Phosphorus use efficiency, tuber yield and quality in potato varieties processing grown under different P levels in the Argentinian Pampas

Abstract

In the southeastern region of Pampas Argentinas (province of Buenos Aires) more than 32,000 hectares of potato are grown annually, this region of the country being the most important in terms of production for processing. To achieve high yield and quality, the demands of crop in terms of resources are high, mainly in terms of water and nutrients. To evaluate the effect of different doses of P (0, 75, 100, 125 and 150 kg ha-1) on the Efficiency in the Use of Phosupo (EUP), the yield of the tuber, quality and economic return, a field trial was carried out under irrigation by central pivot, with the Daisy and Innovator cultivars, two of the main varieties of potatoes destined for the process in froze-frozen process. The rehearsal was performed in Balcarce (37o 45' SL; 58o 18' WL, 130 m snm) on a typical Argiudol floor. Fertiliser doses were applied at the time of planting, while the rest of the management practices were applied as is normally done in the area.

In Daisy, the increase in the P dose increased the accumulation of dry matter in stems and tubers, mainly in the period up to 90 days after planting (DDP). In Innovator, the increase in the P dose led to a significant increase in the growth of stems and tubers. In both cultivars, the higher doses of P increased P content in the petiole at the beginning of the season (43 and 69 DDP). In Daisy, higher P rates increased P-level, both in stalks and in tubers to 90 DAPs. A similar pattern was observed in Innovator, but in this variety, the higher the P levels, the higher the P levels accumulated, mainly in tubers. In Daisy, increasing doses of P decrease USP to the highest dose of P. In Innovator the response to P doses was much greater and this variety was more efficient in using P than Daisy. In Daisy, increased doses of P increased the performance of tubers earlier in the season and to 90 DAP performance in the highest doses of P almost doubled that of the witness. In Innovator, the increase in the P dose led to higher performance of tubers. At the beginning of the season, the performance in the treatment was 30.75 t ha -1, while at the highest dose of P the performance was 48.09 t ha -1-1. The same pattern was observed at the end of the season, where performance was lower in control treatment compared to any of the P rates, especially in the final harvest. In Daisy, higher net yield was estimated at 75 kg P - . On the other hand, in Innovator while the doses of P increase, also the net economic return has greater value. Then, for Pampa Argentina, a different fertilization approach should be followed to improve the efficiency of use of P and the return of cultivation in these two varieties. Daisy can use lower levels of P that will not impact the final yield of the tuber, while Innovator higher levels of P are required to achieve higher yields and increase the net return of the crop.

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