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Exploring genotypic and environmental influences on crop quality January 15, 2013 Canby, 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.
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Exploring genotypic and environmental influences on crop quality January 15, 2013 Canby, Oregon Ted Radovich, Ph.D. Sustainable Farming Systems Laboratory Department of Tropical Plant and Soil Sciences University of Hawaii at Manoa theodore@hawaii.edu
A Shift in Focus • Quality vs. quantity • Antioxidants • Eating quality • “Superfoods” • Farming for functionality and flavor
Color, flavor and human health potential are chemically based, and plant chemistry is influenced by both genotype and environment.
Terroir Cabernet Franc Variety
Produce flavor and nutrient content is dependent on how it's grown. Organic produce tastes better and is better for you!
Crop Management and Quality Examples from Ohio and Hawai'i: • Head cabbage flavor • Pakchoi phytonutrient content • Hot pepper pungency
Glucosinolates • Secondary 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 Date May-planted cabbage was higher in glucosinolates than June-planted across years for all cultivars. Radovich et al. 2005. HortScience 40:106-110.
Planting Date The effect of planting date and year was attributed to the number of days above 30 C during head development May ‘02 May ‘01 June ‘02 June ‘01
Planting Date • Cultivars with high glucosinolates were more pungent. Radovich et al. 2005. HortScience 40:106-110. Radovich et al. 2003. Acta Hort. 628:787-795
Irrigation Plants 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.
Irrigation Total Irrigation effect on glucosinolates was attributed to the fraction of evapotranspiration replaced during head development. Brassicin
Managing phytonutrient content: Pakchoi as model • Glucosinolate, carotenoids, phenolics • High value • Evaluate: • Response to compost tea • Aquaponic variety trials 32
Compost Tea • Uses 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 32
Compost Tea • Positively 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. Oxisol Mollisol Pant et al. 2009. J.Sci.Food Agric. Pant et al. 2011. Compost Science and Utilization. Peat
Mechanisms Growth response associated with improved nutrient status associated increased root growth, increased microbial activity and added nutrients (Pant et al., 2012). 9 9
Phenolics and antioxidant activities were higher under very low nitrogen availability.
Carotenoid and Glucosinolate content increased with nutrient availability. Glucosinolates Carotenoids Total carotenoids (mg kg -1 dry weight) Total glucosinolates (mg kg -1 dw) Above ground dry weight (mg plant -1) Above ground dry weight (mg plant -1) 29 30
Pakchoi variety trials at Waimānalo • 3 week old seedlings of seven Pakchoi varieties were transplanted 7/26/12 at the Waimānalo 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.
It’s “Chile” in Hawai’i ‘Hawaiian’ type; C frutescens • Hot peppers are important in Hawai’i. • 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 Pepper TAMU Mild Habanero
It’s “Chile” in Hawai’i ‘Hawaiian’ type; C frutescens ‘Waialua’ Hot Pepper Photo courtesy Dr. Kevin Crosby TAMU Mild Habanero
Take Home Message • Variety is the most useful tool to maximize quality. • Stress can increase concentrations of some phytonutrients but decease yield • Minimize stress to optimize yield and quality.
Acknowledgements • Kleinhenz Lab (OSU) • Crosby Lab (TAMU) • Talcott Lab (TAMU) • Hue Lab (UHM) • UH Aquaponics Lab • Archana Pant • Jensen Uyeda • Amjad Ahmad • Roger Corrales • Servalano Lamer • Craig Okazaki • USDA Funding: • OREI • TSTAR • WSARE • Hatch