Pérez-Amador¹ MC, V Muñoz Ocotero¹, F García Jiménez²

Phyton-International Journal of Experimental Botany, Vol.77, pp. 21-29, 2008, DOI:10.32604/phyton.2008.77.021

Abstract Leaves of Eupatorium morifolium Mill. were analyzed for phototoxic compounds, and the toxicity of their hexane extract was evaluated against Bacillus subtilis. The phototoxic compounds were analyzed by TLC. In the plate, pale blue spots indicated the presence of these compounds. This was confirmed by the UV extract spectrum and the antibacterial activity against Bacillus subtilis. The biological activity of the leaf extracts (hexane, ethyl acetate or methanol) was also studied. The antiinflammatory activity was determined using the edema test on mouse ears, and the bactericide activity was assayed against Bacillus subtilis and Escherichia coli. A strong anti-inflammatory activity was… More >

Ruiz¹ MA, AD Golberg^1,2, O Martínez²

Phyton-International Journal of Experimental Botany, Vol.77, pp. 7-20, 2008, DOI:10.32604/phyton.2008.77.007

Abstract Tetrachne dregei, Panicum coloratum and Eragrostis curvula are perennial forage C4 grasses, introduced from South Africa to the pampean semiarid region. This work was carried out to compare water stress tolerance; forage production and quality of T. dregei, P. coloratum and E. curvula. Studies were conducted under greenhouse and field conditions. In the greenhouse, watering was stopped after eighty one days of plant emergency in the water stress treatment. Water potential (ψ), stomatal resistance (SR) and shoot and root weights were evaluated. Under water stress, ψ diminished earlier and SR increases were higher in P. coloratum than in T. dregei… More >

Salazar-Sosa¹ E, H I Trejo-Escareño², C Vázquez-Vázquez¹, JD López-Martínez¹

Phyton-International Journal of Experimental Botany, Vol.76, pp. 169-185, 2007, DOI:10.32604/phyton.2007.76.169

Abstract This research was performed at the agricultural experimental center of the Facultad de Agricultura y Zootecnia, Universidad de Durango, Mexico. The main objetive was to determine the best amount of cow manure application and its effect on corn production, quality and nutrient uptake. Two factors were studied in this experiment that started in 2000. The results presented in this paper correspond to 2001. The factors were (1) crop, with the levels corn alone and corn-soybean, and (2) cow manure (with the levels: 0, 40, 80, 120, 160 Mgr/ha) and chemical fertilizer (100-150-0 kg/ha of N, P₂O₅ and K, respectively). The… More >

Brevedan RE, MN Fioretti, SS Baioni, IR Palomo, H Laborde

Phyton-International Journal of Experimental Botany, Vol.76, pp. 153-167, 2007, DOI:10.32604/phyton.2007.76.153

Abstract A long-term study was conducted at different locations of Southwestern Buenos Aires to evaluate the effects of N fertilization at different growth stages of soybean on yield, plant nitrogen concentration and seed protein and oil concentrations. Yields were increased in six out of ten trials, and the response was highest with N fertilization at the beginning of grain development (R5). Different nitrogen sources were applied at seeding which gave higher yields and increased seed protein content than the non-fertilized, non-nodulated treatment. Urea was the most effective N source. More >

Sánchez E¹, G Ávila-Quezada¹, AA Gardea¹, JM Ruiz², L Romero²

Phyton-International Journal of Experimental Botany, Vol.76, pp. 143-152, 2007, DOI:10.32604/phyton.2007.76.143

Abstract The objective of this work was to determine the effect of deficiency versus toxicity of N on biosynthesis of proline in fruits of green bean plants (Phaseolus vulgaris L. cv. Strike). Nitrogen was applied to the nutritive solution in the form of NH₄NO₃ at 1.5 mM (N1), 3.0 mM (N2), 6.0 mM (N3, optimal level), 12.0 mM (N4), 18.0 mM (N5), and 24.0 mM (N6). Nitrogen deficiency (N1 and N2) was characterized by having lower proline accumulation in pods and seeds, mainly because proline degradation was stimulated by the enzyme proline dehydrogenase. On the other hand, N toxicity (N4, N5,… More >

