Rates and Timing of Telone II for the Management of Meloidogyne incognita on Cotton
R. A. Kinloch and J. R. Rich MA 2 9 19
University of Florida
West Florida Research and Education Center
and North Florida Research and Education Center
Research Report 1999-,
The root-knot nematode, Meloidogyne incognita, is widespread in Florida cotton (Kinloch &
Sprenkel, 1994). The recommended time for field application of Telone II [DowAgrosciences]
for management ofM. incognita on cotton is at least one week prior to planting the crop (Dunn
& Noling, 1997). Due to possible weather conditions and other activities of the season, this
timing requirement may present logistical problems to growers. The following field study was
conducted during 1998 to determine the efficacy of applying various rates of the fumigant
nematicide Telone II at selected times relative to cotton planting for the management of root-
knot nematode, Meloidogyne incognita.
A sandy loam field site (82% sand, 10% silt, 8% clay) naturally infested with M incognita on
the Davis' Brothers farm, Santa Rosa County, was disc-cultivated and treated with fertilizer and
herbicides according to standard practices (Sprenkel, 1996). The site was demarcated into 78
two-row plots, 7.2 m long on 0.9 m centers, with 7.2 m-wide alleys separating plot tiers. Each
plot was sampled to determine its nematode soil population density on 6 February by removing
eight soil cores (2.54 cm wide X 20 cm deep), mixing the cores, and processing a 100 cm3 sub-
sample via sugar centrifugation (Jenkins, 1964). Thirteen treatments, including a non-treated
check were assigned to pre-determined plots such that the average levels of pre-treatment
nematode soil population densities was equally distributed among the treatments. Telone II was
applied via a single chisel at a depth of 34 cm beneath the row at rates of 14, 28, and 42 liters/ha.
These treatments were all applied at 92, 63, 36, and 2 days before planting. Delta Pine 458BR
cotton was planted on 3 June. Each rate X timing treatment was replicated X6. Standard
practices of supplemental fertilization, herbicidal, and insecticidal treatments, were performed
according to standard practice throughout the growing season. Plots were harvested on 29
October and each plot was sampled for its nematode soil population density on 3 November.
Pre-treatment soil population densities of second-stage infective juveniles ofM. incognita (J2)
were very high and ranged from 308-363/100 cm3 soil among the treatments (Table 1). There
were no significant differences among these pre-assigned infestation levels. Thus, variation in
pre-treatment soil infestation levels was not considered a factor in influencing individual treatment
The greatest yield was produced by the 42-liter treatment applied two days before planting and
the lowest yield was produced by the non-treated check. These were significantly (P < 0.05)
different. Other treatments producing significantly higher yields than the check were the 42-liter
treatment applied 92 days before planting and the 28-liter treatment applied 2 days before
planting. Factorial analyses of the yield data among the Telone II treatments alone were not
significant, indicating that no rate X timing treatment could be determined as optimal.
All fumigant treatments significantly reduced J2 soil population density levels below that
recovered from the non-treated check. Factorial analyses of the nematode data among the Telone
II treatments alone did not indicate a significant rate X timing interaction. However, the average
post-season soil infestation density from the 42-liter treatments (58 J2/100 cm3) was significantly
(P < 0.05) less than those from the 28- and 14-liter treatments (138 and 164 J2/100 cm3 soil,
respectively) across application times.
Weather conditions during the cotton growing seasonal were far from optimal. During much of
its early development, the crop suffered through considerable drought conditions as recorded at
an approximate distance of 16 km from the experiment site (Table 2). We consider the dry
weather as primarily responsible for the low yields and it probably masked possible yield benefits
that may have accrued from the various treatments. Consequently, we were unable to determine
advantages or disadvantages from early Telone II treatment. However, Telone II performed well
at reducing post-harvest soil infestation levels ofM. incognita and we could determine no
disadvantage of early application of the fumigant for this purpose. This study should be repeated
under more optimal weather conditions or with the availability of irrigation.
Dunn, R. A., and J. W. Noling. 1997. 1997 Florida nematode management guide. University of
Florida, Institute of Food and Agricultural Sciences, Cooperative Extension Service. Gainesville,
Jenkins, W. R. 1964. A rapid centrifugal-flotation technique for separating nematodes from soil.
Plant Disease Reporter 48:692.
Kinloch, R. A., and R. K. Sprenkel. 1994. Plant-parasitic nematodes associated with cotton in
Florida. Supplement to the Journal of Nematology 26:749-752.
Sprenkel, R. K. 1996. 1996 Cotton production guidelines. University of Florida Cooperative
Extension Service publication SS-AGR-62. Gainesville, FL.
Table 1. Influence of rates of Telone II applied at various times on the soil population densities
of second-stage juveniles ofMeloidogyne incognita (J2) and lint yield of Delta Pine 458 BR
Treatment Application J2/100 cm3 soil Lint kg/ha J2/100 cm3 soil
liters/ha Days before 6 February 29 October 3 November
Not treated 317 a 349 c 460 a
14 92 358 a 442 abc 163 bc
14 63 363 a 498 abc 140 bc
14 36 332 a 501 abc 182 bc
14 2 328 a 509 abc 170 be
28 92 322 a 481 abc 125 bc
28 63 312 a 425 bc 75 bc
28 36 327 a 467 abc 105 bc
28 2 320 a 593 ab 250 b
42 92 323 a 561 ab 28 c
42 63 318 a 470 abc 15 c
42 36 317 a 484 abc 116 bc
42 2 308 a 614 a 73 bc
a Telone applied by single-chisel injection 34 cm below row.
Data are averages of six replicates.
Averages followed by similar letters within a column are not significantly different according to
Duncan's multiple range test (P < 0.05).
Table 2. Weekly rainfall (cm) recorded at the West Florida Research and Education Center
from 1 June to 9 August.
Week 1 2 3 4 5 6 7 8 9 10
1998 1.50 0 0 0.74 1.73 2.49 4.06 2.90 3.20 0.51
1993-97 average 5.20 2.00 5.50 4.70 1.22 7.32 4.95 4.32 5.33 7.80