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University of Florida




ROOT-GALLING ON TOBACCO AFTER TREATMENT WITH AN
EXPERIMENTAL NEMATICIDE, CG 860000, FROM CIBA-GIEGY


NFREC Research Report: 96.9


Jimmy R. Rich
University of Florida
Route 3, Box 4370
Quincy, FL 32351


Elmo B. Whitty
University of Florida
304 Newell Hall
Gainesville, FL 32611


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Ciba Giegy Tobacco Nematicide 1995

The trial reported herein was conducted to determine efficacy of an experimental

chemical, CG 860000, for control of Meloidogyne spp. on tobacco.

Materials and Methods

A field trial was conducted in a fine sand soil (93% sand, 4% clay, 3% silt)

infested with root-knot nematodes, Meloidogyne spp. (primarily M. javanica). The test

site was at the University of Florida Green Acres farm in Alachua County and in weed

fallow during 1994. Prior to test initiation, soil at the site was moldboard plowed and

double disced. Treatments of Nemacur 3 SC and CG 860000 were applied with a CO2

sprayer in 20 gallons of water per acre on April 20 as broadcast, band, sweep and

sweep-band applications. The sweep treatment was placed 6" deep and 14" wide, and

surface band treatments were also 14" wide. Broadcast and band treatments were

incorporated by rototilling 3-4" deep. Rows were 48" wide and plots were 2 rows x 20'

long. The experiment was placed in a randomized complete block design with 6

replications. Tobacco was transplanted one day after treatment and placed 18" apart

inrow. Due to a transplant shortage, six tobacco cultivars were used cvs. NC 27NF,

K394, Reams M1, NC 2326, VA 116, and OX 940 and placed in separate replicates.

Tobacco was observed for phytotoxicity and harvested three times over the

season, cured and weighed. Five soil cores (1" diam.) were taken from each plot and

composite. A subsample of 100 cm3 from individual plots was processed by a

centrifugation-flotation technique and second-stage juveniles counted.

Results and Discussion

No phytotoxicity was observed with CG 860000 or the standard, Nemacur 3 SC.









No differences in root galling was found among treatments and the control. A

numerical reduction in root galling, however, was observed with most treatments, and

the CG 860000 compared favorably with the Nemacur 3 SC treatment. Yield data were

highly variable due to fluctuations in plant stand mainly due to Ridomil-resistant blue

mold, and are not reported. Additionally, the low galling of the tobacco plants

indicated nematodes had little effect on plant yield.




I I .


Table 1. Use of an experimental nematicide, CG 860000, from Ciba Giegy Corporation

to reduce root-galling in tobacco, 1995.

Rate in Application Gall
Treatment lbs. a.i./A Method' Index (0-4)

CG 860000 5 14" Band 0.60 a2

CG 860000 5 Broadcast 0.86 ab

Nemacur 3SC 6 Broadcast 1.04 ab

CG 860000 2.5+2.5 14" Band-14" Sweep 1.16 ab

Control ------- ------- 1.40 ab

CG 860000 2.5 Sweep 1.46 b
l'he sweep application was placed 6" deep and was 14" wide. Both broadcast and band
treatments were incorporated by rototilling.

2Means followed by the same letter are not significantly different according to Duncan's


multiple range test.