CHEMICAL WEED CONTROL IN ROUNDUP READY MAIZE PUBLISHEDClaudia Delia Culhavi, Dan Manea
The goal of the research was to test the weed control efficiency of the product Roundup Ready (480 g/l glyphosate) in rates of 2.25 l/ha (1080 g/ha active substance) applied in the 3-leaf and 8-leaf phases of the cultivated hybrid (13 BBCH, and 18 BBCH, respectively). We monitored the effect of tank mixing the herbicide Roundup Ready in the 3-leaf phase in maize (BBCH 13) with products traditionally applied pre-emergently, such as acetochlor, acetochlor + terbuthylazine (CLICK PLUS), dimethenamid (SPECTRUM), pendimethalin + dimethenamid-p (WING), compared to the usual product acetochlor (GUARDIAN) applied pre-emergently or to the post-emergent herbicides nicosulphuron (MISTRAL) + dicamba (BANVEL). Researches were carried out in the experimental field area of the Banat University of Agricultural Science and Veterinary Medicine in Timisoara, College of Agriculture, Timiş County, Romania, from May to October 2010. The cultivated hybrid tolerated very well all the tested herbicides with no phytotoxicity whatsoever (note 1 EWRS grades). The most frequent weed species in the control variant (not treated) (V 1 ), in the stage 13 BBCH in maize were the monocots Setaria sp. and Sorghum halepense from rhizomes and seeds, and Echinochloa crus-galli. All the herbicides applied pre-emergently (V 2 -V 6 ) ensured a very good control of annual monocot weeds but they had no visible effect whatsoever on Sorghum halepense plants from rhizomes or on the perennial dicot species Cirsium arvense and Convolvulus arvensis After the first post-emergent herbicide treatment, we could see a very good control of all weed species in the variants treated with glyphosate (V 3 -V 6 and V 8 ) and variants treated with glyphosate tank-mixed with different herbicides applied usually post-emergently (V 9 -V 12 ). In the variant V 7 , where we used tank-mixed classical herbicides Banvel + Mistral, weed control was less efficient, even slow, with a trend to regeneration. The highest production of grain maize – over 90.0 q/ha – was in the variants V 10 – Acetochlor + Terbuthylazine (CLICK PLUS) + Glyphosate + Glyphosate, V 12 – Dimethenamid - P + Pendimethalin (WING) + Glyphosate + Glyphosate and V 11 – Dimethenamid (SPECTRUM) + Glyphosate + Glyphosate.
corn crop, weed control, herbicides, glyphosate, Roundup Ready