Pacific Island Ecosystems at Risk (PIER)


Sorghum bicolor ssp drummondii


RISK ASSESSMENT RESULTS: High risk, score: 17.5


Australian/New Zealand Weed Risk Assessment adapted for Hawai‘i.
Information on Risk Assessments
Original risk assessment

Sorghum bicolor (L.) Moench ssp. drummondii (Nees ex Steud.) de Wet ex Davidse. Family - Poaceae. Common Names(s) - Shattercane, wildcane. Synonym(s) - Sorghum guineense Stapf, Sorghum nervosum Besser ex Schultes.

Answer

Score

1.01

Is the species highly domesticated?

y=-3, n=0

y

-3

1.02

Has the species become naturalized where grown?

y=1, n=-1

y

1

1.03

Does the species have weedy races?

y=1, n=-1

y

1

2.01

Species suited to tropical or subtropical climate(s) (0-low; 1-intermediate; 2-high) – If island is primarily wet habitat, then substitute “wet tropical” for “tropical or subtropical”

See Append 2

1

2.02

Quality of climate match data (0-low; 1-intermediate; 2-high) see appendix 2

1

2.03

Broad climate suitability (environmental versatility)

y=1, n=0

y

1

2.04

Native or naturalized in regions with tropical or subtropical climates

y=1, n=0

y

1

2.05

Does the species have a history of repeated introductions outside its natural range?

y=-2, ?=-1, n=0

y

3.01

Naturalized beyond native range y = 1*multiplier (see Append 2), n= question 2.05

y

1.5

3.02

Garden/amenity/disturbance weed y = 1*multiplier (see Append 2)

n=0

n

0

3.03

Agricultural/forestry/horticultural weed y = 2*multiplier (see Append 2)

n=0

y

3

3.04

Environmental weed y = 2*multiplier (see Append 2)

n=0

3.05

Congeneric weed y = 1*multiplier (see Append 2)

n=0

y

2

4.01

Produces spines, thorns or burrs

y=1, n=0

n

0

4.02

Allelopathic

y=1, n=0

y

1

4.03

Parasitic

y=1, n=0

n

0

4.04

Unpalatable to grazing animals

y=1, n=-1

n

-1

4.05

Toxic to animals

y=1, n=0

y

1

4.06

Host for recognized pests and pathogens

y=1, n=0

y

1

4.07

Causes allergies or is otherwise toxic to humans

y=1, n=0

4.08

Creates a fire hazard in natural ecosystems

y=1, n=0

4.09

Is a shade tolerant plant at some stage of its life cycle

y=1, n=0

n

0

4.10

Tolerates a wide range of soil conditions (or limestone conditions if not a volcanic island)

y=1, n=0

y

1

4.11

Climbing or smothering growth habit

y=1, n=0

n

0

4.12

Forms dense thickets

y=1, n=0

n

0

5.01

Aquatic

y=5, n=0

n

0

5.02

Grass

y=1, n=0

y

1

5.03

Nitrogen fixing woody plant

y=1, n=0

n

0

5.04

Geophyte (herbaceous with underground storage organs -- bulbs, corms, or tubers)

y=1, n=0

n

0

6.01

Evidence of substantial reproductive failure in native habitat

y=1, n=0

n

0

6.02

Produces viable seed.

y=1, n=-1

y

1

6.03

Hybridizes naturally

y=1, n=-1

y

1

6.04

Self-compatible or apomictic

y=1, n=-1

y

1

6.05

Requires specialist pollinators

y=-1, n=0

n

0

6.06

Reproduction by vegetative fragmentation

y=1, n=-1

n

-1

6.07

Minimum generative time (years) 1 year = 1, 2 or 3 years = 0, 4+ years = -1

See left

1

1

7.01

Propagules likely to be dispersed unintentionally (plants growing in heavily trafficked areas)

y=1, n=-1

n

-1

7.02

Propagules dispersed intentionally by people

y=1, n=-1

y

1

7.03

Propagules likely to disperse as a produce contaminant

y=1, n=-1

y

1

7.04

Propagules adapted to wind dispersal

y=1, n=-1

7.05

Propagules water dispersed

y=1, n=-1

y

1

7.06

Propagules bird dispersed

y=1, n=-1

n

-1

7.07

Propagules dispersed by other animals (externally)

y=1, n=-1

n

-1

7.08

Propagules survive passage through the gut

y=1, n=-1

y

1

8.01

Prolific seed production (>1000/m2)

y=1, n=-1

y

1

8.02

Evidence that a persistent propagule bank is formed (>1 yr)

y=1, n=-1

y

1

8.03

Well controlled by herbicides

y=-1, n=1

y

-1

8.04

Tolerates, or benefits from, mutilation, cultivation, or fire

y=1, n=-1

y

1

8.05

Effective natural enemies present locally (e.g. introduced biocontrol agents)

y=-1, n=1

Total score:

17.5

Supporting data:

