Short Communication Bangladesh Agron. J. 2017, 20 (1): 109-111 EFFECT OF DIFFERENT DOSES OF HERBICIDE (METRO 70WG) ON WEED CONTROL IN MAIZE FIELD Santosh Kumar Paul1**, Shamima Akther2, Towhidi Almas Mujahidi3, Subarna Kundu4 1= Agronomy Division, Bangladesh Agricultural Research Institute, Joydebpur, Gazipur-1701, Bangladesh. 2= Agronomy Division, Bangladesh Agricultural Research Institute, Joydebpur, Gazipur-1701, Bangladesh. 3= Plant Breeding Division, Bangladesh Agricultural Research Institute, Joydebpur, Gazipur-1701, Bangladesh. 4= Planning and Evaluation Division, Bangladesh Agricultural Research Institute, Joydebpur, Gazipur-1701, Bangladesh. Corresponding Author: santosh87dhaka@gmail.com Key words: Herbicide, Metro 70WG, Weeds, Maize Maize is the third important cereal crop in Bangladesh. Maize is valued for its diversified use. Now a days it has been considered as crop for food security. It is can be directly consumed as a nutritious food. Grains and plant are processed into other agro-industrial by-products. Increased maize production can play a vital role in alleviating food shortage in Bangladesh (Paul et al., 2015). The stalk leaves of maize plant and shelled cobs can also be utilized in reducing existing fodder shortage. Though maize production is very high, but due to lack of proper management yield is decreasing compared to other developed countries. Weed infestation is one of them, which decreased the yield (Turk et al., 2002). Many herbicide are used to control the weeds in maize field. A field experiment was conducted at Joydebpur, Gazipur and Regional Agricultural Research Station, Jamalpur of Bangladesh Agricultural Research Institute during the Kharif-I season of 2012 to find out the optimum dose of herbicide Metro 70WG for controlling weeds in maize field. Six treatments viz. T1 = Metro 70WG @ 250 gm ha-1 at sowing, T2 = Metro 70WG @ 500 gm ha-1 at sowing, T3 = Metro 70WG @ 750 gm ha-1 at sowing, T4 = weed free, T5 = Two hand weedings at 20 Days after planting (DAP) and 35 DAP and T6 = Control (untreated) were used. Seeds were sown on 21 March 2012 in Joydebpur and 5 March 2012 in Jamalpur at 60 cm x 20 cm spacing. Crop variety used in the experiment was BARI Hybrid Maize-7. The crop was fertilized with 250-55-110-40 kg NPKS/ha. Thirty percent of N along with full amount of other fertilizers was applied as basal during final land preparation. Remaining 70% N was applied as top dressed at 8-leaf stage. Irrigation and other intercultural operations were done as and when required. The crop was harvested on 4th and 19th July, 2012 at Jamalpur and Joydebpur, respectively. Collected data were analyzed statistically and mean separation was done by LSD test. The Relative Density (RD) and weed control Efficiency (WEC) were calculated by the following formula. Relative Density (RD) = 100 weedsof no. Total species weedspecific of No  Weed Control Efficiency (WEC) = 100 plot control of Dry wt. plot specific of Dry wt.-plot control of Dry wt.  110 Paul et al. The common weeds in maize field were Jussiaea repens (Helencha), Cyperus rotundus (Mutha), Echinochloa crusgalli (Shama) and Cynodon dactylon (Durba). Herbicide reduced weed infestation in maize but none of the herbicidal dose can exceed the weed control efficiency by hand weeding plot in both the locations. At 40 DAE, among the different herbicidal treatments maximum weed control efficiency (WCE: 45.32% at Joydebpur and 20.49% at Jamalpur) was found in treatment T2 (Metro 70WG @ 500 gm ha-1) at Jamalpur and in treatment T3 (Metro 70WG @ 500 gm ha-1) at