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 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… 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 the posted hyphotesis. 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… 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,… 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 >

Grijalba PE, HE Palmucci

Phyton-International Journal of Experimental Botany, Vol.76, pp. 79-84, 2007, DOI:10.32604/phyton.2007.76.079

Abstract A new disease of Spathiphyllum wallisii plants, characterized by leaf yellowing and wilting due to root and crown rot, was observed in nurseries of the Great Buenos Aires, Argentina. A fungus was consistently isolated from diseased tissue and identified as Cylindrocladium spathiphylli, on the base of its morphological and cultural characteristics. Inoculation tests were carried out which confirmed this fungus as the causal agent of the disease. This is the first report of C. spathiphylli causing root and crown rot of S. wallisii in Buenos Aires. More >

Luján-Rangel¹ R, E Olivares-Sáenz², RE Vázquez-Alvarado², L Garza-Ocañas³, O Torres-Alanís³

Phyton-International Journal of Experimental Botany, Vol.76, pp. 61-77, 2007, DOI:10.32604/phyton.2007.76.061

Abstract Karwinskia parvifolia (Kp) and Karwinskia humboldtiana (Kh) are poisonous plants of the rhamnacea family. Toxicological and clinical studies performed with one of the compounds present in the fruit [peroxisomicine A1 (PA1)] suggest its possible pharmacological usefulness in the treatment of certain types of cancer. This is why these plants are cultivated: to increase their productivity of PA1. We studied the effects of nitrogen and species on seed viability. The germination curve was determined for Kp with (Kp-WN) and without (Kp-NN) nitrogen, and for Kh without nitrogen (Kh-NN) using the probit model. This is characterized by the probability of… More >

Bonvissuto¹ GL, CA Busso²

Phyton-International Journal of Experimental Botany, Vol.76, pp. 47-59, 2007, DOI:10.32604/phyton.2007.76.047

Abstract Seed rain has ecological consequences on plant community structure. This study was conducted in the Monte Austral Neuquino nearby the town of Picún Leufú, Province of Neuquén, Argentina, within an area of 15 km x 15 km (39º 20 32' S; 69º19 30' W). Studies were conducted at two sites, distant 1.5 km from one another. Vegetation is distributed on the soil surface as vegetation patches. Four superficial locations may be found in the soil of these patches: location 1, small dune accumulated under the lee; location 2, found at the edge of the small… More >