Research directed by C. Daehler (UH Botany) with funding from the Kaulunani Urban Forestry Program and US Forest Service

Information on Risk Assessments
Original risk assessment

Paspalum notatum; bahia grass

Answer

1.01

Is the species highly domesticated?

y=-3, n=0

n

1.02

Has the species become naturalized where grown?

y=-1, n=-1

y

1.03

Does the species have weedy races?

y=-1, n=-1

n

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

2

2.02

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

2

2.03

Broad climate suitability (environmental versatility)

y=1, n=0

y

2.04

Native or naturalized in regions with tropical or subtropical climates

y=1, n=0

y

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

3.02

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

n=0

n

3.03

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

n=0

y

3.04

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

n=0

n

3.05

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

n=0

y

4.01

Produces spines, thorns or burrs

y=1, n=0

n

4.02

Allelopathic

y=1, n=0

4.03

Parasitic

y=1, n=0

n

4.04

Unpalatable to grazing animals

y=1, n=-1

n

4.05

Toxic to animals

y=1, n=0

n

4.06

Host for recognized pests and pathogens

y=1, n=0

n

4.07

Causes allergies or is otherwise toxic to humans

y=1, n=0

y

4.08

Creates a fire hazard in natural ecosystems

y=1, n=0

n

4.09

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

y=1, n=0

y

4.1

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

y=1, n=0

y

4.11

Climbing or smothering growth habit

y=1, n=0

n

4.12

Forms dense thickets

y=1, n=0

n

5.01

Aquatic

y=5, n=0

n

5.02

Grass

y=1, n=0

y

5.03

Nitrogen fixing woody plant

y=1, n=0

n

5.04

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

y=1, n=0

n

6.01

Evidence of substantial reproductive failure in native habitat

y=1, n=0

n

6.02

Produces viable seed.

y=1, n=-1

y

6.03

Hybridizes naturally

y=1, n=-1

6.04

Self-compatible or apomictic

y=1, n=-1

y

6.05

Requires specialist pollinators

y=-1, n=0

n

6.06

Reproduction by vegetative fragmentation

y=1, n=-1

y

6.07

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

See left

7.01

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

y=1, n=-1

n

7.02

Propagules dispersed intentionally by people

y=1, n=-1

y

7.03

Propagules likely to disperse as a produce contaminant

y=1, n=-1

y

7.04

Propagules adapted to wind dispersal

y=1, n=-1

n

7.05

Propagules water dispersed

y=1, n=-1

n

7.06

Propagules bird dispersed

y=1, n=-1

n

7.07

Propagules dispersed by other animals (externally)

y=1, n=-1

n

7.08

Propagules survive passage through the gut

y=1, n=-1

y

8.01

Prolific seed production (>1000/m2)

y=1, n=-1

y

8.02

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

y=1, n=-1

y

8.03

Well controlled by herbicides

y=-1, n=1

y

8.04

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

y=1, n=-1

y

8.05

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

y=-1, n=1

Total score:

16

Source

Notes

1.01

no evidence

1.02

(1) Tischler, C. R.; Burson, B. L. (1995) Evaluating different bahiagrass cytotypes for heat tolerance and leaf epicuticular wax content. Euphytica, 1995, Vol.84, No.3, pp.229-235, 16 ref. (2)http://www.pi.csiro.au/ahpc/grasses/pdf/competidor.pdf

(1) "Bahiagrass (Paspalum notatum ) is a polymorphic species indigenous to South America which has become naturalized in the southeastern USA. The most common form in the USA is Pensacola bahiagrass, P. notatum var. saurae , which is a valuable forage. Pensacola is a sexual diploid, while most other bahiagrasses are apomictic tetraploids." (2)Pensicla Bahia grass is naturalised over a considerable area of the North Coast of New South Wales and South Coast of Queensland.