Notes

Source

1.01

(1)This crop plant has been cultivated in southern Africa for over 3 000 years...Historical records and archeological data have not been able to clearly state the origin and domestication of Sorghum bicolor. Previously 571 cultivars were recognized, however these cross readily without barriers of sterility or difference in genetic balance, therefore it makes sense to group them into a single species. It is for this reason that it is not an easy task for taxonomists to work with species but it is an advantage to the plant breeder because they can manipulate the genetic make-up of this group to acquire best crops. [Shattercane is a weedy, wild-type of the domesticated S. bicolor] (2)Main center of distribution of cultivated sorghums is in Africa, having been cultivated in Ethiopia for more than 5,000 years; possibly cultivated sorghums were also developed independently in India and China. Forage sorghums introduced in United States about 1850. Now sorghums are widely distributed throughout tropics, subtropics, and warm temperate areas of the world. (3)The wild representatives of S. bicolor are strictly African in distribution (Fig. 5). The cultivated taxa are widely grown across the warmer parts of the Old World, and were introduced since the sixteenth century into the New World (Snowden, 1936). The morphology of the wild varieties of S. bi- color was discussed by de Wet, Harlan, and Price (1970). They differ from each other primarily in respect to inflorescence structure and distribution...Sorghum bicolor var. bicolor includes all cultivated sorghums...Very little is known about the antiquity of sorghum. Its wide distribution and ex- tensive morphological variability suggest an ancient origin. Distribution of the wild relatives of cultivated sorghum in Africa indicates that this crop must have been domesticated on this continent.

(1)http://www.plantzafrica.com/plantqrs/sorghum.htm [Accessed 10 June 2009] (2)http://www.hort.purdue.edu/newcrop/duke_energy/Sorghum_bicolor.html [Accessed 10 June 2009] (3)De Wet, J. M. J. and J. R. Harlan. 1971. The Origin and Domestication of Sorghum bicolor. Economic Botany 25(2): 128-135.

1.02

(1)cultivated and sparingly naturalized along roadsides and in abandoned fields, 20-110 m (2)Occasionally cultivated, sparingly naturalized in Guam

(1)Wagner, W. L., D. R. Herbst, and S. H. Sohmer. 1999. Manual of the flowering plants of Hawaii. Revised edition. Bernice P. Bishop Museum special publication. University of Hawai‘i Press/Bishop Museum Press, Honolulu. (2)Stone, B. C. 1970. The flora of Guam. Micronesica 6:1-659.

1.03

(1)Sorghum bicolor includes all cultivated sorghums as well as a group of semi wild plants often regarded as weeds. (2)Shattercane is an annual weedy sorghum that causes more than fifteen million dollars in lost grain production in Nebraska. (3)Sorghum bicolor is divisible into two subspecies: S. bicolor ssp. bicolor which includes the extremely variable, annual, cultivated grain and forage sorghum, and S. bicolor ssp. drummondii, which is comprised of stabilized weedy derivatives arising from introgression between domesticated sorghum (S. bicolor ssp. bicolor) and closely related wild relatives.

(1)http://www.plantzafrica.com/plantqrs/sorghum.htm [Accessed 10 June 2009] (2)Fellows, G. M. 1990. Shattercane distribution, interference, and economic impact in Nebraska. Ph.D. Dissertation, Univ. Nebraska, Lincoln, NE. (3)Hill, R. J. 1983. Johnsongrass, Sorghum halepense (L.) Pers. and Shattercane, Sorghum bicolor (L.) Moench ssp. drummondii (Steud.) de Wet Gramineae.REGULATORY HORTICULTURE VoI. 9, No.1-2.

2.01

(1)Main center of distribution of cultivated sorghums is in Africa, having been cultivated in Ethiopia for more than 5,000 years; possibly cultivated sorghums were also developed independently in India and China. Forage sorghums introduced in United States about 1850. Now sorghums are widely distributed throughout tropics, subtropics, and warm temperate areas of the world...Adapted to tropical and subtropical summer rainfall climate with rainfall from 25–125 cm annually; of little importance in more humid areas with higher rainfall.

(1)http://www.hort.purdue.edu/newcrop/duke_energy/Sorghum_bicolor.html [Accessed 10 June 2009]

2.02

(1)Main center of distribution of cultivated sorghums is in Africa, having been cultivated in Ethiopia for more than 5,000 years; possibly cultivated sorghums were also developed independently in India and China. Forage sorghums introduced in United States about 1850. Now sorghums are widely distributed throughout tropics, subtropics, and warm temperate areas of the world.

(1)http://www.hort.purdue.edu/newcrop/duke_energy/Sorghum_bicolor.html [Accessed 10 June 2009]

2.03

(1)Ranging from Cool Temperate Steppe to Wet through Tropical Thorn to Wet Forest Life Zones, sorghum is reported to tolerate annual precipitation of 2.0 to 41.0 (mean of 86 cases = 10.9), annual temperature of 7.8 to 27.8°C (mean of 86 cases = 20.1), and pH of 4.3 to 8.7 (mean of 69 cases = 6.7). Adapted to tropical and subtropical summer rainfall climate with rainfall from 25–125 cm annually; of little importance in more humid areas with higher rainfall. Some cvs are short-day plants. Adapted to wide range of soils varying from light loams to heavy clays; thrives best on light, easily worked soils of high fertility, with moderate to high available water, with erosion not a problem. Moderately well-drained soils are suitable for sorghums. Small amounts of alkali in sand reduces performance considerably. Tolerance to salinity is moderate. Prefers moderately acid soil; pH down to 5.7 does not drastically affect production.

