bluuebunny/crossref_metadata_2025 huggingface dataset:
A Gynoecious Line of B+B+ Genotype in Cucurbita pepo
Authors: Shifriss Oved
Published: September 2022

A phenotypically sensitive gynoecious line of Cucurbita pepo L., NJ34, has been synthesized recently through crosses of monoecious inbreds and selection (3). NJ34 is 100% pistillate in some environments, but it differentiates a few staminate flowers in other environments. This line is BB, in which gene B conditions precocious yellow pigmentation of fruit. Since previous observations suggested that B can also increase female expression (1), a question arose: Is B essential for the synthesis of gynoecism in this species?
‘Hansen 2168’ and ‘Hansen 536’: Two New Prunus Rootstock Clones
Authors: Kester Dale E. , Asay R. N.
Published: September 2022

Two new, patented, vegetatively propagated Prunus rootstocks are being released for commercial use. These rootstocks are hybrids of an almond selection, Almond B, crossed with Peach Selection 1-8-2 by the late Carl J. Hansen. These rootstocks are being released primarily for use with almond but also can be used as rootstocks for peach, plum, and prune.
The University Arboretum, Univ. of California, Davis
Authors: Roberts Warren G.
Published: September 2022

The University Arboretum is located on the Davis campus of the Univ. of California. It occupies about 100 acres along the banks of ancient Putah Creek and is close to the middle of the Great Central Valley of California. The prevailing climate closely resembles that of the Mediterranean region, with cool, wet winters and hot, dry summers in which a range of adapted plants will flourish. The extensive collections well illustrate the variety and brilliance of trees, shrubs, and perennials adapted to grow in such conditions.
Orchard Floor Management: An Overview
Authors: Skroch Walter A. , Shribbs J. M.
Published: September 2022

One of the authors (Skroch) has been asking himself since the early years of a long-term study initiated in 1966 (77) “What is a weed to a tree?” Apple trees in the mowed grass check plots grew less than in plots with woody vines. In another test comparing mowed sod, contact herbicide, and residual plus contact herbicide, trees having an herbicide program yielded 400 bushels/acre more fruit in the 5th year than those without. Apples in another orchard were of higher grade in plots with over 50% trailing blackberry (Rubus sp.) and poison ivy (Rhus radicans L.) ground covers than those from an area with a mowed-lawn appearance. The practice of frequent mowing, which increased grass covers in the 1960s, may have been a factor in the small fruit problem of the 1970s.
Comparison of 14 Methods to Determine Heat Unit Requirements for Cucumber Harvest
Authors: Perry Katharine B. , Wehner Todd C. , Johnson Gregory L.
Published: September 2022

Fourteen methods of calculating heat units from planting to harvest were applied to daily maximum and minimum air temperatures taken in a standard weather shelter for 2 growing seasons (spring and summer) over 5 years of cucumber (Cucumis sativus L.) plantings in North Carolina. The coefficient of variation (cv) was used to determine which of the methods was most reliable in predicting day of first harvest. The best method was to sum over days from planting to harvest the difference between the daily maximum and a base temperature of 15.5°C; but if the maximum exceeded 32°, it was replaced by 32° minus the difference between the maximum and 32°, before subtracting the base. This method had a cv of 3%, compared with 10% for the standard method—numbers of days from planting to harvest.
Undercutting Onions
Authors: Maw Bryan W. , Smittle Doyle A.
Published: September 2022

Dry onions of the Granex type were undercut during harvest operations using both oscillating and rotating bar undercutters. Analyses on cleanliness, damage, and disturbance revealed that operating the rotobar with a rotational speed of 540 rpm, a depth of 25 mm below the soil surface, and a forward speed of 6.4 km·hr−1 ensured the most favorable results of the operating speeds, depths, and forward speeds evaluated. Depth of operation was the most important single factor.
The Effect of Woven Plastic Mulch, Herbicides, Grass Sod, and Nitrogen on ‘Foch’ Grapes Under Irrigation
Authors: Stevenson D. S. , Neilsen G. H. , Cornelsen A.
Published: September 2022

