Root-Knot and Root-Lesion Nematode Suppression by Cover Crops, Poultry Litter, and Poultry Litter Compost

Area of Science:

• Agricultural Science
• Plant Pathology
• Soil Science

Background:

• Increasing populations of root-knot nematodes (RKN) and root-lesion nematodes threaten potato production in Maryland.
• Nematode infestations necessitate sustainable management strategies to mitigate crop damage and economic losses.

Purpose of the Study:

• To evaluate the efficacy of soil-incorporated cover crops and poultry litter (PL) amendments in suppressing RKN and root-lesion nematodes.
• To assess the impact of these treatments within a 3-year crop rotation sequence involving potato, cucumber, and various cover crop/legume options.

Main Methods:

• Microplot experiments were conducted using Meloidogyne incognita (RKN) and Pratylenchus penetrans (root-lesion nematode) infested soils.
• A 3-year rotation included potato, cucumber, and soybean (RKN-resistant or susceptible), castor bean, grain sorghum, or sorghum sudangrass.
• Poultry litter (PL) or PL compost were applied to selected plots, with potato and soybean planted in the third year.

Main Results:

• RKN populations were reduced by RKN-resistant soybean, castor bean, sorghum sudangrass, and fallow/tillage, but populations recovered.
• Root-lesion nematodes were reduced following high rates of PL and PL compost application, with sorghum sudangrass and fallow/tillage showing efficacy.
• No treatment provided lasting suppression of root-lesion nematodes into the subsequent year.

Conclusions:

• Cover crops and PL compost can reduce nematode populations, but require consistent incorporation into rotational cropping systems for sustained benefits.
• Integrated nematode management strategies combining crop rotation and organic amendments are crucial for long-term soil health and productivity in potato systems.