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72-7 Biophysical Responses of Young Pomegranate Tree to Different Irrigation and Nitrogen Treatments.
See more from this Division: ASA Section: Climatology & ModelingSee more from this Session: General Agroclimatology and Agronomic Modeling: I
Monday, November 3, 2014: 2:45 PM
Hyatt Regency Long Beach, Seaview A
Due to recurrent water shortages in California, many farmers are looking for crops that have
some degree of drought resistance and higher economic value. Pomegranate has been identified as
a crop with drought and salinity tolerance, and nutritional benefits. There are currently
approximately 6,000 ha of pomegranate under cultivation in California. However, very little is
known about pomegranate tree response to water and/or nitrogen requirements, especially, during
the early plant development. This study was conducted in two experimental orchard fields
located at the USDA-ARS San Joaquin Valley Agricultural Sciences Center and the University of
California Kearney Agricultural Research and Extension (UC KARE) Center in Parlier, CA in 2012-
2013. Both fields have automated weighing lysimeters to determine crop water use. The USDA-ARS
orchard was planted in 2010 with four surface drip irrigation levels: 35%, 50%, 75% and 100% of
crop water use determined by the weighing lysimeter. UC KARE orchard was also planted in 2010
with three nitrogen (N) rates: 50%, 100%, and 150% of the required N and two irrigation
methods: surface drip irrigation (DI) and sub-surface drip irrigation (SDI) all irrigated at
100% of crop water use measured by the weighing lysimeter. Canopy ground cover (fc), normalized
difference vegetation index (NDVI), canopy temperature, and leaf chlorophyll were measured
periodically in 2012-2013. In the USDA-ARS field, the results showed that ground-based NDVI was
highly correlated to fc, and fc was highly correlated to crop coefficient. Canopy temperatures
were higher in irrigation treatments of 30% and 50%, compared to those in the 75% and 100%
irrigation treatments. In the UC-KARE field, results showed that leaf chlorophyll meter
readings responded to N treatment rates; and SDI treatments had higher canopy ground cover
compared to DI treatments. In both fields, total fruit weight was highly correlated to crop
canopy cover. With a potential for increased acreage of pomegranate throughout California,
results from the study provide valuable information needed by both farmers and the water
district managers.
See more from this Division: ASA Section: Climatology & Modelingsome degree of drought resistance and higher economic value. Pomegranate has been identified as
a crop with drought and salinity tolerance, and nutritional benefits. There are currently
approximately 6,000 ha of pomegranate under cultivation in California. However, very little is
known about pomegranate tree response to water and/or nitrogen requirements, especially, during
the early plant development. This study was conducted in two experimental orchard fields
located at the USDA-ARS San Joaquin Valley Agricultural Sciences Center and the University of
California Kearney Agricultural Research and Extension (UC KARE) Center in Parlier, CA in 2012-
2013. Both fields have automated weighing lysimeters to determine crop water use. The USDA-ARS
orchard was planted in 2010 with four surface drip irrigation levels: 35%, 50%, 75% and 100% of
crop water use determined by the weighing lysimeter. UC KARE orchard was also planted in 2010
with three nitrogen (N) rates: 50%, 100%, and 150% of the required N and two irrigation
methods: surface drip irrigation (DI) and sub-surface drip irrigation (SDI) all irrigated at
100% of crop water use measured by the weighing lysimeter. Canopy ground cover (fc), normalized
difference vegetation index (NDVI), canopy temperature, and leaf chlorophyll were measured
periodically in 2012-2013. In the USDA-ARS field, the results showed that ground-based NDVI was
highly correlated to fc, and fc was highly correlated to crop coefficient. Canopy temperatures
were higher in irrigation treatments of 30% and 50%, compared to those in the 75% and 100%
irrigation treatments. In the UC-KARE field, results showed that leaf chlorophyll meter
readings responded to N treatment rates; and SDI treatments had higher canopy ground cover
compared to DI treatments. In both fields, total fruit weight was highly correlated to crop
canopy cover. With a potential for increased acreage of pomegranate throughout California,
results from the study provide valuable information needed by both farmers and the water
district managers.
See more from this Session: General Agroclimatology and Agronomic Modeling: I