The 'Montenegrina' mandarin ( Citrus deliciosa Tenore) is widely cultivated in southern Brazil. This cultivar has a great tendency for alternate bearing, requiring thining of the fruit. However, the chemical thinners studied until now in this cultivar have not been successful. The objective of this research was to evaluate the effect of 3,5,6-trichloro-2-pyridinyloxyacetic acid (3,5,6-TPA) on the production and fruit quality of the 'Montenegrina' mandarin, in comparison with hand thinning and the options of chemical thinning previously studied. Hand thinning and no thinning were used as controls. Ethephon was applied in three doses: 200mg L-1, 300mg L-1 or 200mg L-1 + 3% urea; or 3,5,6-TPA, in four doses: 10, 20, 30 or 40mg L-1. Fruits of the hand thinned trees and those treated with 40mg L-1 showed greater average size, greater distribution of commercial caliber and more orange colors. No treatment reduced alternate bearing. Applications of 40mg L-1 of 3,5,6-TPA as a chemical thinner, during the physiological drop of young fruit, had a similar effect that of hand thinning over yield and quality of fruits of 'Montenegrina' mandarin.

RESUMO Este trabalho teve por objetivo avaliar o efeito da frequência e intensidade de poda sobre a produção e qualidade dos frutos da laranjeira 'Valência

ResumoEste trabalho objetivou testar um método de propagação de abacateiro a partir de estacas estioladas cultivadas em recipientes de diferentes alturas. O experimento foi desenvolvido em câmara de nebulização intermitente. O delineamento experimental foi em blocos ao acaso, em esquema fatorial 3x4, com três repetições, testando-se dois métodos de obstrução de seiva (anelamento da casca, estrangulamento da casca) e quatro alturas de recipientes para o substrato (10, 15, 20 e 25 cm). Decorridos 250 dias, não se observou efeito da altura do recipiente na sobrevivência, no número de folhas desenvolvidas, na altura e no diâmetro das mudas formadas a partir de estacas estioladas. Houve maior sobrevivência e emissão de folhas nas estacas de casca anelada em relação à testemunha; as estacas de casca estrangulada situaram-se em posição intermediá-ria. O prévio anelamento ou estrangulamento da casca de ramos estiolados aumentaram a sobrevivência e o crescimento de mudas na propagação de abacateiro da seleção Viamão, por estaquia.Palavras-chave: Persea americana, obstrução de seiva, estaquia. Avocado propagation by etiolated cuttings AbstractThis research aimed to test a method of avocado propagation from etiolated cuttings in recipients with different heights. The experiment was carried out in an intermittent mist chamber. The experimental design was in randomized blocks with a 3x4 factorial and three replicates. Two methods of sap obstruction (girdling or strangulation) and four heights of containers (10, 15, 20 or 25 cm) were tested. After 250 days, there was no effect of container heights on the survival, the number of developed leaves, plant height and diameter of the seedlings formed from etiolated cuttings. There was a higher survival rate and number of leaves in girdled cuttings as compared to control plants; cuttings obtained from the strangulation treatment had intermediate behavior. The previous bark girdling or strangulation of etiolated avocado branches increased survival and plant growth for the propagation of selection Viamão cuttings.

