Root-knot nematode management in double-cropped plasticulture vegetables

Area of Science:

• Agricultural Science
• Plant Pathology
• Nematology

Background:

• Root-knot nematodes (RKN), particularly Meloidogyne incognita, pose a significant threat to vegetable crop yields.
• Double-cropping systems can exacerbate RKN pressure, leading to substantial crop losses.

Purpose of the Study:

• To evaluate the efficacy of combined chisel-injected and drip-applied fumigant treatments for controlling Meloidogyne incognita.
• To assess the impact of oxamyl applications in conjunction with fumigants on RKN control and crop yields.

Main Methods:

• Field trials were conducted from 2002 to 2004 in Tifton, GA, using eggplant or tomato as first crops and cantaloupe, squash, or jalapeno pepper as second crops.
• Evaluated chisel-injected fumigants (methyl bromide, 1,3-D, metam sodium, chloropicrin) followed by drip-applied fumigants (metam sodium, 1,3-D +/- chloropicrin).
• Investigated the effects of oxamyl drip applications on RKN control and yield in both first and second crops.

Main Results:

• All tested fumigants provided good RKN control and 10-15% yield increases on first crops (eggplant).
• Higher fumigant rates and combinations on second crops improved RKN control, increasing yields by 20-35% compared to controls.
• Oxamyl enhanced first crop yields in 2003 (10-15%) but not in 2004 due to low RKN pressure.
• On double-cropped squash, oxamyl post-fumigation significantly reduced nematode infection and boosted yields by 30-75% in 2003.

Conclusions:

• Combined fumigation strategies are effective for managing RKN in sequential vegetable cropping systems.
• Optimized fumigant application rates and combinations, along with strategic oxamyl use, are crucial for maximizing yield protection against RKN.
• Double-cropping necessitates robust nematicide strategies to mitigate escalating RKN pressure and prevent yield losses.