(1)http://www.hort.purdue.edu/newcrop/duke_energy/Sorghum_bicolor.html [Accessed 10 June 2009]

2.04

(1)cultivated and sparingly naturalized along roadsides and in abandoned fields, 20-110 m (2)Occasionally cultivated, sparingly naturalized in Guam

(1)Wagner, W. L., D. R. Herbst, and S. H. Sohmer. 1999. Manual of the flowering plants of Hawaii. Revised edition. Bernice P. Bishop Museum special publication. University of Hawai‘i Press/Bishop Museum Press, Honolulu. (2)Stone, B. C. 1970. The flora of Guam. Micronesica 6:1-659.

2.05

(1)Sorghum bicolor is an African crop, which is widely distributed throughout the world. Different cultivars are found in different regions depending on the climate. It is adapted to a wider range of ecological conditions. It is mostly a plant of hot, dry regions; still survive in a cool weather as well as waterlogged habitat. (2)Shattercane is now distributed throughout the world wherever grain sorghum is grown. It has also now spread beyond traditional grain sorghum production areas. Weedy S. bicolor ssp. drummondii is widespread throughout Africa, India and the rest of Asia, Australia, and southern and central Europe. It can be found in North America from southern Maine through southern Ontario to southern Michigan, westward to southwest British Columbia, and south to Florida and Mexico. Shattercane has not been reported from Central or South America except in Venezuela (DeFelice and Bryson 2004; Holm et al. 1991; Horak and Mosier 1994; Rosales-Robles 1993; Tutin et al. 1980).

(1)http://www.plantzafrica.com/plantqrs/sorghum.htm [Accessed 10 June 2009]

3.01

(1)cultivated and sparingly naturalized along roadsides and in abandoned fields, 20-110 m (2)Occasionally cultivated, sparingly naturalized in Guam

(1)Wagner, W. L., D. R. Herbst, and S. H. Sohmer. 1999. Manual of the flowering plants of Hawaii. Revised edition. Bernice P. Bishop Museum special publication. University of Hawai‘i Press/Bishop Museum Press, Honolulu. (2)Stone, B. C. 1970. The flora of Guam. Micronesica 6:1-659.

3.02

(1)Mainly a weed of agriculture [see 3.03]

(1)http://www.hear.org/gcw/species/sorghum_bicolor/ [Accessed 12 June 2009]

3.03

(1)Shattercane is an annual weedy sorghum that causes more than fifteen million dollars in lost grain production in Nebraska [weedy type of cultivated S. bicolor an agricultural weed] (2)Furrer and Burnside (1962) indicated that shattercane was becoming a ‘‘serious problem in many parts of Nebraska’’ and was quickly spreading throughout the Midwest from Indiana to Colorado. Shattercane was infesting corn, grain sorghum, castorbean, sugar beet fields, and waste areas. They blamed the spread of shattercane on the introduction of grain sorghum to Nebraska in 1955 and 1956, and farmers switching to continuous corn in place of crop rotations, providing an ideal habitat for the weed. They reported a survey of five corn fields in Nebraska heavily infested with shattercane, causing 15 to 49% yield reductions. They also mentioned other losses including rejected hybrid sorghum seed contaminated with off-types, livestock losses from prussic acid poisoning, and reduced economic returns caused by being forced to switch to lower-value crops. Burnside (1970) reported corn yield reductions of 44 to 72% in shattercane-infested plots compared to plots that were kept weed-free all season in Nebraska. Beckett et al. (1988) reported 22% corn yield reduction from 6.6 shattercane clumps per m of row in Illinois. Vesecky et al. (1973) reported an average grain sorghum yield reduction of about 97% in plots infested with shattercane spaced 7.5 cm apart in the rows compared to weed-free plots. Even the thinnest shattercane population spaced 45 cm apart reduced grain sorghum yields by about 70%. They measured significant reduction in the amount of light reaching into the plant canopy in the shattercane-infested plots as compared to the weed-free plots, and a high correlation between reduction in light reaching the grain sorghum canopy and the reduction in grain yield. Shattercane can also act as an alternate host for pests. Rodriguez-del-Bosque and Rosales-Robles (1992) discovered increased populations of white grub [Pyllophaga crinita (Burmeister)] in corn when shattercane was present in the field. The adults were thought to be either laying eggs more frequently or more attracted to the dense populations of shattercane over corn. Burnside (1968) reported the almost complete loss of soybeans (95 to 99% yield reductions) in shattercane- infested fields as compared to plots kept weedfree all season in Nebraska. Soybean yields in Nebraska were reduced by almost 90% by 12 shattercane plants per m of row and by almost 60% by only two shattercane plants per m of row in another experiment (Fellows and Roeth 1992). They also observed that soybean yield losses began just as the shattercane became taller than the soybeans.