1.03

Foshee, W. G.; Goff, W. D.; Patterson, M. G.; Ball, B. M. (1995) Orchard floor crops reduce growth of young pecan trees. HortScience, 1995, Vol.30, No.5, pp.979-980, 6 ref.

AB: Hairy vetch (Vicia villosa ), common vetch (V. sativa , cv. Cahaba White), arrowleaf clover (Trifolium vesiculosum , cv. Yuchi), crimson clover (T. incarnatum , cv. Tibbee), red clover (T. pratense , cv. Redland II), yellow nutsedge (Cyperus esculentus ), buckwheat (Fagopyrum sagittatum [F. esculentum ]), hairy indigo (Indigofera hirsuta ), bahiagrass (Paspalum notatum , cv. Pensacola), common bermudagrass (Cynodon dactylon ) and centipedegrass (Eremochloa ophiuroides ) were grown for 3 years in a 3 x 3-m spacing around young pecan cv. Desirable trees. Compared with weed-free plots, all cover crops suppressed tree growth substantially; there were no differences among cover crops in the degree of suppression. Mean trunk cross-sectional area of weed-free trees increased 26-fold by the end of the third growing season but increased only 13-fold for trees grown with any cover crop. These results suggest that cover crops, if grown in young pecan orchards to promote beneficial insects, should be excluded from t

2.01

USDA, ARS, National Genetic Resources Program. Germplasm Resources Information Network - (GRIN). [Online Database] National Germplasm Resources Laboratory, Beltsville, Maryland. Available: http://www.ars-grin.gov/cgi-bin/npgs/html/taxon.pl?26889 (18 September 2002)

Distributional range:
Native:
Northern America: Mexico [e.]
Southern America: Antigua and Barbuda; Argentina; Belize; Bolivia; Brazil; Costa Rica; Cuba; Dominica; El Salvador; Grenada; Guadeloupe; Guatemala; Honduras; Jamaica; Martinique; Montserrat; Nicaragua; Panama; Paraguay; Peru; Puerto Rico; St. Lucia; St. Vincent and Grenadines; Uruguay
Other: probably native elsewhere in neotropics, also cult.

2.02

2.03

(1)USDA, NRCS. 2001. The PLANTS Database, Version 3.1 (http://plants.usda.gov). National Plant Data Center, Baton Rouge, LA 70874-4490 USA. (2)http://www.hort.purdue.edu/newcrop/duke_energy/Paspalum_notatum.html

(1)distribution in US: Alabama, Arkansas, California, Florida, Georgia, Illinois, Louisiana, Mississippi, New Jersey, North Carolina, Oklahoma, Puerto Rico, South Carolina, Tennessee, Texas, Virgin Islands, Virginia (2)Found on open ground, savannas, and pastures, up to 2,000 m, Ranging from Cool Temperate Moist to Wet through Tropical Dry to Wet Forest Life Zones

2.04

Tischler, C. R.; Burson, B. L. (1995) Evaluating different bahiagrass cytotypes for heat tolerance and leaf epicuticular wax content. Euphytica, 1995, Vol.84, No.3, pp.229-235, 16 ref.

AB: "Bahiagrass (Paspalum notatum ) is a polymorphic species indigenous to South America which has become naturalized in the southeastern USA. The most common form in the USA is Pensacola bahiagrass, P. notatum var. saurae , which is a valuable forage. Pensacola is a sexual diploid, while most other bahiagrasses are apomictic tetraploids."

2.05

(1) USDA, NRCS. 2001. The PLANTS Database, Version 3.1 (http://plants.usda.gov). National Plant Data Center, Baton Rouge, LA 70874-4490 USA.
(2) Paswan, L.; Machahary, R. K. (2000) Effect of nitrogen on bahiagrass. Journal of Ornamental Horticulture (New Series), 2000, Vol.3, No.2, pp.87-90, 5 ref.
(3) Hirata, M. (2001) Herbage availability and utilisation in small-scale patches in a bahia grass (Paspalum notatum ) pasture under cattle grazing. Tropical Grasslands, 2002, Vol.36, No.1, pp.13-23, 26 ref.

