INTRODUÇÃOO avanço da área de cultivo de soja vem ocorrendo em todas as regiões do País (Conab 2014), especialmente no Nordeste, que possui a maior concentração de solos salinos e baixos índices pluviométricos (Cirilo et al. 2010).Os solos salinizados ocorrem em condições topográficas que não favorecem uma drenagem eficiente, principalmente onde o manejo da irrigação é inadequado ou a água utilizada apresenta problemas de qualidade (Oliveira 1997).A salinidade do solo pode comprometer a germinação das sementes pela diminuição do potencial osmótico externo, impedindo a absorção de água, ou por meio dos efeitos tóxicos da absorção de íons ABSTRACT RESUMOcomo o Na + e o Cl - (Murillo-Amador et al. 2002, Khajeh-Hosseini et al. 2003. Os íons e o estresse osmótico são responsáveis tanto pela inibição quanto pela demora na germinação e estabelecimento das plântulas (Almansouri et al. 2001). Se comparado ao estresse salino, o problema da seca é ainda mais abrangente e economicamente muito prejudicial à agricultura (Pimentel 1999). Para a cultura da soja, os estresses salino e hídrico provocam efeitos negativos na germinação e vigor das sementes e, em condições de estresses ainda mais severas, as sementes de menor vigor são as mais suscetíveis (Braccini et al. 1996).Em diversos trabalhos tem sido avaliado o efeito do estresse hídrico induzido por NaCl na germinação e no crescimento de plântulas (Braccini A importância do tamanho das sementes tem sido relatada para várias espécies, visto que pode afetar a sua germinação e o vigor das plântulas, principalmente sob condições de estresse. Objetivou-se avaliar o efeito do tamanho das sementes na germinação e crescimento inicial de plântulas de soja (cultivares M9144RR e M8527RR), sob condições de estresse hídrico e salino. O estresse hídrico foi induzido por manitol e o salino por cloreto de sódio. Para a avaliação do efeito dos tratamentos, as sementes foram submetidas ao teste de germinação, primeira contagem de germinação e crescimento de plântulas. Utilizou-se delineamento inteiramente casualizado, com quatro repetições. Houve redução na germinação e no vigor das sementes de soja com a diminuição do potencial osmótico. Não foi observado efeito do tamanho das sementes sobre a germinação e comprimento das plântulas, porém, as sementes de maior tamanho resultaram em plântulas com maior massa seca, mesmo quando submetidas a condições de estresse hídrico e salino. PALAVRAS-CHAVE:Glycine max; potencial hídrico; qualidade de sementes.Water and salt stress in soybean seeds classified in different sizesThe importance of seed size has been reported for many species, since it may affect seed germination and seedling vigor, especially under stress conditions. This study aimed at evaluating the effect of seed size on the germination and initial growth of soybean seedlings (M9144RR and M8527RR cultivars), under water and salt stress conditions. Water stress was induced by mannitol and salt stress by sodium chloride. The seeds were submitted to the germination test, first germination co...

Commercial pear varieties worldwide are grafted on rootstocks of Pyrus and Cydonia. Quinces rootstocks have been widely used due to two beneficial characteristics provided to the scion tree as size reduction and yield precocity. However, most pear cultivars exhibit graft incompatibility when grafted on quince rootstocks due to physiologic and biochemical factors. Aiming to compare compatibility levels, 41 five-year-old scion/rootstocks combinations trained in medium/high density (2000 trees/ha) were measured in the region of Pelotas-RS, Brazil during 2007. The pear cvs. tested were 'Carrick'

Low fruiting is the main problem related to the pear production in Brazil, which makes the country one of the major pear importers. This research aimed to evaluate different rootstocks to pear tree cultivar 'Carrick' to be used in commercial orchards. The experiment was carried out in Pelotas/RS, located at latitude 31°52'00"S, longitude 52°21'24"W Greenwich and altitude of 13.24 m. The orchard was set up in 2002 with a density of 2000 trees.ha-1. The trees were conducted in slender spindler system trained on three-wire support with a dripping irrigation system. The treatments assessed were 13 quince rootstocks (Cydonia oblonga

The low fruiting is one of the main problems related to the pear production in Brazil. In this context, this work aimed to determine the fruit set of pear fruits 'Garber' in the different fruiting organs regarding the North, South, West and East quadrant by using physical and chemical treatments. Sixteen-year-old trees were conducted at spacing of 6 × 8 m. The treatments were: 1) control; 2) summer short pruning; 3) branches bending + summer long pruning; 4) winter branches bending; 5) winter pruning; 6) girdling; 7) 560 ml 100 L-1 of H 2 O of Promalina ® (benzyladenine + gibberellins AG 4 +AG 7) or 8) 200 ml 100 L-1 of H 2 O of Biozyme * TF. After 55 days, the fruits fixed in the different fruiting organs as lamburde, brindille, brindille couronnee and bourse were counted. The girdling treatment done in the winter time showed the highest effective fruit set rates independent of fruiting organs. The use of Promalina ® and winter bending were not efficient to the pear tree 'Garber' in this experiment conditions. The effective fruit set was similar at all the orientation quadrants in the region of Pelotas-RS, Brazil. The fruiting organs of the pear trees 'Garber' that showed the highest effective fruit set rates were brindille couronnee and bourses. Lamburde was the fruiting organ with the lowest effective fruit set rates independent of treatment.

The aim of this research was to evaluate the growth and development of pear trees of the cultivar 'Packham's Triumph' grafted on six different quince rootstock cultivars, 'Adams', 'Alongado', 'D'Angers', 'EMC', 'Portugal' and 'Smyrna', and one Pyrus calleryana. The experiment was carried out at the experimental field of the Federal University of Pelotas (FAEM/UFPEL), Palma Agricultural Center, Capão do Leão, Pelotas RS, Brazil. In August 2002, the pear trees were planted at 5 x 1 m (2000 trees.ha-1) and trained as slender spindles on a three-wire support. A drip irrigation system was set for four hours each day (2 L/h/tree). The experimental design was a complete randomized block with three replications of four trees each. Data collected were trunk diameter, tree height, canopy volume, leaf area and fresh and dry leaf weight. In general, 'EMC' supported less plant development (vigour) of 'Packham's Triumph', followed by 'Portugal'. However, 'Smyrna', and to a slightly lesser extent, 'Alongado', had the better (more vigorous) plant development. The reduction in tree height, when grafted on 'EMC' rootstock, was 49.33% in relation to the more vigorous rootstock, 'Smyrna'. 'EMC' had the largest difference among the rootstocks in trunk diameter and showed a reduced diameter of its trunk in comparison to the cultivar (0.37 mm). Moreover, 'EMC' induced a lesser leaf area (54.16 cm 2), fresh (0.01 N) and dry weight (0.01 N) in the scion, whereas 'Smyrna' induced greater averages of leaf area (92.13 cm 2), fresh (0.03 N) and dry weight (0.02 N). Some yields were obtained by using quinces rootstocks cultivars 'D'Angers' and 'Smyrna'.