NCA 2009 President's Award Recipient - The Progressive Rancher ...

More documents

Recommendations

Info

Why Control the First Noxious Weeds? Brad Schultz, Kent McAdoo and Steve Foster. Extension Educator, Winnemucca; Natural Resource Specialist, Elko; Extension Educator, Lovelock. Noxious weeds are an ever increasing problem on range and pasture land in Nevada and surrounding states. Many landowners, for a variety of reasons, do not control weeds on their property when they are first observed and populations are small. Among their reasons are: 1) someone else brought them here, so they should control them; and 2) there are only a few plants, they have not spread and herbicides are costly. The first line of reason may seem to have merit, but is also pointless. Most of the individuals who brought our current suite of noxious weeds into the Great Basin and Intermountain West passed away years ago. If dead men don’t tell tales, it is just as likely they will not be killing their Table 1. Seed production and maximum longevity for some of the noxious weeds found in Nevada. Seed Production Seed Production Longevity Common Name Scientific Name Seeds/Plant Years Canada thistle Cirsium arvense up to 12,000 22 St. Johnswort Hypericum perforatum 15,000 to 33,000 10 Dalmation toadflax Linaria dalmatica up to 500,000 10 Diffuse knapweed Centaurea diffusa 10,000 12 Dyers woad Isatis tinctoria 500 to 10,000 10 Hoary cress Cardaria spp. 1,200 to 4,800 3 Jointed goatgrass Aegilops cylindrica L up to 3,000 5 Leafy spurge Euphorbia esula hundreds 10 Mayweed chamomile Anthemis cotula 550 to 7,000 25 Mediterranean sage Salvia aethiopis up to 100,000 10 Medusahead Taeniatherum caput-medus tens to hundreds 2 Musk thistle Carduus nutans 10,000 10 Perennial pepperweed Lepidium latifolium tens of thousands ? Purple loosestrife Lythrum salicaria up to 2,700,000 15 Rush skeletonweed Chondrilla juncea up to 10,000 2 Russian knapweed Acroptilon repens 1,200 8 Scotch thistle Onopordum acanthium 7,000 to 40,000 16 Salt cedar Tamarix ramosissima 500,000+ 1 Silverleaf nightshade Solanum elaeagnifolium 4,500+ 15 Spotted knapweed Centaurea biebersteinii 1,000 to 30,000 8 Yellow starthistle Centaurea solstitialis up to 100,000 10 Yellow toadflax Linaria vulgaris 15,000 to 30,000 10 weeds. The statement about few plants, slow spread and high treatment cost may be true at first; but given time, most weeds increase rapidly when the right conditions occur for optimum seed germination and seedling survival. Then control becomes very, very costly. Remember, all weed problems started with only a few plants. The University of Nevada Cooperative Extension recently published a number of papers that clearly demonstrate why landowners should control noxious weeds when they are first observed (see list at the end of this article). Live seeds that germinate and grow into a mature plant originate from a pool of seeds called the seedbank. There are two general types of seedbanks: transient and persistent. A transient seedbank is shortlived, with all seeds either germinating or dying within one germination (growing) season following the seed’s maturation (ripening). A persistent seedbank lasts for at least two and often many growing seasons. Seedbanks function much like your bank account. There are annual inputs (deposits) when seed ripens and is dispersed, and withdrawals when seeds germinate, die or are buried too deep to germinate. When the annual inputs exceed the annual losses, the seedbank increases; thus, the potential for new weeds to establish increases. Successful weed management programs must focus on reducing the seedbank by reducing inputs and/or increasing losses so they exceed inputs. One reason to control the first weeds is to prevent them from establishing a long-lived seedbank. Table 1 lists 22 noxious weeds that occur in Nevada and provides information about seed production per plant and how long some of those seeds can survive in the soil. Most weeds produce at least several thousands of seeds per plant, with many species typically producing tens of thousands to hundreds of thousands of seeds per plant. For each annual batch of seed produced, some will survive at least one year. For many species, additional seeds will survive at least 10 years, and for a few species a small percentage will survive for 20 years or more. For a plant that produces 10,000 seeds and has only one-half of one percent alive after 10 years, that means 50 live seeds will reside in the seedbank. Those seeds may remain where the mother plant dropped them, or any number of processes could have been moved them new locations, perhaps where weeds did not previously exist. If the right dispersal, germination, and survival conditions occur, an entirely new population can establish years after seed-drop, and quite possibly at locations far from the mother plant. Once a noxious weed goes to seed once, it can create a weed problem that lasts for many years. Cooperative Extension also has been addressing noxious weed issues at Chimney Dam Reservoir in Humboldt County for a number of years. Two recent publications clearly show that excellent control of perennial pepperweed (tall whitetop) can occur when herbicide is applied to seedlings. In Figure 1, the reddish brown plants are new seedlings of perennial pepperweed shortly after they were treated with full label rate Cimarron®Max herbicide in early June 2007. The seedlings established on the lakebed in early May when the rapid decline in water levels created an ideal germination environment. The brown leaves are the Figure 1 Figure 2 Figure 3 Figure 4 Figures 1 and 2. The treatment area 13 days after treatment (1) and one year later (2). The brownish hue in figure 1 is the leaves of treated perennial pepperweed (tall whitetop) plants. The predominant species in figure 2 is foxtail barley, a short-lived perennial grass. Figures 3 and 4. A mature stand of perennial pepperweed (3) 13 days after treatment in 2007 and in August of 2008 (4). There was evidence of extensive top kill in 2007 (yellowish chlorotic plants) but abundant regrowth in 2008. 36 April 2013 The Progressive Rancher www.progressiverancher.com
