Maine�s Old Apple Trees Show Us the Way

A cobertura do pomar com telas de náilon é uma opção de combate ao granizo, principalmente em pequenas áreas. Durante cinco anos, avaliou-se o efeito do sombreamento provocado pela tela antigranizo, com níveis de sombreamento de 12%, 18% e 30%, sobre os fatores de produção na macieira, cvs. Gala e Fuji. A coloração vermelha dos frutos foi a variável mais afetada pelo sombreamento, reduzindo-se até 14,2% da coloração na cv. Gala e 7,2% na cv. Fuji. O sombreamento reduziu a incidência de "russeting" nos frutos, mas aumentou a incidência da mancha de glomerela. No último ano de avaliação, as plantas com cobertura de tela apresentaram uma redução de 19% no número de gemas com flor, quando comparadas com as plantas sem cobertura.

In modern marketplaces, apple (Malus domestica) production has become reliant on relatively few cultivars. While traditionally hundreds of ‘heritage’ apples have been grown, these have been delegated to cultivar collections over time. With changing consumer demands, such as increased focus on positive compounds for human health and changing consumption patterns such as cider consumption, there is a need for growers to produce fruit that fill these new markets. While breeding new cultivars can accomplish this, an alternative is to reselect cultivars with useful characters from the existing heritage collections. In Tasmania, the government owns a collection of over 850 apple cultivars. While the government no longer actively manages this collection, the site has been leased to Australia’s largest pome fruit nursery, Tahune Fields Nursery, who is maintaining the collection. In order to capitalise from the collection, over the past three seasons, the Nursery has been cataloguing the cultivars to document the fruit characteristics such as harvest date, attractiveness, flavour, texture and polyphenol content. The cultivars have been monitored on a weekly basis and harvested when 50% of the starch has dispersed. In the laboratory fruit weight, starch plate, sugar (%TSS), acidity (pH after NaOH to neutralise 1% malic acid) and polyphenols were recorded. Fruit was organoleptically assessed for texture and flavour. For fruit polyphenol content a very quick method of assessing the fruit was needed and a spectroscopic method, transmission reduction at 360 nm compared to 400 nm as a percentage, was developed. This information has been mounted on the internet and is now being used to identify heritage cultivars with desirable traits for modern markets. The identified cultivars are being propagated and small experimental orchards being established to assess their commercial potential.

Management programs for the apple maggot (AM), Rhagoletis pomonella (Walsh), were tested in small orchards of dwarf and semi-dwarf, disease-resistant apples in New York State. These orchards were exposed to severe AM pressure from nearby unsprayed apple and hawthorn trees. In the Hudson Valley, a standard six-spray schedule of azin-phosmethyl applied every 14 days from June to mid-August reduced AM damage to 1.4% in 1979, and in 1980 a reduced two-spray schedule of azinphosmethyl at the beginning and peak of adult activity gave similar control (1.3% damage). In an adjacent plot, a nonconventional control program of trapping AM flies on red sticky spheres was about as effective (1.0% damage) as the azinphosmethyl program in 1979, but allowed more damage (4.9%) in 1980 than the reduced insecticide schedule. At Geneva, plots treated with carbaryl starting 10 days after AM emergence and thereafter at 14-day intervals during adult activity had 5.7 and 0.4% infested fruit, respectively, during 1980 and 1981. Carbaryl applications in other plots based on Pherocon AM trap catches or fruit maturation were less effective. Sphere trapping programs at Geneva which had 12.8 and 2.9% infested apples, respectively, during 1980 and 1981, were also slightly less effective than the standard protective carbaryl schedules.