Articles
Leaf and fruit nitrogen variability in a uniform population of ‘Wonderful’ pomegranates in California
Article number
1254_30
Pages
199 – 204
Language
English
Abstract
Commercial pomegranate fertilization strategies should provide adequate nutrients for optimized yield as well as minimizing environmental losses.
In-season sampling of leaves and harvest sampling of fruit are strategies to assess nutrient concentrations and crop nutrient removal.
To determine population dynamics, a uniform set of mature trees were monitored in California for two years, with 240 trees as individual units.
Trees were 6 rows (5.2 m) of 40 trees (4.3 m). All trees received a standard commercial fertilizer program, with no experimental treatments.
Both leaf and fruit were analyzed for total N content using commercial agricultural laboratory methods and equipment.
Expanded leaves from the exterior of each tree were collected from 0.6 to 1.6 m height, 100 tree‑1 each spring.
Leaves were precision washed, dried and ground.
For leaf N, year differences were statistically significant, as was tree row.
Mean percent N in 2014 was 2.23 and 2015 was 2.47. For 2014 and 2015 no consistent correlation was found between leaf N and fruit weight or fruit count per tree.
Fruit were strip harvested from each tree at maturity.
A random sample of ten fruit from 102 to 116 mm (size 22) per tree were washed, quartered, and opposite quarters homogenized.
A subsample of fruit puree was analyzed for moisture content and N. Unlike leaf samples, rows did not statistically impact fruit N. Correlation significance was not detected for fruit N and fruit per tree.
Percentages for moisture and N were significantly different between years, with 2014 having means of 76.2 and 0.98, and 2015 of 78.4 and 1.05. Pomegranate fruit N removal was measured as 2.30 kg t-1 fresh yield, and was not significantly different between years.
In-season sampling of leaves and harvest sampling of fruit are strategies to assess nutrient concentrations and crop nutrient removal.
To determine population dynamics, a uniform set of mature trees were monitored in California for two years, with 240 trees as individual units.
Trees were 6 rows (5.2 m) of 40 trees (4.3 m). All trees received a standard commercial fertilizer program, with no experimental treatments.
Both leaf and fruit were analyzed for total N content using commercial agricultural laboratory methods and equipment.
Expanded leaves from the exterior of each tree were collected from 0.6 to 1.6 m height, 100 tree‑1 each spring.
Leaves were precision washed, dried and ground.
For leaf N, year differences were statistically significant, as was tree row.
Mean percent N in 2014 was 2.23 and 2015 was 2.47. For 2014 and 2015 no consistent correlation was found between leaf N and fruit weight or fruit count per tree.
Fruit were strip harvested from each tree at maturity.
A random sample of ten fruit from 102 to 116 mm (size 22) per tree were washed, quartered, and opposite quarters homogenized.
A subsample of fruit puree was analyzed for moisture content and N. Unlike leaf samples, rows did not statistically impact fruit N. Correlation significance was not detected for fruit N and fruit per tree.
Percentages for moisture and N were significantly different between years, with 2014 having means of 76.2 and 0.98, and 2015 of 78.4 and 1.05. Pomegranate fruit N removal was measured as 2.30 kg t-1 fresh yield, and was not significantly different between years.
Authors
E.D. Wilkins, J.S. Iniguez
Keywords
Punica granatum, crop removal, sample technique
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