Porta-Enxertos para a cultura do pêssegueiro do terceiro milênio

O emprego de porta-enxertos sempre responde a modernas exigências pedidas por uma fruticultura tecnicamente evoluída, iniciou-se na Itália e, em geral, na Europa, a partir dos anos 60, mas assumiu importância com o desenvolvimento da fruticultura industrial. Para algumas espécies, dentre as quais particularmente a macieira e a pereira, este processo iniciou-se antes e evidenciou-se com maior rapidez, tanto que, atualmente, vêm-se se usando exclusivamente porta-enxertos clonais. Para outras espécies, como o pessegueiro, o pedido de novos porta-enxertos é mais recente em conseqüência da difusão desta espécie ainda em zonas não de todo evocadas de um ponto de vista pedoclimático, o qual, a exemplo daquelas caracterizadas por terrenos úmidos, maciços/compactos, subcalcários, alcalinos ou afetados pelo cansaço (Loreti, 1988). A vasta gama de porta-enxertos, atualmente disponíveis no mercado de viveiristas internacionais, tornou indispensável o conhecimento das características bioagronômicas dos mesmos, de modo a auxiliar técnicos e fruticultores na tarefa de efetuar uma apropriada escolha deles. Portanto, mantém-se oportuno reportar a descrição dos porta-enxertos mais conhecidos ou, pelo menos, daqueles que, através da recente experimentação, forneceram os resultados mais interessantes, e o que abordaremos nesse artigo

Research on Planting Density of "Sangiovese" and "Cabernet Sauvignon" Varieties

This research was undertaken to improve knowledge of ‘Sangiovese’ and ‘Cabernet Sauvignon’ production behaviour at different planting densities in a vineyard trained to horizontal spur cordon and located on Tuscan coastal area. The trial was conducted during a four year period (1997-2000) in a vineyard set up in 1994, comparing four planting distances (2.8 x 1.2; 2.0 x 1.5; 2.5 x 1.0; 2.0 x 0.75) at a density ranging from a minimum of 2976 to a maximum of 6667 vines/ha. ‘Cabernet Sauvignon’ was more vigorous, produced smaller clusters, had higher bud fertility, a lower yield and Ravaz index than ‘Sangiovese’. The must of ‘Cabernet Sauvignon’ had less titratable acidity and higher pH and total soluble solids content than ‘Sangiovese’. In general yield and production of wood per square meter were positively related to the increase in planting density, while pruning wood per linear meter showed an opposite trend. In ‘Sangiovese’ both inter-row and along the row spacing had a marked influence on yield and vegetative performance while in ‘Cabernet Sauvignon’ the effect of the spacing along the row seems to be prevailing. The results of this research indicate that in the Tuscan coastal area, planting density had no significant influence on grape quality in both cultivars

Observations on nine peach rootstocks grown in a replant soil

‘Flavorcrest’ peach [Prunus persica (L.) Batsch] trees grafted onto nine rootstocks (four hybrids of peach, almond and P. davidiana: Barrier 1, Cadaman, GF 677, and Sirio; five plum clones: Ishtara, Julior, Mr.S.2/5, Penta and Puebla) were grown in a replant soil in the Pisa Province (Italy). Trees were planted on January 1998 at 4.5 x 2.0 m spacing and trained to a free spindle (‘fusetto’). Measurements of the vegetative growth, yield, phenology and fruit quality of each tree were recorded annually. Results of trunk cross-sectional area, size and volume of the canopy, summer and winter pruning weights showed that Barrier 1, GF 677 and Cadaman were the most vigorous rootstocks followed by plum clones and then Sirio. Sirio and plum clones had earlier harvest times compared to the other rootstocks; whereas fruit ripening on GF 677 and Barrier 1 was delayed. Cumulative yield was highest on Cadaman and GF 677 and lowest on Penta, Sirio and Mr.S. 2/5, while yield efficiency was highest on Sirio, Julior, Puebla, Cadaman and Ishtara. Fruit size was highest on Barrier 1, GF 677 and Ishtara and lowest on Julior and Sirio. Flesh firmness was highest on vigorous rootstocks (Barrier 1, Cadaman and GF 677) while a lower soluble solids content was found only on Barrier 1 rootstock. Finally, there was a higher mortality rate, for Ishtara, Julior and Sirio, due to replant disease

