Plant Pathology Commons^™

Grazing Management For Alfalfa Persistence And Productivity In Warm-Climate Regions, D. Basigalup

IGC Proceedings (1977-2023)

Alfalfa is the most important cultivated forage crop in Argentina, where about 3 million hectares are grown. Even though the use of direct grazing is coming down during the last 15 years, it is still important for both beef and dairy production. Alfalfa grazing can play an important role in reducing operative costs and decreasing quality loss due to forage conservation (hay or silage). In this paper, the main concepts necessary to implement adequate and practical rotational grazing systems are briefly discussed. Particular attention is given to issues such as grazing frequency, grazing period, pasture use efficiency, and alfalfa quality …

Assessing The Nutrient Status Of Alfalfa Stands In Kentucky, William R. Fleming, Christopher D. Teutsch, Edwin L. Ritchey, John H. Grove

IGC Proceedings (1977-2023)

Alfalfa (Medicago sativa L.) is a perennial forage legume and is sometimes referred to as the “Queen of Forages” due to its high nutritional value. Alfalfa is commonly produced as hay for use in the dairy and equine industries. Alfalfa yield increased exponentially from the 1950s to the1980s due to new breeding and management innovations. However, during the 1980s yields plateaued at around 7.5 Mg/ha and remain there today. The overarching goal of this study was to determine the role of soil fertility in the observed yield plateau. Fifty alfalfa stands in Kentucky were sampled to gather information about …

Prospects For Improving Alfalfa Yield Using Genomic- And Phenomic-Based Breeding, M. W. Francis, D. Pap, A. Krill-Brown, E. C. Brummer

IGC Proceedings (1977-2023)

Alfalfa (Medicago sativa L.) is a perennial outcrossing legume that is cultivated as an important forage crop in many parts of the world. Yield is the most important trait for profitable alfalfa production, yet over the last 30 years yield improvement in California has stagnated. Current breeding methods focus on recurrent phenotypic selection; however, alternatives incorporating genomic- and phenomic-based information may enhance genetic gain and help to address the lack of yield improvement. Here we attempt to increase the yield potential of alfalfa using genomic selection (GS) in combination with high throughput phenotyping (HTP). A total of 193 families …

Effects Of Fall Dormancy, Cutting Frequency, And K Application Rate On Dry Matter Yield And Nutritive Value Of Alfalfa, Ji Yung Kim, J. S. Choi, M. H. Jo, K. I. Sung

IGC Proceedings (1977-2023)

[Introduction] This study was conducted to determine the effect of the cutting frequency and K application rate on the dry matter yield (DMY) and nutritive value of new alfalfa varieties in Korea.

[Material and Methods] The sowing date and rate were September 21, 2019, and 20 kg/ha, respectively. The treatment was by the split-split plot design, and the main plot was the Fall dormancy (FD) of 3 (Rugged Rancher), 4 (SW4113), and 9 (SW9720), the sub-plot was excess 40 day (LCF), from 31 to 40 days (MCF), and under 30 day (HCF) times of cutting frequency …

Irrigation Effects On Forage Dry Matter Yield And Nutritive Value Of Alfalfa, Rudra Baral, Doohong Min

IGC Proceedings (1977-2023)

Alfalfa (Medicago sativa L.) is among the top four field crops in United States (U.S.) in terms of acreage harvested and economic value. Several studies have documented that alfalfa requires high amount of water compared to other major field crops. However, more than 65% alfalfa in the U.S. is grown under rainfed condition where severe to moderate drought condition has been pronounced during alfalfa growing season. The magnitude of yield loss due to water-limited conditions is still unknown. In this context, the objective of our study is to evaluate the forage dry matter yield and forage nutritive value of …

Farmer Experiences With Alfalfa In The Southern U.S.A., M. K. Mullenix, L. S. Silva, C. G. Prevatt, J. J. Tucker

IGC Proceedings (1977-2023)

Alfalfa (Medicago sativa L.) is a forage crop of primary importance in the United States (USA); however, adoption and use in the southern USA region has been limited. The combination of adapted alfalfa cultivars and management strategies which demonstrate extended forage growing season length, improved forage nutritive value, and reduced N fertilizer inputs have renewed interest in forage-livestock farmers to consider planting alfalfa. A series of Extension-based educational strategies have been used in the southern USA to 1) create awareness on the use of alfalfa, 2) educate farmers regarding establishment and management practices, and 3) showcase opportunities and challenges …