(1)Fellows, G. M. 1990. Shattercane distribution, interference, and economic impact in Nebraska. Ph.D. Dissertation, Univ. Nebraska, Lincoln, NE. (2)Defelice, M. 2006. Shattercane, Sorghum bicolor (L.) Moench ssp. drummondii (Nees ex Steud.) de Wet ex Davidse—Black Sheep of the Family. Weed Technology 20:1076–1083.

3.04

(1)Listed as an environmental weed, but most negative effects manifested in agriculture [see 3.03]

(1)http://www.hear.org/gcw/species/sorghum_bicolor/ [Accessed 12 June 2009]

3.05

(1)Johnson grass (Sorghum halapense) is a noxious weed of Australia

(1)Parsons, W. T., and Cuthbertson, E. G. 2001. Noxious Weeds of Australia. Second Edition. CSIRO Publishing. Melbourne.

4.01

(1)Annual with broad blades up to 30-60 cm long, 4-8 cm wide; the midrib prominent and pale; panicle stiffly erect; sessile spikelets broadly obovate 4-5.5 mm long, 3-4.5 mm wide, subglobose at maturity; upper lemma awned; glumes coriaceous; caryopsis plump, about 4 mm long, barely as broad, yellow to orange or reddish, exposed distally.

(1)Stone, B. C. 1970. The flora of Guam. Micronesica 6:1-659.

4.02

(1)Sorghum bicolor (L.) Moench is one of the most important cereal crops worldwide (6), surpassed only by wheat, rice, corn, and barley in total acreage, with the United States currently accounting for a major portion of total world production and exports (FAOSTAT data). The allelopathic properties of sorghum were first suggested from observations of reduced growth of other crop species when grown in rotation; moreover, certain sorghum species such as Sudan grass (Sorghum sudanense) can produce largely weed-free monocultures without the use of synthetic herbicides

(1)Baerson, Scott R.; Dayan, Franck E.; Rimando, Agnes M.; Nanayakkara, N. P. Dhammika; Liu, Chang-Jun; Schroerder, Joachim; Fishbein, Mark; Pan, Zhiqiang; Kagan, Isabelle A.; Pratt, Lee H.; Le Cordonnier-Pratt, Marie-Miche; Duke, Stephen O. 2008. A functional genomics investigation of allelochemical biosynthesis in Sorghum bicolor root hairs. Journal of Biological Chemistry 283(6): 3231-3247.

4.03

(1)No evidence

(1)Defelice, M. 2006. Shattercane, Sorghum bicolor (L.) Moench ssp. drummondii (Nees ex Steud.) de Wet ex Davidse—Black Sheep of the Family. Weed Technology 20:1076–1083.

4.04

(1)Sorghum is also planted for cattle fodder and other purposes. (2)In Queensland, Australia, the fodder sorghums are used mainly for silage production and the grain sorghums for grain. The fodder sorghums, however, are also used for autumn grazing by dairy and beef cattle to fill in a feed shortage between summer and winter grazing crops. The grain sorghums are valuable for grazing after the grain has been harvested and the crop residues (stubble, dropped seed-heads and regrowth, plus weeds) provide good autumn and winter roughage.

(1)http://www.plantzafrica.com/plantqrs/sorghum.htm [Accessed 10 June 2009] (2)http://www.fao.org/ag/agp/agpc/doc/Gbase/DATA/pf000319.HTM [Accessed 10 June 2009]

4.05

(1)Sorghum contains hydrocyanic acid and the alkaloid hordenine. Sometimes plants accumulate toxic levels of nitrate (Morton, 1981). Varieties differ considerably in HCN poisonings. Danger is slight when grain is nearly mature. Young plants and suckers are dangerous, particularly when suffering from drought. HCN is destroyed when fodder is ensiled or cured as hay. Varieties vary in recovery with rotational grazing or frequent moving, as well as in quality and in HCN content. Kaffir-corn grain is edible, but the plant is toxic to stock, especially when wilted, due to HCN (52–3,000 ppm) and the cyanogenic glucoside durrin (C14H17O7N). In India the intoxication is known as jowar poisoning. Plants may contain 0.07% of the alkaloid hordenine. (2)In common with other Sorghum spp., it can contain lethal amounts of prussic acid (see S. almum for details).

(1)http://www.hort.purdue.edu/newcrop/duke_energy/Sorghum_bicolor.html [Accessed 10 June 2009] (2)http://www.fao.org/ag/agp/agpc/doc/Gbase/DATA/pf000319.HTM [Accessed 10 June 2009] (3)Neuwinger, H. D. 1996. African ethnobotany: poisons and drugs : chemistry, pharmacology, toxicology. Chapman and Hall GmbH, Wienheim, Germany. (4)Defelice, M. 2006. Shattercane, Sorghum bicolor (L.) Moench ssp. drummondii (Nees ex Steud.) de Wet ex Davidse—Black Sheep of the Family. Weed Technology 20:1076–1083.