(1) U.S. Alabama, Arkansas, California, Florida, Georgia, Illinois, Louisiana, Mississippi, New Jersey, North Carolina, Oklahoma, Puerto Rico, South Carolina, Tennessee, Texas, Virgin Islands, Virginia
(2) India (3) Japan

3.01

(1) Tischler, C. R.; Burson, B. L. (1995) Evaluating different bahiagrass cytotypes for heat tolerance and leaf epicuticular wax content. Euphytica, 1995, Vol.84, No.3, pp.229-235, 16 ref. (2)http://www.pi.csiro.au/ahpc/grasses/pdf/competidor.pdf

(1) "Bahiagrass (Paspalum notatum ) is a polymorphic species indigenous to South America which has become naturalized in the southeastern USA. The most common form in the USA is Pensacola bahiagrass, P. notatum var. saurae , which is a valuable forage. Pensacola is a sexual diploid, while most other bahiagrasses are apomictic tetraploids." (2)Pensicla Bahia grass is naturalised over a considerable area of the North Coast of New South Wales and South Coast of Queensland.

3.02

no evidence

3.03

Bacon, P., P.J. Terry, N. Waltham, & P.Castro S. (1997) An Electronic Atlas of World Weed and Invasive Plants. Version 1.0, 1997. A database based on the original work "A Geographical Atlas of World Weeds" by Holm et al 1979.

P. notaum was listed as a principal weed in United States, Uraguay, and Venezuela.

3.04

http://www.unicapinvitrosight.com/templates/Allergens.asp?id=1867

does not appear to invade intact, undisturbed, native systems.

3.05

Bacon, P., P.J. Terry, N. Waltham, & P.Castro S. (1997) An Electronic Atlas of World Weed and Invasive Plants. Version 1.0, 1997. A database based on the original work "A Geographical Atlas of World Weeds" by Holm et al 1979.

Paspalum spp. were listed as serious, principal to common weeds around the world.

4.01

Dehgan, B. (1998) Landscape Plants for Subtropical Climates. University Press of Florida., Gainesville, FL. 638pp. p.192

no description of these traits

4.02

Martin, L. D.; Smith, A. E. (1994) Allelopathic potential of some warm-season grasses. Crop Protection, 1994, Vol.13, No.5, pp.388-392, 18 ref.

AB: Aqueous extracts of tissue from Setaria faberi, Setaria viridis, Setaria glauca [Setaria pumila ], Paspalum notatum, Echinochloa crus-galli, Sorghum halepense and Digitaria sanguinalis , harvested at the vegetative and mature stages, were tested for their allelopathic effects on seed germination and the seedling growth of 2 bioassay species, lucerne cv. Saranac and Lolium multiflorum , under greenhouse conditions. Tissues harvested from D. sanguinalis and E. crus-galli were found not to be allelopathic, whereas only tissue harvested from the 5 other test species during the mature stage of plant growth exhibited allelopathic characteristics. Extracts of stem material reduced seed germination and seedling growth in both bioassay species. It was estimated that 0.30/0.33, 0.23/0.18, 0.20/0.21, 0.31/0.32 and 0.38/0.19% aqueous extracts of mature Sorghum halepense , P. notatum, Setaria faberi, Setaria viridis and Setaria glauca stem tissue resulted in a 50% reduction in seed germination/seedling growth of L. m

4.03

no evidence

4.04

Tischler, C. R.; Burson, B. L. (1995) Evaluating different bahiagrass cytotypes for heat tolerance and leaf epicuticular wax content. Euphytica, 1995, Vol.84, No.3, pp.229-235, 16 ref.

AB: "Bahiagrass (Paspalum notatum ) is a polymorphic species indigenous to South America which has become naturalized in the southeastern USA. The most common form in the USA is Pensacola bahiagrass, P. notatum var. saurae , which is a valuable forage. Pensacola is a sexual diploid, while most other bahiagrasses are apomictic tetraploids."

