|Authors: ||S.A. Oosthuyse, H.T. Holwerda, B. Desmet|
|Keywords: ||Elaeis guineensis Jacq., mineral nutrition, micronutrient, boron|
Two experiments, one carried out by the Makin Group, and the other by the P.T.J.A. Wattie, Indonesia, were conducted to determine whether reduced rates of Speedfol B were as effective as conventional rates of Borax in affecting leaf B concentration of oil palm (Elaeis guineensis Jacq.) In both experiments, leaf samples were taken 2, 6, 10, or 12 weeks after B application to assess if differences in rate of effect would occur.
In the experiment carried out by the Makin Group, where five-year-old palms were used, 100 g of Borax applied per palm was compared with 88 or 53 g of Speedfol B applied per palm.
Fifty-three grams per palm of Speedfol B was applied in both dry powder form, and in suspension with 10 L water around the main stem.
The B concentration in leaves from trees receiving dry Speedfol B applied at 88 g or 53 g per palm did not differ from those of trees receiving 100 g Borax per palm.
In contrast, leaves from the trees receiving the low rate of Speedfol B suspended in water had lower B concentrations than those from trees receiving the higher rate of B as Borax.
Leaf B concentration bore no apparent relation to the time delay in taking leaf samples after application.
In the experiment carried out by P.T.J.A. Wattie, where three-year-old palms growing in peat-soil were used, 50 g of dry Borax, or 40 or 30 g of dry Speedfol B was applied per palm.
Thirty grams of Speedfol B per palm also were applied in 5 L of water around the main stem.
The B concentrations in leaves from trees receiving 40 or 30 g of dry Speedfol B or 30 g of wet Speedfol B were not different from those of trees receiving 50 g of Borax.
Leaf B concentration bore a quadratic relation with the time delay in taking leaf samples after B application.
In both experiments, a difference relating to B product or rate or method of application in relation to leaf sampling date was not apparent.
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