Three soil surface treatments were compared for grape production under irrigation. Plastic mulch was superior to glyphosate and to grass sod in producing yields during the first 2 years of production. By the 3rd year, the glyphosate treatment was equal to the plastic and both were superior to grass sod. Cluster weights and pruning weights were suppressed by grass sod, compared with plastic or herbicide, but were unaffected by nitrogen. Nitrogen fertilizer treatments had no measurable effects on the grapevines and showed no interaction with the soil surface treatments. None of the treatments (soil surface or fertilizer) had any effect on berry soluble solids. The use of plastic mulch is an effective cultural technique, the usefulness of which will depend mostly on cost and environmental comparisons with herbicides.
Response of African Violets to Fertilizer Source and Rate
Authors: Poole R. T. , Conover C. A. , Ozeri Y.
Published: September 2022

Six cultivars of African violet (Saintpaulia ionantha H. Wendl) were grown during 2 seasons. Three fertilizer sources were used: Osmocote 1) 13N-6P-11K; 2) 14N-6P-12K; and 3) 50% each of 13N-6P-11K and 14N-6P-12K (1:1 by weight). Five fertilizer rates, 0, 0.75, 1.5, 2.25, and 3.0 kg·m−3 were tested in factorial combinations for a total of 15 treatments. Source of fertilizer usually had no effect on plant grade, number of flowers, number of days to first flower, number of leaves, total leaf area, and weight. When differences were significant, results were variable. Fertilizer rate affected indicators consistently, with the exception of number of days to flower, which was unaffected in 10 of the 12 experiments. Plant grade increased with an increase in fertilizer to 2.25 kg·m−3 in 11 of 12 experiments, but 3.0 kg·m−3 did not improve plant grade in 7 of 12 experiments. The remaining indicators responded similarly. More flowers were produced during the warm season than during other months.
Effect of Flowers on Stem Elongation in Easter Lily
Authors: Gianfagna T. J. , Wulster G. J. , Teiger G. S.
Published: September 2022

Internode elongation in lily (Lilium longiflorum Thunb.) increased significantly in the uppermost internodes during the development of the flowers. The last 4 internodes contributed as much to plant height as the first 30 internodes. Removal of the flowers reduced internode elongation, and within the range of 1–4 flowers per plant, length of the uppermost internodes was directly related to flower number. Removal of the perianth of the flowers was almost as effective as defloration in reducing internode growth. Application of gibberellic acid to decapitated stems completely replaced the effect of the flowers, whereas indoleacetic acid was only partially effective in restoring internode growth.
Zoysiagrass Competition in Two Cool-season Turfgrasses Treated with Plant Growth Regulators
Authors: Fry J. D. , Dernoeden P. H.
Published: September 2022

This study was conducted to determine if the rate of ‘Meyer’ zoysiagrass (Zoysia japonica Steud.) establishment and spread could be enhanced when plugs were introduced into plant growth regulator-(PGR) treated Kentucky bluegrass (Poa pratensis L.) and perennial ryegrass (Lolium perenne L.) turfs. During the first growing season, PGR treatment made little difference in zoysiagrass spread. Zoysiagrass coverage in perennial ryegrass treated with mefluidide (57%) or amidochlor (63%) was significantly greater than in ryegrass treated with ethephon (47%) or the untreated control (48%) by the end of the 2nd year. Enhanced zoysiagrass spread in perennial ryegrass treated with mefluidide and amidochlor was attributed to stand thinning resulting from PGR phytotoxicity and environmental stress in the first year. Zoysiagrass coverage in Kentucky bluegrass was greatest in mefluidide-treated plots, but the increase over the control was only 6%. Flurprimidol slowed the establishment of zoysiagrass in both cool season turfs. Chemical names used: [(N-[(acetylamino)methyl]-2-chloro-N-(2,6-diethyl phenyl)acetamide (amidochlor); (2-chloroethyl)phosphonic acid (ethephon); α-(l-methylethyl)-α-[4-(trifluoromethoxy)phenyl]-5-pyrimidinemethanol (flurprimidol); and N-[2,4-dimethyl-5-[[(trifluoromethyl)sulfonyl]amino]phenyl]acetamide (mefluidide).
Film Wrapping to Alleviate Chilling Injury of Bell Peppers during Cold Storage
Authors: Miller W. R. , Risse L. A.
Published: September 2022

