Organic and Biologics Plant Science 280 Mr. Gomes

Organic Agriculture A very broad term that covers a multitude of characteristics Is often lumped into one broad category Generally thought of as outside the norm versus conventional Is extremely difficult to manage Until very recently, was virtually ignored universally by most Weed Scientists

Organics in America Very little research in organic weed management. Much more money is invested in the engineering approach to management than the ecological approach One of the fastest growing segments of US Ag for more than a decade In 1990, there were fewer than 1 million acres of certified organic farmland in the US In 2008, it was 4.8 million acres From 2006-2008, there was an increase of 3,440 new certified farms. An increase of 36% Grew 15% a year from 2002-2008

Alternative Names Agroecological Biodynamic Conservation Organic Regenerative

Agroecological Generally labor intensive No or very limited dependence on synthetic fertilizers and pesticides Use of locally produced manure or compost Use of leguminous plants or trees for fertilizer Maintain diverse cropping/livestock systems that are sustainable Advocates believe the system should achieve social (community maintenance), economic (profitability), and ecological (sustainability) objectives

Biodynamic Generally means emphasizing a farms organic unity Encouraged to make their own fertilizer by keeping animals The most integrated when it comes to crops and livestock Advocate against any form of uniformity Encouraged to “Live fully in the organic spirit, including participation in activities intended to promote the biodynamic way of life”

Conservation Often referred to as sustainable Ag Advocates zero or minimal tillage Topsoil management to achieve preservation Crop rotations based on minimal soil disturbance Permanent soil cover Biological pest control

Organics Seek to maintain long term soil health Advocates the use of Crop rotation, green manure, composting, and biological pest control Manage pests based on maintaining biological diversity To be labeled organic you must Exclude the use of synthetic fertilizers, pesticides, plant growth regulators, livestock antibiotics, food additives, and GMO’s Discussion???

Regenerative Essentially Agroecological farming Rooted in the knowledge of how to manage plants, animals, water, soil, and pests Primary objective is to maintain soil and ecological longevity through farming practices

3 Characteristics and Objectives In contrast to conventional, industrial agriculture, organic agriculture has been developed by a farmer dominated process Organic farming systems use integrated management strategies The goals of farmers are multidimensional and go beyond simply maximizing yield and economic return. They include development of social networks and localization of food supply

Operational Goals To meet basic nutrient requirements by creating self- regenerating systems to enrich soil and create a nutrient-rich growing environment To achieve weed control using crop rotation systems to deprive weeds of favorable growing conditions To achieve insect control through reliance on natural predators To achieve plant disease control through use of crop rotation, careful seed selection, and general farming practices

Goals for Weed Management Systems Limiting competitive damage caused by weeds. A primary objective is to reduce weed density to tolerable levels. Redefining when a plant is a weed Minimizing the size of future weed populations by minimizing seed production and survival Preventing introduction of new weed species by monitoring, sanitation, and targeted eradication

Weed Management to protect the crop Reduce weed density to a tolerable level. Very subjective and hard to define Reduce the damage a given density of weeds causes. This can be done by; Reducing weed density Minimize resource consumption, growth, and competitive ability Delaying weed emergence and then encouraging weed emergence Increasing the portion of resources captured by crops Damaging, but not necessarily killing, weeds with one of several techniques Shifting the composition of weed communities to less aggressive, easier to manage species. Ex. Ladino clover

Biological Weed Control Plant distribution is determined by edaphic, climatic, and biotic Soil type and climate and be monitored and discussed, but not controlled by peeps Biotic environment can be manipulated however. Ex?? Biological Control can be very successful but will never be the solution to every weed problem When successful it is implemented as part of a larger plan

Defined Biological Control is usually though of as requiring intentional introduction of a parasite, predator, or pathogen to achieve control, but it is also a natural phenomenon. Scientists can therefore introduce an agent or discover the control potential of a natural biological control agent The ultimate goal is to maintain the bad plant population at a lower average density Not necessarily to eradicate, but to reduce

Advantages Reasonably permanent Self-perpetuating No additional inputs required once agent is established successfully No harmful human side effects Attack is limited to target weed and a few close relatives Risks are known and evaluated before release Control often dependent on host density Costs are non-renewing High benefit:cost ratio for successful programs

Disadvantages Control is slow No guarantee of results Establishment may fail for many reasons There may be unknown ecological effects. Mutation If target is related to a crop, the number of biocontrol agents is low Some risks may not be known and cannot be evaluated Does not work well in short term cropping cycles Restriction of spread is impossible Initial investment of time, money, and personnel can be very high Eradication is not possible.

List of some Biological Agents Weed Type of Agent Field Bindweed Gall Mite Puncturevine seed/stem weevil Russian Knapweed Gall-inducing nematode Prickly Pear Cochineal Scale Tansy Ragwort Flea beetle Yellow Starthistle Bud weevil/Rust Fungus?

Application Methods of Bio Agents Classical Augmentation Innundation Inoculation Conservation Broad Spectrum Control

Classical The intentional introduction, usually from a geographically distant place, adapted to native weeds Has been limited to plants that are not closely related to crop species The first real method of biological control that started in the late 19th century Ca one of the first test sites. Ex Santa Cruz island Works best in areas of relatively undisturbed habitat (i.e. rangeland or permanent crop). Most successful method Target is usually areas of expanded range (puncturevine, Russian thistle, spotted knapweed)

Augmentation Artificial manipulation of a population so a weed is controlled Examples include the use of sheep or goats to manage spurge in parts of Ca Inundation is a method of this where large numbers of an agent are released Generally control is short term (Scale on prickly pear) Inoculation is the intentional release of a known biological organism Success is based on the agents ability to reproduce Generally this is thought to be long term and permanent

Conservation Identify native parasites, predators, and disease of the desired species are conserved or protected Nothing is imported or released Extremely challenging to accomplish Whole, systemic approach is needed to accomplish this task

Broad Spectrum Control The use of herbivorous fish can fall into this category (catfish in rice) Grass carp in canals and ditches is always a hot topic?! Sheep and goats can graze on plants cattle will not eat Can be very hard on the environment with and wild habitat Geese, ducks, and chickens have been used to control nutsedge in multiple crops Not always effective because they can be very picky