This investigation was undertaken to determine, from a dietetic
standpoint, the amounts and proportions of dextrose, levulose and
sucrose present in Bosc pears, and to furnish information that might
be of value in the development of by-products from the off-grade
fruit of this variety.
The attempt was made to carry...
A study has been made of the interrelations between certain of the physical and biochemical changes in three varieties of pears during storage and ripening. The metabolic changes which occurred in the fruit during cold temperature storage were found to influence with development of certain characteristics associated with dessert quality...
The nutrient elements needed for the optimum
growth and yield of pear trees is vitally important to the
pear growers. The knowledge of the amounts and kinds of
fertilizer to apply to obtain this growth could increase
the production and cut the costs for these growers.
Field experiments have been...
Investigations were conducted to study in detail some biochemical and physiological aspects of ripening in pears. Anjou pears
picked at different degrees of maturity were treated with Ethrel
(2-chloroethane phosphonic acid), 4000 ppm, and ethylene, 500 ppm,
for different lengths of time. Respiration rate was measured twice
daily and changes...
This investigation was undertaken to observe possible changes
in growth substances in Pyrus throughout the dormant period. The
primary objective was to determine if a correlation existed between
growth substance content and the inherent chilling requirement of
seeds and buds.
Samples of whole buds were taken at intervals from the...
The influence of evaporative cooling for delay of 'Bartlett' and
'Bosc' fruit bud development for frost avoidance was investigated.
Two mist systems, one in a mature pear orchard and the other in a
young pear hedgerow, delayed 'Bartlett' and 'Bosc' bloom up to 15 and
8 days respectively. A low...
The major phenolics of 'd' Anjou' pear (Pyrus communis L.)
tissues were chlorogenic acid and arbutin. Chlorogenic acid
inhibited mycelial growth and spore germination of Penicillium
expansum and mycelial growth of Mucor piriformis. Slight increases
in radial growth and spore germination of Botrytis cinerea occurred
on chlorogenic acid media. Chlorogenic...
The dynamics of N was studied in field grown Comice/Provence
quince BA29 pears in Medford, Oregon. Total tree biomass, N content,
and ¹⁵N evaluations suggest that young pears require little N (48 kg
N ha⁻¹ yr⁻¹). About 45% of total tree N present in dormant trees was
remobilized into new...
Appropriate micropropagation regimes were developed for four Pyrus species (P.
amygdaliformis Vill., P. betulaefolia Bunge, P. calleryana Dcne., and P. communis L.)
and Cydonia oblonga L. Shoot multiplication was optimal at 10 or 20μM N⁶⁻
benzyladenine (BA) and high light intensity (135μm⁻²s⁻1). Root formation of the
Pyrus species was stimulated...
There was a linear relationship of [alpha]-amylase activity
from 2 to 12 hours incubation in both freeze-dried and fresh
'd'Anjou' pear fruit tissue. Activity was greater, however,
in fresh as compared with freeze-dried tissues. [alpha]-Amylase
activity from both types of samples was not detected until
60 minutes incubation. After 90...
Volatile compounds of eight pear varieties were isolated and identified by
GC/MS. A total of 112 components were identified from headspace of intact fruits,
including 47 compounds reported for the first time in pear. The volatile profiles of
these pear varieties were characterized by esters, alcohols, hydrocarbons, aldehydes
and ketones....