Bell peppers (Capsicum annuum L.), individually wrapped in plastic film or nonwrapped, were held 7, 14, or 21 days at 1°, 4°, or 7°C plus an additional 5 days at 15° to evaluate the effect of film wrapping on chilling injury. Film wrapping did not reduce the incidence of visible chilling injury on either pericarp or seeds. Chilling injury was progressively more severe the lower the storage temperature.
Effects of Vegetable Oils, CO2, and Film Wrapping on Chilling Injury and Decay of Lemons
Authors: McDonald R. E.
Published: September 2022

Film wrapping or holding for 3 days at 21°C reduced chilling injury (CI) and decay of ‘Bearss’ lemons (Citrus limon Burm. f.) stored at 1° for 21 days plus 14 days at 21°. Prestorage treatments of 40% CO2 for 3 days at 21° or dips in 2%, 10%, or 20% vegetable oils were not effective in reducing CI or decay during a similar storage and holding period. The use of 10 μl·liter−1 ethylene to degreen lemons significantly increased CI and decay compared to degreening without ethylene, especially when lemons were stored at 1°.
Effect of Postharvest Moisture Stress on the Keeping Qualities of Douglas-fir Christmas Trees
Authors: Chastagner Gary A
Published: September 2022

On placement of their freshly cut bases in water, cut douglas-fir Christmas trees, which had dried to −2.0 or −3.0 MPa, rehydrated to about −1.0 MPa within 24 hr, and limited needle loss occurred as their water potential gradually decreased to − 6.0 MPa during display. Only 90% and 75% of the trees, dried to water potentials of −4.0 or −5.0 MPa, respectively, rehydrated when placed in water, and water potentials of these trees increased to −1.9 and −2.8 MPa, respectively. About 40% of the trees dried to −4.0 or −5.0 MPa exhibited severe needle loss, characterized by complete abscission of fresh-appearing needles from the stem within a few days of rehydration. These data indicate that douglas-fir has a threshold water potential between − 3.0 and − 4.0 MPa. When trees were allowed to dry to or below this threshold, tree quality was significantly reduced.
Response of Eggplant to a Root Environment Enriched with CO2
Authors: Baron J. J. , Gorski S. F.
Published: September 2022

Several elevated concentrations of CO2 were injected into the root atmosphere to determine the influence of CO2 concentration in the soil on the growth of eggplant (Solanum melongena L.). Elevated CO2 levels in the root atmosphere consistently increased stem diameter while a significant increase in plant total dry weight and leaf area only occurred during long day/warm temperature conditions. Under periods of short days and low light levels, 15% CO2 reduced total dry weight and leaf area. Applications of 14CO2 to the root zone demonstrated that 14C eggplant roots absorb CO2 from the soil environment and translocate labeled compounds into the shoot.
Stimulation of Plant Growth in Pumpkin by Ozone
Authors: Rajput C. B. S. , Ormrod D. P.
Published: September 2022

Pumpkin (Cucurbita moschata Duch. cv. Large Round) seedlings were exposed to 0, 0.1, 0.2, or 0.4 μl·liter−1 ozone for 6 hr·day−1 for 3 days. The naturally chlorotic zones of the leaf became green after ozone exposure. Rate of seedling development was not changed by the ozone treatments, but shoot fresh and dry weights were increased by the 0.2 or 0.4 μl·liter−1 ozone concentrations.
Evidence for a Short-day Flowering Response in Heliconia stricta ‘Dwarf Jamaican’
Authors: Criley Richard A. , Kawabata Osamu
Published: September 2022

A seasonal pattern of flowering was observed in field production records of Heliconia stricta Huber. ‘Dwarf Jamaican’. That this seasonality could be photoperiod-related was indicated in greater yields for plants grown under 8-hr daylengths for 6 weeks when compared to plants given natural daylengths (about 13.5 hr). Depending on the capacity of the plant to respond to photoperiod, 3 or 4 weeks of short daylength (SD) were sufficient durations for flower initiation. Leaf number affected the response, as only 4% of pseudostems with <3 leaves at the onset of SD yielded flowers, while 91% of pseudostems with ≥4 leaves at the onset of SD produced flowers. From the start of SD, about 13 weeks were required for development of the inflorescence to anthesis for pseudostems starting with ≥4 leaves.
Variation Within Vaccinium darrowi Blueberry in Florida
Authors: Lyrene P. M.
Published: September 2022

