r-ipening accoivipanies maturation of the fruit on the tree. Thus^ with our 

 present Imowledge, the measurement of ripening appears to be the best approxi- 

 mation to the measurement of maturity. 



It is generally recognized that the more riiature peaches are i-ihen they are picked, 

 the shorter x-jill be the period required for them to ripen after harvest. Thus, 

 the time required for peaches to ripen after harvest is a good measure of 

 their maturity when picked. In this study we used the time required for 

 peaches to ripen after harvest to distinguish peaches that were mature when 

 picked from those that were no to 



The questions then arise: How long does it take mature peaches to ripen at 

 room temperatures and what ripening period, in terms of days should be used 

 to distinguish mature from immature peaches? Tlie ideal way to determine 

 these points would be to use a taste psjiel, since the overall aim of a more 

 e:-iact definition of maturity is fniit of better dessert quality for the con- 

 sumer. A taste panel is being used in a similar study on westem-grox-m peaches 

 by Paul Rood of our station at Fresno, California. But in our work on 

 eastern-groTfjn peaches this has not been possible because a trained taste panel 

 is not available and not infrequently fruit of borderline maturity from some 

 orchards have had better flavor on ripening than mature fruit from others. 

 Consequently, we have more or less arbitrarily called ma.ture all peaches that 

 ripened 8 days or less after harvest. Peaches requiring longer than 8 days 

 to ripen have been called 1101,-13 ture. A period of 8 days should allow ample 

 time for the transportation and marketing of the fruit. 



If our reasoning is sound, we are now in a position to know x-jhether a peach 

 x-;as m-ature or ii-niaature C days after harvest. However, this information is of 

 little value ujiless it can be translated into some objective measure tha\ can 

 be used at harvest. Of the many measurements of maturity that have been 

 suggested such as ground color, firmness, pit freedom, pit color, chemical 

 composition and fruit size, form and surface blush, the tx-jo that show the most 

 promise are firmness and. ground color. Since the measurement of ground color 

 xcLthout the use of special instruraents is at best partly subjective, the 

 emphasis in our studies has been placed on firmness, 



Tlie firmness of the fruit, as measured by the pressure tester, is the most 

 convenient, practical and objective test of maturity. VJhat is needed and x-:hat 

 we have attempted to d.o is to establish a pressure-test value or point that 

 could be used as a standard, abo\''e xjiiich peaches xjould be judged imiTiature and 

 below x^rhich they xiould be passed as mature, ¥ith a fruit as variable as the 

 peach, we cannot e:cpect to establish any maturity standard so precise that no 

 mature peaches xjould fail to pass or that no immature lots x-jould pass. Kox-xever, 

 it should be possible to establish a standard that x-rould keep the xvorst of the 

 imiaature frudt off the market x-jithout unduly delajd-ng the marketing of peaches 

 that are of satisfactory maturity. 



