Partitioning and recycling of fall applied boron in Comice pears.
Sanchez, E.; Righetti, T.; Sugar, D.;
Acta Horticulturae Year: 1998 Issue: No. 475 Pages: 347-354 Ref: 24 ref.
1998
บทคัดย่อ
This study was carried out on mature Comice [Doyenne du Comice] pear trees on BA29 quince rootstock, on a sandy loam soil near Medford, Oregon, USA. Labelled B was applied postharvest in 1994 as boric acid. Treatments were: foliar B at 500 ppm; foliar B (500 ppm) plus urea (2.5%), and soil B at the same per tree rate as the foliar treatments (8 g boric acid/tree). Postharvest foliar B was mobile and was transported out of the leaves into storage tissues for the next year's growth, but soil-applied B remained in the roots and very little was transferred to the above-ground portions of the tree until one month after full bloom. The storage pool of B was partitioned equally among young developing tissues but fruits were a very strong sink of reserve B. Boron from the storage pool was diluted during the growing season as roots absorbed new-non-labelled B from the soil. Isotope ratios revealed that regardless of tissues sampled, the addition of urea increased B uptake. These results showed that it is
advantageous to mix both compounds in a postharvest fertilizer program.