Study on effect of weed management practices on weed dynamics and productivity of kharif maize

Abstract

during two consecutive kharif (rainy) seasons of 2018 and 2019. The experiment was laid in a randomized block design different weed control methods viz., pre emergence (PE) atrazine at 0.5 kg a.i. ha -1 fb hand weeding (HW) at 20 DAS, PE atrazine at 0.5 kg a.i. ha -1 fb power weeder (PW) at 20 DAS, PE atrazine at 0.5 kg a.i. ha -1 + pendimethalin at 1 kg a.i. ha -1 (Tank mix), PE atrazine at 0.5 kg a.i. ha -1 + pendimethalin at 1 kg a.i. ha -1 fb HW at 20 DAS, early post emergence (EPOE) topramezone at 25.2 g a.i. ha -1 , PE atrazine at 0.5 kg a.i. ha -1 fb EPOE topramezone at 25.2 g a.i. ha -1 , EPOE tembotrione at 122 g a.i. ha -1 , PE atrazine 0.5 kg a.i. ha -1 fb EPOE tembotrione 122 g a.i. ha -1 , hand weeding twice at 20 and 40 DAS and control (weedy check) with 3 replications for each treatment. The results revealed that the experimental field was infested with all categories of weeds including grasses, broad-leaved weeds and sedges. Among them the most predominant weeds were Cynodon dactylon, Dactyloctenium aegyptium, Echinochloa colona, Amaranthus viridis, Digera arvensis and Trianthema portulacastrum. Among the chemical weed control methods PE atrazine at 0.5 kg a.i. ha -1 fb EPOE topramezone at 25.2 g a.i. ha -1 and PE atrazine 0.5 kg a.i. ha -1 fb EPOE tembotrione 122 g a.i. ha -1 recorded significantly lower weed density as well as weed dry weight of BLW, grasses, sedges and total weed at 90 DAS during 2018 and 2019, respectively. As a consequence of effective weed control, the above treatments recorded significantly higher weed control efficiency (WCE) and lower weed index (WI) during 2018 and 2019, at 90 DAS. These treatments were statistically comparable with hand weeding twice at 20 and 45 DAS. Uncontrolled weed growth in control (weedy check) recorded higher weed density and weed dry matter in maize crop during both the years of experimentation.

Impact of weed management practices on weeds and okra crop

“…Significantly highest dry weight of weeds (46.1 g/m 2 and 1047.1 kg/ha) was recorded with weedy check because weeds were allow to grow in plot throughout the cropgrowth period, ultimately increased the population of weeds and dry weight of weeds under this treatment. Our results confirm the findings of Mathukia et al (2018), Patel et al (2020) and Dhivya et al (2021).…”

“…Hand-weeding at 20 and 40 DAS (14.1%) and application of pendimethalin 1.0 kg/ha (PE) fb quizalofop-ethyl 0.04 kg/ha at 30 DAS (16.1%) was also found more effective in controlling the weeds in the okra crop as next 2 superior treatments after weed-free cheek. These findings are in line with those of Patel et al (2004), Shivalingappa et al (2014), andDhivya et al (2021).…”

“…Efficacy of the pre-emergence herbicides alone failed to contribute much in weed control because on fact that, application of herbicide inhibited the germination and emergence of weeds during initial growth stage of crop only but at later stages, these herbicides dissipated and deactivated in the soil and next flush of weeds appeared in such plots. Effectiveness of various herbicides against different weed species in okra crop have been reported by many workers including Sharma and Patel (2011), Mathukia et al (2018) and Dhivya et al (2021).…”

“…The crop-weed competition remains maximum during the early growth stage which slows initial growth rate of the crop and consequently causes poor competitive ability. The uncontrolled weeds exert severe competition for nutrients, water and light, resulting in reduced pod yield of okra by 73-75% (Imoloame and Muinat, 2018), 78-85% (Sah et al, 2018) and 61.99% (Dhivya et al, 2021), depending on the type of weed flora, their intensity and stages. Continuous monitoring and refinement in management strategies is essential for alleviating adverse effects of weeds on agricultural productivity and environmental health (Rao and Nagmani, 2013).…”

Weediness of corn for grain crops by cultivation in the stationary crop rotation and permanent crops in the Eastern Forest Steppe of Ukraine

“…et Schult., Brachiaria reptans L., Amaranthus Ó ²í䳿 òèïîâèìè áóð'ÿíàìè ó ïîñ³âàõ êóêóðóäçè º Cynodon dactylon (L.) Pers., Dactyloctenium aegyptium (L.) Willd., Echinochloa colona (L.) Link., Amaranthus viridis L., Digera arvensis Forsk. òà Trianthema portulacastrum L. [10][11].…”