Four genotypes of shortleaf pine (Pinusechinata Mill.) were grown in open-top chambers in the Piedmont Region of South Carolina. The seedlings were exposed to several combinations of ozone (near zero, ambient, 1.7 × ambient, or 2.5 × ambient) and acid rain (pH 3.3, 4.3, or 5.3). Glucose, sucrose, total reducing sugars, and starch contents of the pine needles were determined initially and at 5- to 12-week intervals during the following 38 weeks of exposure. Needles exposed to acid rain and ozone treatments followed the seasonal trends normally encountered in carbohydrate content, but there were some statistically significant differences in the quantities of individual carbohydrate components after prolonged exposure. In general, those needles exposed to higher levels of ozone (1.7 or 2.5 × ambient) had lower levels of starch and sucrose, with higher levels of both glucose and total reducing sugars. The starch levels in needles exposed to elevated ozone showed decreased values throughout the dormant period at all pH levels. Similarly, the sucrose levels were significantly lower in the high ozone and high acid rain treatment after 38 weeks of exposure. These results indicate that air pollutants may be affecting the carbon allocation balance within the needles.

SUMMARY Pectic constituents were isolated from the alcohol insoluble solids of freestone peaches at four stages of ripeness. The varieties studied were Poppy, Loring, Southland and Rio Oso Gem. The pectic substances were fractionated into pectinic acids, pectic acids and protopectin fractions and the molecular weight of each fraction was calculated from its intrinsic viscosity value. The purity and degree of esterification of each fraction were determined. Corresponding shear press firmness values were also measured. Decrease in the molecular weight values of the pectinic acid fraction was found to be closely related to the increase in proportion of pectinic acids with advancing ripeness. A decrease in esterification of the pectic constituents with advancing ripeness was found mainly in the protopectin fraction. These changes were also closely related to the reduction in shear press firmness of the tissue during the ripening process in all varieties of freestone peaches studied. These results seem to provide a basis for studies of enzymatic reactions which influence fruit ripening.

SUMMARY— 150 broiler‐type chicks were reared from hatching to 4 wk of age on a low‐fat ration before being fed diets containing 10% of either corn oil, lard, beef tallow or hydrogenated coconut oil. Analyses of treatment effects were made at 2 wk intervals until the chicks were 10 wk old. The fatty acid content of extracted total lipids were characteristic of the dietary fats and dietary fatty acid patterns were incorporated into the adipose tissue within 2 wk after the experimental diets were fed. The total lipids when separated into solid fats and liquid oils at room temperature also reflected the fatty acid pattern of the experimental diets. Neutral triglycerides from the adipose tissue contained less linoleic acid and more palmitic and oleic acids than the total lipid fraction. High amounts of palmitic and oleic acids were observed in all of the fractions analyzed. No significant differences were found in total cooking loss, drip loss, taste preference, or TBA values of skin or adipose tissue among the 10 wk old chickens fed different experimental diets.

Detached mature green tomatoes were subjected to illumination from Gro-lux light source (max 675 nm) and/or ethephon treatments and ripened under controlled conditions. The color, texture and flavor parameters of the fruits from the mature green to the senescent stage of maturation were analyzed. The most striking effect of the treatment was on the color development of the fruit. Light treated samples reached lower reflectance (L), higher a/b values and a twofold increase in total carotenoids compared to fruits ripened in the dark. Ethephon advanced the color development of the fruit but had little effect on the final level of pigment concentration and L or a/b values. The final percent lycopene level of ripe tomatoes was not appreciably affected by either treatment. Senescent fruits, which continued to received light treatment, exhibited reductions in both a/b values and carotenoid levels. Decreases in firmness of the fruits were observed as a result of either light or ethephon treatment with the combined treatment giving the most noticeable effect. Other ripening characteristics including total solids, soluble solids, titratable acidity and pH of the puree were not significantly affected by either treatment.

Shortleaf pine (Pinus echinata Mill.) seedlings in 24 open-top chambers were exposed to combinations of ozone (carbon-filtered (control), ambient, 1.7 x ambient, and 2.5 x ambient) and acidic precipitation (pH 5.3, 4.3 and 3.3) for 16 months (1989 harvest) or 28 months (1990 harvest). Although the effects of acid rain were generally not significant, there was a trend toward increased aboveground biomass and leaf area in seedlings subjected to the low pH treatments. Because N concentrations in the soils generally increased with decreasing pH, we concluded that the effects of acid rain on aboveground biomass and leaf area were a consequence of an increasing concentration of soil N. In the 1989 harvest, seedlings in the 2.5 x ambient ozone treatment had significantly less biomass in all aboveground plant components and significantly less total leaf area than seedlings in the 1.7 x ambient ozone treatment. In the 1990 harvest, there were no significant effects of ozone on total aboveground biomass, although there was a trend toward reduced biomass in seedlings in the 2.5 x ambient ozone treatment. Both total leaf area and leaf biomass were significantly less in seedlings exposed to 2.5 x ambient ozone for 28 months than in both control seedlings and seedlings in the 1.7 x ambient ozone treatment. The greater, but not always significant, aboveground biomass and leaf area of seedlings in the 1.7 x ambient ozone treatment compared with control seedlings may be associated with the observed increase in soil nitrate concentration as a result of increased rates of leaf senescence and litterfall.