Paper · 2025 · Nematology

Effect of integrating cover crops and bionematicides on nematode management in organic zucchini

Denis Gitonga; Johan Desaeger; David Shapiro-Ilan; et al.

10
claims
20
verbatim quotes
4
citations
2
research areas
—
Not open access

Abstract

Summary Integrating cover crops and bionematicides presents a sustainable approach to managing plant-parasitic nematodes (PPN) in organic vegetable production systems. The integration of sunn hemp, Crotalaria juncea (‘Crescent sun’) and sorghum-sudangrass, Sorghum bicolor × S. sudanense (‘Sweet Six BMR’) with bionematicides was evaluated in two locations in central (Gulf Coast Research and Educational Centre – GCREC) and south (Fort Lauderdale Research and Educational Centre – FLREC) Florida for the effectiveness of PPN suppression. Field experiments were conducted with establishing cover crops in each location 3 months before planting organic zucchini on plastic beds equipped with a drip application system used to inject three commercial bionematicides (thyme oil, neem oil and azadirachtin) and the broth culture of Xenorhabdus bovienii bacteria associated with Steinernema feltiae . Cover cropping with sunn hemp and sorghum-sudangrass significantly reduced population densities of root-knot nematodes ( Meloidogyne spp.) at GCREC, whereas only sunn hemp reduced the root-knot nematode population at FLREC. Galling severity on zucchini roots caused by Meloidogyne spp. was significantly lower in azadirachtin and neem oil applications integrated with sunn hemp. The impact of integrating cover crops with bionematicides on other PPN, such as Mesocriconema spp., Nanidorus minor and Hoplolaimus spp., varied among the treatments at both locations. Integrating cover crops with bionematicide applications provided additional control options for zucchini, but the efficacy of different bionematicides depended on the nematode species present in the soil and the cover crop species used. These findings underscore the importance of adaptive nematode management, where control strategies are customised to target the specific nematode populations causing economic damage in each field.

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Claims 10

Intervention effectobservedoriginal resultpositivesignificant (as stated)measured

Claim · model-written summary

Sunn hemp cover cropping significantly reduced Meloidogyne density at GCREC.

Taxon
organic zucchinit0
Treatment
sunn hempe0
Interactor
Meloidogyne spp.Meloidogynee0pest
Outcome
population densities of root-knot nematodes ( Meloidogyne spp.)e0
Direction
reducede0
Setting
GCRECe0

Not reportedComparator

Organisms pictured · Representative pictures of the matched species, not figures from the paper.

Meloidogyne
Meloidogyne · Interactor · picture of the genus (one of its species)Photo by William Wergin and Richard Sayre. Colorized by Stephen Ausmus. U.S. Department of Agriculture · CC BY 2.0 · Wikimedia Commons ↗

Verbatim

e0

“Cover cropping with sunn hemp and sorghum-sudangrass significantly reduced population densities of root-knot nematodes ( Meloidogyne spp.) at GCREC”

✓ located verbatim in the source · abstract, characters 896–1043 · show in text ↑
t0

“organic zucchini”

✓ located verbatim in the source · title, characters 79–95 · show in text ↑
Intervention effectobservedoriginal resultpositivesignificant (as stated)measured

Claim · model-written summary

Sorghum-sudangrass cover cropping significantly reduced Meloidogyne density at GCREC.

Taxon
organic zucchinit0
Treatment
sorghum-sudangrasse0
Interactor
Meloidogyne spp.Meloidogynee0pest
Outcome
population densities of root-knot nematodes ( Meloidogyne spp.)e0
Direction
reducede0
Setting
GCRECe0

Not reportedComparator

Organisms pictured · Representative pictures of the matched species, not figures from the paper.

Meloidogyne
Meloidogyne · Interactor · picture of the genus (one of its species)Photo by William Wergin and Richard Sayre. Colorized by Stephen Ausmus. U.S. Department of Agriculture · CC BY 2.0 · Wikimedia Commons ↗

Verbatim

e0

“Cover cropping with sunn hemp and sorghum-sudangrass significantly reduced population densities of root-knot nematodes ( Meloidogyne spp.) at GCREC”

✓ located verbatim in the source · abstract, characters 896–1043 · show in text ↑
t0

“organic zucchini”

✓ located verbatim in the source · title, characters 79–95 · show in text ↑
Intervention effectobservedoriginal resultpositivemeasured

Claim · model-written summary

At FLREC only sunn hemp reduced Meloidogyne population.

Taxon
organic zucchinit0
Treatment
sunn hempe0
Interactor
root-knot nematodeMeloidogynee0pest
Outcome
root-knot nematode populatione0
Direction
reducede0
Setting
FLRECe0

Not reportedComparator

Organisms pictured · Representative pictures of the matched species, not figures from the paper.

Meloidogyne
Meloidogyne · Interactor · picture of the genus (one of its species)Photo by William Wergin and Richard Sayre. Colorized by Stephen Ausmus. U.S. Department of Agriculture · CC BY 2.0 · Wikimedia Commons ↗

Verbatim

e0

“only sunn hemp reduced the root-knot nematode population at FLREC.”

✓ located verbatim in the source · abstract, characters 1053–1119 · show in text ↑
t0

“organic zucchini”

✓ located verbatim in the source · title, characters 79–95 · show in text ↑
Intervention effectobservedoriginal resultpositivesignificant (as stated)measured

Claim · model-written summary

Sunn hemp plus azadirachtin significantly lowered zucchini root galling by Meloidogyne.

Taxon
organic zucchinit0
Treatment
azadirachtine0
Interactor
Meloidogyne spp.Meloidogynee0pest
Outcome
Galling severity on zucchini roots caused by Meloidogyne spp.e0
Direction
lowere0
Qualifier
integrated with sunn hempe0

Not reportedComparator

Organisms pictured · Representative pictures of the matched species, not figures from the paper.