4.06

(1)Sorghum is prone to various pests, including birds and in some parts of Africa parasitic witchweed (Striga). Crop rotation and early weeding by hand helps with the latter. American bollworm, aphids and borer will need to be controlled with pesticides. Birds will need to be kept from ripening grain sorghum. (2)Major diseases reported on sorghums include the following: Cercospora sorghi, Colletotrichum graminicola (Anthracnose of leaves and stems), Helminthosporium turcicum (leaf blight), Macrophomina phaseoli (charcoal rot), Periconia circinata (milo disease), Phyllachora sorghi, Phyllosticta sorghi, Puccinis purpurea (rust), Ramulispora sorghi (sooty strip), Sclerospora sorghi (downy mildew), Sorosporium ehrenbergii, Sphacelia sorghi, Sphacelotheca sorghi (coverd smut), Sph. cruenta (loose smut), Sph. reiliana (head smut). Plants are also severely attacked by various species of Striga (S. lutea, S. hermontheca, S. senegalensis, S. densiflora). Nematodes isolated from sorghum include the following species: Helicotylenchus cavenessi, H. dihystera, H. pseudorobustus, Hoplolaimus pararobustus, Meloidogyne javanica, Peltamigratus nigeriensis, Pratylenchus brachyurus, P. zeae, Quinisulcius acutus, Rotylenchulus reniformis, Scutellonema cavenessi, S. clathricaudatum, Tylenchorhynchus acutus, and T. parvus. (3)There are numerous diseases of sorghum. Leaf diseases are the most troublesome for forage producers. These are anthracnose caused by Colletotrichum graminicola (which can be overcome by using resistant varieties) and leaf blight caused by Helminthosporium turcicum. Charcoal rot (Macrophomina phaseoli) causes plants to lodge badly. Grain may be affected by covered smut (Sphacelotheca sorghi) in which the seed is replaced by a sac of spores; fungicidal seed dressing before planting corrects this malady. The parasitic weed Striga hermonthica occurs in Africa. Its seeds can only germinate when stimulated by a substance from the host root, and must be not more than 1 cm from it. The radicle attaches itself to the host root by a haustorium which penetrates the vascular system and parasitizes the sorghum below ground for three to six weeks; it then emerges and produces chlorophyll and photosynthates. Flowering commences ten to 20 days after emergence. It can be controlled by using a trap crop of Sudan grass, which is ploughed in after two months' growth.

(1)http://www.plantzafrica.com/plantqrs/sorghum.htm [Accessed 10 June 2009] (2)http://www.hort.purdue.edu/newcrop/duke_energy/Sorghum_bicolor.html [Accessed 10 June 2009] (3)http://www.fao.org/ag/agp/agpc/doc/Gbase/DATA/pf000319.HTM [Accessed 10 June 2009]

4.07

(1)Allergenic Components: Pollen; Allergenic Properties: Respiratory [no evidence that pollen from this grass causes widespread allergies]

(1)http://www.weather.com/outlook/health/allergies/common/allergens/OH-allergen-1313?from=allergy_allergenstate_more [Accessed 12 June 2009]

4.08

[No evidence, but as a grass, could probably increase fire hazards in certain situations]

 

4.09

(1)Sorghum requires full harnessing of incoming radiation for high yields of grain and forage, and does not grow well in shade.

(1)http://www.fao.org/ag/agp/agpc/doc/Gbase/DATA/pf000319.HTM [Accessed 10 June 2009]

4.10

(1)Sorghum grows in a wide variety of soils and is drought resistant, but it will do better if the soil is enriched with compost or fertilisers prior to planting. (2)It has adapted to a wide range of soils, from the deep sands of the Goz to the heavy black cracking clays of the Gedaref, Sudan. Varieties to suit each have been selected. Good drainage, however, is necessary. Its deep rooting can extract water from low sources, though not as deep as Pennisetum americanum (pearl millet). Its soil pH range lies between pH 5 and 8.5.

(1)http://www.plantzafrica.com/plantqrs/sorghum.htm [Accessed 10 June 2009] (2)http://www.fao.org/ag/agp/agpc/doc/Gbase/DATA/pf000319.HTM [Accessed 10 June 2009]

4.11

(1)Robust annuals; culms 10-30 dm tall, nodes puberulent to short-pilose.

(1)Wagner, W. L., D. R. Herbst, and S. H. Sohmer. 1999. Manual of the flowering plants of Hawaii. Revised edition. Bernice P. Bishop Museum special publication. University of Hawai‘i Press/Bishop Museum Press, Honolulu.

4.12

(1)most negative impacts associated with lowered crop yields, crop contamination, etc. [see 3.03]

(1)Defelice, M. 2006. Shattercane, Sorghum bicolor (L.) Moench ssp. drummondii (Nees ex Steud.) de Wet ex Davidse—Black Sheep of the Family. Weed Technology 20:1076–1083.