Citrus plants are the most important fruit species in the world, with emphasis to oranges, mandarins and lemons. In Rio Grande do Sul, Brazil, most fruit production is found on small properties under organic cultivation. Soil compaction is one of the factors limiting production and due to the fixed row placement of this crop, compaction can arise in various manners in the interrows of the orchard. The aim of this study was to evaluate soil physical properties and water infiltration capacity in response to interrow management in an orchard of mandarin (Citrus deliciosa Tenore 'Montenegrina') under organic cultivation. Interrow management was performed through harrowing, logs in em "V", mowing, and cutting/knocking down plants with a knife roller. Soil physical properties were evaluated in the wheel tracks of the tractor (WT), between the wheel tracks (BWT), and in the area under the line projection of the canopy (CLP), with undisturbed soil samples collected in the 0.00-0.15, 0.15-0.30, 0.30-0.45, and 0.45-0.60 m layers, with four replicates. The soil water infiltration test was performed using the concentric cylinder method, with a maximum time of 90 min for each test. In general, soil analysis showed a variation in the physical-hydraulic properties of the Argissolo Vermelho-Amarelo distrófico arênico (sandy loam Typic Paleudalf) in the three sampling sites in all layers, regardless of the management procedure in the interrows. Machinery traffic leads to heterogeneity in the soil physical-hydraulic properties in the interrows of the orchard. Soil porosity and bulk density are affected especially in the wheel tracks of the tractor (WT), which causes a reduction in the constant rate of infiltration and in the accumulated infiltration of water in this sampling site. The use of the disk harrow and mower leads to greater harmful effects on the soil, which can interfere with mandarin production.

RESUMO -O objetivo deste trabalho foi avaliar características qualitativas de laranjas 'Valência' (Citrus sinensis (L.) Osb.) produzidas em dois pomares experimentais: um cultivado sob sistema orgânico e outro sob sistema convencional. Os pomares foram instalados no município de Montenegro -RS, em julho de 2001, em espaçamento de 2,5 m x 5,0 m, cada um possuindo uma área de 0,25 ha. A qualidade dos frutos foi determinada de 2005 a 2010 a partir de cinco amostras por tratamento em cada ano. Amostras de frutos colhidos aleatoriamente de cinco plantas foram analisadas para massa média dos frutos (MMF), o teor de suco (Ts), o teor de sólidos solúveis totais (SST), a acidez total titulável (ATT) e a relação SST/ATT. No ano de 2010, também foram determinados o teor de ácido ascórbico (vitamina C) no suco e a coloração da casca. No sistema de produção convencional, o manejo é realizado através da utilização de adubos minerais, calcário dolomítico, herbicidas, fungicidas e inseticidas. Já no sistema orgânico de produção, foi aplicado composto orgânico, biofertilizante líquido, caldas bordalesa e sulfocálcica, e a cobertura do solo foi mantida com vegetação espontânea, que recebeu, no inverno, aveia e ervilhaca e, no verão, feijão-miúdo. Não foram identificadas diferenças nas características qualitativas entre os frutos de ambos os pomares, exceto para o teor de SST, que foi maior, em média, nos frutos do pomar convencional. Os frutos do sistema convencional também apresentaram maior teor de vitamina C e coloração da casca mais intensa na comparação dos frutos provenientes do sistema orgânico. Termos para indexação: Citrus sinensis; ácido ascórbico, cor da casca; sólidos solúveis totais. FRUIT QUALITY OF 'VALÊNCIA' ORANGES HARVESTED FROM ORGANIC AND CONVENTIONAL PRODUCTION SYSTEMSABSTRACT -The objective of the present study was to evaluate fruit quality of 'Valência' (Citrus sinensis (L.) Osb.) oranges harvested from an orchard conducted according to the conventional system and from an organic orchard production system. The orchards were established in July 2001 at a spacing of 2,5m X 5,0 m, both with an area of 0,25 ha and 300 m distant from each other. Fruit quality was determined from 2005 up to 2010 from five samples/treatment collected from five trees every year. The harvested oranges were analyzed for average fruit mass (MMF), juice contents (Ts), soluble solids (SST) and titratable acidity (ATT). The ratio SST/ATT was as well calculated. Only in 2010 ascorbic acid contents and the pericarp color were determined. In the conventional production system mineral fertilizers, dolomitic calcareous, herbicides, fungicides and insecticides were utilized. In the organic production system liquid compost, biofertilizers and bordeaux mixture were utilized. The soil was maintained covered with spontaneous vegetation during the winter season with Avena strigosa and Vicia sativa and Vigna unguiculata were added during the summer season. No differences as to quality parameters were determined amongst both production systems except...