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Abstract

Three mutants that have appeared in trellised plantings of ‘Manapal’ tomato (Lycopersicon esculentum Mill.) in western North Carolina are described. Waxy fruit produced fruit that had a waxy or sticky epidermis, corresponding to the description of the sticky peel (pe), gene. Light green foliage was completely associated with the waxy character. Red vascular had dark red vascular tissue in stems, roots, and petioles. This character was monogenic recessive, and may be the same as red vascular tissue (rvt). Dark green had darker green immature fruit and foliage and deeper red mature fruit than normal ‘Manapal’. It was phenotypically similar to other high pigment (hp) stocks observed, but had darker green fruit and increased beta-carotene content.

Abstract

Dormant one-year-old roots of American ginseng (Panax quinquefolium L.) were exposed to a range of stratification temperatures and times to define limits for these parameters and to quantify their effect on terminating rest when placed in a growing environment. Effective storage temperatures tested ranged from 0° to 9°C. A low percentage of roots produced tops with as few as 30 days of stratification; however, 60 to 90 days were required for 100% emergence. The number of days to emergence, after planting, decreased with increased time in stratification through the maximum storage time of 120 days. The number of days of dormancy (days in stratification + days to emergence) averaged 126 and was relatively constant over the range of effective temperatures and periods of stratification. The minimum predicted period of dormancy was 116 days and was associated with a derived 70 days in storage (1680 hr) at 3.1°. Root growth rate, after emergence, was greatest following 105 days of stratification.

Soil applications of dolomitic limestone and P fertilizer before seeding American ginseng (Panax quinquefolium L.) affected root weight (RW) gain during the first 4 years of growth. At the end of each growing season, root size was greatest with the intermediate liming rate and with the high P rate. Lime resulted in positive linear responses in soil pH, K, Ca, and Mg and in root N, P, Ca, and Mg and curvilinear responses in soil Mn and Zn and in root K, Mn, and Zn. Applied P had a positive linear effect on soil Na and on root N, Ca, and Fe and a curvilinear effect on soil P and on root P and Ca. Terminal RW was positively correlated with soil pH, K, Ca, Mg, and Na and with root P, K, Ca, and Mg; RW was negatively correlated with root Mn and Zn. Regression analyses implicated only soil Ca and Na and root Mg and Zn as significant terms in prediction equations,

Abstract

In studies of seasonal trends in apple leaf nutrients, 5 different seasonal leaf sampling methods using the same shoots of young and old apple trees have been compared with a sampling of mid-shoot leaves on different shoots each sampling date to determine whether there would be any differences in leaf P, K, Ca and Mg trends. Sampling methods resulted in significant interaction with the check only in data for leaf concentration of Ca. The methods which were compared with the check had average seasonal leaf concentrations of P, K, Ca and Mg which differed significantly from the check in a few instances. They also produced slightly to considerably lower coefficients of variation than the check in 78 of 100 possible comparisons. This makes such methods very desirable as alternative sampling procedures where they do not otherwise vary from the standard.

Abstract

Marketable yield increase of 100% resulted from trellising fresh market cucumbers (Cucumis sativus L.) over a 3-year period. Fruit were a more uniform, dark green color and graded more Fancy and fewer Culls. Fungicidal control of scab (causal agents Cladosporium cucumerinum Ell. & Arth.) was improved by trellising and losses to soil rot (causal agentsRhizoctonia solani Kuhn and Pythium spp.) were eliminated. Suggested reasons for improved yield and quality from trellising include less damage to vines, greater photosynthetic efficiency, improved pest control, and more efficient harvesting.

Abstract

Tomato leaf and fruit chlorophyll content of a dark green mutant (dg) of Lycopersicon esculentum Mill cv. Manapal was compared to +/+ and +/dg (within ‘Manapal’) and another high pigment line (hp/hp) from 111. 1252. The mutant dg/dg contained the highest chlorophyll a and total chlorophyll in the exocarp and mesocarp and per unit leaf area. The exocarp and mesocarp of hp/hp contained intermediate chlorophyll concentrations. The mutant dg/dg and hp/hp contained a greater mesocarp chlorophyll b concentration than +/dg or +/+.

Abstract

Single and multiple applications of 2,4-D to American ginseng (Panax quinquefolium L.) with fully expanded leaves during a 3-year period caused no visible injury to foliage or roots. During the final 2 years of the study, percent plant survival was greater with two applications per year than with one, and percent gain in root weight decreased with increased rate of application of the herbicide. Also, terminal weight of roots decreased with increased number of years of herbicide application. Treated plants did not differ from nontreated plants in percent survival, final root weight, or percent gain in root weight. Herbicide residue was not detected (<0.02 ppm) in roots from plants that received multiple applications of the three highest 2,4-D dosages: 0.56, 1.12, or 2.24 kg·ha⁻¹ a.i. Foliar residues were detected in plants treated once or twice per year for 3 years with 0.56 or 1.12 kg·ha⁻¹ a.i. 2,4-D. Chemical name used: (2,4-dichlorophenoxy)acetic acid (2,4-D).

Abstract

Azide as NaN₃ or KN₃ impregnated on clay granules gave excellent control of yellow nutsedge (Cypetus esculentus L.) compared to methyl isothiocyanate combined with chlorinated C₃ hydrocarbons (Vorlex) or a non-hand weeded control. Nematode control was obtained with all treatments. Significant yield responses from the use of azide were obtained with all crops.

Soil-applied dolomitic limestone and fertilizer affected the level of certain root and leaf ginsenosides in 4-year-old American ginseng (Panax quinquefolium L.); however, ginsenoside accumulations in the roots and in the leaves often were not similar. Root and leaf ginsenoside production tended to differ in its response to soil fertility (SF) factors and root tissue nutrient (RN) elements. Leaf ginsenoside production was more often correlated with SF factors and RN elements than that of root ginsenosides, the response of both ginsenoside sources was greater to RN than SF status. Leaf ginsenoside content was positively correlated with the SF factors and RN elements to a greater degree than that of root ginsenosides. Leaf ginsenoside production was more often affected by the same chemical element in the soil and in root tissue than that of root ginsenosides. There was no correlation between the level of any ginsenoside measured in root tissue and the same ginsenoside in leaf tissue.

Abstract

Broccoli plants (Brassica oleraceae L. var. italica Plenk) were grown in an air-conditioned, 22°/18°C day/night temperature, greenhouse in the Southeastern Plant Environmental Laboratories in Raleigh, N.C. Seedlings 6 to 33 days from seeding were exposed to cold treatments of −3° to −5° or +1° to +2° for periods of 7 to 34 days, then returned to higher temperatures. Days from seeding to flowering were determined. Plants 13 or more days from seeding and exposed to 14 or more days of cold treatment were induced to flower earlier than untreated plants. The critical stem size for cold inductions was 5 to 8 mm diameter. Susceptible plants weighed 4 to 50 g at the beginning of the cold treatment phase. Plants outside that range were nonsusceptible.