_____________________________________________________________________________________________________ *Corresponding author: E-mail: mou.mousumi98@gmail.com; Current Journal of Applied Science and Technology 39(2): 23-32, 2020; Article no.CJAST.54843 ISSN: 2457-1024 (Past name: British Journal of Applied Science & Technology, Past ISSN: 2231-0843, NLM ID: 101664541) Efficacy of Herbicides against Broad-spectrum Weed Floras and Their Effect on Non-target Soil Micro-organisms and Productivity in Sugarcane (Saccharum sp.) Rajib Kundu 1 , Mousumi Mondal 1* , Sourav Garai 1 , Ratneswar Poddar 1 and Sibajee Banerjee 1 1 Department of Agronomy, Bidhan Chandra Krishi Viswavidyalaya, Mohanpur - 741252, India. Authors’ contributions This work was carried out in collaboration among all authors. Authors RK and SB designed the study. Authors SG and RP performed the statistical analysis and wrote the protocol. Author MM wrote the first draft of the manuscript. Authors SG and MM managed the analyses of the study. Author RK managed the literature searches. All authors read and approved the final manuscript. Article Information DOI: 10.9734/CJAST/2020/v39i230493 Editor(s): (1) Dr. Osama A. M. Ali, Assistant Professor, Department of Crop Science, Faculty of Agriculture, Menoufia University, Egypt. Reviewers: (1) Guilherme Vieira Pimentel, Federal University of Lavras, Brazil. (2) Jayath P. Kirthisinghe, University of Peradeniya, Sri Lanka. Complete Peer review History: http://www.sdiarticle4.com/review-history/54843 Received 12 December 2019 Accepted 18 February 2020 Published 25 February 2020 ABSTRACT Weeds pose a major challenge at the initial stages of sugarcane and when uncontrolled cause high yield losses. This study was undertaken to define a better and cost-effective weed management strategy. Field experiment was carried out at District Seed Farm (C Unit) of Bidhan Chandra Krishi Viswavidyalaya, West Bengal, India (22°97'N latitude and 88°43'E longitude with the 9.75 meters above the mean sea level) under natural weed infestations in sugarcane in 2017–2018 and 2018- 19. The objective was to evaluate the efficacy of herbicides on weed floras, non-target soil organisms and productivity of sugarcane (cv. CoS 98231). The pattern of nutrient uptake by weed species was also itemized. The treatments were comprised of four doses of Atrazine 50% WP (1.0, 2.0, 3.0 and 4.0 kg a.i. ha -1 ), Trifloxysulfuron-Na (10% OD) 30 g a.i. ha -1 and weedy check within a randomized complete block design, replicated four times. The results revealed that among the tested herbicides, the utmost dose of Atrazine was most efficient against grassy as well as broadleaf weeds. The higher weed control efficiency (> 60%) and cane yield (85.41 t ha -1 ) were recorded from Original Research Article