Joydebpur, respectively. Among the weed species, Echinochola crusgalli (Shama) was found dominant (16-40 weeds/m2) at 20 DAE and 37-52 weeds/m2 at 40 DAE. At Jamalpur, weeds in the maize field comprise helencha, mutha, durba, kalimaina, biskathali, fulka and others. Dry weight of weeds/ m2 varied at different dose of Metro 70WG (Table 1). Maximum dry weight of weeds was recorded in control plots in both the locations. Weed control efficiency (WCE) was highest in hand weeding plots at both the locations. Paul et al., 2014 also observed higher WCE under two hand weddings at 20 and 40 DAS. Although maximum WCE was found in hand weeded plot but hand weeding is laborious, time consuming and expensive. Among the different herbicidal treatments T2 (Metro 70WG @ 500 gm ha-1 at sowing followed by irrigation) showed higher WCE at 20 DAE. The highest WCE (45.32%) was found in T3 (Metro 70WG @ 750 gm ha-1 at 40 DAE (Table 2). Table 1. Dry weight of weed and weed control efficiency in maize as affected by different doses of Metro 70WG over locations Treatments At 20 DAE At harvest Weed dry weight/m2 (g) WCE (%) Weed dry weight/m2 (g) WCE (%) T1 58.63 21.11 135.5 35.29 T2 40.30 45.74 107.2 48.82 T3 40.95 44.90 171.6 17.92 T4 - - - - T5 14.60 80.35 61.30 70.73 T6 74.32 - 209.4 - T1) Metro 70WG @ 250 gm/ha, T2) Metro 70WG @ 500 gm/ha, T3) Metro 70WG @ 750 gm/ha, T4) weed free, T5) Two hand weeding at 20 DAS and 35 DAS, T6) Control (Untreated) The maximum grain yield was found (9.44 t/ha) in T3 treatment (Metro 70WG @ 750 gm ha-1 at sowing followed by irrigation) closely followed by treatment T5 while lowest yield 8.19 t/ha was recorded in T6 treatment (control). The maximum gross return was obtained from treatment T4 which was at par with treatment T5. Similar trend was followed in case of gross margin but higher cost was involved in this treatment. As a result, BCR was higher inT4 which was closely followed by T5 (Table 2). 111 Effect of Different Doses of Herbicide on Weed Control in Maize Field Table 2. Grain yield, Cost and Benefit analysis of maize as influenced by different weed control management practice (across the location) Treatments Grain yield (t/ha) Gross return (Tk. ha-1) Total cost (Tk. ha-1) Gross margin (Tk. ha-1) BCR 1 2 3 4=1/2 T1 8.61 107,000 92,300 14,700 1.16 T2 8.82 111,000 92,500 18,500 1.20 T3 9.44 114,400 92,700 21,700 1.23 T4 8.61 116,600 92,900 23,700 1.26 T5 9.37 118,300 95,000 23,300 1.24 T6 8.19 95,000 89,900 5,100 1.06 LSD (0.05) 0.48 CV(%) 3.04 T1) Metro 70WG @ 250 gm/ha, T2) Metro 70WG @ 500 gm/ha, T3) Metro 70WG @ 750 gm/ha, T4) weed free, T5) Two hand weeding at 20 DAS and 35 DAS, T6) Control (Untreated) Among the weed species, Echinochola crusgalli (Shama) was found dominant in maize field. Hand weeding is the best option for controlling of weeds in maize field. But in labor scarce situation, herbicide Metro 70WG @ 750 gm ha-1 (at sowing followed by irrigation) can be suggested for reasonable yield of maize with reduced weed infestation. References Paul. S. K., S. Mazumder, T. A. Mujahidi, S. K. Roy and S. Kundu. 2015. Optimization of herbicide Teana 9 EC dose for controlling weeds in brinjal. Bangladesh Agron. J., 18(1): 113-119. Paul. S. K., T. A. Mujahidi, M. M. H. Khan, S. K. Roy and M. M. Rahman. 2014. Determination of weed infestation and optimum dose of herbicide (Teana 9 EC) to control weeds in wheat field. Bangladesh J.Weed Sci,. 4 & 5: 93-99. Turk, M. A. and Tawaha, A. R. M. (2002). Effects of sowing rates and weed control methods on winter wheat under Mediterranean environment. Pakistan J. Agron.16(4): 461-464.