5.01

(1)Terrestrial

(1)Wagner, W. L., D. R. Herbst, and S. H. Sohmer. 1999. Manual of the flowering plants of Hawaii. Revised edition. Bernice P. Bishop Museum special publication. University of Hawai‘i Press/Bishop Museum Press, Honolulu.

5.02

(1)Poaceae

(1)Wagner, W. L., D. R. Herbst, and S. H. Sohmer. 1999. Manual of the flowering plants of Hawaii. Revised edition. Bernice P. Bishop Museum special publication. University of Hawai‘i Press/Bishop Museum Press, Honolulu.

5.03

(1)Poaceae

(1)Wagner, W. L., D. R. Herbst, and S. H. Sohmer. 1999. Manual of the flowering plants of Hawaii. Revised edition. Bernice P. Bishop Museum special publication. University of Hawai‘i Press/Bishop Museum Press, Honolulu.

5.04

(1)Weed S. bicolor (shattercane) is an aggressive annual weed, which is well equipped with survival traits that allow it to readily out compete its cultivated progenitor. The shattering ability of the panicles of this weedy intermediate facilitates dispersal of seeds and increases the likelihood for its survival in crop fields. Unlike S. halapense, however, shattercanes lack rhizomes and are annual weeds.

(1)Gressel, J. 2005. Crop ferality and volunteerism. CRC Press, Boca Raton, FL.

6.01

(1)No evidence

(1)De Wet, J. M. J. and J. R. Harlan. 1971. The Origin and Domestication of Sorghum bicolor. Economic Botany 25(2): 128-135.

6.02

(1)Sorgum is planted from seed, usually in rows in spring.

(1)http://www.plantzafrica.com/plantqrs/sorghum.htm [Accessed 10 June 2009]

6.03

(1)Abstract:  The role of crop-to-weed gene flow is often controversial and overlooked. As a consequence, the likelihood of spontaneous crop-to-weed hybridization in most crop/weed systems is generally unknown. The lack of data relating to the formation of crop/weed hybrids has particular contemporary significance when considering the wide scale commercial release of transgenic crop plants and the potential for escape of engineered genes via crop-to-weed hybridization We created an experimental system whereby we could examine the incidence and rate of spontaneous crop-to-weed hybridization between Sorghum bicolor and S halepense, johnsongrass. An isozyme marker was used to identify hybrid plants through progeny testing Incidence and rate of hybridization were highly variable with respect to weed distance from the crop, location of the study site, and year the study was performed. Crop/weed hybrids were detected at distances of 0 5-100 m from the crop Interspecific hybridization can and does occur in this system at a substantial and measurable rate. Transgenes introduced into crop sorghum can be expected to have the opportunity to escape cultivation through interspecific hybridization with johnsongrass. Traits that prove to be beneficial to weeds possessing them can be expected to persist and spread. This is an issue that needs to be addressed when developing biosafety guidelines for the commercial release of transgenic sorghums (2)Johnsongrass (S. halepense) will sometimes cross naturally with S. bicolor to produce vigorous, rhizomatous hybrids.

(1)Arriola, P. E. and N. C. Ellstrand. 1996. Crop-To-Weed Gene Flow in the Genus Sorghum (Poaceae): Spontaneous Interspecific Hybridization between Johnsongrass, Sorghum halepense, and Crop Sorghum, S. Bicolor. American Journal of Botany 83(9): 1153-1159. (2)Sotomayor-Rios, A. and W. D. Pitman. 2000. Tropical forage plants: development and use. CRC Press, Boca Raton, FL.

6.04

(1)Self-pollination and cross-pollination by wind.

(1)http://www.plantzafrica.com/plantqrs/sorghum.htm [Accessed 10 June 2009]

6.05

(1)Self-pollination and cross-pollination by wind.

(1)http://www.plantzafrica.com/plantqrs/sorghum.htm [Accessed 10 June 2009]

6.06

(1)Weed S. bicolor (shattercane) is an aggressive annual weed, which is well equipped with survival traits that allow it to readily out compete its cultivated progenitor. The shattering ability of the panicles of this weedy intermediate facilitates dispersal of seeds and increases the likelihood for its survival in crop fields. Unlike S. halapense, however, shattercanes lack rhizomes and are annual weeds.

(1)Gressel, J. 2005. Crop ferality and volunteerism. CRC Press, Boca Raton, FL.

6.07

(1)Annual with broad blades up to 30-60 cm long, 4-8 cm wide; the midrib prominent and pale; panicle stiffly erect; sessile spikelets broadly obovate 4-5.5 mm long, 3-4.5 mm wide, subglobose at maturity; upper lemma awned; glumes coriaceous; caryopsis plump, about 4 mm long, barely as broad, yellow to orange or reddish, exposed distally.

(1)Stone, B. C. 1970. The flora of Guam. Micronesica 6:1-659.

