Weed Management in Pears

Weed Management in Pears

Weed Management in Pears

Weed Management in Pears ¹
Jeff Williamson²
The following table contains information on chemical weed control for pears grown in Florida. Always read and follow all label directions carefully and exactly when applying any pesticide. Soil types and possible crop injury from herbicides vary greatly throughout Florida. Do not apply a herbicide to an inappropriate soil type even if the herbicide is labeled for that crop. See Table 1 .

Tables
Table 1. Chemical weed control in pears.

Pre-emergence

Common Name
(Trade name)

Pounds active ingredient per acre

Time of Application

Dichlorbenil
(Casoron 4G)

4 to 6
Apply in January or February, but no sooner than 4 weeks after transplanting.

Weeds Controlled and Remarks: Annual and perennial grasses and broadleaf weeds. Use higher rate for control of perennial weeds. May be used on bearing, non-bearing and nursery stock.

Diuron
(Karmex) 80 WDG
(Diuron) 80 WDG
(Direx) 4L

1.6 to 3.2
In the spring - March through May. Trees established for at least one year in orchard.

Weeds Controlled and Remarks: Annual broadleaf weeds, annual grasses and perennial weed seedlings. Use only under trees established at least 1 year in the orchard. Do not treat varieties grafted on full-dwarf rootstocks. Do not use on sand, loamy sand, gravelly soils, exposed subsoils, nor where organic matter is less than 1%. See label for additional use restrictions based on soil type. Best results occur when rainfall occurs with in 2 weeks of application.

Oryzalin
(Surflan) 4 AS

2 to 4
Allow soil to settle around newly planted plants before treatment.

Weeds Controlled and Remarks: Annual grasses and broadleaf weeds. Only 1 application per year. Existing vegetation should be tilled prior to application or destroyed by a contact herbicide. A single ½ to 1 inch rainfall or sprinkler irrigation is necessary to move the herbicide into the zone of weed seed germination. May be tank mixed with certain other pre and post-emergence herbicides (See label).

Oxyfluorfen
(Goal 2xl or OxiFlo) 2EC
(Galigan) 2E
(GoalTender) 4E

1.25 to 2
Apply to dormant trees until just before bud swell. Do not apply when foliage or fruit are present.

Weeds Controlled and Remarks: Controls annual broadleaf weeds and some grass weeds. Avoid direct contact with crop plant. May be tank mixed with certain other pre and post-emergence herbicides (See label).

Pendimethalin
(Prowl H₂O) 4AS

2 to 4
Do not apply to newly planted trees until soil has settled around roots.

Weeds Controlled and Remarks: Most effective when adequate irrigation or rainfall occurs within 7 days following application. Can be applied with paraquat for control of emerged weeds. Do not apply within 60 days of harvest.

Simazine
(Princep, Simazine) 4L WDG

2 to 4
See label

Weeds Controlled and Remarks: Controls certain annual grasses and broadleaf weeds. Do not use on sand, loamy sand or gravelly soils. Trees must be established at least 1 year. Avoid contact with fruit, foliage or stems. Do not allow animals to graze treated areas.

Oryazlin
(Oryzalin, Surflan) 4AS
+
Simazine
(Princep, Simazine) 4L WDG

2 to 4

+
2 to 4
See label for directions.

Weeds Controlled and remarks: Can be used in combination with certain post emergence herbicides to control existing weeds.

Pre-emergence - nonbearing only

Flumioxazin
(Chateu 51 WDG)

See label
Non-bearing trees only.

Weeds Controlled and Remarks: Do not make sequential applications within 30 days of the first application. May be tank mixed with a labeled burndown herbicide for control of emerged weeds. Do not exceed 6 oz per acre to trees planted less than 3 years in soil with a sand and/or gravel content exceeding 80%. Do not harvest fruit within 60 days of application. Do not tank mix with glyphosate or 2,4 -D amine after trees break dormancy.

Post-emergence

Common Name
(Trade name)

Pounds active ingredient per acre

Time of Application

Carfentrazone-ethyl
(Aim 2EC)

.008 to 0.031
Best results when applied to weeds that are in the 2-3 leaf stage.

