Search
Search results for
We found
24 results for you
-
Die beheer van Amaranthus spp. en die invloed daarvan op Digitaria eriantha gedurende die vestigingsjaar
Item type: Journal Article • Journal: Journal of the Grassland Society of Southern Africa • Authors: C.S. Dannhauser --- Departement Landbou en Watervoorsiening, Republiek van Suid‐Afrika AnnelieS. deBeer --- Departement Landbou en Watervoorsiening, Republiek van Suid‐AfrikaThe control of Amaranthus spp. and the influence thereof on Digitaria eriantha during the season of establishment. Chemical control of Amaranthus spp. in newly established Smuts finger grass (D. eriantha) was investigated. A mixture of 800 ml 2,4‐D Amine+1200 ml... -
Factors affecting the activity of atrazine in plants and soil
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: P.C. Nel --- Department of Plant Production, C.F. Reinhardt --- Department of Plant Production,Available research findings concerning (he activity of atrazine in the plant and soil are presented in a brief review. The role of the environment is emphasized. This review is supplemented by recent research results of the University of Pretoria concerning... -
Growth responses of inbred maize lines with high and low DIMBOA (benzoxazinone) contents to atrazine
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: C. Malan --- , J.H. Visser --- Department of Botany, H.A. van de Venter --- Department of Botany,The growth response of five inbred maize lines with high and low DIMBOA content were compared in the presence of 3 and 12 ppm atrazine. A growth-promoting effect of atrazine on roots, mesocotyls and coleoptiles was observed in dark-grown seedlings... -
Ultrastructural changes in the leaves of Zea mays L. plants treated with atrazine
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: C. Malan --- , J.H. Visser --- Department of Botany, H.A. van de Venter --- Department of Botany,Veinal chlorosis was induced in the lower leaves of young maize plants following treatment with atrazine (2-chloro-4-ethylamino-6- isopropylamino-s-triazine). An ultrastructural investigation indicated that mesophyll chloroplasts, consisting of grana, thylakoids and stroma showed severe disintegration. The seemingly unaffected bundle sheath chloroplasts... -
Tolerance of South African maize (Zea mays L.) cultivars to atrazine
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: M.R. Le Court De Billot --- Summer Grain Centre, P.C. Nel --- Department of Plant Production,Sixty-seven maize cultivars were evaluated for tolerance to atrazine (4 p.p.m. v/v) in nutrient solution. Shoot dry masses (SDM) of only two cultivars, SAB149 and NPP x K64r, were reduced more than 40% and another 14 were reduced by more... -
Recovery of grain sorghum [Sorghum bicolor (L.) Moench] from atrazine and cyanazine phytotoxicity
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: M.R. le Court de Billot --- , P.C. Nel --- Department of Plant Production,Recovery of growth following atrazine and cyanazine toxicity and the effect on subsequent grain yield of sorghum were studied in nutrient solutions in two separate experiments. In Experiment I, concentrations of atrazine and cyanazine were decreased at weekly intervals based... -
Reduced leaf diffusive resistance with re-exposure of maize (Zea mays L.) to atrazine
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: M.R. le Court de Billot --- Summer Grain Centre, Republic of South Africa P.C. Nel --- Department of Plant Production, Republic of South AfricaApplication and subsequent removal of atrazine in a nutrient solution resulted in changes in leaf diffusive resistance in maize. Re-exposure to atrazine elicited lower responses in leaf diffusive resistance, suggesting an improved tolerance to atrazine by maize. The time elapsed... -
Evaluation of the effects of scorching caused by the directed application of a paraquat-containing herbicide mixture to the base of maize plants at various ages
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: P. E.L. Thomas --- ,The effect of herbicides which scorched the lower leaves of maize was compared in three seasons. The first season was relatively dry whilst the other two were wetter seasons. A mixture of cyanazine + atrazine + paraquat + a wetting... -
Preliminary studies on the inheritance of atrazine tolerance in maize (Zea mays L.)
