EFFICACY OF PRE AND POST EMERGENCE HERBICIDES AGAINST WEED FLORA IN ONION (Allium cepa L.).

THAKARE, AKANKSHA MANOJ.

EFFICACY OF PRE AND POST EMERGENCE HERBICIDES AGAINST WEED FLORA IN ONION (Allium cepa L.).

Date

2020-09-30

Authors

THAKARE, AKANKSHA MANOJ.

Publisher

Publisher : Dr. Panjabrao Deshmukh Krishi Vidyapeeth, Akola, Maharashtra.

Abstract

Abstract: The field experiment was conducted at AICRP-Weed Management, Agronomy farm, Dr. Panjabrao Deshmukh Krishi Vidyapith, Akola to study the “Efficacy of pre and post emergence herbicides against weed flora in onion (Allium cepa L.)” during the year of 2018-19 in rabi season. The experiment was carried out to study the relative efficacy of herbicides and cultural practice on weed control in onion as well as to study its effect on growth and yield of onion. The experiment was laidout in randomized block design with nine treatment replicated thrice. In the present experimentation, chemical weed management practices i.e. herbicides used under treatment were Pendimethalin 24% + Oxyfluorfen 4% ZE @480+82 g a.i./ha (T1), Pendimethalin 24% + Oxyfluorfen 4% ZE @541.80+92.56 g a.i./ha (T2), Pendimethalin 24% + Oxyfluorfen 4% ZE @600+102.5 g a.i./ha (T3), Pendimethalin 24% + Oxyfluorfen 4% ZE @1083.60+185.12 g a.i./ha (T4) are the herbicide with combine (pre-mix) formulation with different concentration of active ingredient and other treatments were Pendimethalin 38.7% CS @ 677.25 g a.i./ha (T5), Oxyfluorfen 23.5% EC@ 200 g a.i./ha (T6), Quizalofop ethyl 5% EC@ 50 g a.i./ha (T7), 2 HW 25 & 45 DAT (T8) and weedy check (T9). All the recommended agronomic practices were followed for raising the crop. The soil of experimental field characterized as clayey in texture, having slightly alkaline pH (7.7), moderate organic carbon status (0.41%), low nitrogen content (197.21 kg ha-1), medium available phosphorus content (18.76 kg ha-1), high potassium status (366.49 kg ha-1). Onion (Variety-Akola safed) was transplanted on 14th December 2018 at 20 x 10 cm spacing with 100:50:50 kg ha-1 NPK. The crop was harvested on 9th April 2019. Weed species recorded in experimental field were Stromatium dhatura, Parthenium hysterophorus, Euphorbia hirta L., Commelina benghalensis, Alternanathera triandra., Digera arvensis Forst., Tridax procumbens L., Euphorbia geniculata Orteg., Argemone mexicana L., Xanthium strumarium L., Chenopodium album L., Phyllanthus niruri L., Portulaca oleracea L., Lagasca mollis, Acalypha indica among the dicot weeds and among monocot the dominant weeds were Cyprus rotundus, Cynodon dactylon, Eleusin indica L. and Dactyloctenium aegyptium L. Weedy condition throughout the crop growth period caused 40 to 80 % reduction in bulb yield of onion. Among the herbicidal treatments, Pendimethalin 24% + Oxyfluorfen 4% ZE @600+102.5 g a.i./ha was found to be effective in controlling weeds across the crop growth period. Among the various treatments under study weed free recorded significantly higher values of major parameters whereas, in herbicidal treatments, the maximum growth and yield attributes were recorded with treatment Pendimethalin 24% + Oxyfluorfen 4% ZE @600+102.5 g a.i./ha which were at par with Pendimethalin 24% + Oxyfluorfen 4% ZE @1083.60+185.12 g a.i./ha. The same treatment recorded better weed control efficiency and lowest weed index. The lowest weed density of both monocot as well as dicot was observed in treatment with spraying of pendimethalin 24% + oxyfluorfen 4% ZE @600+102.5 g a.i./ha as pre emergence which ultimately result in lowest weed dry matter accumulation , higher weed control efficiency and lower weed index. The nutrients uptake by weeds was more in weedy condition. However, total nutrient uptake by crop was observed maximum with application of Quizalofop ethyl 5% EC@ 50 g a.i./ha. Treatment with application of pendimethalin 24% + oxyfluorfen 4% ZE @600+102.5 g a.i./ha PE was recorded with highest onion bulb yield production and hence these treatment was found most economical with maximum value of GMR (188290 Rs ha-1) and B: C ratio (3.04).

Description

Description: A field investigation was carried out at AICRP on weed management field of Agronomy Department, Dr. Panjabrao Deshmukh Krishi Vidyapeeth, Akola during the Rabi season of 2018. The present experiment was laid out in Randomized Block Design (RBD) with nine treatments replicated three times, allocation of treatment at each plot in each replication was done by randomization. In the present experiment a serious attempt has been made to study the effect of combinations of different newly released herbicides having new mode of action on weed flora as well as growth and yield of onion for better crop productivity and profitability.

Citation

THAKARE, AKANKSHA MANOJ. (2020). Efficacy of pre and post emergence herbicides against weed flora in onion. Department of Agronomy, Dr. Panjabrao Deshmukh Krishi Vidyapeeth, Akola. M. Sc. 2020. Print. xvi, 144p. (Unpublished).