نوع مقاله : علمی- ترویجی
نویسندگان
1 عضو هیئت علمی مرکز تحقیقات کشاورزی خراسان رضوی، مشهد
2 عضو هیئت علمی موسسه تحقیقات چغندرقند، کرج. ایران
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسندگان [English]
To study the critical period of weeds competition with sugar beet and to determine the duration that the crop can tolerate the weeds, a field experiment was carried out at Khorasan Agricultural Research Center, in Mashhad, during 1994-96. The experiment conducted in RCB design with 12 treatments and four replications. The treatments were weed control throughout the growth season (as a check), till and after 2, 4, 6, 8 and IO weeks from crop emergence, and no weed control during the whole growing season. The results showed that the weeds should be removed until four weeks after emergence to avoid sugar beet yield loss. The results also indicated that sugar beet can tolerate annual weeds in the first 6 weeks after the crop emergence. Sugar content was increased by weed competition, presumably due to reduction in sugar beet root weight. However, highest white sugar yield was obtained from weed free treatment. Annual weeds such as fat-hen, common amaranth. black nightshade and bamyardgrass with a pop~lation of 40 plants per m2 caused up to 71 % yield reduction in no weed control treatment. In general, under conditions considered critical period of weed competition in sugar beet was between four and six weeks after emergence.
کلیدواژهها [English]
)