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United States Department of Agriculture

Agricultural Research Service

Related Topics

Research Project: Improving Quality and Maturity Consistency of ‘d’anjou’

Location: Physiology and Pathology of Tree Fruits Research

Project Number: 2094-43000-006-35
Project Type: Trust

Start Date: Jul 01, 2014
End Date: Jun 30, 2017

Objective:
1) Determine maturity and quality variation as impacted by tree and orchard management regimes. 2) Correlate pear quality, maturity, and chemistry with DA meter evaluation and storability.

Approach:
1) Determine maturity and quality variation as impacted by tree and orchard management regimes. New Trial 2014 We will identify 15 similar trees in a mature D’Anjou orchard trained at open vase for our tests. On six of these trees, we will harvest and weigh fruit in order to have the yield/tree and the number of pears/tree. Fruit from the remaining trees will be harvested according to the level of light (Fig. 1A), selecting fruit from two extreme light environments. Fruit that received less light (<30%) will be classified as internal, while those harvested from the outer layer of the canopy (71-100% of radiation) will be labeled as external (Fig. 1A). Fruit from these two different canopy positions will be kept separate and evaluated using the DA meter. This new non-destructive device evaluates peel and flesh degreening (ground color change) by estimating chlorophyll content (index of absorbance difference as reported in Ziosi et al., 2008) well correlated with the level of ripening of the fruit. The instrument can detect changes that are, sometimes, imperceptible to the naked eye and may allow sorting fruit into more homogenous ripening classes, as we have previously reported for cv. Abbé Fétel (Gagliardi et al., 2012). 2) Correlate pear quality, maturity, and chemistry with DA meter evaluation and storability. After harvest, fruit will be classified using the DA meter into four groups. These four groups will be sampled immediately or following 3, 6, and 9 months in CA: o T0= at harvest, no storage o T1= 3 months (CA) o T2= 6 months (CA) o T3= 8-9 months (CA) At each storage pull, fruit quality will be determined and peel and cortex will be sampled for analysis of natural pear chemicals. Approach Peel and cortex chemicals that comprise most aspects of fruit structure and quality will be evaluated using existing protocols adapted from apple fruit evaluation. Protocols will be expanded to include natural chemicals specific to pear. It is expected that, by comparing IAD classes, we will define the differences in fruit maturity and ripening potential to try to achieve enhanced postharvest performance for D’Anjou pear.

Last Modified: 10/21/2014
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