Purple Nutsedge Control and Cucumber Tolerance to Sandea

(Halosulfuron).

Ginger K. Perdue Long County Cooperative Extension Service

A. Stanley Culpepper Extension Agronomist – Weed Science

Purple Nutsedge Competition

Trial Information

Daytona Cucumbers planted Aug 25, 2001.38” rows, 12” spacing.Harrowed, ripped, bedded.Plant bed prepared with Telone and ethylfluralin. Trial used a randomized complete block experimental design, replicated 4 times. Plots were two rows by 25 feet in length.

Cucumber injury symptoms from Sandea applied POST.

05

101520253035404550

0.5 oz 0.75 oz 1.0 oz

plants/plot# fruitlb/plot

Pre-emergence Applications

Application on Aug. 26, 2001. Soil moisture –fair.11 days after app. – control of purple nutsedge 51-80%.By late-season, control dropped to 36-61%.

05

101520253035404550

0.5 oz 0.75 oz 1.0 oz

plants/plot# fruitlb/plot

Post-emergence 2 WAE

Application on Sept. 7, 2001. Soil moisture – moist.

Control of purple nutsedge 75 – 83% at 14 DAT.

Late Season control held to 82 – 93%.

05

101520253035404550

0.5 oz 0.75 oz 1.0 oz

plants/plot# fruitlb/plot

Post-emergence 4 WAE

Application on Sept. 21, 2001. Soil moisture – dry. Control of purple nutsedge 12-16% at 9 DAT.Late season control rose to 43-53%.

05

101520253035404550

0.5 oz 0.5 oz none

plants/plot# fruitlb/plot

Split Applications

PRE/2WAE 2 & 4 WAE

Split applications were very effective in controlling purple nutsedge at 88% by late season.

Non-treated control Sandea (0.5 oz/A) PRE

Sandea (0.5 oz/A) 2 WAP

Yield in pounds

11.2

8.510.2

11.312.2

10.1

5.2

2.2

5.6

11.912.5

6.7

0

2

4

6

8

10

12

14pr

e-0.

5

pre-

0.75

pre-

1.0

2w

0.5

2w

0.75

2w 1

.0

4w

0.5

4w 0

.75

4w

1.0

pre/

po 0

.5

2w/4

w 0

.5

non-

trea

ted

Conclusions

Applications of Sandea are most effective prior to 4 weeks after emergence.

Conclusions

Applications of Sandea are most effective prior to 4 weeks after emergence.

Early season weed competition reduced yield for late application treatments.

Conclusions

Applications of Sandea are most effective prior to 4 weeks after emergence.

Early season weed competition reduced yield for late application treatments.

Greatest consistency of all measured variables seen with split applications of Sandea.

Conclusions

Applications of Sandea are most effective prior to 4 weeks after emergence.

Early season weed competition reduced yield for late application treatments.

Greatest consistency of all measured variables seen with split applications of Sandea.

Premier program may be 0.5 oz PRE, followed by 0.5 oz at 3 weeks after emergence.