7.01

(1)Seed dispersal is primarily through its namesake shattering habit. Seed shattering can occur in two ways. Some sorgo and sudangrass types shatter seeds when the pedicel at the base of the spikelet is broken by a strong mechanical force such as crop harvesting. [no means of external attachment]

(1)Defelice, M. 2006. Shattercane, Sorghum bicolor (L.) Moench ssp. drummondii (Nees ex Steud.) de Wet ex Davidse—Black Sheep of the Family. Weed Technology 20:1076–1083.

7.02

(1)Uses and cultural aspects: Sorghum bicolor is an important crop providing food and fodder in the semi-arid tropics of the world. It is a staple food for more than 500 million people in more than 30 countries, although maize has to some extent replaced its use in southern africa.. It has been used in the production of alcohol. The whole plant is used for forage, hay or silage. The stem of some types is used for building; fencing, weaving, broom making and firewood. Industrially it can be used for vegetable oil, waxes and dyes.

(1)http://www.plantzafrica.com/plantqrs/sorghum.htm [Accessed 10 June 2009]

7.03

(1)Shattercane (S. bicolor spp. drummondii) occurs as a weed in Africa wherever cultivated grain sorghums and their wild relatives grow in the same region. All races of the subspecies bicolor and all wild kinds of S. bicolor can hybridize into the weedy shattercanes. There is ample evidence of gene movement between both the wild and cultivated types in the region. Genes from the cultivated types also move readily into the wild types creating a range of weed–crop hybrids. Shattercane appears in intermediate habitats of recently abandoned fields and field margins, and in cultivated fields in Africa and elsewhere (2)Contamination of crop seed lots by weed seed and rapid retrogression of crop varieties of Sorghum bicolor (L.) Moench (sorghum) to the wild progenitor of the species may also contribute to the persistence of S. bicolor.

(1)Defelice, M. 2006. Shattercane, Sorghum bicolor (L.) Moench ssp. drummondii (Nees ex Steud.) de Wet ex Davidse—Black Sheep of the Family. Weed Technology 20:1076–1083. (2)Teo-Sherrell, C. P. A. and D. A. Mortensen. 2000. Fates of buried Sorghum bicolor ssp. drummondii seed. Weed Science, 48:549–554.

7.04

(1)However, shattercane has a more efficient type of shattering caused by an abscission layer that forms at the base of the spikelet. The abscission layer forms at the approximate time of seed maturity, and all of the seeds are readily dropped from the plant with only a light breeze. [wind-dispersed very short distances]

(1)Defelice, M. 2006. Shattercane, Sorghum bicolor (L.) Moench ssp. drummondii (Nees ex Steud.) de Wet ex Davidse—Black Sheep of the Family. Weed Technology 20:1076–1083.

7.05

(1)Shattercane seeds can also float, allowing irrigation and runoff water to disperse viable seeds greater distances

(1)Defelice, M. 2006. Shattercane, Sorghum bicolor (L.) Moench ssp. drummondii (Nees ex Steud.) de Wet ex Davidse—Black Sheep of the Family. Weed Technology 20:1076–1083.

7.06

(1)Seed dispersal is primarily through its namesake shattering habit. Seed shattering can occur in two ways. Some sorgo and sudangrass types shatter seeds when the pedicel at the base of the spikelet is broken by a strong mechanical force such as crop harvesting.

(1)Defelice, M. 2006. Shattercane, Sorghum bicolor (L.) Moench ssp. drummondii (Nees ex Steud.) de Wet ex Davidse—Black Sheep of the Family. Weed Technology 20:1076–1083.

7.07

(1)Seed dispersal is primarily through its namesake shattering habit. Seed shattering can occur in two ways. Some sorgo and sudangrass types shatter seeds when the pedicel at the base of the spikelet is broken by a strong mechanical force such as crop harvesting. [no means of external attachment]

(1)Defelice, M. 2006. Shattercane, Sorghum bicolor (L.) Moench ssp. drummondii (Nees ex Steud.) de Wet ex Davidse—Black Sheep of the Family. Weed Technology 20:1076–1083.

7.08

(1)Shattercane seeds can also survive digestion by livestock, allowing spread to new areas in manure.

(1)Defelice, M. 2006. Shattercane, Sorghum bicolor (L.) Moench ssp. drummondii (Nees ex Steud.) de Wet ex Davidse—Black Sheep of the Family. Weed Technology 20:1076–1083.

8.01

(1)Sorghum bicolor is a persistent weed in the midwestern United States despite low seed survival rates. This could be due to high seed production by the weed. Sorghum bicolor inflorescences contain up to 2,000 seeds (Roeth et al. 1994).

(1)Teo-Sherrell, C. P. A. and D. A. Mortensen. 2000. Fates of buried Sorghum bicolor ssp. drummondii seed. Weed Science, 48:549–554.

