Numbered Publications: PPFS-AG-F
PPFS-AG-F-10: Possible Causes of Yellowing Alfalfa
Chris Teutsch, Paul Vincelli, Kiersten Wise | Feb. 16, 2018 (New)
During spring, several leaf spotting diseases--including Leptosphaerulina (Lepto) leaf spot and spring black stem/leaf spot--are common in alfalfa. Leaf spotting diseases result in distinct round to elongated spots that sometimes have a dark margin. Very wet weather in spring and early summer favor activity of leaf spotting diseases in first and second cuttings. Wet and humid weather during summer favor other leaf spotting and blighting diseases. All leaf spots and blights weaken plants, but alfalfa often outgrows the damage in later cuttings. Maintain a regular cutting schedule, cutting at 30- to 35-day intervals.
PPFS-AG-F-9: Managing Diseases of Alfalfa
Ray Smith, Paul Vincelli | Dec. 1, 2014 (New)
Alfalfa can be a vigorous and productive forage crop for Kentucky farmers. Like all farm crops, however, alfalfa is subject to infectious diseases that can limit forage production. Managing these diseases is an important part of economical alfalfa production.
PPFS-AG-F-8: Kentucky Plant Disease Management Guide for Forage Legumes
Paul Vincelli | Oct. 1, 2014 (New)
Disease management in forage legumes relies heavily on using disease-resistant varieties and employing sound agronomic practices. It is important to integrate both of these strategies into a comprehensive disease management program. Failure to consider one or the other will compromise the success of your efforts. The appropriate use of pesticides sometimes plays a significant role in managing certain diseases, but it is secondary to sound cultural practices and proper variety selection.
PPFS-AG-F-7: Rating Scale for Brown Stripe of Orchardgrass
Leah Saylor, Ray Smith, Paul Vincelli | Jul. 1, 2013 (New)
As of right now, there is little published on how to assess foliar disease severity in forage grasses in order to determine the percentage which may be diseased. This publication provides a tool for visually determining the percentage of diseased foliar tissue in orchardgrass. It is based on the observation of individual leaves; however, it is hoped that eventually a rating system will be devised that provides disease percentages for entire plots.
PPFS-AG-F-5: Crown Rots of Alfalfa
Paul Vincelli | May. 1, 2009 (Minor Revision)
Crown rots are chronic disease problems of alfalfa throughout the world. Crown rots cause loss of stand and forage yield in several ways. If the crowns are rotted severely enough, infected plants will die simply by being choked off. Carbohydrates for winter survival are stored in the crown and upper taproot. By rotting this area, crown rots also make alfalfa plants more sensitive to winter kill. Some crown rot fungi produce toxins, thus weakening or even killing the plant.
PPFS-AG-F-3: Common Alfalfa Seedling Diseases and Disorders
Ray Smith, Paul Vincelli | Mar. 1, 2009 (Minor Revision)
Alfalfa seedlings are subject to a number of biotic and abiotic problems which can affect establishment. Several of the more common seedling diseases and disorders are described below. This information is being provided as a diagnostic aid; publications which provide specific management and production information can be found in the resource list.
PPFS-AG-F-4: "Emergency" Inoculation for Poorly Inoculated Legumes
Garry Lacefield, Ray Smith, Paul Vincelli | Feb. 1, 2009 (Minor Revision)
Frequently, stunted and yellowed legumes are thought by growers to be diseased. Close examination often reveals that such "diseased" plants are actually just poorly nodulated.
PPFS-AG-F-2: Risk Factors for Sclerotinia Crown and Stem Rot in Fall-Seeded Alfalfa
Paul Vincelli | Dec. 1, 2008 (Minor Revision)
Alfalfa seeded during late summer or fall is susceptible to the destructive disease Sclerotinia crown and stem rot. Fall-seeded stands are particularly vulnerable to this disease because the young seedlings have not had sufficient time to develop adequate resistance before infectious spores of the pathogen are produced in late October. In contrast, spring-seeded stands are able to develop larger, more resistant crowns prior to this infectious period. Thus, spring plantings are better able to withstand an attack, should these air-borne spores be present in the field.
PPFS-AG-F-1: Summertime Foliar Diseases of Alfalfa
Paul Vincelli | Nov. 1, 2008 (Minor Revision)
Warm, humid weather can favor development of foliar diseases of alfalfa during summer.
PPFS-AG-F-6: Alfalfa Diseases Caused by Rhizoctonia Fungi
Paul Vincelli | Nov. 1, 2008 (Minor Revision)
Rhizoctonia fungi, particularly Rhizoctonia solani, are found in most agricultural soils in Kentucky. These fungi are natural soil inhabitants that colonize and live on dead organic matter. Under the right environmental conditions, the Rhizoctonia organisms are often able to attack living plants, including alfalfa. When warm, wet conditions prevail, Rhizoctonia fungi can cause just about every conceivable type of alfalfa disease.