MiPAF targeted project for evaluation of peach rootstocks in Italy: results of six years of observations

The MiPAF (Italian Ministry of Agricultural) targeted project “National Lists of Recommended Rootstocks and Fruit Varieties” aims to evaluate the performance of cultivars and rootstocks introduced in the Italian nursery market. As part of this project, trials were established to compare some of the most interesting rootstocks for peach in eight different locations in Italy. The rootstocks tested were: Rubira, P.S.A5, P.S.A6, Ishtara-Ferciana, Julior-Ferdor, Jaspi-Fereley, Citation-Zaipime, Barrier 1 and GF 677. In 1995, 8 orchards were planted at 5 by 5 m spacing; in each orchard 15 trees per rootstock, grafted with ‘Suncrest’ peach cv. and trained to open vase, were randomly distributed in a single plot. Locations of the orchards were distributed throughout Italy: two in the north (Cuneo and Forlì), two in the centre (Pisa and Ancona) and four in the south of the peninsula (Caserta, Metaponto, Catanzaro and Cagliari). This report highlights the main results obtained after 6 years of growth (3 years of production). Data are summarized either per rootstocks or per location. In each location, trees grafted on GF 677 were the most vigorous and very productive (109.7 kg/tree cumulative yield); they also had fruit size from medium to large. Also Barrier 1, showed good adaptability to various climate and soil conditions but vegetative growth and yield of this rootstocks were lower (15%) than GF 677. This clone constantly delayed (5-7 days) bud burst, bloom, harvest and leaf fall time. Peach seedling rootstocks (P.S.A5, P.S.A6 and Rubira) performed very well in good soil conditions, where yield per tree was only slightly lower than GF 677, but vigour was at least 20% lower than GF 677. Ishtara appeared as the better plum clone in this trial because of its high productivity (like that of peach seedlings), good vigour control (38% less than GF 677), good fruit size (183 g) and very low root suckering. Also Julior showed good soil adaptability but its root suckering appeared too high. Finally, Citation and Jaspi performed poorly because of high mortality rate of the grafted trees and poor vegetative growth and productivity

State of the art on peach rootstocks and orchard systems

The increasing competition between the various peach-growing countries in different parts of the world makes it necessary to engage in continuous innovation and refinement of orchard management techniques, in order to reduce production costs and ensure the profit margins that are indispensable for the survival of fruit peach industry. The decisions taken at the moment of orchard establishment, aiming at quanti-qualitative maximization of fruit production at the lowest production costs, thus become of crucial strategic importance. In this perspective, the paper examines two factors considered to be of fundamental importance in orchard design: choice of the rootstock regarded as most suitable in terms of soil, degree of vigor induced in the scion varieties and resistance to biotic and abiotic stress; choice of the appropriate planting system, which implies knowledge of the tree's response to the planting density training systems and pruning techniques. Choice of rootstock is becoming increasingly difficult as a result of the availability of numerous new rootstocks. Therefore, careful attention is paid to the various factors involved: in particular, for each of the problems considered we provide an internationally recognized list of stocks representing the best option for overcoming such problems. Among the most important nursery characteristics, emphasis is placed on aspects linked to propagation techniques and graft compatibility of the various stocks. As regards characteristics induced in the grafted cultivar, special attention is devoted to the degree of vigor, productivity and fruit quality. Finally, resistance of the main available rootstocks to the most serious abiotic (active limestone, soil sickness, waterlogging, drought, winter cold) and biotic (nematodes, fungi, bacteria, soil sickness and PTSL) sources of stress is described. Subsequently, we report on the results of a worldwide survey showing that open vase and just a few other traditional training systems still represent the standard in peach orchards. This suggests that choice of orchard design and planting density is influenced above all by factors other than the maximization of photosynthetic efficiency, rapid entry into production, or orchard management techniques. In order to seek to clarify the conditions underlying this situation, we offer an overview of the main factors to be taken into consideration in designing an orchard system and which can favor the technical-economic success of the orchard. We briefly describe the advantages and disadvantages of the various training systems currently used for low (400-600 trees/ha; open vase and its variants, Californian vase, etc.), medium (600-1,000 trees/ha; palmette and its variants, delayed vase) and high (1,000-2,000 trees/ha; spindle, transverse Y and its variants, KACV) planting systems