8.02

(1)Jacques et al. (14) found that 32% of shattercane seed were viable following 36 mo of burial whereas only 0.13% of sorghum seed survived 4 mo burial. Burnside et al. (6) showed shattercane seed with tightly enclosed glumes could survive up to 13 yr when buried at 22 cm [shattercane, a wild sorghum, has long seed dormancy] (2)Sorghum seed shows dormancy for the- first month after harvest.[cultivated sorghum does not have long seed viability]

(1)Fellows, G. M. and F. W. Roeth. 1992. Factors Influencing Shattercane (Sorghum bicolor) Seed Survival. Weed Science 40: 434-440. (2)http://www.fao.org/ag/agp/agpc/doc/Gbase/DATA/pf000319.HTM [Accessed 10 June 2009]

8.03

(1)Abstract: Growers from three counties in Virginia have recently experienced difficulty controlling shattercane in corn with acetolactate synthase (ALS)–inhibiting herbicides. Seed was collected from these locations and from a susceptible biotype and tested for resistance to imazethapyr, imazapyr, and nicosulfuron in greenhouse trials. Seedlings from these locations were also treated with glufosinate and glyphosate. Greenhouse experiments indicated that one of the four shattercane biotypes was resistant to ALS-inhibiting herbicides. Effective control of the resistant biotype was possible with glufosinate or glyphosate. Field experiments were conducted in 2003 and 2004 to determine the most effective herbicide program utilizing herbicide-tolerant/-resistant corn hybrids for the control of shattercane. Early postemergence (EP) and late postemergence (LP) applications of imazethapyr plus imazapyr or EP nicosulfuron did not control shattercane, and yield from the imidazolinonetolerant (IT) hybrid was equivalent between these treatments and was equivalent to yield from the weedy control (WC). At 23 wk after planting (WAP), EP applications of glyphosate controlled shattercane 71 and 75% compared to only 21 and 66% with EP applications of glufosinate in 2003 and 2004, respectively. In both years, LP applications of glufosinate or glyphosate controlled shattercane better than did EP applications of glufosinate or glyphosate. Treatment timing with respect to corn yield within either the glufosinate-resistant (LL) or glyphosate-resistant (RR) corn hybrid was critical. EP treatments of glufosinate or glyphosate resulted in yields that were equivalent to yield from the weed-free control (WFC) of each hybrid. LP treatments of glufosinate or glyphosate, however, resulted in yields that were equivalent to only 90 and 91% of yield from the WFC of each hybrid, respectively...Generally, no difference in shattercane control between glufosinate and glyphosate occurred at the LP treatment timing. Although LP applications of glufosinate or glyphosate controlled shattercane better than EP applications, it is recommended that early shattercane competition with corn be reduced through EP applications. Results indicate that by delaying the herbicide application, corn yields are reduced in comparison to treatments applied EP. (2)Shattercane can be controlled in corn with several postemergence- applied herbicides including nicosulfuron {2- [[[[(4,6-dimethoxy-2-pyrimidinyl)amino]carbonyl]amino] sulfonyl]-N,N-dimethyl-3-pyridinecarboxamide}, primisulfuron {methyl 2-[[[[[4,6-bis(difluoromethoxy)-2- pyrimidinyl]amino]carbonyl]amino]sulfonyl]benzoic acid, sethoxydim {2-[1-(ethoxyimino)butyl]-5-[2-(ethylthio) propyl]-3-hydroxy-2-cyclohexen-1-one} in sethoxydimtolerant corn, glufosinate [2-amino-4-(hydroxymethylphosphinyl) butanoic acid] in glufosinate-tolerant corn, imazethapyr {2-[4,5-dihydro-4-methyl-4-(1-methylethyl)- 5-oxo-1H-imidazol-2-yl]-5-ethyl-3-pyridinecarboxylic acid} in imidazolinone-tolerant corn, and glyphosate [N- (phosphonomethyl)glycine] in glyphosate-tolerant corn (Johnson and Kendig 1999). However, field research in Missouri (Bradley 1999) has shown that under cool weather conditions, shattercane control with glyphosate plus atrazine tank mix was significantly less than with glyphosate alone. Other researchers have also noted this antagonistic interaction on corn (Appleby and Somabhi 1978), grain sorghum (Stahlman and Phillips 1979b), quackgrass [Elytrigia repens (L.) Nevski], common dandelion (Taraxacum officinale Weber in Wiggers), and Canada thistle [Circium arvense (L.) Scop.] (Selleck and Baird 1981)

(1)King, S. R. and E. S. Hagwood, Jr. 2006. Herbicide Programs for the Control of ALS-Resistant Shattercane (Sorghum bicolor) in Corn (Zea mays). Weed Technology 20: 416–421. (2)Bradley, P. R., W. G. Johnson, and R. J. Smeda. 2000. Response of Sorghum (Sorghum bicolor) to Atrazine, Ammonium Sulfate, and Glyphosate. Weed Technology 14: 15–18.

8.04

(1)Sweet forage sorghum will stand a series of grazings where soil moisture and the temperature remain adequate, new branches and tillers being produced. Stalks may become thick and fibrous in the fodder types, and the forage or grass sorghums, such as Sudan grass, make better grazing. [can withstand grazing and mowing]

(1)http://www.fao.org/ag/agp/agpc/doc/Gbase/DATA/pf000319.HTM [Accessed 10 June 2009]

8.05

Unknown


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