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Abstract
The arrival of spring is signaled by masses of bright-yellow forsythia flowers in much of east-central United States, but in more northern areas, the forsythia flower buds often do not survive the winter. ‘Sunrise’ is the result of our program to develop new cultivars with increased flower-bud hardiness.
Abstract
Twenty-seven lines of Impatiens, including I. mooreana Schlect and I. schlecteri Warb, were screened for resistance to the two-spotted spider mite, Tetranychus urticae Koch, in both spring and fall of 1979. The assocation of this resistance with cuticle content of the leaves was tested. Different lines showed different resistance levels and resistance and cuticle content of the leaves was significantly correlated.
Abstract
Weigelas were popular in Western Europe during the late 1800s and early 1900s and the French and Germans released scores of cultivars (1). Since that time, cultivar releases have been sporadic. The exception was a government breeding program in The Netherlands, which resulted in a number of cultivars being released in the 1950s (3).
Abstract
Plural-seeded acorns of bur oak (Quercus macrocarpa) were observed in seven of 18 trees, with one tree producing acorns containing as many as five seeds. The frequency of plural-seeded acorns for individual trees ranged from 0% to 62%. There was no correlation between diameter of acorns and number of seeds per acorn.
Abstract
Tomato plants, cvs. Campbell 1327 in 1967 and Heinz 1350 in 1968, were grown in 6 plastic greenhouses (2,4-D added, filtered or ambient atmospheres) and outside plots.
The effect of 2,4-D added application on the yield and appearance of tomatoes was observed. Measurements were made of total solids content, color, amount of pigment and pH of juice from the tomatoes. Flavor of juice was evaluated by a trained laboratory taste panel.
Although plants in greenhouses with 2,4-D added tended to produce fewer, but larger, fruit than the other treatments, no significant differences were found among the treatments on yield of fruit per plant. But pH, color, beta-carotene, total pigment and flavor of juice were not affected. The lycopene content was similar for the tomato juices from fruit grown in the various greenhouses. But the juice from tomatoes grown in outside plots had a lycopene content significantly lower than that from tomatoes grown in greenhouses. The trace level of 2,4-D used had a significant effect (P<0.005) on total solids content of the juice.
Abstract
Dime thy letrachloroterephthalate (DCPA) and N,N-dimethyl-2,2-diphenylacetamide (diphenamid) were effective herbicides for sweetpotato on coarse sand soil. DCPA applied through a sprinkler irrigation system proved effective and reduced costs.
Exposure to exogenous ethylene (C2H4) caused corolla abscission of New Guinea impatiens (Impatiens × hawkeri `Sunfire'). Abscission varied with time of exposure and C2H4 concentration. Ethylene at ≥ 1 μl·liter-1 and exposure times of 4 or more hours caused 80% to 100% corolla abscission. Simulated shipping of untreated control plants caused ≈ 65% corolla abscission. Plants pretreated with silver thiosulfate (STS) and (aminooxy)acetic acid (AOA) and subsequently exposed to simulated shipping were not different from one another, and both treatments reduced corolla abscission to ≈ 20% when applied at 1.0 mm. Plants pretreated with STS and exposed to `exogenous C2H4 showed 0% abscission, whereas plants pretreated with AOA showed no reduction in abscission when compared with control plants.