Field surveys of soybean aphid, Aphis glycines Matsumura, and its natural enemies, as well as natural enemy exclosure experiments, were conducted during 2003 and 2004 in soybean fields near Langfang, China. In 2003, aphid density increased six-fold during 12 d in July from 66+/-12 per 10 plants to a seasonal peak of 401+/-79 per 10 plants. Aphid density remained high for another 10 d and declin...

In addition to obviating the use of synthetic agrochemicals and emphasizing farming in accordance with agro-ecological guidelines, organic farming acknowledges the integrity of plants as an essential element of its natural approaches to crop production. For cultivated plants, integrity refers to their inherent nature, wholeness, completeness, species-specific characteristics, and their being in...

Dr. Abbasali Sanadgol is an associate professor in rangelands and forests research institute, IRAN, He is retired now. He earned his undergraduate and master degrees in natural resources and range management in 1976 and 1992 respectively from natural resources faculty of Tehran University and worked as a natural resources and range management researcher for 29 years at education and research ag...

background and objectives: there is a growing trend towards investigating natural products as sources of compounds with biological effects and many researches have been carried out in order to find effective medications against many diseases. cancer is no exception and studies focusing on evaluating the effects of different materials on dna, give valuable information in cancer researches and ca...

calendula (calendula officinalis) is relatively cold tolerant plant, but in some years plant seriously injured due to harsh winter. in order to evaluate freezing tolerance of calendula an experiment was carried out at college of agriculture, ferdowsi university of mashhadin a factorial-completely randomized design with three replications and plants of two sowing dates (summer and autumn) were e...

First, a geographical barrier must be overcome, which often occurs as a mountain range, ocean, or similar physical barrier to movement of seeds and other reproductive plant parts. Plants that overcome geographical barriers are known as alien plants or alien species. Alien plants are non-native plants and alien species are nonnative species. Therefore, non-native plants are those that occur outs...

BACKGROUND AND AIMS Experimental crosses between the diploid woodland strawberry (Fragaria vesca L.) and the octoploid garden strawberry (F. × ananassa Duch.) can lead to the formation of viable hybrids. However, the extent of such hybrid formation under natural conditions is unknown, but is of fundamental interest and importance in the light of the potential future cultivation of transgenic st...

We investigated whether development of resistance to a Bt crop in the presence of a natural enemy would be slower than without the natural enemy and whether biological control, in conjunction with a Bt crop, could effectively suppress the pest population. Additionally, we investigated whether insecticide-sprayed refuges of non-Bt crops would delay or accelerate resistance to the Bt crop. We use...

Land plants are a natural group, and Charophyte algae are the closest lineages of land plants and have six morphologically diverged groups. The conjugating green algae (Zygnematales) are now suggested to be the extant sister group to land plants, providing the novel understanding for character evolution and early multicellular innovations in land plants. We review recent molecular phylogenetic ...