Grafting and Paladin Pic-21 for Nematode and Weed Management in Vegetable Production.
Two years of field trials conducted in aMeloidogyne incognita-infested field evaluated grafting and Paladin Pic-21 (dimethyl disulfide:chloropicrin [DMDS:Pic] 79:21) for root-knot nematode and weed control in tomato and melon. Tomato rootstocks evaluated were; 'TX301', 'Multifort', and 'Aloha'. 'Florida 47' was the scion and the nongrafted control. A double crop of melon was planted into existing beds following tomato harvest. Melon rootstocks,C. metuliferand 'Tetsukabuto', were evaluated with nongrafted 'Athena' in year 1. In year 2, watermelon followed tomato with scion variety 'Tri-X Palomar' as the control and also grafted onto 'Emphasis' and 'Strongtosa' rootstocks. Four soil treatments were applied in fall both years under Canslit metalized film; Paladin Pic-21, methyl bromide:chloropicrin (MeBr:C33, 67:33), Midas (iodomethane:chloropicrin 50:50), and a herbicide-treated control.M. incognitaJ2in soil were highest in herbicide control plots and nongrafted tomato. All soil treatments produced similar tomato growth, which was greater than the herbicide control. All treatments reducedM. incognitaJ2in roots compared to the herbicide control. 'Multifort' rootstock produced the largest and healthiest roots; however, the number ofM. incognitaisolated from roots did not differ among the tomato rootstocks tested. Galling on tomato was highest in herbicide control plots and nongrafted plants. In melon,M. incognitaJ2in soil did not differ among melon rootstocks, but numbers isolated from melon rootstocks increased in 'Tetsukabuto' compared withC. metuliferus. 'Tetsukabuto' were larger root systems than nongrafted 'Athena'. All fumigants provided protection for all melon rootstocks against galling byM. incognitacompared to the herbicide control. Galling onC. metuliferusrootstock was less in all fumigant treatments compared with nongrafted 'Athena' and 'Tetsukabuto'. In watermelon,M. incognitain soil and roots did not differ among soil treatments or watermelon rootstocks, and yield was lower in both grafted rootstocks compared with the nongrafted control. All soil treatments increased average fruit weight of watermelon compared with the herbicide control, and provided effective weed control, keeping the most predominant weed, purple nutsedge (Cyperus rotundusL.), density at or below 1/m row. Grafting commercial scions ontoM. incognita-resistant rootstocks has potential for nematode management combined with soil treatments or as a stand-alone component in crop production systems.
USDA-ARS, U.S. Horticultural Research Lab, 2001 South Rock Rd., Fort Pierce, FL, 34945.
Nancy
N
Kokalis-Burelle
University of Tennessee, Knoxville, TN.
David M
DM
Butler
USDA-ARS, U.S. Horticultural Research Lab, 2001 South Rock Rd., Fort Pierce, FL, 34945.
Jason C
JC
Hong
Retired.
Michael G
MG
Bausher
USDA-ARS, U.S. Horticultural Research Lab, 2001 South Rock Rd., Fort Pierce, FL, 34945.
Greg
G
McCollum
USDA-ARS, U.S. Horticultural Research Lab, 2001 South Rock Rd., Fort Pierce, FL, 34945.
Erin N
EN
Rosskopf
Meloidogyne incognita; dimethyl disulfide; methyl bromide; root-knot nematodes.