Nematodes are microscopic worms that feed on plant roots, attacking and killing them on every continent as well as deserts, swamps, oceans, and tropical regions.
Germs can spread by any object that carries soil particles, including dirty shoes and garden tools. Additionally, transplanting cuttings into infected soil could further spread them.
Keep the Soil Moisturized
A healthy garden provides the ideal conditions for numerous beneficial organisms that can assist in controlling and even preventing nematode infestations, including bacteria that produce antifungal agents to kill nematodes, as well as fungi that suppress them by secreting an enzyme that prevents them from absorbing nutrients. Furthermore, keeping soil biologically active along with cover crops and crop rotation are both essential strategies in combatting nematode infestation. There are some organic nematicides such as those made of geraniol or azadirachtin which tends to work better against pests rather than nematodes.
A surefire way to reduce nematode populations is planting flowers that are toxic to root knot nematodes. According to the University of Arkansas, French marigold cultivars Tangerine Gem, Petite Harmony and Tangerine produce compounds toxic to root knot nematodes; for optimal results plant these in an even bed spaced 7 inches apart for best results.
Solarization, or using the sun’s heat to cook them in the soil, is another means of decreasing nematode populations. After tilling and covering with clear plastic for several days or weeks, bury the edges in dirt or bricks to prevent blow-away. Optimally, temperatures in the soil must reach at least 140 degrees Fahrenheit to kill off the nematodes.
Other techniques for controlling nematode populations include covering soil with cardboard or newspapers before adding mulch of hay, sawdust or shredded bark – this method deprives nematodes of sunlight, thus decreasing their numbers; however, this may require considerable labor as well as may not work in all climates.
Clean fallowing has long been used to deprive nematodes of their food source and decrease populations, but should only be undertaken sparingly due to possible consequences on soil structure. If using this approach, any fallen plants should be collected separately before being added directly into a compost pile since most compost piles don’t reach high enough temperatures to effectively dispose of them.
Remove Infected Plants
Nematodes are microscopic roundworms that feed off of plant roots to feast and kill them, such as vegetables, fruit trees, ornamentals or ornamental grasses. There are multiple strategies available for combatting them – growing cover crops can also help significantly. Most nematodes species target specific vegetable crops, while some are parasitic. While some attack the entire root system simultaneously, others form galls on individual root segments. To identify whether you have a nematode infestation in your garden, the easiest way is to examine its soil and root systems of vegetable and fruit trees. Signs of damage caused by nematodes include symptoms like wilting in hot temperatures of the day and slow growth rates with yellowed leaves; vegetables with heavy infestations often produce less than desired yields or even die altogether.
One of the best ways to eliminate nematodes from your garden is through growing non-host cover crops. Cover crops act to block out nematodes while also adding nutrients back into the soil, such as clover, rye, wheat and fescue. Certain Tagetes species marigold varieties have also proven effective at suppressing both root knot and lesion nematodes; they work best when grown as solid plantings throughout a season compared with intercropped plantings under vines or trees.
Crop rotation can also help control nematode populations. Rotating susceptible vegetables between different locations each year prevents nematodes from migrating from one site to the next and attacking your crops, while planting resistant varieties in spots where susceptible ones had already been grown will eliminate any further invasion.
Solarizing your garden is another effective method for eliminating nematodes, using clear plastic sheeting sealed around its edges to cover soil in your garden and creating an increase in temperature that kills off nematodes. Solarization works best during summer, when sunlight provides maximum heating. Though solarizing won’t eliminate root knot nematodes directly, solarizing does kill off nitrogen-fixing bacteria which cause galls on legume roots such as peas and beans that form galls when pierced; you can tell these apart from galls caused by root knot nematodes by looking out for loosely attached nodules releasing milky pink-brown liquid when punctured.
Keep Equipment Clean
Nematodes are microscopically small roundworms found living in soil. Nematodes may be both beneficial and harmful. One harmful nematode known as the root-knot nematode invades vegetable roots, hindering their ability to absorb water and nutrients and decreasing productivity of a garden. While these creatures may seem inconsequential at first glance, their effects can have serious ramifications on productivity if left unchecked; there are numerous strategies you can employ in your vegetable garden to combat their presence.
Many home gardeners don’t recognize they have a nematode infestation until their vegetables start showing symptoms such as wilting or stunted growth, due to invisible nematodes being impossible to see by naked eye and difficult to diagnose and treat.
Crop rotation is one of the best ways to manage nematodes. This involves planting different vegetables each year in their place and never growing those susceptible to nematodes back-to-back, thus helping reduce damage and possibly eliminating it altogether.
Tilling the soil can also help alleviate nematode issues in your garden, as this pulverization kills any that are living within its root zone. As with any gardening venture, make sure your soil remains moist – too dry conditions could compromise its ability to function correctly and cause further nematode problems in your plot!
Home gardeners can supplement tilling with additional organic matter like compost. Compost is an excellent source of slow-release nutrients which may help control nematode populations. Furthermore, each garden bed should be fertilized according to a soil test; potassium may prove particularly helpful in controlling these microorganisms.
Home gardeners have several nematicide products they can purchase; however, according to research conducted at the University of Florida many do not work as effectively as homemade solutions. As such, gardeners are encouraged to eschew chemical solutions and instead implement those described above.
Before transporting equipment from an infested to noninfested garden area, it is a wise move to power wash any dirt or debris off of tools prior to using them in their new location. This will decrease the amount of nematodes carried from one garden area to the next and further spread across gardens.
Identify the Problem
Identification of an infestation of nematodes is crucial to combatting them, yet can often prove difficult due to their microscopic size and damage-inducing nature. Damage caused by these pests often goes undetected in home gardens due to being microscopic in size; and their symptoms often resemble drought stress or insect pests. Soil samples need to be sent off for lab analysis in order to confirm a problem is indeed being caused by these micro-critters.
There are a few strategies available to you in order to combat root knot nematodes effectively. First, it is recommended to rotate your planting sites every year, which will prevent root knot nematodes from becoming established in your soil. Also using cover crops – plants planted and then left growing until harvest time – in the garden can help reduce populations of unwanted nematodes such as rye, wheat, fescue clover and sudangrass cover crops can help. Nonhost plants like french marigolds, Tiger Lilies and miracle-gro dahlias also play key roles.
One way of increasing soil microbiota diversity and potentially suppressing nematode populations is adding organic matter regularly to a garden bed. Compost, manure or other forms of microbially active material like oyster shells or shrimp hulls should do well; soil amendments with chitin-containing oyster shells or shrimp hulls or eggshells could also prove helpful as these contain compounds which are toxic to nematodes.
Finally, there are a number of nematicide products on the market designed to combat nematodes. Two popular options include products based on geraniol or natural neem oil-derived azadirachtin extract for fighting root-knot nematodes; this latter approach tends to be more successful against parasitic root-knots while former methods are better at targeting other forms of nematodes.
At MSU Plant and Pest Diagnostics, our experts can assist in devising the most efficient means for managing nematode infestation. With proper planning, your garden can quickly return to being productive space!
