Fruit growing around Lake Constance
This area known as the Bodensee in Germany, is a very important fruit growing area for both Germany and Switzerland.
It is around 300 to 400m above sea level with much of the land surrounding the lake sloping gently towards it. This gives good cold air drainage towards the lake, while the lake itself moderates the temperatures so it is a micro climate which usually suits fruit production.
This year the heavy frosts in late April which swept through northern Europe decimated their crops. Overall, losses on the German side of the lake are estimated to be in the order of 50% with some crops wiped out. The Swiss side of the
lake has fared better, probably because there are fewer frost pockets on that side. Also, as the frost was caused by a cold air mass moving down from the north, the air temperatures may have been lifted a bit as they crossed over the lake.
Among varieties, Royal Gala types have come through the frost much better than other varieties and is not far below a full crop on many orchards. Braeburn, another of their main varieties has been severely affected, which is very bad news for them because of the adverse effect the light crops and resultant high tree vigour will have on storage disorders,
which even in a normal season give them quite a lot of grief. They already have a lot of problem with Braeburn browning disorder (BBD) with significant losses when fruit is stored longer than two to three months. The light crops this year will probably increase BBD susceptibility.
There is a lot of interest in branded and “club” varieties. High colour Fuji marketed under the Kiku brand is giving very satisfactory returns, whereas standard Fuji returns are well below cost of production at around Euro 0.17 (NZ$0.28) per kilo orchard gate return. Kanzi is an important variety for them however, it is very susceptible to European Canker which gives them a lot of grief.
Although not specifically mentioned to me, I suspect that Jonagold, particularly the red strains are a major variety as this variety has been widely planted throughout northern
Europe. Prognosfruit crop estimates indicate that over the whole of Europe the Jonagold crop will be down around 40% or more. Other newer varieties being planted include Pinova, red strains of Elstar and Opal ® .
All orchards are intensively planted on dwarfing rootstocks, generally the weaker growing strains of Malling 9 such as M9 T337. Tree density is around about 3,000 trees per hectare on single leader spindle bush training systems. In general, orchardists in this area tend to be rather conservative so you do not see the range of planting systems we see here. They have a good intensive system which is simple and works well for them, so they stick with it.
Rainfall is relatively high with much of it falling over the summer months, so there is little need for irrigation. Many orchards lack access to sufficient water supply so cannot irrigate or use water for frost protection. There is quite a lot of interest in organic production among the fruit growers in this region, hence the interest in Topaz and Opal ® , varieties which have some disease tolerance.
I was fortunate to accompany Michael Weber, a consultant specialising in the introduction and management of new fruit varieties to an open day at the Swiss Fruit Research Centre for this area. This station has a huge range of varieties on it including many of our varieties.
“In general, orchardists in this area tend to be rather conservative so you do not see the range of planting systems we see here. They have a good intensive system which is simple and works well for them, so they stick with it.”
New Zealand varieties being looked at were Galaxy Royal Gala which is now one of their standard varieties, Scifresh, Scilate, several Braeburn strains including Mariri Red and Rockit ® . There were also many European varieties. These included Robijn Jonagold, a red strain, Sirius from the Czech Republic and its sibling Opal ® , Mochi ® , an Italian Gala/Liberty
cross, Greenstar ® , Delcorf/Granny Smith from Belgium, Kanzi ® also from Belgium, Golden Clone B and Golden Parsi, both strains of Golden Delicious, Milwa and Topaz.
Although pears are not widely grown in the district, there was some pear variety testing under way. One new pear variety which showed a lot of promise was CH201, a Swiss bred variety from a cross between Verdi and Harrow Sweet a Canadian fireblight tolerant variety. This variety has a red blush and appeared to have set a full crop in spite of the frost.
Due to its latitude and altitude the harvest season in this area is several weeks later than fruit growing areas south of the Alps. Royal Gala harvest was expected to occur in the first week of September, equivalent to early March here. At the time, I was there in mid-August, southern European Royal Gala, particularly Spanish fruit, were readily available in the shops, along with local early apple varieties such as Gravenstein.
Among Gala strains, Galaxy was widely planted but it was said that it was being replaced in new plantings by an Italian trademarked strain called Schniga ® which was thought to have better colour, although still a striped colour strain. As here the striped Royal Gala strains were showing some colour reversion problems.
CODLING MOTH PHEROMONE DISRUPTION
The research station was using pheromone disruption for codling moth control with very good results. A number of different dispensers were being trialled including the aerosol dispenser “Isomate CM Mister” which require two to three per hectare. This dispenser was programmed to only dispense the pheromone at times and under conditions when codling moths were actively flying giving significant cost savings on materials.
ORCHARD SUPPORT STRUCTURES
Support structures are designed to carry hail net as well as support trees. Posts are either full round wooden or prestressed concrete. In order to give a stable structure strong enough to support hail net the whole support structure is tied together by wires or cables running across the rows. Screw anchors are used to tie down the whole structure. Support posts are 6 to 9m apart and have polythene caps to prevent chaffing damage to the nets they support.
Because snow often occurs over the winter, hail nets are rolled up to the centre wire after the crop is harvested. This is a pretty standard support system I have seen in many European fruit growing areas.
As well as apples, which are the main crop, the area is important for berry fruits of which strawberries are the main crop. There are about 200 hectares of cherries on the German side of the lake mainly grown on dwarfing rootstocks such as Gisela 5 and 6. It is a difficult area in which to grow cherries because of its high rainfall. Kordia and Regina are important cherry varieties.
European plums, usually of the prune type were also seen.
From left: Fig 1. A general view of the Bodensee fruit growing area. Young cherries are in the foreground, the lake in the middle and Switzerland on the other shore. Fig 2. This Braeburn crop has been badly damaged by spring frost. Fruit is large, tree...
Fig 11. The cross tie anchor system used in European orchard support systems. Note the screw anchors immediately below the angled strainer posts and the weed mat along the row between the anchors and the tree row.