Stability and selectivity of some herbicides, herbicide combinations and herbicide tank mixtures on winter forage pea (Pisum sativum L. var. arvense)

Grozi Delchev, Delcho Delchev

Abstract: The research was conducted during 2015 – 2017 on pellic vertisol soil type. Under investigation was Bulgarian winter forage pea cultivar Mir (Pisum sativum var. arvense). Factor A included the years of investigation. Factor B included untreated control and 2 soil-applied herbicides – Dual gold 960 EC (S-metolachlor) – 1.5 l.ha-1, Stomp aqua (pendimethalin) – 3 l.ha-1. Factor С included untreated control, 5 foliar-applied herbicides – Basagran 480 CL (bentazone) – 2 l.ha-1, Pulsar 40 (imazamox) – 1.2 l.ha-1, Korum (bentazone + imazamox) – 1.25 l.ha-1, Zencor 70 WG (metribuzine) – 500 g.ha-1 , Maton 600 EK (2.4-D ethylhexyl ester) – 100 ml.ha-1 and 2 herbicide tank mixtures – Zencor 70 WG (metribuzine) – 500 g.ha-1 + Targa super 5 EC (quizalofop-P-ethyl) – 2 l.ha-1, Maton 600 EK (2.4-D ethylhexyl ester) – 100 ml.ha-1 + Targa super 5 EC (quizalofop-Pethyl) – 2 l.ha-1. Soil herbicides were applied during the period after sowing before emergence. Foliar herbicides were applied during 2 – 3 real leaf stage of the pea. The highest yields of winter forage pea seeds are obtained by treatment with foliar applied herbicide Korum after soil-applied herbicides Stomp aqua and Dual gold. High yields are obtained also by treatment with foliar-applied herbicide Pulsar after soil-applied herbicides Stomp aqua and Dual gold, as well as by foliar treatment with herbicide tank-mixture Zencor + Targa super after soil-applied herbicides Stomp aqua and Dual gold. Herbicide Maton and herbicide tank mixture Maton + Targa super, both in separated use and in combined use with soil-applied herbicides Dual gold and Stomp aqua are the most unstable for seed yield. Combinations of foliar-applied herbicide Korum with soil-applied herbicides Stomp aqua and Dual gold are technological the most valuable. They are followed by combinations of foliar-applied herbicide Pulsar with soil-applied herbicides Stomp aqua and Dual gold. They combine high seed yield with high stability with relation to diff erent years. Alone uses of soil-applied herbicides Dual gold and Stomp aqua, of foliar-applied herbicides Basagran, Pulsar, Korum and Zencor, and of herbicide tank mixture Zencor + Targa super have low estimates and do not be used. For complete control of all weeds and self-sown plants in winter forage pea crops, two herbicides should be combined – both soil-applied and foliar-applied.

Keywords: herbicide combinations; herbicides; pea; seed yield; selectivity; stability; winter forage

Date published: 2019-12-29