abstract field bindweed is an important perinial weed of agricultural crops word-wide. there are plant pathogen fungus which could cause necrotic spots on the leaves and stems of convolvulus arvensis under natural coditions. in order to evaluate the effects of weed growth stage and length of dew period on disease development causes by aletrnaria alternata and fusarium sp. two expriments were pe...

in order to study of some effective phenologic and physiologic characteristics on 18 sunflower hybrids yield under optimum conditions, an experiment was conducted as randomized complete block design with three replications at the research field of seed and plant improvement institute-karaj in 2006-2007. the result indicated that the hybrids showed significant difference in phonologic characteri...

determination of chlorophyll content and chlorophyll fluorescence has the potential needed to analyze the efficiency of photosynthesis in plants against environmental stresses, especially salinity, and its simplicity facilitates stress evaluation. in order to study the response of different photosynthetic characters to salinity stress at different sugar beet growth stages, two separate experime...

The critical period for weed control (CPWC) is the period in the crop growth cycle during which weeds must be controlled to prevent unacceptable yield losses. Field studies were conducted in 2005 and 2006 in the University of Birjand at the south east of Iran to determine CPWC of corn using a randomized complete block design with 14 treatments and three replications. The treatments consisted of...

background and objectives. integrated weed management approaches can help to decline costs weed control and improve its condition. critical period of weed control (cpwc) is defined as the best time for weeding. if cpwc is recognized we can accurately use herbicides and prevent environmental pollutions. beginning and duration of cpwc despond on some agents such as crop and weed traits, environme...

Class 1 KNOTTED1-LIKE HOMEOBOX (KNOXI) genes encode transcription factors that are expressed in the shoot apical meristem (SAM) and are essential for SAM maintenance. In some species with compound leaves, including tomato (Solanum lycopersicum), KNOXI genes are also expressed during leaf development and affect leaf morphology. To dissect the role of KNOXI proteins in leaf patterning, we express...

they are simply a set of features, that when combined, best discriminate 600 one biological process (e.g., evolutionary history) from others (e.g., developmental 601 stage). The shapes that arise through this combination of features are latent only 602 because they are not immediately recognizable when each of their component 603 landmarks is considered alone; the effects of genetics and develo...

Growth pattern dynamics lie at the heart of morphogenesis. Here, we investigate the growth of plant leaves. We compute the conformal transformation that maps the contour of a leaf at a given stage onto the contour of the same leaf at a later stage. Based on the mapping we predict the local displacement field in the leaf blade and find it to agree with the experimentally measured displacement fi...

Chloroplasts are the central nodes of the metabolic network in leaf cells of higher plants, and the conversion of proplastids into chloroplasts is tightly coupled to leaf development. During early leaf development, the structure and function of the chloroplasts differ greatly from those in a mature leaf, suggesting the existence of a stage-specific mechanism regulating chloroplast development d...