Effect of weed management practices on weeds and Nitrogen removal by weeds in Japanese mint (Mentha arvensis L.)

Abstract

The field experiment was conducted during summer season of 2015 and 2017 at Agronomy Research Farm of N. D. University of Agriculture and Technology, Kumarganj, Ayodhya (U.P.), to study the “Weed management studies in Japanese mint (Mentha arvensis L.)”. The experiment consisted of 14 treatment combination with propaquizafop - p - ethyl @ 40 g ha-1 as post-emergence (T1), propaquizafop - p - ethyl @ 60 g ha-1 as post-emergence (T2), propaquizafop - p - ethyl @ 80 g ha-1 as post-emergence (T3), propaquizafop - p - ethyl @ 100 g ha-1 as post-emergence (T4), clodinafop propargyl @ 40 g ha-1 as post-emergence (T5), clodinafop propargyl @ 60 g ha-1 as post-emergence (T6), clodinafop propargyl @ 80 g ha-1 as post-emergence (T7), Pendimethalin @ 1000 g ha-1 as pre-emergence (T8), oxyfluorfen @ 200 g ha-1 as pre-emergence (T9), imazethapyr + imazamox @ 80 g ha-1 as post-emergence (T10), imazethapyr + pendimethal in (RM) @1000 g ha-1 as pre-emergence (T11), imazethapyr @ 60 g ha-1 as post-emergence (T12), Weed free (Three hand weeding at 20, 45 and 65 DAP) (T13) and weedy check (T14). The treatments were replicated three times in a randomized block design. All weed management practices proved effectiveness for controlling the weeds in Japanese mint and recorded significantly lesser weed density, dry weight, weed index, nitrogen removal by weeds and higher weed control efficiency over weedy check. Pre emergence application of imazethapyr + pendimethalin at 1000 g ha-1 was found most effective for control of all major weeds and recorded minimum weed density (29.68 and 27.11), dry matter (29.07 and 27.08g.), weed index (8.82 and 8.68%), nitrogen removal (7.19 and 5.90 kg ha-1) and maximum WCE 92.76 and 93.88% during 2015 and 2017, respectively, which was significantly superior to rest of the treatments while at par with application of imazethapyr + and @ 80 g ha-1 as post emergence, pendimethalin @ 1000 g ha-1 as pre emergence and imazethapyr @ 60 g ha-1 as post-emergence for effective control of weeds.