Browsing by Author "Rotaru, Vladimir"

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    CREŞTEREA PLANTELOR DE SOIA ŞI MODIFICĂRILE CONŢINUTULUI DE AMIDON INDUSE DE APLICAREA FOSFORULUI ŞI FIERULUI ÎN CONDIŢII SUBOPTIMALE DE UMIDITATE
    (CEP USM, 2011) Rotaru, Vladimir; Bîrsan, Ana; Tverdohleb, Anatolie
    Soybean (Glycine max. L.,) is a tropical legume and it is susceptible to environmental stresses. Dry matter (DM) production and starch contents in plant parts of two soybean cultivars were determined during reproductive stage inrelation to phosphorus (P) and iron (Fe) supply under water stress conditions. Soybean plants were represented by Zodiac and Licurici cultivars differing in potential of productivity. Plants were grown in a soil cultural with either a non-limiting or low P supply and harvested at pod setting stage development. The Licurici cultivar produced a higher DM than the Zodiac in well-watered conditions. Leaves growth and expansion were sensitive to both abiotic factors than roots. No difference between cultivars was detected on the total DM in treatments with adequate P supply (100 mg P kg soil) under water stress. The starch concentration in the plant tissues exhibited differences between both cultivars with Licurici generally having lower levels in roots. P deficiency increased starch contents in leaves irrespective of water regime. We concluded that adequate P and Fe supply decreased the carbohydrates concentration in nodules and support a vigorous roots system growth.
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    EFECTUL TRATĂRII SEMINŢELOR DE SOIA CU SUBSTANŢE DE NATURĂ HUMICĂ ŞI FENOLICĂ ASUPRA CREŞTERII ŞI DEZVOLTĂRII SISTEMULUI RADICULAR
    (CEP USM, 2012) Bîrsan, Ana; Rotaru, Vladimir; Scutaru, Iurii; Cucer, Ana; Bîrsan, Dăgălina
    The radicular system has the ability to react to unfavorable environmental changes via morphological, structural and physiological modifications, feature defined as root plasticity. Changes in root plasticity, in response to environmental conditions were demonstrated in various agricultural crops. In order to highlight the effect of the humic and phenolic compounds on plants the reaction of different soybean genotypes has been studied. The radicular system parameters: the length of main root, the root volume, the root biomass, the number and biomass of the nodules formed by nitric fixing bacteria have been investigated. The analyses have been done at the stage of soybeen blossoming. The plans have been grown in optimal condition of cultivation. The chemical seed treatment has caused the reduction of fresh rootsbiomass of genotypes sensitive to drought (Licurici and Horboveanca), fa vouring the accumulation of biomass of bacterial nodules in the Licurici genotype and raising the number of nitric fixing formations in the Horboveanca genotype. Small concentrations of substances have increased the volume of radicular system and the root biomass, while higher concentrations did not affect the radicular system development in drought tolerant genotypes (Zodiac and S4-04). Administrating a combination of LG 1.0% and 0.05%OC substances favored the development of the soybean symbiotic system.
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    INFLUENŢA NUTRIŢIEI CU FOSFOR ŞI FIER ASUPRA DEZVOLTĂRII NODOZITĂŢILOR LA PLANTELE DE SOIA ÎN CONDIŢII DE SECETĂ TEMPORARĂ
    (Tipografia "Reclama", 2013-09-12) Rotaru, Vladimir; Bîrsan, Ana
    Low-phosphorus availability and water stress are main environmental constraints of soybean growth and nodulation. A pot experiment was carried out to investigate the effect of phosphorus (P) and iron (Fe) application on nodulation in water-stressed soybean plants. Phosphorus (KH2PO4) and Fe (FE-EDTA) were applied in soil in dose 100 mg per kg of soil and 5 mg respectively. One set of plants was subjected to suboptimal water regime (35% WHC) at flowering stage for 12 days. Another set served as control was grown at normal moisture of soil (70 % WHC). Nodulation and plant growth were significantly decreased by low nutrient supply and drought. Combined effect of drought and P deficiency decreased most the growth of nodules and plants of both cultivars Zodiac and Licurici. Supplemental P nutrition alone or in combination with Fe significantly increased nodules biomass irrespective of soil water regime. However, its effect was more pronounced on cultivar of Licurici. It is concluded that harmful effects of water deficits can be attenuated by adequate nutrition with P and Fe of soybean plants.