The lowest ET value was calculated for 2,4-D amine and the highest for florasulam + flumetsulam. It is therefore concluded that wild radish in wheat should be controlled by herbicides if the density is between and plants m-2. | Turk J Agric For 29 (2005) 173-177 © TÜB‹TAK Economic Threshold for Wild Radish (Raphanus raphanistrum L.) Control in Wheat Fields Özhan BOZ* Adnan Menderes University, Faculty of Agriculture, Plant Protection Department, 09970 Ayd›n - TURKEY Received: Abstract: Field experiments were conducted in Ayd›n province in 1998 and 1999 to determine the economic threshold (ET) using florasulam + flumetsulam, 2,4-D amine, thifensulfuron methyl + tribenuron-methyl, and tribenuron-methyl for wild radish (Raphanus raphanistrum L.) in wheat. The effect of wild radish density (1, 2, 4, 8 and 16 plants m-2) on wheat yield was investigated using an adjacent plot design with 4 fields. For each weed density, yield was compared with that in the adjacent weed-free control plot. The grain yield in wild radish-free wheat was 4079 kg ha-1 in 1998, 4369 kg ha-1 in 1999 and 4224 kg ha-1 averaged over the 2 years. Results over the 2 years showed that the ET of wild radish in wheat varied from to plants m-2 depending on the herbicide applied. The lowest ET value was calculated for 2,4-D amine and the highest for florasulam + flumetsulam. It is therefore concluded that wild radish in wheat should be controlled by herbicides if the density is between and plants m-2. Below this level, a certain amount of damage and the presence of weeds can be tolerated, thus minimizing herbicide use. Key Words: Wild radish (Raphanus raphanistrum), economic threshold, wheat (Triticum aestivum), florasulam + flumetsulam, 2,4D amine, thifensulfuron methyl + tribenuron-methyl, tribenuron-methyl Bu¤day Alan›nda Yabani Turpun (Raphanus raphanistrum L.) Ekonomik Zarar Efli¤i Özet: Çal›flma, florasulam + flumetsulam, 2,4-D amine, thifensulfuron methyl + tribenuron-methyl, ve tribenuron-methyl kullan›larak yabani turpun bu¤daydaki ekonomik zarar efli¤ini saptamak amac›yla 1998 ve 1999 y›llar›nda Ayd›n’da gerçeklefltirilmifltir. Bu amaçla farkl› yabanc› ot yo¤unlu¤unun (1, 2, 4, 8 ve 16 bitki .