Performing Department
Horticulture
Non Technical Summary
The marketplace for fruit is becoming very competitive with year-around supplies of most crops available to consumers. Growers who produce the most flavorful fruit will have a competitive edge. New York's primary advantage over other regions has been flavor. However, other regions are paying more attention to flavor and are working to improve the perception that fruit from distant locations is of poorer quality. Certainly, genetics play a major role in flavor development, but undoubtedly the conditions under which fruit is grown can also affect fruit flavor. Considerable debate exists as to what cultural factors affect flavor and quality in fruit crops. While this association has been best explored in grapes with the concept of terroir, similar studies have not been conducted with strawberries which is now a $3 billion industry in the US and $10 billion worldwide. The media often report that organically-grown fruit tastes better, or worldwide. The media often report that organically-grown fruit tastes better, or that highly-fertile soils or plantings treated with pesticides produce fruit with poorer flavor, but comparisons are usually made between one farm and another, and across different varieties, without controlling for the multiplicity of factors that could contribute to differences. Replicated trials in a single location are needed to explore variation in single varieties under different management regimes, but the large size of most fruit crop plants makes such comparisons difficult. Strawberry plants are a perennial fruit crop that are sufficiently small so that different cultural practices can be implemented and replicated on a manageable scale. We will establish 9 management regimes that will allow us to make comparisons of great interest to the fruit-growing community, particularly as it relates to the role of organic matter and soil fertility in the development of flavor and enhancement of yield. We will compare organic and conventional management practices at varying levels of soil organic matter additions, soil nitrogen additions, and pest management intensity to identify any underlying factors that directly impact fruit yield, quality and flavor. The experiment will be conducted on a virgin site and another with a history of strawberry production. At the same time, fruit will be purchased at strawberry farms across the state and evaluated for flavor attributes to estimate the range of variability possible in the traits. Ultimately, we will be able to quantify the range in flavor within a single variety, determine the magnitude of influence that soil management practices have on flavor, and make recommendations on how to improve flavor in strawberries.
Animal Health Component
0%
Research Effort Categories
Basic
0%
Applied
100%
Developmental
0%
Goals / Objectives
Our ultimate goal is to identify any underlying relationships between soil microbial dynamics and flavor and quality so these factors can be managed for optimal flavor in an increasingly competitive marketplace. Then we will extend this information to growers with appropriate recommendations. Specifically, we will test the following null hypotheses: 1) Strawberries of the same variety do not different significantly in flavor components across farms in New York State. 2) Conventionally-grown and organically-grown strawberries do not differ in yield, quality or flavor when controlling for nitrogen level and soil organic matter content. 3) The level of management intensity (i.e. quantity of inputs) does not impact yield, quality or flavor. 4) The level of nitrogen availability does not affect yield, quality or flavor. 5) The level of soil organic matter does not affect yield, quality or flavor.
Project Methods
This experiment will utilize Fragaria x ananassa cv. Jewel, a June-bearing cultivar noted for its pleasing flavor. The strawberry plants will be grown outdoors on a silty loam soil. Two fields will be used - one in which strawberries have been growing for the past 4 years and the other which has no recent history of strawberries, thereby reducing the likelihood of soil-borne pathogens from previous strawberry crops. There will be three management systems (organic, conventional, low organic matter) each with three levels of management intensity, each replicated 4 times in a completely randomized design on both sites. Plot size is 120 square feet (8 m2). The set of organic system treatments will be managed using organic practices. Conventional system treatments will be managed using standard practices. The low organic matter system will use conventional practices but without any organic matter additions through cover cropping or use of mulch or compost. Each of these systems will be managed at different levels of intensity. Low intensity systems will receive low nitrogen additions and minimum pesticide applications, regardless of system. The moderate level of intensity will receive standard rates of nitrogen and minimum pesticide additions. The highest level of intensity will receive the standard rate of pesticide additions. The highest level of intensity will receive the standard rate of nitrogen plus calendar-based pesticide sprays. Of course, the nitrogen source and pesticide active ingredients will differ depending on the management system. Comparisons of fruit yield, quality and flavor then can be made across management regime at the same level of applied N, across different levels of N, across different levels of management intensity, and between low and high organic matter systems. Prior to planting in April 2018, a comprehensive soil analysis will be performed by collecting one composite soil sample from each field to provide baseline information for the study. The field soil will be tested again at the end of the first growing season in August 2018, and upon final harvest of strawberries in August 2019. The second and third analyses will quantify soil nutrient availability, microbial respiration, soil organic carbon content, and mineralizable nitrogen. Yields will be quantified and fruit quality assessed in 2019 during the first fruiting season. Flavor will be evaluated by measuring volatile aromatic compounds within the strawberries. Anthocyanin content will be evaluated by measuring absorbance at appropriate wavelengths. Sugar content will be evaluated by juicing five samples of berries from each harvest and measuring with a refractometer. Fragrance will be evaluated by measuring volatile aromatic compounds using SPME GC/MS. Whole, frozen strawberry samples, will be thawed for 90 minutes, have leaves removed, and blended into a puree. 10 g of pureed strawberries will be placed into a 40mL amber-glass vial and combined with 1g of 1% calcium chloride solution, and 100 µL of an internal standard consisting of 3-heptanone, 2-decanol, -undecalactone, d3-IPMP, 2-methyl-4-pentanol, 3-heptanone, 2-decanol, -undecalactone, d3-IPMP, 2-methyl-4-pentanol, d8-napthalene, d2-E2-hexenal, E2-hexenal, and d12-hexanal. A calibration curve will be constructed using volatiles detected in Jewel strawberry samples with known associated aromas, and odor thresholds at or below 100 ppb, such as linalool, nonanal, hexanoic acid, butanoic acid, acetic acid, and ethyl hexanoate. The resulting calibration curve will be integrated against the peaks of the selected compounds detected within the strawberries. A sensory evaluation will be performed by asking tasters to sample three berries from selected treatment levels, two of which will be from the same treatment to determine if differences are detectable. Relationships will be examined between management practices, soil characteristics and fruit quality components.Growers (target is 50 over two years) will be asked to participate in the research by providing a small sample of 'Jewel' strawberry for analysis. Berries will be sorted to the same stage of ripeness and analyzed for sugar content and flavor components. Individual growers will learn where their strawberries fall within the range of sugar content, flavor components and other measures of quality. Correlations will be made between management practices on these farms and these results. Farm visits will provide an opportunity for outreach on soil management and soil health.