Login | Request Account (DAF staff only)

Changing sink strengths influence translocation of phosphonate in avocado (Persea americana Mill.) trees

View Altmetrics

Whiley, A.W., Hargreaves, P.A., Pegg, K. G., Doogan, V.J., Ruddle, L.J., Saranah, J.B. and Langdon, P.W. (1995) Changing sink strengths influence translocation of phosphonate in avocado (Persea americana Mill.) trees. Australian Journal of Agricultural Research, 46 (5). pp. 1079-1090. ISSN 1836-0947


Article Link: https://doi.org/10.1071/AR9951079


Translocation of phosphonic acid (H3PO3) in cv. Hass avocado trees was studied after trunk injection with 20% H3PO3, formulated as potassium phosphonate, at three stages of tree phenology during the growing season. Initially, translocation was solely acropetal in the xylem, and H3PO3was detected in the leaves 24 h after treatment. Several days after injection, H3PO3 concentration in the bark of trunks and in roots increased, indicating basipetal phloem transport of H3PO3 from leaves. The rate of accumulation and the final concentration of H3PO3in the roots were directly related to the sink strength of the shoot at the time of injection. For example, trunk injection at the beginning of spring growth flush, when renewal shoots were strong sinks, resulted in low H3PO3 root concentrations (<9 8g gfw-1) which peaked about 45 days after treatment. When potassium phosphonate was injected after the transition of spring-grown shoots from sinks to sources, or at summer shoot maturity, root concentrations of H3PO3increased to >25 8g gfw-1 by 30 days after treatment. These results suggest that strategic timing of injections according to phenological events may greatly improve fungicide efficacy when targeting specific organs for protection.

Item Type:Article
Keywords:avocado; phosphates; phosphonic acid; Phytophthora cinnamoni; sink strength
Subjects:Science > Biology > Biochemistry
Science > Botany > Plant physiology
Plant culture > Fruit and fruit culture
Live Archive:16 Apr 2024 01:59
Last Modified:16 Apr 2024 01:59

Repository Staff Only: item control page


Downloads per month over past year

View more statistics