Impacts of Fertilizers on Insect Pests

By modifying the nutrient composition of crops, fertilizer practices can influence plant defenses. A review of 50 years of research identified 135 studies showing more plant damage and or greater numbers of leaf-chewing insects or mites in nitrogen-fertilized crops, while fewer than 50 studies reported less pest damage. Researchers have demonstrated that high nitrogen levels in plant tissue can decrease resistance and increase susceptibility to pest attacks (Table 2). Although more research is...

Manage flexibly and responsively

On the rare occasions that leafhoppers or thrips exceed economic thresholds in his clients' vineyards, Berkowitz recommends insecticides. We try to use systems that control pests without chemicals, but sometimes you're just stuck. That's often the case with Pierces disease, whose damage can force frequent replanting. Berkowitz says insecticide treatment for the blue-green sharpshooter during the first hot spells can regulate this vectors early movement into vineyards. Another approach showing...

Enhancing Biota and Improving Soil Health

Managing soil for improved health demands a long-term commitment to using combinations of soil-enhancing practices. The strategies listed below can aid you in inhibiting pests, stimulating natural enemies and by alleviating plant stress fortifying crops' abilities to resist or compete with pests. When designing fields to manage specific pests, other pests can reach damaging levels. For example, spacing crops closely can prompt disease outbreaks. Add plentiful amounts of organic materials from...

Farm Feature

TRiPLE threat TO Pests COvER CROPS, NO-TiLL, ROTATiON Uses cover crops to break up insect and disease cycles Releases parasites against pests Controls weeds with crop rotations, cover crops and no-till Uses no-till to conserve moisture Since the early 1980s, Steve Groff has been building a sustainable farming system on the triple foundations of cover crops, intensive crop rotation and long-term no-tillage. After more than 20 years seven of them in no-till vegetables Groff says he would never...

Healthy Soils Produce Healthy Crops

A healthy soil produces healthy crops with minimal amounts of external inputs and few to no adverse ecological effects. It contains favorable biological, physical and chemical properties. A biologically healthy soil harbors a multitude of different organisms microorganisms such as bacteria, fungi, amoebae and paramecia, as well as larger organisms like nematodes, springtails, insect larvae, ants, earthworms and ground beetles. Most are helpful to plants, enhancing the availability of nutrients...

How Ecologically Based Pest Management Works

To bring ecological pest management to your farm, consider three key strategies Select and grow a diversity of crops that are healthy, have natural defenses against pests, and or are unattractive or unpalatable to the pests on your farm. Choose varieties with resistance or tolerance to those pests. Build your soil to produce healthy crops that can withstand pest pressure. Use crop rotation and avoid large areas of monoculture. Stress the pests. You can do this using various management...

Introduction

Agricultural pests insects, weeds, nematodes and disease pathogens blemish, damage or destroy more than 30 percent of crops worldwide. This annual loss has remained constant since the 1940s, when most farmers and ranchers began using agrichemi-cals to control pests. Agrichemical methods of protecting crops are costly to the farmer, potentially harmful to the environment and, despite widespread use, have not proved 100-percent effective. Problems persist due to pest resistance and the uncanny...

Less tillage fewer weeds

The very first year he strip-tilled, Nugent also noticed many more weeds where he tilled than where he didn't. He responded by narrowing the tilled strip and now needs a third less herbicide. He also uses very little commercial fertilizer, depending instead on poultry litter and on recycled nutrients that are pulled from the ground by his oats and returned through their dead straw. In the beginning, his neighbors were skeptical. Now, Nugent says, they've switched over, too, because they've seen...

Livestock enrich soils

If he had to offer just one reason why his farming system is so resilient, Rosmann would say it's his healthy soils. He beds his livestock in oat, rye and barley straw his hogs are treated to the Swedish deep-bedding system of 2-foot-thick straw then composts the straw with their manure. He feeds his soils every cubic inch of that compost and tills his fields very minimally. For example, he plants his corn and soybeans into ridges and turns those fields under only after the rotation's third...

