ARS | Publication request: Water and nitrogen management effects on biomass accumulation and partitioning in two potato cultivars

Submitted to: American Journal of Plant Sciences
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 31, 2011
Publication Date: March 6, 2012
Citation: Alva, A.K., Ren, H., Moore, A.D. 2012. Water and nitrogen management effects on biomass accumulation and partitioning in two potato cultivars. American Journal of Plant Sciences. 3:164-170.

Interpretive Summary: Crop production and productivity are influenced by climatic factors and management of production inputs. The production of tubers in potato plant is the net effect of assimilation of photosynthates leading to production of total plant biomass as well as partitioning of biomass into different plant parts, especially tubers. In this study the total plant biomass and biomass partitioning into different plant parts during the growing season of Ranger Russet and Umatilla Russet cultivars are evaluated under two irrigation regimes (irrigated to replenish full evapotranspiration, FI; and replenish 80% ET, i.e. deficit irrigation, DI), and two N levels (i.e. pre-plant and in-season applications of 56 + 112 or 168 + 336 kg/ha). The above evaluations were done by sampling plants on 22, 44, 66, and 98 days after seedling emergence (DAE). The tuber biomass as percent of plant total biomass was greater at high N rate as compared to that at the low N rate in both cultivars across both irrigation regimes. Therefore optimal N management is the key for maximizing biomass partitioning into tubers.

Technical Abstract: Biomass accumulation and partitioning into different plant parts is a dynamic process during the plant growing period, which is influenced by crop management and climate factors. Adequate knowledge of biomass partitioning is important to manage the crops to gain maximum partitioning of assimilates into plant parts of economic significance, i.e. tubers in potato. This study was conducted using two potato cultivars grown in a sandy soil with center pivot irrigation under full irrigation (FI; irrigation to replenish 100% of water loss by evapotranspiration [ET]) and deficit irrigation (DI; replenish only 80% ET) and two nitrogen (N) rates (pre-plant + in-season N rates of 56 + 112 or 168 + 336 kg/ha). Plant samples were taken on 22, 44, 66, and 98 days after seedling emergence (DAE). With high N rate, tuber biomass of ‘Umatilla Russet’ cultivar in relation to total plant biomass varied from 23-88 and 25-86% over 22 to 98 DAE for the FI and DI treatments, respectively. The corresponding partitioning ranges were 30-93 and 38-93% at the low N rate. With respect to the ‘Ranger Russet’ cultivar, biomass partitioning to tubers ranged from 36-82 and 23-84% for the FI and DI, respectively, at the high N rate, and 29-87 and 39-95% at the low N rate. Overall, this study demonstrated that within the range of N rate and irrigation treatments the biomass portioning into tubers was largely similar in both cultivars.