Page 1 Page 2 Page 3 Page 4 Page 5 Page 6 Page 7 Page 8 Page 9 Page 10 Page 11 Page 12 Page 13 Page 14 Page 15 Page 16 Page 17 Page 18 Page 19 Page 20 Page 21 Page 22 Page 23 Page 24 Page 25 Page 26 Page 27 Page 28 Page 29 Page 30 Page 31 Page 32 Page 33 Page 34 Page 35 Page 36 Page 37 Page 38 Page 39 Page 40 Page 41 Page 42 Page 43 Page 44 Page 45 Page 46 Page 47 Page 48 Page 49 Page 50 Page 51 Page 52 Page 53 Page 54 Page 55 Page 56 Page 57 Page 58 Page 59 Page 60 Page 61 Page 62 Page 63 Page 64 Page 65 Page 66 Page 67 Page 68 Page 69 Page 70 Page 71 Page 72 Page 73 Page 74 Page 75 Page 7623 IREC Farmers' Newsletter No. 195 ­ – Rice R&D 2016 3.85 8.78 8.94 9.07 1.39 2.61 4.99 4.99 4.99 0 1 2 3 4 5 6 7 8 9 10 Ordram f/b Londax Ordram + Taipan Ordram f/b Exp A Ordram f/b BAS 800 LSD (p=0.05) Cumulative weed control (0-5 scale) Grain yield t/ha Widespread experience with the rapid development of resistance to Londax® has taught us to ensure that wherever possible herbicides with multiple modes of action are used on the same cohort of weeds each season. Accordingly, we search for new herbicides that offer alternative modes of action to the products already in commercial use. As part of this search an annual experiment is conducted that compares existing and new herbicides (i.e. with registrations pending) in programs for water seeded rice. Nineteen treatments were compared in the 2015–16 season to enable agronomists and rice growers to observe how existing and pending treatments may fit into recommended herbicide programs. Treatments were applied into floodwater in bunded plots and replicated four times. 2015–16 results Rainfall occurred during levee construction at the experimental site, enabling barnyard grass to germinate prior to inundation of the plots. Severe competition occurred from early germinating barnyard grass that survived many of the treatments (e.g. Magister® and Saturn®). Ordram® proved effective against this advanced barnyard grass, removing competition early. Barnstorm® was only marginally effective against barnyard grass due to high plant density and late removal. Rice injury levels were generally low. The highest injury ratings were for Magister plus Taipan® and Ordram followed by BAS 800. Londax was ineffective against dirty Dora, arrowhead and water plantain. Starfruit remained susceptible to Londax. Taipan applied at sowing was effective against dirty Dora, arrowhead, water plantain and starfruit. BAS 800 at 2-leaf stage (rice) also proved effective against these four weeds. Gator® at 2-leaf stage (rice) controlled arrowhead and water plantain, but was less effective than BAS 800 against dirty Dora and starfruit. A product identified as Experimental A controlled all four aquatic weed species at both application timings (rice 4-leaf and 1–2 tillers). A product identified as Experimental B controlled all four aquatic weed species when applied at sowing. The highest grain yield was obtained in treatments using Ordram followed by BAS 800, Ordram followed by experimental A and Ordram plus Taipan (-/+ Basagran M60). These results were encouraging as they demonstrated both the effectiveness of the commercial standard of Ordram plus Taipan but also that of two new treatments under development, BAS 800 (HRAC Group G) and Experimental A (HRAC Group undisclosed). Both herbicides have been evaluated for multiple seasons in Australian rice. New treatments will offer rotational options of alternate modes of action to existing herbicides, thus broadening weed management options and bolstering the sustainability of rice weed management practices. RIRDC Project PRJ-009923 Weed control in Australian rice More information Malcolm Taylor T: 03 5872 2892 M: 0427 722 892 E: [email protected] l Figure 1. Cumulative weed control ratings (0–5 scale) for barnyard grass, dirty Dora, starfruit, arrowhead and water plantain and grain yields (t/ha) for existing and new herbicides in water seeded Sherpa rice, Cobram, Victoria, 2015–16 season. n Cumulative weed control (0-5 scale) n Grain yield t/ha l Ordram plus Taipan controlled dirty Dora, starfruit, arrowhead and water plantain. Two new products (still at the experimental stage) provided similar results. l Ordram followed by Londax failed to effectively control dirty Dora, arrowhead and water plantain. Table 1. Tradename and active ingredients of rice herbicides Tradename Active ingredient Londax bensulfuron methyl Ordram molinate Magister clomazone Saturn thiobencarb Barnstorm cyhalofop-butyl Gator carfentrazone ethyl BAS 800 saflufenacil Basagran M60 bentazon plus MCPA Experimental A undisclosed Experimental B undisclosed Ordram f/b Londax Ordram + Taipan Ordram f/b Exp A Ordram f/b BAS 800 LSD (p=0.05)