ISHS Acta Horticulturae 619: XXVI International Horticultural Congress: Potatoes, Healthy Food for Humanity: International Developments in Breeding, Production, Protection and Utilization
PHOSPHORUS RESEARCH ON POTATO IN PEI |
| Authors: | J.B. Sanderson, J.A. MacLeod, B. Douglas, R. Coffin, T. Bruulsema |
| Keywords: | Solanum tuberosum; lime, soil pH, petiole P content, diammonium phosphate (DAP), monoammonium phosphate (MAP), Ca uptake |
| Abstract:
Producers in Prince Edward Island (PEI) have typically applied phosphorus (P) fertilizer at 80 to 115 kg ha-1 of P and have built soil levels to where 63% of grower samples tested over 108 µg g-1 by Mehlich III extraction in 1999. Many producers maintain soil pH below 5.8, which may reduce P availability. The current work examined the effect of diammonium phosphate (DAP) and monoammonium phosphate (MAP) at three rates, with lime-adjusted pH, on P and Ca uptake, yield, and processing quality of potato (cv. ‘Shepody’ and cv. ‘Russet Burbank’). Work was conducted from 1998-2000 at sites which tested over 200 µg g-1 for P (H+) and pH of 5.7-5.9. Five P treatments ranging from 0 to 109 kg ha-1 of P with two levels of lime (nil and 2 t ha-1) were examined with six replications. Lime had no significant effect on soil P levels in the autumn sampling or on petiole P content at four samplings. Petiole P was higher at the first two samplings and there were differences between rates of application. By the third sampling, petiole P content had declined, with only small differences found between P application rates. Although petiole P content patterns were similar at each time of sampling, ‘Shepody’ maintained a higher petiole P content in comparison to ‘Russet Burbank’ at all rates of applied P. Optimum ‘Shepody’ yields were obtained with 34 kg ha-1 of applied P; higher rates were required for ‘Russet Burbank’. There was no consistent difference between the MAP and DAP sources of P. Rate of applied P did not influence specific gravity or processing quality of either cultivar. Based on these and other results, P recommendations are now lower for ‘Shepody’ than ‘Russet Burbank’. | |
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