FRUIT PRESSURE TESTERS 15 



test values of 12 pounds or more for Bartlett pears in a hard condition, 

 11.5 to 8 pounds for firm fruit, and 7.5 pounds or less for ripe fruit. 

 With Hardy pears, Pentzer 5 found that the fruit in the hard condi- 

 tion described by the Agricultural Marketing Service as giving to the 

 thumb pressure with a cracking noise tested 8 pounds or more; firm 

 pears, giving to pressure without breaking, tested from 7.9 to 5.6 

 pounds; and firm-ripe pears tested from 5.2 to 3 pounds. Lutz and 

 Culpepper (41) stated that Kieffer pears testing 3 to 4 pounds were 

 at optimum dessert or canning quality. 



With pears, the pressure test has been found of value as an index of 

 maturity, but has not proved satisfactory as a measure of ripeness 

 during cold storage. 



Peaches 



Peaches tend to mature unevenly on the tree and fruit of different 

 degrees of maturity are present at a time ; consequently, several pick- 

 ings are generally made, and the larger fruit of lighter green color is 

 picked first. The firmness or pressure test cannot be used as an index 

 to maturity except to indicate the size or color of fruit that should 

 be picked. Morris (51) studied the maturity and ripening of peaches 

 and concluded that the pressure test could often be used to determine 

 the color standards for each picking, but he did not recommend pres- 

 sure-test ranges for this. He indicated that the firmness or standards 

 may vary, depending on growing conditions. Coe (14) also indicated 

 that the pressure test and color standard may vary but considered 

 the tree vigor to be an important factor. Blake and Davidson (10) 

 also found that tests for the firmness of flesh should be employed as a 

 supplement to the color basis for judging degree of maturity or ripe- 

 ness and gave two sets of standards, depending on the distance of 

 shipping. 



Pressure-test standards of maturity that have been determined for 

 peaches are presented in table 4. The standards for Colorado and New 

 Jersey are generally higher than those for California and Virginia, as 

 they are based on tests of unpared peaches. With Elberta peaches, 

 tests on the unpared surface are reported (10) to be 2.5 pounds higher 

 with soft-ripe fruit and 6.4 pounds higher with shipping-ripe fruit 

 than tests on pared surfaces. If such allowance is made for the skin, 

 the New Jersey and Colorado results become as low as or lower than 

 those reported for California and Virginia. Based on 1 year's results 

 with several varieties (Hiley, Champion, Early Crawford, Late Craw- 

 ford, Augbert (Roberta), and Slappey), Haller and Harding (27) 

 stated that the pressure tests were fairly uniform for the different 

 varieties and indicated that for many eastern-grown varieties a pres- 

 sure test of 14 to 10 pounds at harvest represents a condition of the 

 fruit at which it ripens with good dessert quality and would hold up 

 well for shipping. Additional studies might indicate a modification of 

 these recommendations. In view of the results for other varieties it 

 seems likely that the recommendation for Carman, given in table 4, 

 should also be somewhat higher (i. e., probably 13 and 10 pounds). 



As with pears, the pressure tester has not been found of value in 

 following the ripening of peaches in cold storage. Haller and Harding 

 reported very little or no softening of shipping-ripe peaches at 



Unpublished data by W. T. Pentzer. 