Meloidogyne
Meloidogyne · Interactor · picture of the genus (one of its species)Photo by William Wergin and Richard Sayre. Colorized by Stephen Ausmus. U.S. Department of Agriculture · CC BY 2.0 · Wikimedia Commons ↗

Verbatim

e0

“Galling severity on zucchini roots caused by Meloidogyne spp. was significantly lower in azadirachtin and neem oil applications integrated with sunn hemp.”

✓ located verbatim in the source · abstract, characters 1120–1274 · show in text ↑
t0

“organic zucchini”

✓ located verbatim in the source · title, characters 79–95 · show in text ↑
Intervention effectobservedoriginal resultpositivesignificant (as stated)measured

Claim · model-written summary

Sunn hemp plus neem oil significantly lowered zucchini root galling by Meloidogyne.

Taxon
organic zucchinit0
Treatment
neem oile0
Interactor
Meloidogyne spp.Meloidogynee0pest
Outcome
Galling severity on zucchini roots caused by Meloidogyne spp.e0
Direction
lowere0
Qualifier
integrated with sunn hempe0

Not reportedComparator

Organisms pictured · Representative pictures of the matched species, not figures from the paper.

Meloidogyne
Meloidogyne · Interactor · picture of the genus (one of its species)Photo by William Wergin and Richard Sayre. Colorized by Stephen Ausmus. U.S. Department of Agriculture · CC BY 2.0 · Wikimedia Commons ↗

Verbatim

e0

“Galling severity on zucchini roots caused by Meloidogyne spp. was significantly lower in azadirachtin and neem oil applications integrated with sunn hemp.”

✓ located verbatim in the source · abstract, characters 1120–1274 · show in text ↑
t0

“organic zucchini”

✓ located verbatim in the source · title, characters 79–95 · show in text ↑
Observationobservedoriginal resultmeasured

Claim · model-written summary

Responses of Mesocriconema spp. to the cover crop and bionematicide integrations varied by treatment and site.

Taxon
organic zucchinit0
Interactor
Mesocriconema spp.Mesocriconemae0pest
Outcome
impact of integrating cover crops with bionematicides on other PPNe0
Direction
variede0

Verbatim

e0

“The impact of integrating cover crops with bionematicides on other PPN, such as Mesocriconema spp., Nanidorus minor and Hoplolaimus spp., varied among the treatments at both locations.”

✓ located verbatim in the source · abstract, characters 1275–1459 · show in text ↑
t0

“organic zucchini”

✓ located verbatim in the source · title, characters 79–95 · show in text ↑
Observationobservedoriginal resultmeasured

Claim · model-written summary

Responses of Nanidorus minor varied by treatment and site.

Taxon
organic zucchinit0
Interactor
Nanidorus minorParatrichodorus minore0pest
Outcome
impact of integrating cover crops with bionematicides on other PPNe0
Direction
variede0

Verbatim

e0

“The impact of integrating cover crops with bionematicides on other PPN, such as Mesocriconema spp., Nanidorus minor and Hoplolaimus spp., varied among the treatments at both locations.”

✓ located verbatim in the source · abstract, characters 1275–1459 · show in text ↑
t0

“organic zucchini”

✓ located verbatim in the source · title, characters 79–95 · show in text ↑
Observationobservedoriginal resultmeasured

Claim · model-written summary

Responses of Hoplolaimus spp. varied by treatment and site.

Taxon
organic zucchinit0
Interactor
Hoplolaimus spp.Hoplolaimuse0pest
Outcome
impact of integrating cover crops with bionematicides on other PPNe0
Direction
variede0

Verbatim

e0

“The impact of integrating cover crops with bionematicides on other PPN, such as Mesocriconema spp., Nanidorus minor and Hoplolaimus spp., varied among the treatments at both locations.”

✓ located verbatim in the source · abstract, characters 1275–1459 · show in text ↑
t0

“organic zucchini”

✓ located verbatim in the source · title, characters 79–95 · show in text ↑
Associationauthor interpretationoriginal resultmeasured

Claim · model-written summary

Bionematicide efficacy depended on nematode and cover crop species.

Taxon
organic zucchinit0
Treatment
cover crop species usede0
Interactor
nematode speciesNematodae0pest
Outcome
efficacy of different bionematicidese0

Not reportedDirection

Verbatim

e0

“the efficacy of different bionematicides depended on the nematode species present in the soil and the cover crop species used.”

✓ located verbatim in the source · abstract, characters 1570–1696 · show in text ↑
t0

“organic zucchini”

✓ located verbatim in the source · title, characters 79–95 · show in text ↑
Recommendationauthor interpretationoriginal resultbasis n/a

Claim · model-written summary

The authors recommend tailoring nematode control to damaging populations in each field.

Taxon
organic zucchinit0
Outcome
control strategies are customised to target the specific nematode populations causing economic damage in each fielde0

Verbatim

e0

“control strategies are customised to target the specific nematode populations causing economic damage in each field.”

✓ located verbatim in the source · abstract, characters 1777–1893 · show in text ↑
t0

“organic zucchini”

✓ located verbatim in the source · title, characters 79–95 · show in text ↑

Crotalaria juncea · Meloidogyne · Cucurbita pepoPositive and negative results

2 papers: 1 positive, 1 negative or no effect

1 in the opposite direction

  1. no effect
See all 2 papers →

azadirachtin · Meloidogyne · Cucurbita pepoPositive and negative results

2 papers: 1 positive, 1 negative or no effect

1 in the opposite direction

  1. no effect
See all 2 papers →

Claims are grouped by organism, treatment and what was measured or targeted. A paper counts as positive when any of its claims in the group is positive.