Yield potential estimation of potato in Córdoba, Argentina by radiation use efficiency and water productivity

Abstract

Knowing the potential yield (RP) of potato crop (Solanum tuberosum L.) is needed to establish the productivity gap compared to yields obtained by producers. This article uses different models to estimate the RP for late potato growing season in Córdoba, Argentina, comparing two methods based on: a) radiation use efficiency (RPe) and b) efficiency or productivity of water (w), which was normalized according to vapor pressure deficit (RPwD) and the reference crop evapotranspiration (RPwETo). The RPe for four planting dates from 2007 to 2012 was highly variable (CV = 17.7%), with a mean value of 9.7 Mg ha-1 of dry weight (PS), showing a gradual trend to decrease with the delay of planting, with a rate between 1 and 1.4% of RP per day of delay. The average RPwD was significantly (P < 0.001) lower (8.4 Mg PS ha-1), with similar variability between years and planting dates (CV = 17.3%), and the same trend to decrease was observed as planting was delayed. The RPwETo tended to be only slightly lower (9.3 Mg PS ha-1) than those obtained with Rpe. This difference was not significant (P > 0.05), and its estimates were less variable (CV = 9.7%).