4.05

Varella, A. C.; Saibro, J. C. de (1999) Use of cattle and sheep as agents to control the growth of native vegetation underneath three eucalyptus populations.[FT: Uso de bovinos e de ovinos como agentes de controle da vegetação nativa sob três populações de eucalipto.] Revista Brasileira de Zootecnia, 1999, Vol.28, No.1, pp.30-34, 4 ref.

AB: A study was conducted during 1992 in Rio Grande do Sul, Brazil, to evaluate 5 control methods for native vegetation (e.g. Axonopus affinis , Paspalum notatum and Desmodium incanum ) in eucalyptus populations. A split-plot experimental design in two randomized blocks was utilised. Treatments were conducted on 3 populations of Eucalyptus saligna (204, 400 or 816 plants/ha) with (i) no weed control, (ii) pre-emergent herbicide (Oxyfluorfen 240g/litre), (iii) pre- and post-emergent herbicides (Oxyfluorfen 240 g/litre + Glyphosate 520 g/litre), (iv) cattle grazing or (v) sheep grazing. Cattle and sheep grazing were the most efficient control methods, the cattle causing more damage to the trees than the sheep. A significant relationship between tree height and damage caused by cattle and sheep was observed with the introduction of these animals in the understorey.

4.06

Reinert, J. A. (1977) Field biology and control of Haplaxius crudus on St. Augustine grass and Christmas palm. Journal of Economic Entomology, 1977, Vol.70, No.1, pp.54-56, 6 ref.

(1) AB: Field studies were carried out in Florida on the biology and control of Haplaxius crudus (Van D.). Development of the cixiid readily occurred on St. Augustine grass (Stenotaphrum secondatum), Bahia grass (Paspalum notatum) and Bermuda grass (Cynodon dactylon). Adults fed on these turf grasses and on at least 9 species of palms, including Christmas palm (Veitchia merrillii) and coconut palm. Mean populations on Christmas palm and St. Augustine grass were 3.1 examples/leaf and 23.7 examples/0.09 m2 of turf, respectively. Soil drenches of aldicarb, carbofuran and dimethoate at a rate of 28 g toxicant/tree controlled the pest on mature Christmas palms. Application of chlorpyrifos, diazinon, propyl thiopyrophosphate, carbaryl and carbofuran from a watering can at rates of 1.12, 4.48, 4.20, 5.60 and 5.60 kg toxicant/ha, respectively, gave excellent control of the pest on St. Augustine grass.
(2) <http://www.plantapalm.com/vpe/pestsndiseases/vpe_coconutly2.htm> [Haplaxius crudus (Van D.). is a vector of

4.07

(1)Sam ChoonKook; Kesavan-Padmaja; Liam ChongKin; Soon SiewChoo; Lim AhLan; Ong EngKok (1998) A study of pollen prevalence in relation to pollen allergy in Malaysian asthmatics. Asian Pacific Journal of Allergy and Immunology, 1998, Vol.16, No.1, pp.1-4, 9 ref. (2)http://www.unicapinvitrosight.com/templates/Allergens.asp?id=1867

(1) Results are presented of skin prick tests (SPT) of 200 patients with clinical symptoms of asthma registered at the University Hospital in Kuala Lumpur, Malaysia. Pollen extracts of 2 grasses (Bahia [Paspalum notatum ] and Bermuda [Cynodon dactylon ]), rough pigweed [Amaranthus sp.] and 2 flowering trees (Acacia and Melaleuca ) were collected during 1996-97 near the University Hospital. Of the 29.5% asthmatics with positive SPT reactions, 21.5% reacted to one or more of the grasses or pigweed, 21.5% to Acacia and 7.5% to Melaleuca pollen. Acacia and Bermuda grass extracts were the most allergenic, and this agreed with the results of pollen collection which showed Bermuda grass and Acacia pollen as the most common. (2)A grass species producing pollen, which often induces hayfever, asthma and conjunctivitis in sensitised individuals.Multiple antigenic components have been detected but no allergens from this plant have yet been characterised. Various studies around the world have demonstrated the importance

