely low temperatures that commonly occur in this production region. To broaden the genetic base for winter hardiness in the University of Minnesota breeding program, 2,214 accessions from the …

Structural Stability Of Short Latency Alfalfa-Based Pastures In The Humid Pampa, Argentina, R. O. Refi, B. Martín

IGC Proceedings (1977-2023)

The aim of this study was to search the effects of grazing intensity and nitrogen fertilization on the structural stability of a mixed pasture composed by alfalfa (latency group 9), brome grass, tall fescue and white clover, sown in April 1997. Rotational grazing was carried out with dairy cattle with high intensity (HI: up to 3-4 cm) or moderate intensity (LI: up to 8-10 cm), whenever the alfalfa showed basal regrowth. According to a split-plot design, grazing intensities were subdivided to assign three levels of nitrogen fertilization: N0, without fertilization; N1 with 50 kg N/ha per year; and N2 with …

Late Winter Dietary Overlap Among Greater Rheas And Domestic Herbivores On The Argentinean Flooding Pampa, G. Vacarezza, M. S. Cid, F. Milano

IGC Proceedings (1977-2023)

This study evaluates the dietary overlap among greater rheas (Rhea americana L.) sheep and cattle in the Flooding Pampa, Buenos Aires, Argentina during late winter, when is observed the lowest forage availability. The work was carried out with the following forage classes (FC): warm and cool season grasses and forbs (legumes and no-legumes). Diet botanical composition was estimated by microanalysis of faeces. Principal Component Analysis and Kulcyznsky´s index of similarity were used for data analysis. Rhea populations selected diets with higher forb percentages. On the contrary, vegetation structure and their own morpho-physiology conditioned cattle to diets almost exclusively gramineous. …

Beef Calf Production Using Year-Round Grazing On Tropical Grass Pasture In Summer Combined With Cool Temperate Grass Pasture In Winter, Y. Nakanishi, K. Shindou, S. Watanabe, K. Yamamoto, K. Hagino

IGC Proceedings (1977-2023)

Bahiagrass (Paspalum notatum Fluegge) showed a poor quality with low crude protein in summer but blood biochemical levels of grazing beef cows were similar to drylot feeding cows except of concentration of urea nitrogen. Italian ryegrass (Lolium multiflorum Lam) showed very good quality with high crude protein (about 20 percentage) in winter. And so, suckler cows gained live weight in winter and suckling calves were showed very high growth rate (daily gain was about 1.0 kg). Total live weight gains of grazing cows were higher than those of drylot feeding cows. Postpartum reproductive performances of grazing cows were …

Winter Grazing And Feeding Systems In Western Canada, Duane H. Mccartney, V. Baron, J. Basarab, E. Okine, G. Lastiwka, A. Depalme, D. Young

IGC Proceedings (1977-2023)

Beef cow calf producers in Western Canada are looking for methods of extending the grazing season into the winter in order to lower winter feed costs. Dry beef cows were early or late weaned and grazed during the early months of winter on late seeded barley swaths (Hardlum vulgare L.) and compared to cows fed barley silage and free choice barley straw in a feeding yard. The swath grazed barley was late seeded in June and swathed in the silage stage in mid September. Cows successfully swath grazed for three winters from mid November until mid to late February …

Forage Management For Extending The Grazing Season, David W. Koch, C. M. Lux, J. W. Flake

IGC Proceedings (1977-2023)

Studies were conducted to determine ways to extend grazing season with forages adequate to meet the needs of grazing animals and to reduce the cost of livestock production. Perennial grasses were swathed, windrowed and left in the field until they were winter-grazed with bred heifers. Corn (Zea mays L.) was stockpiled for winter grazing with lambs and ewes. Windrowed grasses increased in acid detergent fiber (ADF) and neutral detergent fiber (NDF) compared with stored hay, but crude protein content, heifer weight gain and body condition change was similar for both forages. An economic value of $218 ha^-1 from …

Pengaruh Cara Pemberian Pupuk Npk Dan Frekuensi Pemberian Paklobutrazol Terhadap Pertumbuhan Dan Hasil Benih Kentang G0 Di Dataran Medium, Jajang Sauman Hamdani, Sumadi, Kusumiyati, Syariful Mubarok

Jurnal Kultivasi

Produksi benih kentang (Solanum tuberosum L) di dataran medium dapat menjadi pilihan untuk menghindari kerusakan lingkungan dan terbatasnya areal untuk produksi benih kentang di dataran tinggi. Salah satu upaya untuk peningkatan produksi benih kentang generasi ke-0 (G0) adalah pemberian pupuk NPK dan zat pengatur tumbuh. Sehubungan hal tersebut, maka perlu dilakukan kajian cara pemberian pupuk NPK dan frekuensi pemberian paklobutrazol yang tepat untuk meningkatkan pertumbuhan dan hasil benih kentang G0 di dataran medium. Percobaan ini bertujuan untuk mengetahui interaksi antara cara pemberian pupuk NPK dan frekuensi pemberian paklobutrazol yang dapat meningkatkan pertumbuhan dan hasil benih kentang G0 di dataran medium. …

Biodiversity And Fire In Shortgrass Steppe, Paulette L. Ford

IGC Proceedings (1977-2023)

Effects of fire at two levels of intensity on beetle diversity in shortgrass steppe were examined. The experimental design was completely randomized, with 3 treatments and 4 replicates per treatment. Treatments were two levels of fire 1) dormant-season fire (relatively hot), and 2) growing-season fire (relatively cool), and unburned plots. The response variables were arthropod species richness and abundance. The intermediate disturbance hypothesis predicts that maximum species richness occurs at intermediate levels of disturbance. Data obtained in this study support that prediction. Species richness was higher on plots of intermediate fire intensity than the more intensely burned plots, and almost …

Mechanization: Planning And Selection Of Equipment, C. A. Rotz

IGC Proceedings (1977-2023)

The planning and selection of equipment for harvest and handling of forage crops can greatly impact the performance and profitability of a farm. The type and size of equipment used affects the harvested yield and nutritive value of the forage crop as well as production costs. Through interactions with other parts of the farm, these effects can impact market value of the forage, animal intake and performance, delays in other farm operations, other production costs, and ultimately farm profit. Standard procedures and relationships have been developed for determining the most appropriate equipment for a given production system. Because of the …

Conserved Forage (Silage And Hay): Progress And Priorities, R. E. Muck, K. J. Shinners

IGC Proceedings (1977-2023)

Forage conservation permits a better supply of quality feed when forage production is low. While haymaking and ensiling have been practiced for generations, research is still needed to 1) understand the processes affecting quality during harvesting and storage and 2) develop practical means to minimize losses and enhance quality.

Several trends in harvesting forages for silage are notable. Kernel processing of maize, once confined to Europe, has become popular in North America. Self-propelled forage harvesters have a larger share of the market due to more contract harvesting and larger farms. Larger harvesters, rakes and mergers help improve productivity and forage …