FACTORS INFLUENCING BUDDING SUCCES

GRAFTING AND BUDDING are common to me as method of planting material production. In Malaysia this techniques normally practiced for fruit tree planting material production by many private sector in a mass production. From my literature reading I found that grafting is a historic method of propagating fruit, nut and ornamental trees. Its use by the Chinese has been documented as early as 1560 BC. The technique was discussed in detail by historic writers including Aristotle and Theophrastus and it became very popular in Europe during the Renaissance (1350 to 1600). Grafting is still important today and is the basis for commercial production of fruit, nut and many ornamental trees. This article I would like to share my knowledge of the factors influencing the budding succes based on my own experience and reading from few books regarding on budding techniques.

There are reasons for grafting and budding techniques being practiced for many decades. From my observation on many private nurseries in Johor especially in Muar District, the grafting and budding are the most expensive forms of propagation. This issue frequently surpassing even micropropagation in terms of cost and labor involved. This techniques need skilled workers and genuine mother plants to ensure high successful rate. The skill worker sometimes fail to achieve a high successful rate due to weather condition such as long drought, heavy rainfall and other factors. However, grafting allows propagators to perpetuate clones that cannot be readily maintained or economically propagated by other means. From my experience shows that this method able to combine different cultivars into a composite plant with each part contributing a special characteristic. Change cultivars of established plants – TOPWORKING – including combining more than one scion cultivar on the same plant and for repair the plant injuries. It also able for disease indexing to test latent viral diseases. I found that this techniques suitable to study plant development and physiological processes. Grafting involves the union of a root system (called the UNDERSTOCK) with a shoot system (the SCION) in such a way that the cambiums are aligned and they subsequently grow to develop one composite plant. There are many methods and techniques used to accomplish this goal including BUDDING, a process wherein the scion is reduced in size and usually consists of only a single bud. 

FACTORS THAT INFLUENCE GRAFTING SUCCESS

The success of budding activities varies depend on many factors. From my survey done around Muar District for 134 private nursery operators in Johor in 2011 seems that many factors affect the success of budding and grafting activities. Cost of production of each planting material increase due to this factors. Many factors influence graft success including:

1. Plant
2. Temperature
3. Moisture
4. Growth activity of rootstock
5. Polarity
6. Craftsmanship
7. Pests and diseases
8. Compatibility

Some plant species and types of grafts take more easily than others do. According to my lecturer at Universiti Pertanian Malaysia some tree will graft as long as “the rootstock and scion are in the same room”. However, some species are so difficult to graft that they are approach grafted. The scion is grafted to the rootstock while still maintained on its own roots and the roots aren’t severed until the graft union forms which may take months or even years. Gymnosperms tend to be grafted while angiosperms tend to be budded. The temperature is important because callus growth does not occur below 0 Celsius. Above 60 Celsius tissue death occurs. Plants are usually held at 45 to 50 F for several months to promote callus formation without pushing vegetative growth on the scion. Higher temperatures can cause excessive callus growth that can result in depletion of the plant’s carbohydrate reserves. It is important to maintain adequate moisture and high relative humidity around the graft union to prevent uncontrolled water loss and dessication. This is usually achieved by wrapping the union and sealing it with grafting wax or cellophane to prevent moisture loss.

The growth activity of the rootstock is important as well. Some methods of grafting including T-budding and bark grafting require actively dividing cambium (so the bark will “slip”). In the case of bench grafting, the rootstock is usually grafted just as new roots start to grow in the later winter. Outdoor grafting and budding is usually done in the early spring when the temperatures are favorable and the cambium is active. Plants with strong root pressure may bleed – leading to exudation at the graft union. Polarity is important in grafting and appropriate polarity must be maintained in the scion and rootstock. However, in nurse-grafting, the rootstock may be inserted with reduced polarity in order to stimulate selfrooting. Craftsmanship is critical to the success of the graft. Craftsmanship determines how far apart the cambia are and the amount of space that must be overcome during the healing process. Craftsmanship plays a role not only in initiatial graft union healing but also in how well the plant grows out after grafting. The stress of contamination by viruses, insects or disease organisms can overwhelm the already stressed, grafted plant. Infested materials may result in poor graft take and poor outgrowth of the grafted plants. Likewise, latent infestations may result in the death of a more susceptible rootstock or scion cultivar. I hope this article able to provide significant information to all of you there. Thanks.

By,
M Anem
Senior Agronomist,
Bukit Beruang, Air Keroh,
Melaka, 
Malaysia.
(28 RabiulAkhir 1433H)