4.08

http://www.pi.csiro.au/ahpc/grasses/pdf/competidor.pdf

It does not produce a large amount of combustible stem and leaf litter, as do most other subtropical grasses. It tolerates controlled burning during winter and spring but can be damaged by the intense heat of an uncontrolled summer grass fire.

4.09

(1)Mannetje , L. & R.M. Jones (1992) Plant Resourcesof South -East Asia no.4 Forages. Prosea Fundation, Bogor, Indonesia. p.182 (2)http://floridaturf.com/bahia/origins.htm

(1)"It is very tolerant of shades and 35% higher yield has been measured under 50% shade than in full sunlight." (2)bahiagrass grows poorly in areas with moderate or heavy shade (3)fairly tolerant of shade [Argentinian cultivars]

4.1

Dehgan, B. (1998) Landscape Plants for Subtropical Climates. University Press of Florida., Gainesville, FL. 638pp. p.192

"Culture: various soils"

4.11

Dehgan, B. (1998) Landscape Plants for Subtropical Climates. University Press of Florida., Gainesville, FL. 638pp. p.192

tall-growing perennial grass

4.12

no evidence

5.01

terrestrial

5.02

Dehgan, B. (1998) Landscape Plants for Subtropical Climates. University Press of Florida., Gainesville, FL. 638pp. p.192

Poaceae; tall-growing grass

5.03

Boddey, R. M.; Chalk, P. M.; Victoria R.; Matsui, E. (1983) The 15N-isotope dilution technique applied to the estimation of biological nitrogen fixation associated with Paspalum notatum cv. batatais in the field. Soil Biology & Biochemistry, 1983, Vol.15, No.1, pp.25-32, 35 ref.

grass, but fix notrogen. AB: The contribution of associated biological nitrogen fixation to the nitrogen nutrition of Paspalum notatum cv. batatais was estimated using the 15N-isotope dilution technique. Plants were grown in the field in concrete cylinders (60 cm dia) filled with soil, to which were added small quantities of 15N-labelled fertilizer at frequent intervals over 12 months. The pensacola cultivar of P. notatum was used as a non-N2-fixing control plant, since the nitrogenase (intact core C2H2 reduction) activity associated with this cultivar was consistently much less than that of the batatais cultivar. At the first harvest, no evidence for N2 fixation associated with the batatais cultivar was obtained, probably because of slow establishment of the N2-fixing association. However, at the subsequent three harvests the batatais cultivar exhibited a lower 15N-enrichment and yielded more N than the pensacola cultivar. The data indicate that 8-25% of the N in the batatais cultivar originated from N2 fix

5.04

Dehgan, B. (1998) Landscape Plants for Subtropical Climates. University Press of Florida., Gainesville, FL. 638pp. p.192

perennial grass with stout rhizome [grass not geophyte]

6.01

no evidence

6.02

Dehgan, B. (1998) Landscape Plants for Subtropical Climates. University Press of Florida., Gainesville, FL. 638pp. p.192

"Propagation: seed (which is abundant and relatively inexpensive.)"

6.03

Quarin, C. L. (1983) Interspecific hybrids of Paspalum notatum x P. modestum. [FT: Híbridos interespecíficos de Paspalum notatum x P. modestum.] Bonplandia, 1983, Vol.5, pp.235-242, 8 ref.

