Background
It is well known that pecan trees are heavy users of Zinc as it is an essential nutrient for good growth and nut production. The size and quality of pecan nuts are influenced by the leaf nut ratio (The number of leaves per nut.) Pecan trees with sufficient Zinc tend to have bigger leaves than zinc deficient trees.
Soil applications of Zinc are not as effective as foliar applications and so foliar zinc sprays have become standard practice amongst Pecan growers.
Currently the use of chelated Zinc products is common practice in South Africa. EzyFlow Nano Zinc is a Zinc oxide product and traditionally oxides were not favourably viewed as the particles were too large for most plants to absorb. Nutrian’s technology allows Zinc oxides to be milled down into the Nano range where absorption in plants can take place very effectively.
Methodology
In the 2018 /19 southern hemisphere summer trials were conducted on Wichita Pecan trees in the Cradock area of the Eastern Cape province of South Africa. The reason for the trials was to ascertain what form of Zinc achieved the best absorption when applied by foliar sprays.
EzyFlow Nano Zinc, which is an oxide, was trialled against a popular Zinc Chelate product widely available in South Africa.
For the trial 5 random places in an orchard 7 years old were chosen. At each site three trees next to each other were chosen for the trial. The areas chosen were not on the periphery of the orchard but rather within the orchard. Of the three trees chosen, one tree was treated with the Zinc chelate product, another was treated with EzyFlow Nano Zinc and the final tree was kept as a control.
Leaf analyses were taken at each of the 5 trial places on each tree before the first application. Another leaf analysis was taken two weeks after the first application.
Over the course of the season three applications were applied. On each and every occasion leaf samples were taken and a leaf analysis completed.
The dosage rate applied at each occasion was as stipulated by the manufactures.
Results
The leaf analysis post the first application showed a better result (zinc up-take) with EzyFlow Nano Zinc compared to the Zinc chelate product.
After the second application there was a better uptake of the Zinc chelate but it was not as good as the uptake of EzyFlow Nano Zinc.
The third application saw a small increase in the take up of the Zinc Chelate. Again the EzyFlow Nano Zinc outperformed the Zinc chelate product.
Conclusion
From the trial results, EzyFlow Zinc provides a more consistent up-take of Zinc throughout the whole phenological cycle of the Pecan Tree. In comparison, the Zinc Chelate product shows a reduced uptake which will have an effect on the Zinc levels in the tree, its leaf/nut ratio and thus ultimately yield.
More details on the trial available from Wessel Cloete wessel@goldsuite.com.au