Coffee Senna, Cassia occidentalis L. 1 - Orange County Extension ...

<strong>Coffee</strong> <strong>Senna</strong>, <strong>Cassia</strong> <strong>occidentalis</strong> L. 1<br />

David W. Hall, Vernon V. Vandiver, and Jason A. Ferrell 2<br />

Classification<br />

Common Name: <strong>Coffee</strong> <strong>Senna</strong><br />

Scientific Name: <strong>Cassia</strong> <strong>occidentalis</strong> L. , <strong>Senna</strong><br />

<strong>occidentalis</strong> (L.) Link<br />

Family: Leguminosae (Fabaceae), Bean Family<br />

Seedling<br />

The cotyledons are smooth, round, about 1 cm<br />

long, and usually less than 1 cm wide with 3 distinct<br />

veins in the upper surface (Figure 1). The stems have<br />

visible hairs just above and below the cotyledons.<br />

Mature Plant<br />

<strong>Coffee</strong> <strong>Senna</strong> is a smooth annual that can be 2 m<br />

tall (Figure 2). The leaves are compound. The leaflets<br />

are in 4-6 pairs and have a sharp leaf apex. These<br />

leaflets are 2-9 cm long and 2-3 cm wide with a<br />

distinct gland 3-5 mm from the base of the stalk.<br />

Flowering occurs in the leaf axils. The sepals are<br />

green and 6-9 mm long. The petals are yellow and 1-2<br />

SP 37<br />

Figure 1. Seedling, <strong>Coffee</strong> <strong>Senna</strong> (<strong>Cassia</strong> <strong>occidentalis</strong> L.)<br />

cm long. The 6-7 stamens are of two different<br />

lengths. The seed pods are dark brown, 8 to 12 cm<br />

long, 7-10 mm wide and curve slightly upward. The<br />

seeds are dull brown, 4-5 mm long and flattened on<br />

both ends.<br />

1. This document is an excerpt from Weeds in Florida, SP 37, Florida Cooperative <strong>Extension</strong> Service, Institute of Food and Agricultural Sciences, University<br />

of Florida. Publication date: May 1991. Revised: December 2004. Reviewed: November 2006. Please visit the EDIS Website at http://edis.ifas.ufl.edu.<br />

2. David W. Hall, former extension botanist, Herbarium, Florida Museum of Natural History; Vernon V. Vandiver, associate professor emeritus, Agronomy<br />

Department; Jason A. Ferrell, assistant professor, Agronomy Department; Florida Cooperative <strong>Extension</strong> Service, Institute of Food and Agricultural<br />

Sciences, University of Florida, Gainesville FL 32611.<br />

The use of trade names in this publication is solely for the purpose of providing specific information. UF/IFAS does not guarantee or warranty the<br />

products named, and references to them in this publication does not signify our approval to the exclusion of other products of suitable composition.<br />

The Institute of Food and Agricultural Sciences (IFAS) is an Equal Opportunity Institution authorized to provide research, educational information and<br />

other services only to individuals and institutions that function with non-discrimination with respect to race, creed, color, religion, age, disability, sex,<br />

sexual orientation, marital status, national origin, political opinions or affiliations. U.S. Department of Agriculture, Cooperative <strong>Extension</strong> Service,<br />

University of Florida, IFAS, Florida A. & M. University Cooperative <strong>Extension</strong> Program, and Boards of <strong>County</strong> Commissioners Cooperating. Larry<br />

Arrington, Dean

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<strong>Coffee</strong> <strong>Senna</strong>, <strong>Cassia</strong> <strong>occidentalis</strong> L. 2<br />

Figure 2. Mature plant, <strong>Coffee</strong> <strong>Senna</strong> (<strong>Cassia</strong> <strong>occidentalis</strong><br />

L.)<br />

History<br />

<strong>Cassia</strong> is ancient Greek for a particular aromatic<br />

plant. <strong>Senna</strong> is an ancient Arabic name for these<br />

plants. The Latin word <strong>occidentalis</strong> means western,<br />

and refers to the origin.<br />

Habitat<br />

C. <strong>occidentalis</strong> is widespread in warm areas of<br />

the world except for Australasia.<br />

Biology<br />

On two different soil types growth was greater<br />

the higher the pH, 4.7-6.3. The seeds are known to be<br />

weakly toxic to various stock animals. Animals<br />

normally avoid ingesting these seeds. Increased<br />

germination is obtained by seed scarification.<br />

Control<br />

Peanuts<br />

There are effectively no preemergence herbicides<br />

that provide highly effective coffee senna control.<br />

Pursuit, applied preemergence, will deliver<br />

approximately 70% control, but all other herbicides<br />

will provide 50% control or less.<br />

The most effective herbicide combination is<br />

paraquat plus Basagran or Storm applied at-cracking.<br />

These combinations will commonly control greater<br />

than 90% of all coffee senna present at time of<br />

application; no soil-residual activity will be observed.<br />

Conversely, paraquat applied alone will not<br />

satisfactorily control coffee senna. Postemergence<br />

applications of Cadre or Basagran are effective<br />

against coffee senna. Although Cadre and Basagran<br />

will generally not provide 100% control, 80 to 90%<br />

control is commonly observed.<br />

Cotton<br />

Staple has been shown to provide good control<br />

of coffee senna when applied preemergence. All<br />

other preemergence herbicides are considered<br />

ineffective. Although sicklepod and coffee senna are<br />

closely related species, Cotoran does not possess<br />

adequate levels of coffee senna activity, as is<br />

commonly observed with sicklepod. Postemergence<br />

applications of glyphosate and/or Staple provide<br />

greater than 90% control of coffee senna. All<br />

postemergence directed herbicides, except Cobra and<br />

MSMA, provide greater than 90% coffee senna<br />

control.