HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Bovey, R. W. Articles by Meyer, R. E. Search for Related Content PubMed Articles by Bovey, R. W. Articles by Meyer, R. E. Agricola Articles by Bovey, R. W. Articles by Meyer, R. E.

Loss of Spray and Pelleted Picloram in Surface Runoff Water¹

ABSTRACT

This investigation was conducted to determine the concentration of piclorum (4-amino-3,5,6-trichloropicollnic acid), applied as the pelleted formulation, in surface runoff water that may move from a treated watershed to untreated areas as a result of natural or simulated rainfall. Movement of surface and subsurface applied picloram in surface runoff water was also investigated.

The potassium salt of pelleted picloram was applied at 2.24 kg/ha (acid equivalent) to a 1.3-ha rangeland watershed supporting stands honey mesquite (Prosopis juliflora [Swartz] DC. var. glandulosa [Torr.] Cockerell). Surface runoff of 1.5 cm from a 2.1-cm rain received 2 days after treatment contained an average of 2.8 ppm picloram. Picloram content declined rapidly and runoff water contained < 5 ppm picloram by 2.5 mo after application. Loss of the potassium salt of picloram from grassland watersheds in surface runoff water was similar whether the picloram was applied as an aqueous spray or pellet. Picloram applied subsurface was lost in surface runoff water, but in lower concentration than when applied to the soil surface.

Key Words: herbicide • residue • watershed

¹ Cooperative investigations of the USDA-SEA and the Texas Agric. Exp. Stn. at Temple and College Station, Tex.

² Agronomist, Agricultural Engineer, Soil Scientist, and Plant Physiologist, respectively, USDA-SEA, College Station and Temple, Tex.

³ Professor, Dep. of Soil and Crop Sci., Texas A&M Univ., College Station, TX 77843.

Received for publication May 18, 1977.