Effects Of Insecticide And Tolerant Alfalfa Cultivars On Potato Leafhopper (Empoasca Fabae) Populations And Forage Yields In Quebec (Canada), Philippe Seguin, X. Shi, J. Saguez, Huguette Martel, A. Claessens

IGC Proceedings (1977-2023)

The potato leafhopper [PLH, Empoasca fabae (Harris)], which affects several crops including alfalfa (Medicago sativa L.), is a recurrent problem in several regions of Quebec. The objective was to evaluate alfalfa management tools in order to reduce yield losses caused by this pest. An experiment was conducted at two sites in Quebec over three field seasons to evaluate the impact of insecticide applications and the use of PLHtolerant cultivars on forage yield and PLH populations. Foliar insecticide applications in the seeding year reduced PLH populations but generally failed to impact alfalfa yields compared to untreated alfalfa. However, in one …

A New Perennial Legume To Combat Dryland Salinity In South-Western Australia, L. W. Bell, M. A. Ewing, M. Ryan, S. J. Bennett, G. A. Moore

IGC Proceedings (1977-2023)

Dryland salinity has devastated large tracts of productive land in Australia. This has resulted from the clearing of native perennial vegetation and its replacement with annual crops and pastures. As annual plants are shallow rooted and only use water during their winter-spring growing season, unutilised rainwater leaks into groundwater tables which rise and bring stored salt to the soil surface. The adoption of deep rooted perennial pasture plants that increase the water use can help to manage dryland salinity whilst maintaining productivity. However, new plants are needed as few perennial pasture options currently exist. Preliminary research into the potential of …

Soil Carbon Sequestration Under Three Years Of No-Till Forage Cropping Systems, D. H. Min, J. D. Deyoung, Richard Leep

IGC Proceedings (1977-2023)

The effects of reduced tillage on soil organic carbon (SOC) are generally well established (Chan et al., 2002; Cabardella & Elliott, 1992). The effects of different crops are also somewhat understood (Drinkwater et al., 1998). However, many of these studies are done in the laboratory to study the effects of crop residues on SOC. Many forage-based systems have very little crop residue returned to the field. What residue does return is often in the form of manure or compost, which is usually broken down much more rapidly than most crop residues. The objective of this study is to …

Antioxidative Activities Of Alfalfa And Timothy Varieties, J. K. Lee, H. S. Park, J. G. Kim, B. H. Paek, J. H. Fike

IGC Proceedings (1977-2023)

The term "functional foods" is often used as a generic description for the beneficial effects of ingested foods that go beyond their traditional nutritive value (Bauman et al., 2001). Milk and dairy products are important dietary sources of nutrients, providing energy, high quality protein, and a variety of vitamins and minerals. Recent research has focused on altering the fat and protein content of milk and other dairy products in order to improve their nutrient content to more aptly reflect current dietary recommendations and trends. As a result, additional focus is being given to designing foods that have beneficial effects …

Increased Cuticular Wax Accumulation And Enhanced Drought Tolerance In Transgenic Alfalfa By Overexpression Of A Transcription Factor Gene, Z. -Y. Wang, J. -Y. Zhang, C. Broeckling, E. Blancaflor, M. Sledge, L. Summer

IGC Proceedings (1977-2023)

Plant cuticular waxes play an important role in protecting aerial organs from damage caused by multiple environmental stresses such as drought, cold, UV radiation, pathogen infection and insect attack. The identification of leaf wax genes involved in stress tolerance is expected to have great potential for crop improvement. Cuticular waxes are complex mixtures of very long chain fatty acids, alkanes, primary and/or secondary alcohols, aldehydes, ketones, esters, triterpenes, sterols and flavonoids. Mutant analysis in Arabidopsis has contributed to the identification of the components and genes involved in wax deposition. However, no information is available on the effects of overexpression of …

Development Of Alfalfa (Medicago Sativa L.) Transgenic Plants Expressing A Bacillus Thuringiensis Endotoxin And Their Evaluation Against Alfalfa Caterpillar (Colias Lesbia), F. Ardila, M. C. Gómez, M. J. Diéguez, E. M. Pagano, M. Turica, R. Lecuona, V. Arolfo, D. Basigalup, C. Vázquez Rovere, E. Hopp, P. Franzone, R. D. Rios

IGC Proceedings (1977-2023)