Weeds Controlled and Remarks: Apply within at a minimum spray volume of 22 gpa. Do not allow contact of spray with green bark, or desirable foliage flowers or fruit of the crop. Do not harvest fruit within 7 days of application. Use with a nonionic surfactant or crop oil concentrate (See label).

Glyphosate
(Roundup)
(Touchdown)
(Others)

See label
See label for specific rates and timings.

Weeds Controlled and Remarks: Postemergence activity only. Damages all green tissue contacted. Has no effective residual activity. Rate used depends on weed species to be controlled. Avoid contact of spray, drift, or mist with foliage, green bark, or bark of trees established less than 2 years, suckers or fruit of desirable trees, crops, plants or other desirable vegetation. See label for restrictions on application equipment.

Paraquat
(Various)

0.6 to 1
Apply to weeds when succulent and 1-6" high.

Weeds Controlled and Remarks: Controls most annual grasses and broadleaf weeds. Perennial weeds are desiccated. Use a non-ionic surfactant (see label). Do not allow spray to contact green stems, fruit or foliage. Do not spray under windy conditions and use a shield for young trees. Do not graze on treated areas.

Post-emergence nonbearing only

Common Name
(Trade name)

Pounds active ingredient per acre

Time of Application

Clethodim
(Arrow)
(Intensity)
(Select)

0.094 to 0.125
Treat activity growing, non-stressed, grasses. Use only on non-bearing trees.

Weeds Controlled and Remarks: Controls annual and perennial grasses. Multiple applications may be needed to control some perennial grasses. See labels for use of nonionic surfactants or concentrated crop oils.

Footnotes
1. This document is HS94, one of a series of the Horticultural Sciences Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Original publication date: 1994. Revised: November, 2007. Please visit the EDIS Web site at http://edis.ifas.ufl.edu.
2. Jeff Williamson, professor, Horticultural Sciences Department, Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL 32611.

The Institute of Food and Agricultural Sciences (IFAS) is an Equal Opportunity Institution authorized to provide research, educational information and other services only to individuals and institutions that function with non-discrimination with respect to race, creed, color, religion, age, disability, sex, sexual orientation, marital status, national origin, political opinions or affiliations. For more information on obtaining other extension publications, contact your county Cooperative Extension service.

U.S. Department of Agriculture, Cooperative Extension Service, University of Florida, IFAS, Florida A. & M. University Cooperative Extension Program, and Boards of County Commissioners Cooperating. Larry Arrington, Dean.

Copyright Information
This document is copyrighted by the University of Florida, Institute of Food and Agricultural Sciences (UF/IFAS) for the people of the State of Florida. UF/IFAS retains all rights under all conventions, but permits free reproduction by all agents and offices of the Cooperative Extension Service and the people of the State of Florida. Permission is granted to others to use these materials in part or in full for educational purposes, provided that full credit is given to the UF/IFAS, citing the publication, its source, and date of publication.

