caa a22 4500 465725384 CHVBK 20180323111727.0 cr unu---uuuuu 170327e19901201xx s 000 0 eng 10.1071/APP9900130 doi (NATIONALLICENCE)springer-10.1071/APP9900130 Holderness M. PNG Cocoa and Coconut Research Institute, PO Box 1846, Rabaul, Papua New Guinea aut Efficacy of neutralised phosphonic acid (phosphorous acid) against Phytophthora palmivora pod rot and canker of cocoa [Elektronische Daten] [M. Holderness] In comparative trials under a wide range of environmental conditions and management inputs, injection of cocoa trees with partially pH-neutralised phosphonic acid (H3PO3) gave similar, or better, control of pod rot caused by Phytophthora palmivora to that obtained with metalaxyl/cuprous oxide pod sprays. lnjection reduced canker incidence by up to 90% at some sites. Foliar sprays of phosphonic acid had little effect on yield or pod rot incidence at rates up to 24 g a.i./tree/application. Studies to determine the optimum dose and frequency of injection have shown a clear benefit of treatment, with both increased yields and reduced pod rot incidence, but no yield advantage was obtained through high dose rates. Alginate gel paints and direct root uptake were evaluated as alternative application methods, but were less effective than injection. H3PO3 was ineffective against vascular-streak dieback disease of cocoa, caused by Oncobasidium theobromae. Australasian Plant Pathology Society, 1990 Australasian Plant Pathology Springer Netherlands 19/4(1990-12-01), 130-131 0815-3191 19:4<130 1990 19 13313 https://doi.org/10.1071/APP9900130 text/html Onlinezugriff via DOI 1 brief-communication jats NATIONALLICENCE 856 40 https://doi.org/10.1071/APP9900130 text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Holderness M. PNG Cocoa and Coconut Research Institute, PO Box 1846, Rabaul, Papua New Guinea aut NATIONALLICENCE 773 0- Australasian Plant Pathology Springer Netherlands 19/4(1990-12-01), 130-131 0815-3191 19:4<130 1990 19 13313 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer