Research Knowledge and Needs for Orchard Floor Management in Organic Tree Fruit Systems

While pest management and tree horticulture dominate the research agenda for temperate tree fruits, organic production requires more attention to weed control and nutrient management because of the limited options growers have. Weed control and tree nutrition are interlinked and can have impacts on other parts of the system such as rodent pests, beneficial insect habitat, water use, and soil quality. Trade-offs commonly occur when trying to solve weed control and nutrient management in organic orchards. This article reviews numerous orchard-floor management studies relevant to finding solutions for organic systems and suggests areas for further research. Alternatives to soil tillage are needed, as it can degrade soil and tree performance. Conversely, mulching frequently leads to improved tree performance and increased soil quality but can be a costly practice relative to other options. Currently effective organic analogues to the herbicide strip-grass alley system are lacking. A plant-based solution would be ideal from a sustainability standpoint, but no satisfactory solution has been developed for widespread use.EEA Alto ValleFil: Granatstein, David. Washington State University. Center for Sustaining Agriculture and Natural Resources; Wenatchee; Estados UnidosFil: Sánchez, Enrique Eduardo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Alto Valle; Argentin

A aplicação de nitrogênio ao solo em diferentes estádios não afetou o rendimento de frutos de cultivares de macieira Application of nitrogen to the soil in different stages did not affect on fruit yield of apple cultivars

Tanto o excesso quanto a deficiência de N causam efeitos negativos na produtividade e na qualidade dos frutos de macieira. Como a taxa de absorção de N pelas árvores de macieira é afetada pela demanda das mesmas, dentro da estação de crescimento, e pelo N disponível no solo, é importante conhecer a necessidade da adição suplementar desse nutriente e a melhor época para aplicá-lo. O presente trabalho objetivou avaliar o efeito da época de aplicação de N ao solo na produtividade de frutos de duas cultivares de macieira. Os experimentos, um para a Gala e outro para a Fuji, foram conduzidos de 1990 a 1996, em Vacaria, RS, num pomar plantado em 1988, na densidade de1481 árvores ha-1, sobre um Latossolo bruno com 4,0% de matéria orgânica, 60% de argila e pH 6,9. Os tratamentos constaram de 50kg de N ha-1 nos três primeiros anos, e 60kg de N ha-1 nas outras três safras, aplicados no inchamento das gemas (IG), ou na queda de pétalas (QP), ou dividido 2/3 no IG + 1/3 na QP, ou 2/3 na QP + 1/3 trinta dias após. O N foi sempre aplicado sobre a superfície do solo, sem incorporação, numa faixa de 2,0m ao longo da fila de plantio. Houve também um tratamento sem a aplicação de N. A produtividade média anual de frutos variou de 40 a 112t ha-1 para a cultivar Gala e de 38 a 76t ha-1 para a Fuji, e a produtividade média da Gala, no período, foi 35% superior à da Fuji. A aplicação de N ao solo, independentemente da época, não teve efeito na produtividade de frutos, no tamanho das brotações, na concentração de N nas folhas e no diâmetro do tronco das duas cultivares. Presume-se, portanto, que a quantidade de N liberada a partir da decomposição da matéria orgânica do solo foi suficiente para atender à demanda das plantas e permitir uma alta produtividade de frutos de macieira.<br>Excess or deficiency of N have deleterious effects on apple yield and fruit quality. Since the rate of N uptake by apple trees depends on crop requirement within the season and on N available in the soil, it is important to know the need for supplemental N addition and the best application time. This study was carried out to evaluate the effect of timing of N application to the soil on fruit yield of apple cultivars. The experiments, one for 'Gala' and other for 'Fuji', were conducted from 1990 to 1996 in an orchard planted in 1988, with a density of 1481 trees ha-1, in an Oxisol with pH of 6.9, 4,0% of organic matter, and 60% of clay. Nitrogen treatments (50kg ha-1 year-1 during the first three growing seasons, and 60kg ha-1 year-1 afterwards) were applied at bud break (BB), or at petal fall (PF), or split 2/3 at BB + 1/3 at PF, or 2/3 at PF + 1/3 thirty-days later, always broadcast over the soil surface, without incorporation, in a 2-m-wide strip in the planting row. There was also a treatment without N addition. Average annual fruit yield varied from 40 to 112t ha-1 for 'Gala', and from 38 to 84t ha-1 for 'Fuji', and in the entire period it was 35% greater for 'Gala' than for 'Fuji'. Application of N to the soil, regardless of timing, had no effect on fruit yield, on N content in the leaves, and on canopy growth of both cultivars, in any year evaluated. It was assumed that N released from soil organic matter decay was sufficient to promote normal growth and high fruit productivity for these two apple cultivars