Time for greater diversity in our orchards?

The prolonged cold and wet weather this spring resulted in poor pollination of many fruit and vegetables.  Apple harvests are, on average, about 30% down but hardest hit will have been those growers who put all their eggs in one basket by concentrating on just one or two commercial varieties.   But this is not the only reason we should be reviewing the way we grow orchard fruit nowadays.  Research carried out in Germany by Hans-Joachim Bannier and published on the Diversity website suggests that the dominance of just six varieties worldwide is having a longer term affect on their vitality, contributing to their dependence on chemical fungicides.

Commercial orchards may be sprayed with chemicals up to 30 times a year, such is the range of pests and diseases that can afflict them coupled with the supermarket requirement for blemish free apples.  You are unlikely to find organically certified top-fruit grown in this country and there is controversy over whether those certified in other countries would be generally accepted as organic here.  For example, one method is to build a “firewall” against disease by spraying trees around the perimeter so that those fruit within that perimeter can be classified as organic.

Bannier’s research highlights the fact that at the time most countries made their decision about which varieties to grow commercially the key considerations were factors such as shelf-life, hardiness for transportation and crop yields, but little consideration was given to disease because of the easy availability of chemicals to deal with this.  Where disease was considered, such as scab, this was dealt with by including crab apple in the cross, but unfortunately, because everyone used the same variety, we have ended up relying on a single gene and resistance based on a single gene is not particularly stable.

Many growers are not even aware of the extent to which the varieties they grow draw on such a small gene pool.  New varieties advertise the immediate parentage, but rarely go back much further.  Tracing a few generations quickly shows the extent to which the world’s commercial varieties share many of the same genes.  By far the most commonly used “ancestor variety” is Golden Delicious – 347 times crossed into a total of 255 of the 500 varieties examined by Bannier.  Yet Golden Delicious is particularly susceptible to scab, a fact which Bannier considers the root cause of the majority of scab problems in modern orchards.  In contrast he notes that there are orchards growing older varieties that thrive virtually scab-free for generations.  The extensive use of fungicides masks the natural attributes of different varieties and in order to properly assess these it is necessary to grow both old and post 1920 varieties in untreated orchards.

Unlike modern mono-cultural commercial orchards, traditional orchards contained not only a wide variety of fruit trees but also developed an ecosystem built around a species rich orchard floor.   This was beneficial for wildlife, hence the inclusion of Traditional Orchards in the UK’s Biodiversity Action Plan, but also helped ensure that there were insects for pollination and also as helpful predators.  Writing on his blog Real English Fruit, Dan Neuteboom, discusses how such an orchard floor might have helped with pollination this year.

In fact traditional orchards, where the trees were often under planted with other crops or shared with chickens and pigs, were excellent examples of the type of thinking that is now being put forward by proponents of Permaculture₁ and Agroforestry₂.  Both talk of the benefits of incorporating fruit trees into the wider picture of agriculture for their mutual benefit.  Perhaps this year’s poor harvest, which has already resulted in supermarkets having to relax their usual requirements in respect of the appearance of fruit and vegetables, will be a catalyst for a complete review of how we grow our orchard fruit.

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2 thoughts on “Time for greater diversity in our orchards?

  1. Great article. Organic Research Centre are doing some really good work on Agroforestry. But even Unilever are looking at nutrient levels in older varieties. The drive to use less pesticides and fungicides in all fruit growing might actually help organic growers as disease resistance is becoming more important for everyone.
    Also important to recognise the importance of rootstocks, mostly orchards have moved towards more dwarfing rootstocks, which help in keeping trees small (easy for picking) and quick fruiting (less time in ground before you get some return on investment), however more vigourous rootstocks (or even growing on their own rootstocks – particular interest of mine) allow trees more nutrient and lead to stronger more resilient tree, as well as potentially better fruit set / keeping quality of apples etc.

    1. Thanks for your comment Ben. What you say about rootstock is particularly interesting as it indicates that traditional full sized trees not only enable them to be incorporated into other agriculture but also benefits the tree and fruit. I know that some varieties take a good time to display their full flavour potential, which may never happen with dwarfing rootstock.

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