|Ivy, Taylor - Isagro Usa, Inc|
|Holzinger, John - Holzinger Flowers, Inc|
Submitted to: Journal of Nematology
Publication Type: Abstract Only
Publication Acceptance Date: 5/1/2016
Publication Date: N/A
Technical Abstract: Two years of field research was conducted at a commercial flower farm in Florida to evaluate DOMINUS® (allylisothiocyanate (AITC); 374 L/ha) for nematode and weed control compared to methyl bromide (MeBr 392 kg/ha 80:20 MeBr:chlorpicrin). Dominus is a biofumigant registered for conventional and organic farms. The field site had high populations of M. arenaria and weeds including nutsedge (Cyperus rotundus), Carolina geranium (Geranium carolinianum), and goosegrass (Eleusine indica). Floral crops grown were sunflower, millet, zinnia, celosia, and tuber rose. MeBr and Dominus were shank applied to 3.6 m x 33.5 m plots and covered with totally impermeable film (TIF) for 2 weeks. Plots were replicated 4 times and split among cut flower species. Soil samples were collected throughout the season for nematode analysis. Weed emergence was evaluated in two 1-m2 areas within each plot. After harvest, plant growth and disease were assessed, and nematodes were isolated from soil and roots. In the first season, low numbers of M. arenaria juveniles (J2) were present in pre-treatment soil samples and no M. arenaria J2 were detected in either treatment 18 days after application. There were no differences among genera of plant-parasitic or non-parasitic nematodes between treatments with numbers of plant parasites averaging fewer than 10 J2/g of soil. At snapdragon harvest, there were no differences between root condition ratings and root galling. Roots harvested from Dominus plots were heavier than roots from MeBr. At larkspur and delphinium harvest there were no differences between treatments, except that root galling in MeBr was slightly higher in delphinium. Lupin had larger root systems and stems from Dominus plots. No differences occurred in M. arenaria in roots or soil of snapdragons, larkspur, delphiniums, and lupin. Total number of marketable cut stems harvested from Dominus and MeBr plots was not different for any of the flower species tested. Weed control was similar between treatments and neither provided control of Carolina geranium (Geranium carolinianum). In the second season with plots in the same location, two highly susceptible crops, Celosia argentea (cockscomb) and Helianthus annuus (sunflower) were grown. The only weed species present immediately after treatment was annual sedge (Cyperus compressus), which occurred only in the Dominus treatment. M. arenaria in soil were not different between treatments, but were numerically higher in MeBr compared to Dominus. Celosia root populations were similar between treatments and roots were equivalently galled. Plants from Dominus-treated plots were taller than those in MeBr. M. arenaria did not increase at the end of the season with no differences between treatments for soil or root nematodes. Overall, there were no differences in the total number of marketable stems from either celosia or sunflower plots. Dominus was comparable to MeBr for control of nematodes and weeds in cut flower production in Florida.