Exploring genotypic and environmental influences on crop quality

January 15, 2013Canby, Oregon

Ted Radovich, Ph.D. Sustainable Farming Systems Laboratory Department of Tropical Plant and Soil Sciences University of Hawaii at Manoa

theodore@hawaii.edu

Big = Blue Ribbon

A Shift in FocusQuality vs. quantity AntioxidantsEating qualitySuperfoodsFarming for functionality and flavor

Color, flavor and human health potential are chemically based, and plant chemistry is influenced by both genotype and environment.

TerroirCabernet FrancVariety

Organic produce tastes better and is better for you!Produce flavor and nutrient content is dependent on how it's grown.

Crop Management and QualityExamples from Ohio and Hawai'i:

Head cabbage flavor

Pakchoi phytonutrient content

Hot pepper pungency

GlucosinolatesSecondary metabolites in found in cabbage family.

Derived from amino acids

Anti-carcinogenic

Pungency, typical cabbage flavor.

Problem:Buyers in Ohio began rejecting cabbage that was perceived as too pungent.

How do growers produce cabbage with low pungency?

Planting DateMay-planted cabbage was higher in glucosinolates than June-planted across years for all cultivars.Radovich et al. 2005. HortScience 40:106-110.

Planting DateThe effect of planting date and year was attributed to the number of days above 30 C during head development

June 01May 01June 02May 02

Planting DateCultivars with high glucosinolates were more pungent.

Radovich et al. 2005. HortScience 40:106-110.Radovich et al. 2003. Acta Hort. 628:787-795

IrrigationPlants receiving irrigation during head development were lower in all glucosinolates.

Radovich et al. 2005. Journal of the American Society for Horticultural Science 130: 943-949.

IrrigationIrrigation effect on glucosinolates was attributed to the fraction of evapotranspiration replaced during head development.

TotalBrassicin

32Managing phytonutrient content: Pakchoi as model Glucosinolate, carotenoids, phenolics

High value

Evaluate:Response to compost tea Aquaponic variety trials

32Compost TeaUses air and water to extract: Nutrients Organic acids Microbes Ratio of water to compost ranges 10:1-100:1 Water is not circulated, only air 12-24 hrs

Compost TeaPositively impacts growth. Glucosinolate and carotenoid follow biomass. Effect is consistant across soil and media. Response dependent on rate and quality of compost. Aeration and additives not necessary.OxisolMollisolPeatPant et al. 2011. Compost Science and Utilization.Pant et al. 2009. J.Sci.Food Agric.

9Mechanisms9Growth response associated with improved nutrient status associated increased root growth, increased microbial activity and added nutrients (Pant et al., 2012).

Phenolics and antioxidant activities were higher under very low nitrogen availability.

29Above ground dry weight (mg plant -1)Total carotenoids (mg kg -1 dry weight)30Above ground dry weight (mg plant -1)Total glucosinolates (mg kg -1 dw)GlucosinolatesCarotenoidsCarotenoid and Glucosinolate content increased with nutrient availability.

Aquaponics

Aquaponics

Pakchoi variety trials at Waimnalo3 week old seedlings of seven Pakchoi varieties were transplanted 7/26/12 at the Waimnalo Research Station.

4 reps, 6 plants per rep with 8 inch spacing between and within rows.

Effluent from 350 fish in a 650 gallon tank was recirculated through 4'x48' beds with black cinder media.

Head weights were recorded on 3 plants from each rep 28 days after transplanting. The 4th leaf from the center was collect for mineral and phytonutrients analyses.

Glucosinolate content

Total Phenolic content

Its Chile in HawaiiHot peppers are important in Hawaii.Hot sauces, Asian-Pacific & Latin Cuisine.Hawaii has done some breeding and selecting.TAMU has extensive chile breeding program. No data on capsaicinoid concentrations in peppers grown under Hawaii conditions.

Waialua Hot PepperHawaiian type; C frutescensTAMU Mild Habanero

Its Chile in HawaiiWaialua Hot PepperHawaiian type; C frutescensTAMU Mild HabaneroPhoto courtesy Dr. Kevin Crosby

Range of Capsaicinoid Concentration

Habanero

Jalapeo

Hawaiian & Thai types

Take Home MessageVariety is the most useful tool to maximize quality.Stress can increase concentrations of some phytonutrients but decease yieldMinimize stress to optimize yield and quality.

AcknowledgementsKleinhenz Lab (OSU)Crosby Lab (TAMU) Talcott Lab (TAMU)Hue Lab (UHM) UH Aquaponics LabArchana Pant Jensen Uyeda Amjad Ahmad Roger CorralesServalano LamerCraig OkazakiUSDA Funding: OREI TSTAR WSAREHatch

http://www.ctahr.hawaii.edu/sustainag/

SHU= Scoville heat unit. Multipply ppm * 16Hawaii program has two hot peppers: a C. frutescens selection with relatively large fruit for that type. Waialua pepper is bacterial wilt resistant, similar to jalapeno thinner wall, reportedly sweeter, good flavor.TAMU- long time breeding program. Working with breeder Kevin Crosby (UH alumni) who has been evealuating pungency of 100s of lines across the country.Hawaii program has two hot peppers: a C. frutescens selection with relatively large fruit for that type. Waialua pepper is bacterial wilt resistant, similar to jalapeno thinner wall, reportedly sweeter, good flavor.TAMU- long time breeding program. Working with breeder Kevin Crosby (UH alumni) who has been evealuating pungency of 100s of lines across the country.Broad range across gerplasm. SHU= Scoville heat unit. Multipply ppm * 16SHU= Scoville heat unit. Multipply ppm * 16