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...

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...

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...

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...

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...

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...