Gr. DELCHEV and A. STOYANOVA
Trakia University, Faculty of Agriculture, BG – 6000 Stara Zagora, Bulgaria
DELCHEV, Gr. and A. STOYANOVA, 2015. Stability estimation of some mixtures between retardants and anticereal herbicides for grain yield of durum wheat. Bulg. J. Agric. Sci., 21: 358–362
The research was conducted during 2010-2012 on pellic vertisol soil type. Under investigation was Bulgarian durum wheat cultivar Progress, which belongs to Triticum durum var. leucurum. Factor A included the years of investigation. Factor B included no treated control and 3 retardants – Stabilan (chlormequat) – 2 l.ha–1, Flordimex extra (ethephon) – 750 ml.ha–1, Terpal (ethephon + mepiquat) – 3 l.ha–1. Factor C included weeded no treated control and 3 anticereal herbicides – Scorpio super 100 EC (phenoxaprop-ethyl) – 700 ml.ha–1, Grasp 25 SC (tralkoxidym) – 1.2 l.ha–1, Topik 080 EC (clodinafop) – 450 ml.ha–1. The weak adhesion of Grasp required its application with adjuvant Atplus – 1.2 l.ha–1. Investigated herbicides have not antibroadleaved effect and control of broadleaved weeds in all variants was done with herbicide Secator OD in dose 100 ml.ha–1. All of retardants, herbicides and their tank-mixtures were treated in tillering stage of the durum wheat.
The most increase of grain yield is obtained by combined use of retardant Terpal with herbicide Grasp, of retardant Flordimex extra with herbicides Grasp and Scorpio super and of retardant Stabilan with herbicides Grasp and Topik. Tank mixtures of Scorpio super with Stabilan and Terpal and tank mixtures of Topik with Flordimex extra and Terpal are the most unstable for grain yield. Tank mixtures Terpal + Grasp, Flordimex extra + Scorpio super, Stabilan + Grasp, Flordimex extra + Grasp and Stabilan + Topik are technological the most valuable. They combine high grain yield with high stability with relation to different years. Application of retardants Stabilan, Flordimex extra and Terpal without herbicides have low estimate and could not be used in the durum wheat crops.