Alfalfa (Medicago sativa L.) is the most important forage crop in Argentina, with ca. 6 million cultivated hectares. The production of this crop is limited by the alfalfa caterpillar (Colias lesbia) which causes a loss equivalent to at least 10% of the biomass per year. No natural tolerance against this lepidoptera was found in alfalfa germplasm, hampering the development of tolerant cultivars by conventional breeding. This pest is usually controlled by using chemical insecticides but this has adverse effects on beneficial insects and the environment. Alternatively, low doses of commercial Bt insecticides (40 to 70 g/ha) also …

A Medicago Truncatula Population Segregating For Aluminum Tolerance, M. Sledge, B. Narasimhamoorthy, G. Jiang

IGC Proceedings (1977-2023)

Aluminium (Al) toxicity, manifested in inhibition of root elongation and reduced plant growth, is a major cause of poor crop yields on acid soils, which comprise up to 40% of the world’s arable land. Al toxicity associated with acid soils has been a major obstacle in alfalfa (Medicago sativa) production in the USA, as well as in tropical areas of the world. Recent molecular marker mapping studies indicate that the genomes of M. truncatula and M. sativa are highly similar (Choi et al., 2004). Thus, M. truncatula could be used as a source of genes that could …

A New Perennial Legume To Combat Dryland Salinity In South-Western Australia, L. W. Bell, M. A. Ewing, M. Ryan, S. J. Bennett, G. A. Moore

IGC Proceedings (1977-2023)

Dryland salinity has devastated large tracts of productive land in Australia. This has resulted from the clearing of native perennial vegetation and its replacement with annual crops and pastures. As annual plants are shallow rooted and only use water during their winter-spring growing season, unutilised rainwater leaks into groundwater tables which rise and bring stored salt to the soil surface. The adoption of deep rooted perennial pasture plants that increase the water use can help to manage dryland salinity whilst maintaining productivity. However, new plants are needed as few perennial pasture options currently exist. Preliminary research into the potential of …

Translational Genomics For Alfalfa Varietal Improvement, G. D. May

IGC Proceedings (1977-2023)

Key points

1. Medicago truncatula is a model legume with available mapping, genome, and RNA, protein and metabolite profiling databases and genetically diverse populations.
2. Genomics resources developed for M. truncatula have application in the study and improvement of alfalfa making it an excellent model for this forage legume.

Visual Modelling Of Alfalfa Growth And Persistence Under Grazing, S. R. Smith Jr., L. Muendermann, A. Singh

IGC Proceedings (1977-2023)

A ‘virtual’ alfalfa plant model was developed at the University of Manitoba in Canada as part of a comprehensive grazing research project. This model shows an alfalfa plant ‘growing’ on a computer screen and the plant’s response to grazing (similar to time-lapse photography). The original model was constructed by Singh (2005) to show the research potential of visually modelling alfalfa plant growth. The ability to visually ‘grow’ a plant on a computer screen also offers tremendous opportunities for teaching and extension. Detailed morphological measurements were used in the construction of Singh’s model, based on single plants subjected to the following …

Autumn Root Reserves Of Lucerne Affected Shoot Yields During The Following Spring, D. J. Moot, E. I. Teixeira

IGC Proceedings (1977-2023)

Frequent grazing affects shoot yield of lucerne (Medicago sativa L.) by limiting radiation interception (Teixeira et al., 2005b) and the accumulation of endogenous reserves (C and N) in perennial storage organs like crowns and taproots (Teixeira et al., 2005a). In temperate regions, the impact of low level of perennial reserves is particularly evident during early-spring, when lucerne regrowth resumes after an overwintering period. The analysis of lucerne yield can be fragmented into its yield components of plant population, shoots per plant and yield per shoot (Volenec et al., 1987). The objective of this research was to quantify …

Lucerne Crown And Taproot Biomass Affected Early-Spring Canopy Expansion, E. I. Teixeira, D. J. Moot, A. L. Fletcher

IGC Proceedings (1977-2023)

Leaf area index (LAI) quantifies canopy expansion in crops and is used in lucerne (Medicago sativa L.) simulation models to predict daily PAR interception (PAR i). This then drives yield through radiation use efficiency (RUE) (Gosse et al., 1984). In perennial crops, like lucerne, the level of biomass stored in crown and taproot may affect canopy expansion in subsequent regrowth cycles (Avice et al., 1997). In temperate regions the impact of this is likely to be greatest in early-spring, when low temperatures delay development. The objective of the current research was to identify whether contrasting levels of winter biomass in …

