ANR-1128, New Sept 1998. Mike Patterson, Extension Weed Scientist, Professor, and Dale Monks, Extension Crop Physiologist, Associate Professor, both in Agronomy and Soils at Auburn University, and Bobby Boozer, Area Horticulturist, and Jim Bannon, Director, E.V. Smith Research Center

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Weed Identification for Horticultural Crops

Most of the weeds that infest vegetable crops are indigenous to all row crops grown in Alabama. Annual and perennial weeds and grasses can cause yield and quality losses in commercial vegetable crops and often are harder to remove in vegetables because of the limited herbicide registrations for these crops. Because herbicides available for weed management in commercial vegetables are limited, we have listed a number of Integrated Pest Management (IPM) practices that can be used to help manage weeds in these crops. This is certainly not an exhaustive list--it is a list of suggestions for your consideration. IPM practices can be used in combination with registered herbicides to help obtain the weed control level required to make good yields and high-quality vegetables.

A table that lists the botanical attributes of each weed shown in this publication is provided. The table tells whether a weed grows in the summer or winter and whether it has an annual, biennial, or perennial life cycle. Being able to properly identify weeds and having some knowledge of the weed's growth habit will help you select management options.

The chemical pest control recommendations for most vegetable crops grown in Alabama are listed in IPM publication 98IPM-2, Commercial Vegetable Insects, Disease, Nematode and Weed Control. This publication can be obtained from your county Extension office and should be replaced each year due to changes in herbicide labels and recommendations. We hope that this publication will be helpful to you in managing weeds in your vegetable crops.

IPM Practices for Vegetable Weed Management

Exclusion--Clean equipment before moving it to new fields. Make sure organic mulching material is free of weed seeds.

Crop Rotation--Rotate to a competitive crop such as sweet corn or beans. Rotating crops will also allow you to use alternative herbicides that have different modes of action.

Selective Fertilization--Because some weeds grow better than row crops do under low soil fertility conditions, place fertilizer in a band over the row to promote good vegetable growth without encouraging weed growth between rows.

Mulching--Use either plastic or organic mulch to discourage weed germination and growth.

Selective Watering--Water with drop irrigation or microirrigation as opposed to sprinkler irrigation to help keep water away from the weeds growing in the middles.

Cultivation--Use mechanical cultivation in vegetables to help control weeds in the middles. Flame cultivation has the potential to control weeds in the rows of crops that have an upright growth habit, such as tomatoes, sweet corn, and okra.

Hand Hoeing--Hand hoeing and pulling, although labor intensive, are often needed to remove weeds that cultivation and herbicides will not control in the row.

Sprayer Calibration--Properly calibrate sprayers, and make timely applications of postemergence herbicides to small weeds to reduce herbicide rates and the possibility of crop injury.

Banding Herbicide Treatments--Apply herbicides on a band centered on the row, and use cultivation in the middles to lower costs and help reduce herbicide load on the environment.

Weed Maps--Make maps of specific weed infestations to help target herbicide applications in future years and to reduce the amount of chemical needed in many cases.

Weeds Common in Alabama Vegetable Production

The following table describes the weeds shown in this publication. The abbreviations for life cycle are as follows: A = annual; B = biennial; P = perennial; S = summer; W = winter.

Grasses

Common name	Scientific name	Life cycle
bermudagrass, common	Cynodon dactylon (L.) Pers.	S, P
broadleaf signalgrass	Brachiaria platyphylla (Griseb.)Nash	S, A
large crabgrass	Digitaria sanguinalis (L.) Scop.	S, A
goosegrass	Eleusine indica (L.) Gaertn.	S, A
johnsongrass	Sorghum halepense (L.) Pers.	S, P
Texas panicum	Panicum texanum Buckl.	S, A

Small-seeded broadleaf weeds

bristly starbur	Acanthospermum hispidum DC.	S, A
burgherkin	Cucumis anguria L.	S, A
carpetweed	Mollugo verticillata L.	S, A
cocklebur, common	Xanthium strumarium L.	S, A
coffee senna	Senna occidentalis S.Wats.	S, A
croton, tropic	Croton glandulosus var. septentrionalis Muell.-Arg.	S, A
croton, woolly	Croton capitatus Michx.	S, A
cutleaf eveningprimrose	Oenothera laciniata Hill	W, A/B
dodder	Cuscuta species	parasitic A
Florida beggarweed	Desmodium tortuosum (Sw.) DC.	S, A
Florida pusley	Richardia scabra L.	S, A
horseweed	Conyza canadensis (L.) Cronq.	W/S, A
jimsonweed	Datura stramonium L.	S, A
lambsquarters, common	Chenopodium album L.	S, A
pigweed, redroot	Amaranthus retroflexus L.	S, A
pigweed, tumble	Amaranthus albus L.	S, A
ragweed, common	Ambrosia artemisiifolia L.	S, A
sida, arrowleaf	Sida rhombifolia L.	S, A
sida, prickly	Sida spinosa L.	S, A
sicklepod	Senna obtusifolia L.	S, A
spiny amaranth	Amaranthus spinosus L.	S, A
spurge, prostrate	Euphorbia humistrata Engelm. ex Gray	S, A
spurge, spotted	Euphorbia maculata L.	S, A
Virginia pepperweed	Lepidium virginicum L.	W, A
citronmelon	Citrullus lanatus var. citroides (Bailey) Mansf.	S, A
wild poinsettia	Euphorbia heterophylla L.	S, A

Morningglories

bigroot morningglory	Ipomoea pandurata (L.) G.F.W. Meyer	S, P
cypressvine morningglory	Ipomoea quamoclit L.	S, A
entireleaf morningglory	Ipomoea hederacea var. integriuscula Gray	S, A
ivyleaf morningglory	Ipomoea hederacea (L.) Jacq.	S, A
palmleaf morningglory	Ipomoea wrightii Gray	S, A
pitted morningglory	Ipomoea lacunosa L.	S, A
purple morningglory	Ipomoea turbinata Lag.	S, A
red morningglory	Ipomoea coccinea L.	S, A
smallflower morningglory	Jacquemontia tamnifolia (L.) Griseb.	S, A
tall morningglory	Ipomoea purpurea (L.) Roth	S, A

Other perennial weeds

Carolina horsenettle	Solanum carolinense L.	S, P
nutsedge, purple	Cyperus rotundus L.	S, P
nutsedge, yellow	Cyperus esculentus L.	S, P
maypop passionflower	Passiflora incarnata L.	S, P
trumpetcreeper	Campsis radicans (L.) Seem. ex Bureau	S, P

common bermudagrass	broadleaf signalgrass	large crabgrass
goosegrass	johnsongrass	Texas panicum
bristly starbur	burgherkin	carpetweed
coffee senna	common cocklebur	tropic croton
woolly croton	cutleaf eveningprimrose	dodder
Florida beggarweed	Florida pusley	horseweed

jimsonweed	common lambsquarters	redroot pigweed
tumble pigweed	common ragweed	arrowleaf sida
prickly sida	sicklepod	spiny amaranth
prostrate spurge	spotted spurge	Virginia pepperweed
citronmelon	wild poinsettia	bigroot morningglory

cypressvine morningglory	entireleaf morningglory	ivyleaf morningglory
palmleaf morningglory	pitted morningglory	purple morningglory
red morningglory	smallflower morningglory	tall morningglory
Carolina horsenettle	purple nutsedge	yellow nutsedge
maypop passionflower	trumpetcreeper

For more information, contact your county Extension office. Look in your telephone directory under your county's name to find the number.