Raghad Soufan<\/strong>
\nGeneral Commission for Scientific Agricultural Research-<\/strong>
\nAdmin. of Plant Protection Research<\/strong>
\nDamascus University, Faculty of Agriculture<\/strong>
\n\u00a02009<\/strong><\/p>\n

Abstract<\/strong><\/p>\n

Maize (Zea mays<\/em> L.) is one of the important agronomic summer crops. Many annual weeds can infest and compete this crop like: Amaranthus retroflexus<\/em> L., Chenopodium album<\/em> L., Portulaca oleracea<\/em> L., Xanthium strumarium<\/em> L. and Datura stramonium<\/em> L. in addition to some\u00a0 perennial weeds like: Cyperus rotundus<\/em> L.,\u00a0 Convolvulus arvensis<\/em> L. and Sorghum halepense<\/em> L.. These species differ in their competeition ability the maize and in their effects on plant height at flowering stage, and seed yield. The results revealed that maize production was affected by S. halepense<\/em>, and this effect was proportional to weed’s density. Also, C. rotundus<\/em> has negatively affected maize.
\nThe results determined the economic threshold level of S. halepense <\/em>in maize crop was (22-6) plant\/m\u00b2, and 20 plant\/ m\u00b2 for C. rotundus<\/em> for two growing seasons (2006 and 2007).
\nYield losses does not explain by the traditional competition between maize and weeds, but it certainly occurred by the inhibitory effects of allelochemicals.
\nWeeds aqueous extract of C. rotundus<\/em>, C. arvensis<\/em> and S. halepense<\/em> at the concentration of 20% and 80% exhibited inhibition of germination percentage (%), plant height and fresh and dry weight of maize.
\nThe variable effects have related to the plant parts, extract concentration and different isolation methods.
\nThe results showed that weeds affect on the maize growth by producing\u00a0 inhibitors and activators chemical substances which is called (allelochemicals), and not only by\u00a0 competing the crops for place, soil, moisture, light and nutrients.<\/p>\n","protected":false},"excerpt":{"rendered":"

Raghad Soufan General Commission for Scientific Agricultural Research- Admin. of Plant Protection Research Damascus University, Faculty of Agriculture \u00a02009 Abstract Maize (Zea mays L.) is one of the important agronomic summer crops. Many annual weeds can infest and compete this crop like: Amaranthus retroflexus L., Chenopodium album L., Portulaca oleracea L., Xanthium strumarium L. and … Continue reading Allelopathic Effects of Some Weeds on Growth and Yield of Maize<\/span> →<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"parent":704,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-429","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/gcsar.gov.sy\/en\/wp-json\/wp\/v2\/pages\/429","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/gcsar.gov.sy\/en\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/gcsar.gov.sy\/en\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/gcsar.gov.sy\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/gcsar.gov.sy\/en\/wp-json\/wp\/v2\/comments?post=429"}],"version-history":[{"count":0,"href":"https:\/\/gcsar.gov.sy\/en\/wp-json\/wp\/v2\/pages\/429\/revisions"}],"up":[{"embeddable":true,"href":"https:\/\/gcsar.gov.sy\/en\/wp-json\/wp\/v2\/pages\/704"}],"wp:attachment":[{"href":"https:\/\/gcsar.gov.sy\/en\/wp-json\/wp\/v2\/media?parent=429"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}