Kiwifruit Fruitlet Analysis
Latest research is now clearly indicating that early season fruitlet analysis can be a good indicator of mineral composition and the eventual storage potential of kiwifruit. Phosyn, international specialists in crop nutrition, have been investing in the research of kiwifruit fruitlet analysis in New Zealand and this coming season are considerably stepping up this research. When mineral deficiencies or imbalances occur, kiwifruit can be susceptible to poor fruit firmness and breakdown in storage. These quality issues affect the storage potential of kiwifruit and limit the profitability of production.
The ability to predict storage potential and shelf quality from mineral analysis at an early stage in crop growth would be of enormous benefit to growers. The information would enable growers to adjust nutritional levels and inputs during the season and make more informed judgements about the storage potential of their kiwifruit. Phosyn has achieved this with the development of Megalab and kiwifruit fruitlet analysis, which allows the grower to analyse his fruit from late December/early January and receive advance warning of nutritional status of his kiwifruit and any potential nutritional imbalances.
Megalab - A unique database
Megalab is a unique database of information using the results of many analyses of kiwifruit fruitlets from the major growing regions around New Zealand. This last season saw approximately 150 fruitlet samples entered into Megalab from participating orchards and pack-houses.
Statistical or biometric analysis of the information in the database shows how the nutrient levels change in the kiwifruit as the season progresses and the fruit gets larger. The database is indicating that kiwifruit with the higher calcium, (see graph) zinc, magnesium and manganese are storing better than kiwifruit with lower levels of these nutrients. The leaf is not a good indicator of calcium in the fruit so fruitlet analysis is recommended.
The large amount of information built up in the database can be filtered to give separate information for Hayward and Hort 16A. The information can easily be filtered further and results can be looked at on a national basis or filtered again to different growing regions, growers and individual orchard samples. The database continues to evolve with new information being added constantly to further enhance the accuracy of the predictions.
The kiwifruit fruitlet samples are analysed at Hill Laboratories and the analysis result, along with the accompanying grower ID, orchard ID and fruit nutrient level information is e-mailed into the Megalab computer database. The grower quickly receives a free Megalab Interpretation Analysis Report telling him how each nutrient is tracking and giving recommendations where necessary. Megalab interpretation is also available and widely used for kiwifruit leaf analysis. Critical guidelines have been established for Hayward and Hort 16A for spring, summer and autumn samples.
The information is indicating that in some situations new product formulations would be of benefit to kiwifruit and to general vine health. For example, where calcium is identified as being low, in relation to the kiwifruit with higher levels of calcium and excellent storage history, up to 3 applications of Stopit-N would be recommended to improve levels. Stopit-N is a true liquid with no impurities, so there are no settling out problems. It has been fully tested for nutrient uptake and crop safety on a wide range of crops and Phosyn´s own research has shown it to be as safe as Stopit, even when used at high rates.
Other quality Phosyn products, for example Tracel SP, Kiwi-K, Hydromag and Safe-N, are recommended on Megalab where nutrient levels are recorded as low and inputs would be benefit quality and yield.
Author: Michael Waites, New Zealand
Published: November 2000