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: M.R. Le Court De Billot --- Department of Plant Production, A.P. Fourie --- Department of Plant Production, P.C. Nel --- Department of Plant Production,Thirty-three maize (Zea mays L.) inbreds were screened for tolerance to atrazine (2-chloro-4-ethylamino-6- isopropylamino-1,3,5-triazine) in a glasshouse using a sand culture technique. Tolerance ranged from 95,7–51,0% of the control. The continuous pattern of tolerance exhibited by the inbreds indicated polygenic... -
Qualitative estimation of atrazine, hydroxyatrazine and 6-methoxy-2-benzoxazinone (MBOA) in maize plants
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: C. Malan --- , Republic of South Africa J.H. Visser --- Department of Botany, Republic of South Africa H.A. van de Venter --- Department of Botany, Republic of South AfricaA rapid and simple method for the extraction and quantification of the herbicide atrazine, the atrazine hydroxylating agent in maize plants DIMBOA, and the hydroxylated product hydroxy-atrazine, is described. These substances were quantified by means of HPLC techniques, employing a... -
In vivo atrazine hydroxylation in maize plants exposed to five different temperature regimes
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: C. Malan --- , J.H. Visser --- Department of Botany, H.A. van de Venter --- Department of Botany,Maize plants exposed to atrazine at temperatures ranging from 10°C to 30°C showed increased hydroxylation of atrazine to form the non-toxic hydroxy-atrazine metabolite as temperature increased to 25°C, above which hydroxylation decreased again. When exposed to 12 ppm atrazine, accumulation... -
Rol van tekorte aan sekere makro-elemente by verdraagsaamheid van mielies (Zea mays L.) teenoor atrasien
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: C.F. Reinhardt --- Departement Plantproduksie, P.C. Nel --- Departement Plantproduksie, N. M.J. Vermeulen --- Departement Biochemie, Z. Apostolides --- Departement Biochemie, D. J.J. Potgieter --- Departement Biochemie,Die verdraagsaamheid van mieliesaailinge (Zea mays L. kv SSM2041) teenoor atrasien is in 'n glashuis ondersoek. Plante is in potte gekweek, in voedingsoplossings met tekorte aan sekere makro-elemente. Atrasien in die voedingsoplossings is periodiek bepaal met behulp van hoëdrukvloeistofchromatografie. Tekorte... -
Relationship between DIMBOA content and atrazine tolerance in maize
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: C. Malan --- , Republic of South Africa M.R. le Court de Billot --- , Republic of South AfricaData of two independent studies are presented to illustrate the relationship between DIMBOA content of maize inbreds and their tolerance to atrazine. Polynomial regression curves best described this relationship. R-squared values of 0,48 and 0,87 between DIMBOA content and tolerance... -
Atrazine metabolism in field-grown maize and the effect of atrazine phototoxicity on yield
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: C. Malan --- , Republic of South Africa J.H. Visser --- Department of Botany, Republic of South Africa H.A. van de Venter --- Department of Botany, Republic of South AfricaMaize was grown under field conditions, applying conventional farming practices. Atrazine was sprayed pre- emergence at concentrations of 1,25 I ha−1ai. and 5 I ha−1ai. Severe phytotoxicity symptoms were visible from the first- to about the sixth-leaf stage i.e. 25–30... -
Die invloed van verskillende tipes en hoeveelhede plantresmateriaal op onkruiddodereffektiwiteit
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: T.C. van Eeden --- , Republiek van Suid-Afrika D. du Toit --- Departement Agronomie en Hortologie, Republiek van Suid-AfrikaDie invloed van agt verskillende plantreshoeveelhede (0–3 500 kg ha−1), sowel as verskiHende tipes plantreste (graansorghum- en mieliereste) op onkruiddodereffektiwiteit is ondersoek in 'n glashuisproef. Onkruiddodereffektiwiteit is bepaal deur middel van 'n indikatorplant, Avena sativa. Droëmassaopbrengs en planttellings van die... -
Invloed van sekere grondeienskappe op aktiwiteit van atrasien
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: J.G. Ehlers --- Departement Plantproduksie, Republiek van Suid-Afrika C.F. Reinhardt --- Departement Plantproduksie, Republiek van Suid-Afrika P.C. Nel --- Departement Plantproduksie, Republiek van Suid-AfrikaDie aktiwiteit van atrasien is in biotoetse onder gekontroleerde toestande ondersoek in 43 gronde vanaf 29 lokaliteite geleë in die somerreënvalstreek van Suid-Afrika. Sojabone en hawer is in afsonderlike proewe as toetsgewas gebruik. Geselekteerde grondeienskappe is met atrasienaktiwiteit gekorreleer. In... -
Inheritance of atrazine tolerance in South African maize
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: M.R. Le Court De Billot --- , Republic of South Africa P.C. Nel --- Department of Plant Production, Republic of South Africa H.O. Gevers --- , Republic of South AfricaForty-five maize (Zea mays L.) inbreds were screened for tolerance to atrazine (2-chloro-4-ethylamino-6- isopropylamino-1, 3, 5-triazine) in a glasshouse using a sand culture technique. Ten inbreds displaying a spectrum of tolerance were hybridized in all possible combinations including reciprocals to... -
