How to Manage Pests

UC Pest Management Guidelines

Herbicide		Amount/Acre	R.E.I.+
(commercial name)			(hours)
When choosing a pesticide, consider information relating to environmental impact. Not all registered pesticides are listed. Always read label of product being used.
PREEMERGENT HERBICIDES
A.	ORYZALIN		2–4 lb a.i.
	(Surflan)	2–4 qt	24
	WSSA MODE OF ACTION GROUP NUMBER1: 3
	COMMENTS: Apply to weeds or combine with a postemergent herbicide if young weeds are present. May be combined with other preemergent herbicides to control grass and some broadleaf weeds.
B.	PRODIAMINE
	(Endurance, Barricade)	0.65–1.495 lb	12
	MODE OF ACTION: Unknown.
	COMMENTS: Apply as a preemergent treatment. May be combined with a postemergent herbicide if young weeds are present. May be combined with other preemergent herbicides to control grasses and some broadleaf weeds.
C.	PENDIMETHALIN
	(Pendulum) 3.3 EC or 60% WDG	2–3.96 lb a.i.	24
	WSSA MODE OF ACTION GROUP NUMBER1: 3
	COMMENTS: Apply as a preemergent treatment. May be combined with a postemergent herbicide if young weeds are present. May be combined with other preemergent herbicides to control grasses and some broadleaf weeds.
E.	ISOXABEN
	(Gallery)	0.9975 lb	12
	WSSA MODE OF ACTION GROUP NUMBER1: 21
	COMMENTS: Apply preemergent or combine with a postemergent herbicide if young weeds are established. May be combined with other preemergent herbicides to control additional broadleaf weeds.
POSTEMERGENT HERBICIDES
A.	GLYPHOSATE
	(Roundup Pro, Touchdown)	Annuals: 2 qt–1 gal/100gal water or 0.66–1.33 oz/gal water	see comments
		Perennials: see comments
	WSSA MODE OF ACTION GROUP NUMBER1: 9
	COMMENTS: Apply lower rates to young weeds. Apply to perennials when in flower stage and the soil moisture is good enough to maintain active growth of the weeds. Maximum application rates are up to 2 gal/100 gal water for Roundup Pro and up to 5 qt/100 gal for Touchdown. Restricted entry interval for Roundup Pro is 4 hours and 12 hours for Touchdown.
B.	GLUFOSINATE
	(Finale)	Spot application: 1.5 fl oz/1 gal water	12
		Broadcast application: 3 qt when weeds less than 6 inches tall or 5 qt when weeds are 6 inches or taller
	WSSA MODE OF ACTION GROUP NUMBER1: 10
	COMMENTS: Apply as directed spray under benches or on floors of the greenhouse or around the periphery of the greenhouse. Do not have air circulation fans running. Apply using large droplets and low pressure to avoid drift or contact with green leaves or stems. Do not use in greenhouses with edible crops.
C.	DIQUAT
	(Reward)	1–2 pt plus 16–32 oz nonionic surfactant/100 gal water	24
	WSSA MODE OF ACTION GROUP NUMBER1: 22
	COMMENTS: Apply 15–40 gal/acre or enough to wet young weeds. Apply to young weeds for improved control.
1	Group numbers are assigned by the Weed Science Society of America (WSSA) according to different modes of action. Although weeds may exhibit multiple resistance across many groups, mode of action numbers are useful in planning mixtures or rotations of herbicides with different modes of action. For more information, see http://www.hracglobal.com.
+	Restricted entry interval (R.E.I.) is the number of hours (unless otherwise noted) from treatment until the treated area can be safely entered without protective clothing.

PUBLICATION

UC IPM Pest Management Guidelines: Floriculture and Ornamental Nurseries
UC ANR Publication 3392
Weeds
C. A. Wilen, UC IPM Program, UC Cooperative Extension, San Diego County
Acknowledgment for contributions to Weeds:
C. L. Elmore, Vegetable Crops/Weed Science, UC Davis

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