How is food quality affected by fertilization?

Functional food examples

Food Component Possible benefit

Green tea flavanols reduced cancer riskCruciferous veg. indoles,

isothiocyanates, carotenoids

cancer prevention

Flax (seeds,flour) lignands reduced cancer riskBerries

(blueberries, raspberries, etc.)

anthocyanidins, ellagic acid

Cancer and heart disease prevention, lower chosterolWhole grains saponins,

terpenoids, etc.Cancer and heart disease prevention, lower chosterol

From PPI

Phytochemicals

Science 285:377, 1999

Potassium increases total carotenoid content and quality of tomatoes

Trudel and Ozbun. 1971.

J. Amer. Soc. Hort. Sci. 96(6)

Nutrient solution Total carotenoids Change Meq K/l ug/g fr. wt. due to K, % Internal External

0.0 71.58 --- 1.86 3.310.5 64.97 -9 1.45 2.951.0 74.86 5 2.19 3.812.0 91.48 28 2.41 3.654.0 91.92 28 2.44 3.986.0 110.5 54 2.51 4.078.0 111.5 56 2.86 4.21

10.0 104.5 46 3.36 3.98Fruit rating 5=no disorders, 1=severly affected

Fruit rating

K influences lycopene and b-carotene content of tomatoes

Nutrient solution Lycopene Change -carotene Change Meq K/l ug/g fr. wt. due to K, % ug/g fr. wt. due to K, %

0.0 36.81 --- 3.48 ---0.5 33.75 -8 3.36 -31.0 41.88 14 3.62 42.0 53.6 46 3.07 -124.0 52.67 43 2.8 -206.0 59.33 61 2.8 -208.0 61.51 67 2.56 -26

10.0 52.39 42 2.36 -32

Trudel and Ozbun. 1971.

J. Amer. Soc. Hort. Sci. 96(6)

Effect of KNO3 on grapefruit carotenoids

B. Patil, 2001 (one year data)

Texas Rio Grande Valley

Treatments: F= fertigation, S= foliar

F1-Jan-Mar, F2-Feb-April, F3-April-June

S1-April-June, S2-May-July, S3- July-Sept

From PPI

F.B.T. Hernandez, J.C. ModestoI, M.A. SuzukiI, L.S. CorrêaI, K. Reichardt

Piracicaba, Braz. vol.51 no.2  Pircicaba May/Aug. 1994

Effects of irrigation and nitrogen levels on qualitative and nutritional aspects of fig-trees (Ficus carica L.)1

 

 

Increased yields may lead to nutrient dilution (plant growth is

increased more than nutrient uptake)