|Moore, Amber -|
Submitted to: Journal of Crop Improvement
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 21, 2011
Publication Date: March 1, 2012
Citation: Alva, A.K., Moore, A.D., Collins, H.P. 2012. Impact of deficit irrigation on tuber yield and quality of potato cultivars. Journal of Crop Improvement. 26:211-227. Interpretive Summary: Optimal management of irrigation and nitrogen fertilization is critical to attain high yields of good quality potato tubers. The Columbia basin production region in the Northwest is characterized by high evapotranspiration and soils are sandy with very low retention of nutrients and water. The most common current practice is to irrigate potatoes to replenish water loss by evapotranspiration. In this study the magnitude of yield loss in response to deficit irrigation was investigated on some recently popular cultivar, i.e. Ranger Russet and Umatilla Russet. All deficit irrigation treatments began four weeks after seedling emergence. First year, application of 20% deficit irrigation as compared to irrigation to replenish full evapotranspiration decreased tuber yield by 28%. In the subsequent two years, 14% to 17% deficit irrigation decreased tuber yield by 7% to 10%. This study suggests the need for further investigation to understand the least sensitive growing stages for deficit irrigation so that water conservation can be accomplished without significant economic losses.
Technical Abstract: Potato (Solanum tuberosum L.) tuber yield and quality are impacted by irrigation and nitrogen (N) management. This study was conducted in the Pacific Northwest to evaluate effects of deficit irrigation (DI) and rates of pre-plant and in-season N applications on Ranger Russet and Umatilla Russet cultivars. In 2004, with ‘Ranger Russet’ only, DI with 20% lower total irrigation for the entire growing period resulted in 28% tuber yield reduction compared to that with full evapotranspiration (ET) irrigation. Subsequent studies in 2006-2007 with DI (14 to 17% deficit) resulted in tuber yield reduction of 7 to 10% in both cultivars compared to full ET irrigation. Yield reduction in DI was generally attributed to reduction in large weight tubers, >0.227 kg/tuber, in both cultivars across three years. Petiole NO3-N concentrations were greater in DI compared to those in full ET irrigation across all years and cultivars, particularly during tuber maturation stage. This is an important consideration as increased N availability during the late growing season adversely affects tuber quality. Petiole NO3-N concentrations increased with increased in-season N rates; however, in 2007, 112 kg•ha-1 in-season N resulted in petiole NO3-N concentrations below desirable concentrations across most of the growing season in both cultivars. This, in turn, contributed to a significant reduction in tuber yield as compared to 224 kg•ha-1 in-season N rate. Continuous DI with 14 to 20% reduction in water as compared to full ET irrigation, begun three to four weeks after seedling emergence, had significant negative effects on tuber yields of both cultivars in high-production irrigated growing conditions. Application of N up to 112 kg ha-1 as pre-plant soil applied plus 224 kg ha-1 of in-season fertigation in five applications at two-week intervals beginning four weeks after seedling emergence appears to be adequate to support high yields of high quality tubers.