Phosphorus and Potassium Fertility Management for Maximizing Tart Cherry Fruit Quality and Productivity on Alkaline Soils

• Main Author: Rowley, Sean D.
• Format: Others
• Published: DigitalCommons@USU 2013
• Subjects: Alkaline; Cherry; Fertility; Productivity; Quality; Soil; Horticulture
• Online Access: http://digitalcommons.usu.edu/etd/1518; http://digitalcommons.usu.edu/cgi/viewcontent.cgi?article=2530&context=etd

Suitable orchard land in regions of high elevation, arid climates, and alkaline soil conditions is becoming more limited due to urban sprawl. With the loss of suitable farmland, increasing input costs, and the lack of sound fertility information for these regions, fruit growers face challenges in producing high quality fruit to meet local and general market demand. The question that arises is whether fruit growers can supply sufficient quantities of quality fruit to take full advantage of local and global demand. Government data for population, fruit production, and fruit consumption in Utah were reviewed to determine the potential size of the local market, and determine whether growers have opportunities to increase production to meet unsatisfied demand for high quality local produce. In addition to market analysis, fertility-based management strategies are needed to optimize yield and fruit quality in production areas of high elevation, arid climates, and alkaline soils. Three different approaches were used to investigate the effect of phosphorus (P) and potassium (K) on tart cherry fruit quality and yield at high elevations, arid climate conditions, and in alkaline soils. The approaches of this study include: a rate-response evaluation using the industry-standard Triple-16 fertilizer (16-16-16), and comparison of P and K fertilizer formulations to determine the most cost effective sources of these nutrients with regard to yield and fruit quality. Additions of P and K maintained adequate yield and fruit quality, but showed no significant difference among treatments, where historically aggressive nutrient management had been practiced. Fertilizer additions did result in a significant increase in yield and fruit quality where nutrient management programs were historically much less aggressive. There is no advantage of higher cost fertilizer formulations over standard low-cost sources (i.e.; Triple-16). Moreover, there is no significant advantage to splitting fertilizer application over time during the growing season. An analysis of government data indicates that, over the past 40 years, Utah has become a net importer of apples (1997), peaches (1987), and sweet cherries (2005), indicating increased local market opportunities. Increasing the fruit supply to the local market can best be accomplished by increasing yields and fruit quality on existing orchard acreage. Optimizing annual P and K nutrient management is an important key to maximizing yield and fruit quality. The results provide foundational guidelines of nutrient management for optimizing tart cherry production and fruit quality under regionally specific conditions.