Merchán HD, EE Lutz, AE Morant

Phyton-International Journal of Experimental Botany, Vol.76, pp. 133-142, 2007, DOI:10.32604/phyton.2007.76.133

Abstract In mixed systems (beef and grain), double purpose wheat is an alternative to reduce competition between the winter cereals for grazing and wheat for harvesting. In order to optimize grass production and avoid grain yield decreases, it is necessary to use varieties with long vegetative periods and the last defoliation should be made before the apex changes to the reproductive developmental stage. A study was conducted in the experimental field of the Asociación de Cooperativas Argentinas in Cabildo (38º 36' S, 61º 58' W) to evaluate grass and grain production of the facultative wheat variety (Triticum aestivum L) Buck Charrúa,… More >

Bonvissuto GL¹, CA Busso²

Phyton-International Journal of Experimental Botany, Vol.76, pp. 119-131, 2007, DOI:10.32604/phyton.2007.76.119

Abstract The effects of various temperature combinations and water potentials were determined on the germination of Atriplex lampa Gill. ex Moquin, Larrea divaricata Cav., Leymus erianthus (Phil.) Dubcovsky, Stipa neaei Nees ex Steudel and Poa ligularis Nees ap. Steudel under controlled conditions. The tested hypothesis was that seed germination increases with increasing temperatures and water potentials in A. lampa, L. divaricata, L. erianthus, S. neaei and P. ligularis, and that time to reach 50% of total germination is greater at lower than higher water potentials. PEG 2000 was used to impose water stress conditions. In general, obtained results conducted to accept… More >

Premuzic¹ Z, HE Palmucci¹, J Tamborenea¹, M Nakama²

Phyton-International Journal of Experimental Botany, Vol.76, pp. 103-117, 2007, DOI:10.32604/phyton.2007.76.103

Abstract The addition of chlorine constitutes an economical disinfection method for closed, soil-less systems. Three quantities of sodium hypochlorite (0.55, 5.5 and 11 ppm) were applied to closed, soil-less greenhouse- grown lettuce (Lactuca sativa), to study the effect on its production (fresh weight and dry matter) and some commercial and nutritional quality factors (phytotoxicity, Vitamin C, nitrates). Sodium hypochlorite was weekly added within the nutrient solution, and the chemical properties (pH, EC and chlorides) of the recycled solution were measured. Damage to leaves was evaluated 15 days before harvest. Chlorination produced different effects regarding both production and quality. All treatments presented… More >

Morant AE, HD Merchán, EE Lutz

Phyton-International Journal of Experimental Botany, Vol.76, pp. 95-102, 2007, DOI:10.32604/phyton.2007.76.095

Abstract Length of the vegetative period and forage production were evaluated in ten commercial, long term cycle wheat varieties: Buck Charrúa, Cooperación Nanihué, Buck Cacique, Cooperación Maipún, Buck Catriel, ProINTA Pigüé, Buck Poncho, ProINTA Pincén, ProINTA Super and Cooperación Liquén. The study was conducted in the experimental field of the Departmento de Agronomia, Universidad Nacional del Sur, Bahía Blanca, Argentina, under dry land conditions. A completely Randomized Block Design with five replicates was used. Seeding was effected on 9 April 1996. From the time the plant had three leaves to the Double Ridge (DA) apex stage, the apex development, tiller number… More >

Kiehr M, R Delhey

Phyton-International Journal of Experimental Botany, Vol.76, pp. 85-94, 2007, DOI:10.32604/phyton.2007.76.085

Abstract Wheat (Triticum aestivum) plants showing leaf spots associated with pycnidia of Stagonospora sp. were collected near the city of Tres Arroyos (Province of Buenos Aires, Argentina). The fungus was isolated in artificial media where it formed asexual and sexual fructifications which permitted its identification as Phaeosphaeria avenaria f. sp. triticea (anamorph S. avenae f. sp. triticea). The fungus was experimentally transmitted to wheat and barley plants and re-isolated, fulfilling Koch´s Postulates. This is the first record of P. avenaria f. sp. triticea in Argentina. More >