AB: All 5 seedlings obtained by pollinating the autotetraploid P. notatum clone SWSB (2n = 40, NNNN) with P. modestum (2n = 20) were 2n = 30 and generally resembled the female parent. In meiosis, 10 univalents and 10 bivalents were observed, indicating that the two parental species have different genomes. It is suggested that P. notatum contributed NN to the hybrid, while P. modestum contributed a different genome, tentatively designated P, as this species is included in the Plicatula group of Paspalum. Only 4 hybrids produced inflorescences and none produced caryopses. In a high percentage of cases, glume I was to some extent present, which is rare in the genus and unknown in the parental species.  [no evidence of natural hybrid]

6.04

Espinoza, F.; Pessino, S. C.; Quarín, C. L.; Valle, E. M. (2002) Effect of pollination timing on the rate of apomictic reproduction revealed by RAPD markers in Paspalum notatum . Annals of Botany, 2002, Vol.89, No.2, pp.165-170, 20 ref.

AB: Progeny tests employing molecular markers allow the identification of individuals originated by sexual means among the offspring of a facultative apomict. The objective of this work was to evaluate the effect of the pollination timing on the proportion of sexually formed individuals in progenies of a facultative apomictic Paspalum notatum genotype. Progeny families of approx. 30 plants each were generated at five different pollination times: 1-3 d pre-anthesis; at anthesis; and 2, 4 and 6 d post-anthesis. Cytoembryological analyses indicated that approx. 17% of the ovules carried a meiotic cytologically reduced embryo sac in florets formed simultaneously with those used for crosses. The parental plants and the five F1 families were analysed using RAPD molecular markers. Ninety-five oligonucleotides were assayed on the progenitors in order to search for male-specific bands. Eight primers presenting clear polymorphic bands were selected for use in the progeny tests. The proportion of sexually produced prog

6.05

http://www.unicapinvitrosight.com/templates/Allergens.asp?id=1867

sexually reproducing varieties are wind-pollinated.

6.06

Dehgan, B. (1998) Landscape Plants for Subtropical Climates. University Press of Florida., Gainesville, FL. 638pp. p.192

"spread by stout rhizomes"

6.07

(1)http://www2.ctahr.hawaii.edu/sustainag/bahiagrass.htm (2)http://www.pi.csiro.au/ahpc/grasses/pdf/competidor.pdf

no evidence [Days to Maturity : No information is available in this database on this topic.] (2)spreads laterally at a much slower rate than kikuyu grass 

7.01

no evidence

7.02

Mannetje , L. & R.M. Jones (1992) Plant Resourcesof South -East Asia no.4 Forages. Prosea Fundation, Bogor, Indonesia. p.182

"Bahia grasss can be established from seed or vegetatively, from pieces of rhiozomes or stolons planted closely at spacing of 15-25 cm."

7.03

USDA, ARS, National Genetic Resources Program. Germplasm Resources Information Network - (GRIN). [Online Database] National Germplasm Resources Laboratory, Beltsville, Maryland. Available: http://www.ars-grin.gov/cgi-bin/npgs/html/taxon.pl?26889 (18 September 2002)

Weed: potential seed contaminant (fide Weed CIBA)

7.04

no evidence

7.05

no evidence

7.06

no evidence

7.07

(1)Mannetje , L. & R.M. Jones (1992) Plant Resourcesof South -East Asia no.4 Forages. Prosea Fundation, Bogor, Indonesia. p.182 (2)http://www.pi.csiro.au/ahpc/grasses/pdf/competidor.pdf

(1)spikelet is smooth (2)ripening seed crops are attacked by Eastern Rosella parrots and mature seed is very attractive to mice and rats.[predators, internal]

7.08

Mannetje , L. & R.M. Jones (1992) Plant Resourcesof South -East Asia no.4 Forages. Prosea Fundation, Bogor, Indonesia. p.182

"Viable seeds is spread through dissemination in faeces."