Pre-emergence
Common Name (Trade name)	Pounds active ingredient per acre	Time of Application
Dichlorbenil (Casoron 4G)	4 to 6	Apply in January or February, but no sooner than 4 weeks after transplanting.
Weeds Controlled and Remarks: Annual and perennial grasses and broadleaf weeds. Use higher rate for control of perennial weeds. May be used on bearing, non-bearing and nursery stock.
Diuron (Karmex) 80 WDG (Diuron) 80 WDG (Direx) 4L	1.6 to 3.2	In the spring - March through May. Trees established for at least one year in orchard.
Weeds Controlled and Remarks: Annual broadleaf weeds, annual grasses and perennial weed seedlings. Use only under trees established at least 1 year in the orchard. Do not treat varieties grafted on full-dwarf rootstocks. Do not use on sand, loamy sand, gravelly soils, exposed subsoils, nor where organic matter is less than 1%. See label for additional use restrictions based on soil type. Best results occur when rainfall occurs with in 2 weeks of application.
Oryzalin (Surflan) 4 AS	2 to 4	Allow soil to settle around newly planted plants before treatment.
Weeds Controlled and Remarks: Annual grasses and broadleaf weeds. Only 1 application per year. Existing vegetation should be tilled prior to application or destroyed by a contact herbicide. A single ½ to 1 inch rainfall or sprinkler irrigation is necessary to move the herbicide into the zone of weed seed germination. May be tank mixed with certain other pre and post-emergence herbicides (See label).
Oxyfluorfen (Goal 2xl or OxiFlo) 2EC (Galigan) 2E (GoalTender) 4E	1.25 to 2	Apply to dormant trees until just before bud swell. Do not apply when foliage or fruit are present.
Weeds Controlled and Remarks: Controls annual broadleaf weeds and some grass weeds. Avoid direct contact with crop plant. May be tank mixed with certain other pre and post-emergence herbicides (See label).
Pendimethalin (Prowl H₂O) 4AS	2 to 4	Do not apply to newly planted trees until soil has settled around roots.
Weeds Controlled and Remarks: Most effective when adequate irrigation or rainfall occurs within 7 days following application. Can be applied with paraquat for control of emerged weeds. Do not apply within 60 days of harvest.
Simazine (Princep, Simazine) 4L WDG	2 to 4	See label
Weeds Controlled and Remarks: Controls certain annual grasses and broadleaf weeds. Do not use on sand, loamy sand or gravelly soils. Trees must be established at least 1 year. Avoid contact with fruit, foliage or stems. Do not allow animals to graze treated areas.
Oryazlin (Oryzalin, Surflan) 4AS + Simazine (Princep, Simazine) 4L WDG	2 to 4 + 2 to 4	See label for directions.
Weeds Controlled and remarks: Can be used in combination with certain post emergence herbicides to control existing weeds.
Pre-emergence - nonbearing only
Flumioxazin (Chateu 51 WDG)	See label	Non-bearing trees only.
Weeds Controlled and Remarks: Do not make sequential applications within 30 days of the first application. May be tank mixed with a labeled burndown herbicide for control of emerged weeds. Do not exceed 6 oz per acre to trees planted less than 3 years in soil with a sand and/or gravel content exceeding 80%. Do not harvest fruit within 60 days of application. Do not tank mix with glyphosate or 2,4 -D amine after trees break dormancy.
Post-emergence
Common Name (Trade name)	Pounds active ingredient per acre	Time of Application
Carfentrazone-ethyl (Aim 2EC)	.008 to 0.031	Best results when applied to weeds that are in the 2-3 leaf stage.
Weeds Controlled and Remarks: Apply within at a minimum spray volume of 22 gpa. Do not allow contact of spray with green bark, or desirable foliage flowers or fruit of the crop. Do not harvest fruit within 7 days of application. Use with a nonionic surfactant or crop oil concentrate (See label).
Glyphosate (Roundup) (Touchdown) (Others)	See label	See label for specific rates and timings.
Weeds Controlled and Remarks: Postemergence activity only. Damages all green tissue contacted. Has no effective residual activity. Rate used depends on weed species to be controlled. Avoid contact of spray, drift, or mist with foliage, green bark, or bark of trees established less than 2 years, suckers or fruit of desirable trees, crops, plants or other desirable vegetation. See label for restrictions on application equipment.
Paraquat (Various)	0.6 to 1	Apply to weeds when succulent and 1-6" high.
Weeds Controlled and Remarks: Controls most annual grasses and broadleaf weeds. Perennial weeds are desiccated. Use a non-ionic surfactant (see label). Do not allow spray to contact green stems, fruit or foliage. Do not spray under windy conditions and use a shield for young trees. Do not graze on treated areas.
Post-emergence nonbearing only
Common Name (Trade name)	Pounds active ingredient per acre	Time of Application
Clethodim (Arrow) (Intensity) (Select)	0.094 to 0.125	Treat activity growing, non-stressed, grasses. Use only on non-bearing trees.
Weeds Controlled and Remarks: Controls annual and perennial grasses. Multiple applications may be needed to control some perennial grasses. See labels for use of nonionic surfactants or concentrated crop oils.

Weed Management in Pears 1

Tables

Footnotes

Copyright Information

Weed Management in Pears ¹