Science-based information for a healthier garden
If you ’re the type of person who like to determine about industrial plant pests in your free time , odds are you have already heard or understand about a grouping of organism known as nematodes . Many nematodes are good and used as biological control condition agents of specific pest organisms in husbandry . Others , however , are problematic parasite of animals and plants , such as the dog heartworm ( Dirofilaria immitis ) and beech - leaf disease nematode ( Litylenchus crenatae ) . One group of nematodes that should be restrain on your radar are beginning - greyback nematodes ( any member of the genusMeloidogyne ) , which are coarse plant sponge .
The 411 on root-knot nematodes
theme - knot nematodes cause damage to a mixture of crop and cosmetic plant and can be found in temperate and tropical areas around the Earth . Sometimes this harm can be severe and cause significant crop red . ascendent - knot nematodes get their common name from the “ grayback , ” the swellings or galls , that develop at their feeding sites on roots . The size of it of a swelling varies and depends on the legion , the species of root - knot roundworm , and the number of adult female person within the cheekiness .
Adult female ascendant - knot nematode are sedentary , swollen , and cystlike , while the males and juveniles are motile and vermiform ( wormlike ) . adult set out from 0.5 to 1.5 millimeters in duration . Their numbers increase in step with the growth of the host plant , so they incline to be most abundant in summertime when their Host are growing vigorously . ascendent - knot nematodes move most well in wet , sandy soil . This surround is most probable to leave in significant nematode damage . In the South , plants that are grown in sand — such as golfing turf and peanut — are commonly affected .
Besides the shaping of etymon galls , there are other symptom to look out for when scout for root - knot nematodes . Aboveground parting of the plant often experience leafage greensickness ( yellowing ) , stunt ( reduced ontogenesis ) , poor blossom and fruit set , and soft wilting . Certain crop , such as carrot , develop misshapen , forked , or “ hairy ” roots , with a proliferation of subaltern roots off the taproot . Keep in mind , however , that these symptom can also be cause by rocky grease , fresh manure as a fertilizer author , or some root - putrefaction pathogen . If you suspect a nematode infestation , have your plant tested by a local diagnostic clinic before strike frontwards with management .
Helpful tips on prevention and management
in advance geomorphological or molecular recognition is usually required to determine the species of root - knot nematode , but management recommendation tend to vary by harvest eccentric , not nematode species , with possible options include the use of goods and services of nematicides .
If you get verification of a tooth root - knot nematode plague , the upright first stride is to transfer the infested plant(s ) and those nearby as soon as practical and replant with a tolerant alternate plant .
Marigolds ( Tagetesspp . and cvs . , one-year ) are often a great option for replanting in an infected nematode area , as they produce an allelopathic chemical compound called alpha - terthienyl . This chemical substance is toxic to other types of being , including nematode , insects , and certain pathogenic fungi and bacteria , and can significantly suppress their growth . The University of Florida has a helpful usher for using marigolds to reduce nematode atmospheric pressure . The guide admit a table at the very bottom of the document that provide a leaning of various marigold cultivar and their resistance to nematode impairment .
If you would like to render to your original plant , whether or not you plan to use nematicides , allow the marigolds to grow for at least a full twelvemonth ( sooner long ) , then remove them and interchange them with your desired plant . If you may do a three - crop rotary motion , decorative grasses ( landscapes ) or Gunter Wilhelm Grass comprehend crops ( commercial-grade / farming ) are a good second - season selection , as they often tolerate hard soil and have few problems with nematodes . To utilise pachysandra ( Pachysandraspp . and cvs . , Zones 4–9 ) as an example “ antecedent - mile - susceptible ” industrial plant , count rotate from pachysandra to marigold to grass to pachysandra or pachysandra to marigold to grass to marigold to pachysandra . ( The two rotation of marigold in the second option will be particularly helpful if you do not plan to also employ a nematicide . )
When you remove your original works , this will be a commodious time for you to make any necessary soil amendments . source - knot nematodes prefer wet , sandy , acidulent soil , so making any adjustments to avoid that environment will likely help reduce nematode pressure . Additionally , the period between removal and planting is a convenient time to have the sphere treated with a nematicide . Some nematicides , such as Azadirachtin , are more effective if lime is applied immediately later on . Note that sure organic nematicides derived from black walnut tree ( 5 - hydroxy-1,4 - naphthalenedione , aka juglone ) may get reduced performance of plants grown in the sphere at once after app , so use with precaution .
Remember to always wear protective equipment and to cautiously succeed the instructions on the label of a product . Some Cartesian product will require to be purchased and practice by a certified professional . see to it that origin - knot nematodes ( which may sometimes be name as simply “ Meloidogyne , ” “ dirt - borne nematodes , ” or “ root - feeding roundworm ” ) are managed with the production you use , and apply it at appropriate rates .
— Nicholas Goltz , DPM , is a industrial plant diagnostician and extension pedagogue in the northeastern United States , where he help raiser and homeowners find holistic and comprehensive solutions for plant problems .
Fine Gardening urge Products
A.M. Leonard Deluxe Soil Knife & Leather Sheath Combo
Fine Gardening receive a commission for item purchased through links on this internet site , including Amazon Associates and other affiliate advert programs .
Gardena 3103 Combisystem 12 - column inch To 20 - in Adjustable Metal Fan Rake Head
Get our latest tips , how - to articles , and instructional video mail to your inbox .
Signing you up …
Related Articles
Root Rot Identification and Treatment
How to Identify and Treat Sudden Oak Death
Can My Plant Be Saved from Root Rot?
What You Need to Know About Beech Leaf Disease
bring together Fine horticulture for a free engaging live webinar featuring Dr. Janna Beckerman , a famed plant diagnostician as well as prof emerita at Purdue University and the ornamentals technological manager …
When I spotted a particular sand dollar cactus ( Astrophytum asterias ) at the Philadelphia Flower Show a few month ago , I knew I was in bother . With a delicious people of colour pattern …
When we only prioritize plant we want over plants our landscape painting need , each season is filled with a never - ending lean of chores : pruning , pinching , watering , treating , remediate , and fertilizing , with …
Subscribe today and save up to 47%
Video
Touring an Eco-friendly, Shady Backyard Retreat
You must be deliberate when you insert the backyard of garden interior decorator Jeff Epping — not because you ’re probable to trip on something , but because you might be dive - bombed by a pair …
4 Midsummer Favorites From a Plant Breeder’s Garden
Episode 181: Plants You Can’t Kill
Episode 180: Plants with Big, Bold Foliage
4 Steps to Remove Invasive Plants in Your Yard
All Access member get more
ratify up for afree trialand get access to ALL our regional content , plus the repose of the member - only content program library .
Start Free Trial
The telltale sign a plant has root-knot nematodes is the presence of root galls.Photo: courtesy of Jeffrey W. Lotz, Florida Department of Agriculture and Consumer Services /bugwood.org
Get complete site access to expert advice , regional content , and more , plus the photographic print cartridge clip .
Start your FREE test
Already a member?access
The telltale sign a plant has root-knot nematodes is the presence of root galls.Photo: courtesy of Jeffrey W. Lotz, Florida Department of Agriculture and Consumer Services /bugwood.org
Under a microscope, the nematodes can be detected within the gall tissue.Photo: courtesy of Nicholas Goltz
French marigolds (Tagetespatulaand cvs.) are particularly resistant to nematode damage. For best results, plant marigolds densely, with no more than 7 inches between plants.Photo: Michelle Gervais
