Factors affecting the activity of atrazine in plants and soil

Abstract

Available research findings concerning the 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 evaluation of soil characteristics as a norm for the prediction of atrazine activity in turf soils, the comparison of a few maize hybrids with respect to their resistance towards atrazine and the influence of moisture and temperature on atrazine activity in light· textured soils. Guidelines for future research and for the use of atrazine are given. S. Afr. J. Plant Saif 1984, 1: 67 -72 'n Beknopte oorsig oor beskikbare navorsingsbevindinge betref· fende die aktiwiteit van atrasien in plante en in die grond word aangebied. Klem word gell3 op die rol van omgewingsfaktore. Hierdie oorsig word aangevul deur onlangse navorsingsresultate van die Universiteit van Pretoria, wat handel oor evaluasie van grondeienskappe as norm vir voorspelling van atrasien·aktiwiteit in turfgronde, vergelyking van enkele mieliebasters ten opsigte van verdraagsaamheid teenoor atrasien en die invloed van vog en temperatuur op atrasien·aktiwiteit in ligter gronde. Riglyne vir toekomstige navorsing en die gebruik van atrasien word verskaf. S.·Afr. Tydskr. Plant Grand 1984, 1: 67 -72 IntroductionDespite continuous research on factors affecting the activity of the triazines, conducted over almost a decade in South Africa and two decades in some overseas countries, knowledge of this subject remains insufficient. Unexpected cases of damage to crops or poor weed control still occur and confusion exists among scientists as to the exact cause of such occurrences.Atrazine is the most important herbicide in the summergrain producing regions of South Africa. A better understanding of the effect of the environment on the activity of this herbicide and related herbicides would be of immense value for agriculture in South Africa and the rest of the world.The purpose of this article is to give a concise review of research results concerning the use of atrazine. Emphasis is placed on the role of environmental conditions. An attempt is made to classify published data, while hitherto unpublished results of recent research at the University of Pretoria are briefly presented.

Persistence of atrazine as affected by selected soil properties

“…Cation exchange capacity and soil pH were significantly less iniportant than the first three characteristics. These results correspond with those reported by Smit et al (1981), Nel & Reinhardt (1984) and Ehlers et ai. (1988).…”

Invloed van sekere grondeienskappe op aktiwiteit van atrasien

“…Hierdie resuItate stem ooreen met die van Smit et al (1981) en Nel & Reinhardt (1984) wat met aansienlik minder grande gewerk het.…”

“…Navorsers aan die Universiteit van Pretoria het egter reeds vir 'n beperkte getal gronde aangetoon dat organiese materiaalinhoud (070 C) en fosforvaslegging die aktiwiteit van atrasien in sekere Suid-Afrikaanse gronde beter voorspel het as klei-persentasie (Smit, Nel & Foischer, 1981;Nel & Reinhardt, 1984).…”

The influence of phosphorus on the tolerance of maize (Zea maysL.) to atrazine

“…Loneragen et al (1982) and Claassens & FOlscher (1985) observed that the symptoms associated with the accumulation of P to toxic levels in top growth of wheat are interveinal chlorosis and leaf tip necrosis. Nel & Reinhardt (1984) reported that high levels of atrazine induce veinal chlorosis in the lower leaves of young maize plants. Ultrastructural investigations (Malan, Visser & Van de Venter, 1985) revealed changes in mesophyll chloroplasts of such plants, while bundle sheath chloroplasts were virtually unaffected.…”