Managing Pests With Healthy Soils

Healthier soils produce crops that are less damaged by pests. Some soil-management practices boost plant-defense mechanisms, making plants more resistant and or less attractive to pests. Other practices or the favorable conditions they produce restrict the severity of pest damage by decreasing pest numbers or building beneficials. Using multiple tactics rather than one major tactic like a single pesticide lessens pest damage through a third strategy it diminishes the odds that a pest will adapt...

Managing Soils To Minimize Crop Pests

Agricultural practices that promote healthy soils are a pillar of ecologically based pest management. Good soil management can improve water storage, drainage, nutrient availability and root development, all of which may, in turn, influence crop-defense mechanisms and populations of potential beneficials and pests. In contrast, adverse soil conditions can hinder plants' abilities to use their natural defenses against insects, diseases, nematodes and weeds. Poor soils can cause plants to emit...

Predators

Predators occur in most orders of insects but primarily in the beetle, dragonfly, lacewing, wasp and true bug families (Coleoptera, Odonata, Neuroptera, Hemiptera and Diptera, respectively). Their impacts have been highlighted worldwide by eruptions of spider mite pests where chemical insecticides have eliminated the mites' predators. Tetranychid mites, for example, are usually very abundant in apple orchards where pesticides have destroyed natural predator populations. The diversity of...

Principal Parasitoids

Entomologists have described more than 18,000 species of dipteran, or fly, parasites, which have diversified over an expansive range of hosts (Table 5). Unlike parasitic wasps, most species of parasitic flies lack a hardened structure with which to deposit eggs inside their hosts. Instead, they lay their eggs or larvae on plants, where the parasitoid larvae can easily penetrate the host but also where their target victims can eat them. Individual species of parasitic flies are...

Principles of Ecologically Based Pest Management

A whole farm approach calls for designing a system that integrates ecological pest management into other aspects of crop and soil management. Each decision you make in designing your system for managing pests should be based in part on the impacts on the rest of the system. Your steps toward implementing ecological pest management should be linked with soil organic matter management, soil nutrient management, tillage, and other efforts to reduce erosion and compaction. Creating field...

Principles Of Ecologically Based Pest Management18

Diversify plants within agroecosystems 18 Strategies to Enhance Beneficials 21 SIDEBAR innovative Tart Cherry Orchard Systems (Michigan) 22 increase the population of natural enemies 24 Provide supplementary resources 25 Manage vegetation in field margins 25 FARM FEATURE No-Till Cover Crops Yield Soil and Pest Benefits (Georgia) 27 FARM FEATURE A Toast to Ecological Grape Production (California) 30 Manage plants surrounding fields to manage specific pests 34 SIDEBAR Reduce Mowing Frequency to...

Rolling out your Strategy

Once you have a thorough knowledge of the characteristics and needs of key pests and natural enemies, you're ready to begin designing a habitat-management strategy specifically for your farm. Choose plants that offer multiple benefits for example, ones that improve soil fertility, weed suppression and pest regulation and that don't disrupt desirable farming practices. Avoid potential conflicts. In California, planting blackberries around vineyards boosts populations of grape leafhopper...

Standout cover crop is rye

Although Vickers grows wheat, rye and oats as high-residue winter covers and also sells the oats it's the rye that's made him a believer in the value of cover crops. He uses it to prevent root-knot nematode problems and credits it with dramatically boosting his weed control, deterring weeds and shading everything out. Vickers sows his cover crops all the way to his field edges and even into his roads. He feeds them lightly with nitrogen if he thinks they need it. In spring, when he plants his...

Strategies to Enhance Beneficials

One of the most powerful and long-lasting ways to minimize economic damage from pests is to boost populations of existing or naturally occurring beneficial organisms by supplying them with appropriate habitat and alternative food sources. Beneficial organisms such as predators, parasites and pest-sickening pathogens are found far more frequently on diverse farms where fewer pesticides are used, than in monocultures or in fields routinely treated with pesticides. The following characteristics...

