Pear Rootstocks. How many trees would I plant? ± 3,000 per ha. What I believe growers need to be doing to be successful in the Year 2012.

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1 How many trees would I plant? What I believe growers need to be doing to be successful in the Year ± 3,000 per ha. Marcel Veens Horticultural Adviser Pear Rootstocks Apple Rootstocks Virus free M. 9 : Plant distance: 3.25 m x 1 m (3000) Virus free M.26 : Plant distance: 3.50 m x 1 m (2500) Quincy: plant distance 4m x1.2m. BP1: plant distance Tatura trellis 5m x 1.5m BP2000 :plant distance Tatura trellis 5m x1.5m 1

2 QuickTime and a decompressor are needed to see this picture. Australian varieties - 3 Ladies Pink Lady Granny Smith Sundowner, call it Red Lady New pear varieties for Europe: Concorde: Doyenné du Comice x Conference (UK) Sweet Sensation : Mutation of Doyenné du Comice (NL) Dicolor : Winterforelle x Williams (Cz) Angelis: Doyenné du Comice x Doyenné d hiver (F) Xenia : (Noiabriskaia) Moldavië Eliot (F) cold storage problems P.6R31A18 (Angers F.) Looks like Concorde Better size than Conference (>40%) Less taste Picking time = Conference + 3 weeks Firmness brix-acidity = Conference Shenandoah : Erwinia resistant variety Colour: purple-red gr. Picking time: Williams + 4 weeks 2

3 Apple rootstock. Why is it important to use dwarfing rootstock M.9 or semi dwarfing M.26? These start cropping early. Rootstock influence on precocity, yield efficiency and biennial bearing. Dwarfing clones such as M.9 for apples may increase fruit size. Trees on M.9 are much more efficient fruit producers than those on more vigorous rootstocks. It is a general rule that trees on dwarfing rootstock produces more fruit per unit of growth. M.26 is quite tolerant to drought stress, possible because it is able to increase root growth, of both coarse and fine roots, as the soil dries. With some other rootstocks a decline in the growth of both root types was observed under such conditions. With M.9, coarse-root dry matter declines, but fine-root matter increases, which may enhance the capacity of the root system to extract water from the soil. Drought. In several short-term studies with young trees, the dwarfing rootstock M.9 proved more tolerant to drought stress than the vigorous MM.111 Extended root systems, from vigorous rootstocks, can take up water from deeper soil layers in comparison with the more limited and usually shallower root systems of dwarfing rootstocks. Nevertheless, M.9 is not very sensitive, to short periods of drought stress. Possible, the limited shoot growth of trees on dwarfing rootstocks is a positive factor as it keeps the transpiring leaf areas smaller compared to trees on vigorous rootstocks. 3

4 The optimum temperatures for root growth are in the range from 20ºC and 25ºC. At higher temperatures growth starts to decline and above 35ºC new roots are not longer formed. This is one of the reason that I don t like to hill up the soil. The soil warms up quicker and the temperatures are in general higher in the hilled up areas. Organic mulching materials protect the soil from extreme temperature fluctuations. In apple, biennial bearing tendencies increase as rootstock vigour increases, but there is an exception for spur-type apples. Rootstocks should be free of damaging pest and diseases, especially viruses which can infect the graft and may result in reduced growth, yield and fruit quality, or even tree death. If an infected graft is put onto a virus free rootstocks it will have the same result. Therefore, only virus-indexed rootstock and scion material should be used. 4

5 The availability of sufficient water for irrigation is an essential. In my ideal block I want 6 mega-liter/ ha of good water with freedom of damaging salts. Have under-tree micro-jets,which should apply 4 mm of water per hour with a full automatic irrigation system. Over-head irrigation for frost control and to cool the trees on hot days. Soil texture, structure and depth. Most fruit trees grow best on fertile sandy or silty loam soils with at least 1 to 2 meters of top soil, good organic matter content and fee drainage. Ideally a soil suitable for fruits should have a cation exchange capacity (CEC) of 25-35; Values lower than 20 indicate a soil with low buffering and potentially poor fertility. Soils with a layer or pan are to be avoided as they inhibit water drainage leading to anaerobic conditions and roots death, and preventing deep rooting of the trees. Before planting we should dig a few holes and look to the soil structure of the block. 5

6 Sandy and gravely soils are often acidic and infested heavily with nematodes that can cause significant damage to new planted trees. Sites previously planted with similar fruit crop can also cause significant problems; Replant diseases. Improving soils. Improve soil structure by adding organic matter, e.g. compost. Improve soil drainage by plowing and deep ripping. In The Netherlands most orchards have drainage pipes in the ground: every 8 to 12 m and about 1.5 m deep. Use more lime to increase the ph. Remember this: the soil is the stomach of the plant Organic carbon is the store house for nutrients and moisture.it also acts as a homebase for soil-microbes. 6

7 QuickTime and a decompressor are needed to see this picture. On heavy soils the replant problem is usually due to fungi ( Phytophthora etc). These are much more difficult to identify. The most common treatment is fumigation. In conventional Dutch apple growing, the specific apple replant disease has been solved to a great extend by incorporating fresh organic (potted) soil in the planting hole, covering up the hole after planting the trees with organic materials such mushroom compost and applying fertigation to the trees from the first year onwards. Mushroom compost applied with a rate of 18 tonne /ha will produce bigger apples after 3 years and will increase the production with 5 kg/tree in the 3rd year. When planting dwarfing rootstocks it is very important to make sure that the soil is prepared as good as possible. For plant and crop to produce to their full potential, soil water must not be limiting. Young trees need water : 2 liters a day in the first year after planting. They need fertiliser ; the best way is through fertigation. Look after young trees like babies:control weeds,take leaf samples monitor regular so that you can finetune fertiliser input. To get early production bend the branches. New system of bending. Using two wires and a crossbar. 7

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9 Create the optimum soil conditions before you start planting. The healthier the soil the healthier the trees Thank you. Marcel Veens, Horticultural Adviser. Mob