Supplementation Under Intensive Grazing, Silage- Or Grain-Based Diets For Beef Production On Steer Performance And Meat Fatty Acid Composition, J. Martínez Ferrer, E. Ustarroz, C. G. Ferrayoli, A. R. Castillo, D. Alomar

IGC Proceedings (1977-2023)

Alfalfa (Medicago sativa L.) is the main cultivated pasture in Argentina. In beef production enhanced productivity and profit depend on high stocking rates and pasture utilisation, with grain supplementation necessary to maintain high individual live weight gains (LWG) and to increase production per ha (Ustarroz, 1999). Substitution of grazed grass by concentrate can affect meat fatty acid (FA) composition (French et al., 2000). The objective of this study was to evaluate the effects of intensifying an alfalfa-based grazing system and two confinement dietary regimens for beef steer finishing on animal performance and meat FA composition.

Effect Of Stage Of Maturity On The Nutrient Content Of Alfalfa, Y. Tyrolova, A. Vyborna

IGC Proceedings (1977-2023)

Alfalfa (Medicago sativa), one of the major agricultural crops in the Czech Republic, is grown on 15.8% of the arable land. Alfalfa silage forms a substantial part of diets for farm animals. It is very important to choose a suitable term of harvesting for ensilage from the view of optimal nutrient content. The stage of maturity at cutting has large effects on each component, except crude protein (Yu et al., 2004). Alfalfa can be difficult to ensile due to a high buffering capacity and a low WSC content.

The Effects Of Alfalfa Silage Harvesting Systems On Dry Matter Intake Of Friesland Dairy Ewes In Late Pregnancy, H. F. Elizalde

IGC Proceedings (1977-2023)

With the recent introduction of alfalfa in Chilean Patagonia (Aisén), its utilisation as silage has to be reviewed relative to animal performance. The effect of silage chop length on the voluntary intake has been evaluated in different species, with sheep being more sensitive to chop length than cattle (Dulphy et al., 1984). The objective of this experiment was to evaluate the effects of different alfalfa silage chop lengths on dry matter (DM) intake and eating behaviour of Friesland dairy ewes in late pregnancy.

Implications For N Transformations In Acidic Soils Of Replacing Annual-Based Legume Pastures With Lucerne-Based Pasture In Dryland Farming Systems Of Southern Australia, I. R. P. Fillery

IGC Proceedings (1977-2023)

The supply and demand for nitrogen (N) in annual-based pasture-crop rotations in southern Australia is often poorly synchronised, leading to large losses of inorganic N (Fillery, 2001). Perennial pasture species, particularly lucerne, are being recommended to minimise dryland salinity. The implications for N cycling of using lucerne in place of annual legumes on acidic sandy soils that are widespread have not been widely studied. Lucerne is less tolerant of acidity and could fix less N than annual legumes. Lucerne root residues mineralise at slower rates than annual pasture residues with lower N release to subsequent wheat crops (Bolger et al …

Management Strategies And Distribution Of Aphanomyces Root Rot Of Alfalfa (Medicago Sativa), A Continuing Threat To Forage Production In The United States, Jennifer M. Giles, Conner L. Tordsen, Travis R. Rebstock, Bruna Bucciarelli, Deborah A. Samac, Andrew E. Sathoff

Research & Publications

Alfalfa (Medicago sativa) is one of several legumes that is affected by Aphanomyces root rot (ARR) caused by Aphanomyces euteiches. Symptoms of ARR on alfalfa seedlings include a yellow-grey discolouration of roots, rotting and loss of lateral roots, stunted growth, chlorotic foliage and reduction of nitrogen-producing nodules on roots. Infection can also occur on adult plants leading to loss of lateral roots and nodules. At the seedling stage, ARR decreases alfalfa stand establishment, and field longevity is reduced when adult plants are infected. A. euteiches is an oomycete pathogen that has motile zoospores and thick-walled oospores that …

Red Clover Improves The Energy To Protein Balance Of Lucerne-Grass Herbage, X. Godin, Gaëtan F. Tremblay, P. Seguin, S. Bittman, D. Hunt, J. Hakl, G. Bélanger, M.-N. Thivierge, A. Bertrand, M. Thériault, A. Claessens

IGC Proceedings (1977-2023)

Low ratio of readily fermentable carbohydrate to soluble protein concentrations in lucerne (Medicago sativa L.) leads to inefficient use of herbage N by ruminants. To improve the energy to protein balance in lucerne-grass herbage, four proportions of lucerne:red clover (Trifolium pratense L.) were compared in mixtures with and without grasses: timothy (Phleum pratense L.) and tall fescue (Schedonorus arundinaceus Schreb. Dumort.) in Quebec (QC, Canada). In the first post-seeding year, red clover proportion averaged (across grasses and four harvests) 0, 37, 59, and 74% in herbage mixtures. Increasing the proportion of red clover caused a slight …