Universal Principles Farm Specific Strategies

The key challenge for farmers in the 21st century is to translate the principles of agroecology into practical systems that meet the needs of their farming communities and ecosystems. You can apply these principles through various techniques and strategies, each of which will affect your farm differently, depending on local opportunities and resources and, of course, on markets. Some options may include both annual and perennial crops, while others do not. Some may transcend field and farm to...

Uses diseaseresistant varieties

Wisconsin fruit grower Eric Carlson pays twice the price of conventional fertilizers to feed his half-acre of transitional-organic blueberries with composted poultry manure, augmented with elemental sulfur, potassium and magnesium. He calculates that those blueberries need a half-mile of weeding every two or three weeks a full mile if you figure both sides. The semi-load of mulches he buys each year suppresses his annual weeds, but perennials like sorrel and quackgrass the latter so tenacious...

What Does A Biodiverse Farm Look Like

Agricultural practices that increase the abundance and diversity of above-and below-ground organisms strengthen your crops' abilities to withstand pests. In the process, you also improve soil fertility and crop productivity. Diversity on the farm includes the following components Spatial diversity across the landscape (within fields, on the farm as a whole and throughout a local watershed) Genetic diversity (different varieties, mixtures, multilines, and local germplasm) Temporal diversity,...

Rested raspberries reward their producers

Carlson is also experimenting with alternate-row production in raspberries. By mowing every other row of his berries, he hopes to significantly reduce fungicide applications and to use preemergence herbicides only once every three or four years. You would think you would also cut your yields in half, but that's not necessarily the case, he says. Because of how well the plant responds to a rest year, the research shows that you can get up to 75 percent of your normal production. According to...

Designing a Habitat Management Strategy

The most successful examples of ecologically based pest management systems are those that have been derived and fine-tuned by farmers to fit their particular circumstances. To design an effective plan for successful habitat management, first gather as much information as you can. Make a list of the most economically damaging pests on your farm. For each pest, try to find out What are its food and habitat requirements What factors influence its abundance When does it enter the field and from...

Beneficial Agents On the Farm

Biological control is the use of natural enemies to manage pests. The natural enemy might be a predator, parasite, or disease that will attack the insect pest. Biological control is a form of enhancing natural defenses to achieve a desired effect. It usually involves raising and releasing one insect to have it attack another, almost like a living insecticide. You can facilitate a biological control program by timing pesticide applications or choosing pesticides that will be least harmful to...

Matches flowers to resource needs of beneficials

Few wine drinkers are in the market for Cabernet Sauvignon with hints of asparagus or green pepper herbaceous or green characters prompted by overly vigorous vines. Fewer still want utterly tasteless wines that have been drained of their flavors by spider mites. In the vineyards of California's North Coast, consultant Zach Berko-witz's clients know that their wines will inevitably tell the tale of how their grapes were grown. During his three decades of advising grape growers, Berkowitz has...

Start with cover crops

At the very least, Berkowitz says all grape growers can sow a no-till cover crop in the highly trafficked avenues surrounding their vineyards. If those areas are seeded and mowed, that helps keep down dust, which helps keep down mites. He also advises his clients to plant either annual or perennial cover crops in their vineyard rows preferably between mid-September and mid-October. For vineyards whose soil is shallow or whose vines aren't strong, he recommends an annual mix of 'Zorro' fescue,...

Parasitoids

Most parasitoids parasitic insects that kill their hosts live freely and independently as adults they are lethal and dependent only in their immature stages. Parasitoids can be specialists, targeting either a single host species or several related species, or they can be generalists, attacking many types of hosts. Typically, they attack hosts larger than themselves, eating most or all of their hosts' bodies before pupating inside or outside them. When the parasitoid emerges from its pupa as an...