We are just coming to the end of one of the main parts of the production process for our deciduous fruit trees. February and March are a very busy time at the nursery with the 'Budding' season, when the varieties are 'budded' onto the rootstocks which were planted last Winter (mainly in the ground, except for Citrus which are all container grown).
It is quite amazing that a wee part of one tree can be attached onto another tree, and it will actually grow. There are several important parts to make a successful bud. The budwood must be of good quality, meaning it must be freshly cut (or chilled). The budder must cut a clean bud from the 'scion' material and then an equal sized cut in the rootstock, which the bud is carefully inserted into, so that the cambium layers (the thin layer of tissue between the bark and the wood of a stem) will match and callous (join and grow together).
There are a number of parts to the process, from Budwood Collection, Preparation and Storage, through to the actual Budding procedure with a 'budder' inserting the buds onto the rootstocks followed by a 'tier' who secures each bud with the specially designed 'Buddy Tape'.
A proficient budder will do around 3700 buds per day (for apple trees). This season our top budder has done over 100,000 buds! This is out of a total production this season of 900,000 buds (including where trees are 'doubled budded'). We mainly use our own employees for the budding season, but occasionally employ contract budders who often travel the world following the budding seasons for fruit trees, roses and citrus.
Below are photos demonstrating the process.
BUDWOOD COLLECTION
Most of the budwood we use is collected from our own onsite 'budwood orchards' which are specifically grown and trimmed to produce lots of vegetative branches.
1. Cath collects budwood from our budwood orchard. She selects wood that has grown this summer that is about pencil-thickness. She also checks the tree for fruit to double-check that the tree is correctly labelled, and avoids any trees showing signs of disease (eg. European Canker for apples).
An important first step is to clean the secateurs to avoid the possibility of spreading diseases (using Methylated Spirits as a sterilizer).
The budwood orchard with plenty of current season's growth to choose from.
Cath shows where there is two year old wood, compared to the new growth which is wanted for budwood.
2. Snip Snip Snip!
Now back to the shed to prepare and package the budwood sticks.
3. An important but tedious job to remove the leaves from the cut budwood sticks (Costa Simpson pictured). This helps to prevent the wood from drying out, and so that it is ready for the budders to use.
4. The ready budwood sticks are wrapped in bundles, labelled, and wrapped in wet newspaper.
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5. Marion admires her expanding collection of budwood. The bags of budwood are stored in a chiller at 3-4 degrees until the budders are ready for it. The wood is then stored in a mobile chiller in the field, brought out by the bundle as required. It is important to store budwood away from fruit and vegetables as the ethylene released by fresh produce will cause the wood to deteriorate. Therefore we use dedicated budwood facilities to ensure the quality of the material.
BUDDING IN THE FIELD
Two teams of budders in our nursery block near Brightwater, Nelson. In the foreground is Hector cutting a bud from a stick, while his tier Cath follows tying his previous bud. In the background is Dylan with his tier Melanie hidden behind him.
1. The buds are cut from the budwood sticks. This is a chip bud. It is important to get the technique right to cut the bud cleanly without scooping it, so that the layers of cambium can match to the rootstock. We use specially designed budding knives that are imported from Germany from Hermann Meyer.
2. A cut is made on the rootstock about 20cm above the ground, in the same size, shape and depth as the bud, so that they will match and callous strongly.
The bud is inserted into the cut.
3. The bud is then secured to the rootstock using specially formulated Buddy Tape. This ties the bud onto the stock tightly enough so that the cambium will callous but not so tightly that the bud can't burst through it when it starts growing.
4. A row of budded apple rootstocks. You can see where the buds have been tied with Buddy Tape at about 20cm from ground level. The growth above the bud is the rootstock. The top half of rootstock growth is removed next month (April), with the remainder removed in July to allow the bud to the trained up as the main leader.
Later in the year we'll post about the next steps of the process once the buds have calloused and started growing. We will also post about grafting in Winter, when we do field grafting and bench grafting.