Evaluation Of Annual Companion Crops For The Establishment Of Perennial Forage Crops In Eastern Canada, Philippe Seguin, Sandrine St-Pierre-Lepage, Céline Georlette, Caroline Halde, Gaëtan F. Tremblay, Huguette Martel, Ayitre Akpakouma

IGC Proceedings (1977-2023)

The use of companion crops when establishing perennial forages is desirable as it often reduces weed growth and increases forage biomass in the seeding year. In eastern Canada, oat (Avena sativa L.) is the main species used as companion crop; although other species are used, they have not been systematically evaluated. A field study was established in 2019 at three sites in Québec, Canada, to contrast the use of six annual species as companion crops for the establishment of lucerne (Medicago sativa L.)-timothy (Phleum pratense L.) mixtures. Species evaluated include berseem clover (Trifolium alexandrinum L.), annual …

Increasing Precipitation Decreases Water Use Efficiency Of Alfalfa (Medicago Sativa L.) In A Semiarid Region, H. Ni, H. K. Chu, X. F. Lai, J. Q. Deng, Yuying Shen

IGC Proceedings (1977-2023)

Alfalfa (Medicago sativa L.) plays an important role within the integrated farming systems in Northwestern Loess Plateau of China, because of its traits on a high productivity, prolonged growing season, and excellent nutritive value. However, water use efficiency (WUE) is a crucial indicator for forage production under different water conditions in the semiarid regions. To explore the responses of alfalfa growth and water use to precipitation variability, we set precipitation shelters to manipulate precipitation scenario as 30% precipitation increased (P+30), normal precipitation (CK), and 30% precipitation decreased (P-30) with the measurement of dry matter yield and soil water content. …

Effect Of Seeding Rates On Productivity And Quality Of Alfalfa In Northern Area Of Korea, Jong Geun Kim, C. Liu, S. N. Wei, Y. F. Li, E. C. Jeong, H. J. Kim

IGC Proceedings (1977-2023)

Alfalfa cultivation in South Korea is not common. There are many reasons, but low productivity has been extremely limited. Although alfalfa growth was poor due to boron deficiency in the soil, the problem has recently been solved. Nevertheless, the cultivation of alfalfa is not expanding. About 200,000 tonnes of alfalfa hay are imported every year. Therefore, this study was conducted to find a way to replace imported hay by expanding alfalfa cultivation in Korea. Alfalfa (P5444) was sown in northern part of South Korea (Pyeongchang). Alfalfa was sown in September 2018 with different seeding rates (20, 30 and 40 kg/ha) …

Effect Of Cutting Height On Productivity And Quality Of Alfalfa In Northern Area Of Korea, Jong Geun Kim, C. Liu, S. N. Wei, Y. F. Li, E. C. Jeong, H. J. Kim

IGC Proceedings (1977-2023)

Alfalfa is a very important forage for livestock feeding. In particular, due to the high crude protein content, it is widely used as a dairy cattle feeds. However, the cultivation of alfalfa is quite limited and main source is imported hay in Korea. There are many reasons, but most importantly, low productivity due to lack of boron in the soil. This experiment was conducted to expand domestic production and use of alfalfa. Alfalfa was sown in the fall of 2018 at 30 kg/ha seeding rate. Alfalfa was harvested four times (3 May, 2 July, 11 September and 13 October) in …

Kentucky Alfalfa Conference: A Team Approach To Alfalfa Education And Technology Transfer, Garry D. Lacefield, Monroe Rasnake, Christi L. Forsythe, Jimmy C. Henning, Bill Talley

IGC Proceedings (1977-2023)

Alfalfa has played an important role in providing farmers of Kentucky with a high yielding, high quality, persistent forage legume for many years. In 1980, a group of individuals under the leadership of University of Kentucky Forage Extension Specialists organized and implemented the first statewide educational event on alfalfa. This initial meeting gave rise to the Kentucky Alfalfa Conference that celebrated it’s twentieth anniversary in February 2000. This annual event has been co-sponsored by the University of Kentucky, Kentucky Forage and Grassland Council, along with other state and national groups including Certified Alfalfa Seed Council, Kentucky Department of Agriculture, Kentucky …

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 …