Quantitative bioassays for monitoring the dissipation of atrazine in soil
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: C.F. Reinhardt --- Department of Plant Production, Republic of South Africa P.C. Nel --- Department of Plant Production, Republic of South AfricaA simple bioassay technique was used to study the residual activity of atrazine [2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine] applied at 0.25 kg ai ha−1 at different depths in a sandy clay loam (22% clay; 0.31% organic C) soil. Oats (Avena sativa L. cv. SWK001)... -
Variable tolerance of some crop species to atrazine in various soils
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: C.F. Reinhardt --- Department of Plant Production, Republic of South Africa P.C. Nel --- Department of Plant Production, Republic of South AfricaThe carry-over of atrazine (2-chloro-4-ethylamino-6-isopropylamino-1,3,5-s-triazine), which occasionally causes damage to susceptible crops grown in rotation with atrazine-treated maize (Zea mays L.), calls for a refinement of the specified recropping intervals. Bioassays were conducted in a glasshouse to evaluate, with nine... -
Residual effect of atrazine on field-grown dry beans and sunflower
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: C.F. Reinhardt --- Department of Plant Production and Soil Science, Republic of South AfricaThe applicability of fixed recropping intervals for crops that are sensitive to atrazine (2-chloro-4-ethylamino-6-isopropylamino-1,3,5-striazine) was assessed. Atrazine carry-over was monitored 12 and 24 months after its application at six different rates to maize (Zea mays L.) grown in eight trials... -
Simple regression models for the qualitative prediction of atrazine and terbuthylazine leaching
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: C.F. Reinhardt --- Department of Plant Production and Soil Science, South Africa K.J. Hugo --- Department of Plant Production and Soil Science, South AfricaLeaching of atrazine [6-chloro-N-ethyf-N′-(methylethyl)-1,3,5-triazine-2,4-dlamine] and terbuthylazine [6-chloro- N-(1,1-dirnelhylethyt)-N′-ethyl-1,3,5-triazlne-2,4-diamine] was studied in 23 soils by means of the soil thick-layer leaching method. The equivalent of 4 kg ai ha−1 of both herbicides was leached with water equivalent to 129 mm rain... -
Factors influencing the tolerance of maize to atrazine and terbuthylazine applied post-emergence
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: N. G.R. Khorommbi --- , South Africa C.F. Reinhardt --- Department of Plant Production and Soil Science, South AfricaHerbicide damage to maize seedlings reported in the 1997/98 season from certain maize-growing areas where atrazine or atrazine/terbuthylazine was applied post-emergence, prompted this investigation. Pot experiments were conducted to assess the role of growth stage, cultivar and temperature on the... -
Population structure of the African Clawed Frog (Xenopus laevis) in maize‐growing areas with atrazine application versus non‐maize‐growing areas in South Africa
Item type: Journal Article • Journal: African Journal of Herpetology • Authors: LouisH. Du Preez --- North‐West University, South Africa KeithR. Solomon --- University of Guelph, Canada JimA. Carr --- Texas Tech University, JohnP. Giesy --- Michigan State University, USA TimothyS. Gross --- Florida Caribbean Science Center‐USGS‐BRD, USA RonaldJ. Kendall --- Texas Tech University, USA ErnestE. Smith --- Texas Tech University, USA GlenL. Van der Kraak --- University of Guelph, Canada Ché Weldon --- North‐West University, South AfricaThe herbicide atrazine has been suggested to cause gonadal deformities in frogs and could possibly impact on reproduction. Since the early 1960s, atrazine has been used in large amounts in maize production areas of South Africa. These areas overlap with... -
Assessment of laryngeal muscle and testicular cell types in Xenopus laevis (Anura Pipidae) inhabiting maize and non‐maize growing areas of South Africa
Item type: Journal Article • Journal: African Journal of Herpetology • Authors: ErnestE. Smith --- Texas Tech University, LouisH. Du Preez --- North‐West University, South Africa Angella Gentles --- Texas Tech University, KeithR. Solomon --- University of Guelph, Canada Bernard Tandler --- Case Reserve University, JamesA. Carr --- Texas Tech University, GlenL. Van Der Kraak --- University of Guelph, Canada RonaldJ. Kendall --- Texas Tech University, JohnP. Giesy --- Michigan State University, TimothyS. Gross --- Florida Caribbean Science Center‐USGS‐BRD,We tested the hypothesis that adult African clawed frogs (Xenopus laevis) inhabiting water bodies in maize‐growing areas (MGA) of South Africa would exhibit differences in testicular structure compared to frogs from water bodies in non‐maize‐growing areas (NMGA) in the same...