8.01

(1)Mannetje , L. & R.M. Jones (1992) Plant Resourcesof South -East Asia no.4 Forages. Prosea Fundation, Bogor, Indonesia. p.182, 183 (2)http://www.hort.purdue.edu/newcrop/duke_energy/Paspalum_notatum.html (3)http://floridaturf.com/bahia/origins.htm

(1)" There are 300-500 seeds/gram"; "It is a heay seeder and seed yields of 100-350 kg/ha have been reported." [400x225000 seeds/10000 m2 = 9000 seeds/m2] (2)Seed production is low and is often reduced further by ergot. (3)Seed production is meager (225 to 350 kg ha-1 would be the high range)

8.02

Maeda, J. A.; Pereira, M. de F. D. A.; Medina, P. F. (1997) Seed dormancy and storage of Paspalum notatum Flügge. [FT: Conservação e superação da dormência de sementes de Paspalum notatum Flügge.] Revista Brasileira de Sementes, 1997, Vol.19, No.2, pp.165-171, 20 ref.

AB: A study was conducted to verify the long-term longevity and dormancy persistence in Paspalum notatum seeds stored for three years under controlled temperature (kept under 10 deg C) and air relative humidity conditions. Significant increase in germination was observed when the seeds were stored in uncontrolled conditions for 12 months without overcoming all the dormancy. In order to evaluate the effect of high temperature, fresh seeds were kept at 40 deg C in hermetic bottles for 180 days. This condition led to rapid loss of seed viability. When the seeds were placed at 40 deg C but in permeable containers, the dormancy was almost suppressed in 120 days; at that time, the seeds' moisture content was 5%. Since germination occurred when the water content of the seeds was low, a sample of seeds was placed in an oven at 60 deg C with air circulation, where the seed moisture content decreased from 10 to 3% in 7 days. There was no improvement in germination and no damage due to high temperature effect since the

8.03

(1) Singh, M.; Mack, R. E. (1993) Effect of organosilicone-based adjuvants on herbicide efficacy. Pesticide Science, 1993, Vol.38, No.2-3, pp.219-225, 13 ref.
(2) Ferri, M. V. W.; Eltz, F. L. F.; Lopes, S. J. (2001) Application of desiccant herbicides on native pasture composed of different species of the genus Paspalum . [FT: Aplicação de herbicidas dessecantes em pastagens nativas constituídas por differentes espécies do gênero Paspalum .] Ciência Rural, 2001, Vol.31, No.4, pp.589-595, 22 ref.

(1) AB: Field trials in Citrus plots at Lake Alfred during 1991 and laboratory experiments were conducted to evaluate the efficacy of the post-em. herbicides, fluazifop-P-butyl (125 g/litre), glyphosate-isopropylammonium (480 g), paraquat dichloride (250 g) and glyphosate-trimesium (sulfosate at 480 g), as influenced by the organosilicone-based adjuvants, Dyne-Amic and Kinetic. The conventional adjuvants, Agri-Dex and Induce, were included in all experiments for comparison. The experimental plots were naturally infested with Paspalum notatum , Heterotheca subaxillaris , Chenopodium album , Richardia scabra , Chenopodium abrosioides , Bidens pilosa , Amaranthus viridis and Sida acuta . Dyne-Amic (2.5 ml/litre) was as effective as Agri-dex (10 ml) in increasing the efficacy of herbicides against the grassy and broadleaved weeds studied. Kinetic (2.5 ml) was as effective as Induce (2.5 ml). Paraquat tank-mixtures with the pre-em. herbicides bromacil + diuron (800 g/kg) were more effective when applied at a spra

8.04

(1)Mannetje , L. & R.M. Jones (1992) Plant Resourcesof South -East Asia no.4 Forages. Prosea Fundation, Bogor, Indonesia. p.183 (2)http://www.pi.csiro.au/ahpc/grasses/pdf/competidor.pdf

(1)"Frequently defoliation closed to ground level is not only tolerated but is desirable to keep the sward leafy and acceptable o animals." (2)It tolerates controlled burning during winter and spring but can be damaged by the intense heat of an uncontrolled summer grass fire.

8.05

no evidence