Spotted Knapweed appeared near Missoula before 1925 and is now in every county in Montana. effect of the herbicide. Figure 2 shows the same spot one year later. The herbicide application eliminated over 99 percent of the seedlings and facilitated establishment of foxtail barley. Foxtail barley generally is not considered a desired species, but on a lakebed that is flooded every few years and has alkaline soil when exposed, foxtail barley probably is the best vegetation one can expect. At this location, cattle consume the foxtail barley quite readily in the fall and winter. The area shown in Figure 3 is about 200 yards from the location of Figures 1 and 2, and was inhabited by a very mature stand of perennial pepperweed. This site location was treated on the same day, and with the same chemical and application rate, as the perennial pepperweed seedlings shown in Figure 1. One year later there was no effective control of the mature perennial pepperweed plants (Figure 4). The mature stand of perennial pepperweed was eventually controlled (not eradicated), but it took several more annual treatments. One critical reason for successful control of the seedlings and unsuccessful control of the mature perennial pepperweed is the respective root structure of the different age classes. For about the first 6-8 eight weeks of growth, perennial pepperweed seedlings behave as an annual, not a perennial plant. The roots are short and they have not developed any perennial buds. The buds that develop on the root crown and the roots after eight weeks of age are what allow this weed to regrow the next year. When the leaves are killed before the seedling can develop perennial buds on the roots and root crown the plant dies. Mature perennial pepperweed plants have roots that extend several feet or more into the soil and can extend laterally for 10-20 feet or more. Every inch of these roots has developed a bud that can produce a new plant. It is literally impossible to place enough herbicide on the relatively small amount of leaf area of mature plants to kill all of the buds found on their very large root system. Some buds will survive and eventually produce stems that emerge the following growing season. Furthermore, emergence may not occur until the middle or latter part of the next growing season. Another challenge with applying herbicides to mature perennial pepperweed is appropriate location of the chemical. The lower leaves are the ones that export most of their carbohydrates from photosynthesis to the roots, and thus move the herbicide to the roots. The upper leaves deliver most of their energy production to the flowers and seed. It is very difficult to get herbicide, especially from an aerial application, through the flowers and upper leaves to the lower leaves, where it is most effective. As Figure 1 shows, all of the seedlings had leaves that were completely exposed and therefore had the maximum potential for herbicide contact, uptake and movement to the site of action in the plant. The work at Chimney Dam showed that perennial pepperweed up to two years old could be successfully treated with Cimaron ® Max provided their leaves were readily accessible to the herbicide. Complete documentation of the effort to control perennial peppewrweed at Chimeny Dam Reservoir can be found in two publications available on the internet at the URL addresses found at the end of this article. Papers described in the text. Please see these for additional discussion of this topic and photos of the success of the treatments applied. Schultz. B. W. 2012. The Noxious Weed Seedbank: Out of Sight – Out of mind and eventually out of control. UNCE Fact Sheet 12-01. Available at: http://www.unce.unr.edu/publications/ search/details.asp?searchby=keywordsearch&searchtext=seedbank&submit=Search Schultz, B. W. 2012. Response of seedling and two-year-old perennial pepperweed (Lepidium latifolium) plants to herbicide control. Journal of the NACAA, Volume 5, Issue 1. May. Available at: http://www.nacaa.com/journal/index.php?jid=136. Schultz, B. W. 2011. Differential Herbicide Effectiveness on Adjacent Populations of Young (Seedling) And Mature Perennial Pepperweed (Lepidium latifolium). Journal of the NACAA. Volume 4, Issue 1. November. Available at: http://www.nacaa.com/journal/index.php?jid=103 The use of herbicide names in this paper does not imply any recommendation from the University of Nevada Cooperative Extension. Perennial pepperweed can be treated successfully with a number of herbicides and any applicator should know the benefits and constraints of each herbicide and make their selection based upon their specific circumstances. Specializing In Long Term Farm & Ranch Real Estate Loans 2420 Main St. Baker City, OR 97814 Incredibly Comfortable Phone: 775-738-9500 Fax: 775-753-7169 Call Or Visit Today Toll Free: 800-444-7101 Website: www. pacificim.net Furniture as as You Are! 2990 Idaho St. Elko, NV 89801 LEATHER: • Outlasts Fabric Four-To-One • Offers Year Round Comfort • Is Extremely Durable • Ages Well • Color Stays Vibrant • Is Easy To Care For La-z-boy Ashley Sunny Designs Serta Mattresses Hours: Mon-Fri 8:30-5:30 Saturday 9-5 Closed Sundays www.progressiverancher.com The Progressive Rancher April 2013 37
Page 1 and 2: NCA 2009 President’s Award Recipi
Page 3 and 4: As we look forward to spring and tu
Page 5 and 6: The Progressive R ancher newly earm
Page 7 and 8: Cooperative Extension Announces Wee
Page 9 and 10: OFFICE: 775-423-7760 JACK PAYNE Cel
Page 11 and 12: Flying In the Face of Common Sense
Page 13 and 14: You can’t make this stuff up!!!!!
Page 15 and 16: Invited Property Rights Editorial N
Page 17 and 18: Nutrition & Health Your success dep
Page 19 and 20: 4 control of public lands in Nevada
Page 21 and 22: Table 2. Vegetation Cover by Treatm
Page 23 and 24: Selecting Alfalfa Varieties: Fall D
Page 25 and 26: Federal Coordination with County Pl
Page 27 and 28: Handling and Stockmanship Skills Fl
Page 29 and 30: Shaw Cattle Co. Production Sale Rep
Page 31 and 32: The Return of an Uphill Domestic Ho
Page 33 and 34: Range Plants for the Rancher By Pau
Page 35: Canada Thistle Background Photo: UA
Page 39 and 40: The Progressive Rancher Coloring Pa

NCA 2009 President's Award Recipient - The Progressive Rancher ...

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?