Ten colonies of Vaccinium darrowi Camp were sampled at each of 9 sites in the Florida panhandle and 6 sites in and around the Ocala National Forest in the central Florida peninsula. The colonies averaged 53 cm tall in the panhandle, with leaves 9.8 mm long and 4.1 mm wide. By contrast, colonies in the peninsula averaged 136 cm tall—well outside the range described for the species—with leaves 12.7 mm long and 5.7 mm wide. The species was diploid and entirely evergreen in both regions. In the central Florida peninsula, natural hybrids between V. darrowi and a 3-m tall, deciduous, diploid race of highbush blueberry (V. corymbosum L.) are common where streams and lakes border the dry scrub habitat of V. darrowi. The robust form of V. darrowi in the Florida peninsula may have evolved from the petite form in the panhandle as a result of introgression from the highbush coupled with selection for characteristics that enhance survival on the deep, xeric sands of the peninsula. V. darrowi from the central peninsula has characteristics that make it valuable in breeding blueberry cultivars.
‘Hidalgo’ Serrano Pepper
Authors: Villalon Benigno
Published: September 2022

The major diseases responsible for the decline of profitable pepper (Capsicum annuum L.) production in Texas have been the potato-Y-type viruses. This viral complex also causes major losses in the pungent serrano-type pepper. The hot serrano, one of about 20 different cultivated types, has fruits that may be between 2 to 10 cm long by 1 to 1.5 cm in diameter, conical to cylindrical and tapering to a pointed or blunt end. It is grown throughout the United States but is most popular in the southwest.
Pear Fruit Growth and the Use of Diameter to Estimate Fruit Volume and Weight
Authors: Mitchell P. D.
Published: September 2022

From the mean of weekly measurements of diameter, volume, and weight of the pear (Pyrus communis L. ‘Bartlett’ and ‘Packham Triumph’), equations were developed for predicting fruit volume and weight from diameter. Equations also are presented for the relationship between days from full bloom and diameter and length (linearly related) and volume, fresh weight, and dry weight (curvilinearly related).
Nitrogen Source Effects on Growth and Tissue Content of Selected Foliage Plants
Authors: Conover Charles A. , Poole Richard T.
Published: September 2022

Nine nitrogen fertilizer treatments composed of 25% NH4:75% NO3, 50% NH4:50% NO3, 75% NH4:25% NO3, 25% urea:75% NO3, 50% urea:50% NO3, 75% urea:25% NO3, 100% NH4, 100% urea, and 100% NO3 were applied to Aglaonema Schott, × Silver Queen, Dieffenbachia maculata (Lodd.) G. Don ‘Camille’, Aphelandra squarrosa Nees ‘Dania’, Chamaedorea elegans Mart., Nephrolepis exaltata (L.) Schott. ‘Florida Ruffle’, Peperomia obtusifolia (L.) A. Dietr., and Philodendron scandens oxycardium (Schott) Bunt. Growth and grade of Dieffenbachia and Nephrolepis were not influenced by N source, whereas Aglaonema and Philodendron were improved when they received N sources containing 25% to 100% NH4-N or 100% urea-N. Aphelandra, Chamaedorea, and Peperomia responded to N source, but differences were of no commercial significance.
ACC and Ethylene Levels in ‘d’Anjou’ Pears in Air and Controlled-atmosphere Storage
Authors: Blankenship Sylvia M. , Richardson Daryl G.
Published: September 2022

‘d’Anjou’ pear fruit (Pyrus communis L.) stored at −1°C for 125 days in 3% O2, or 153 days in 1% O2 storage had internal ethylene levels equal to those of air-stored fruit. Fruit softened faster during subsequent ripening at 20° after 1% or 3% O2 storage than after air storage. Endogenous ACC levels were 20 times higher in fruit stored in 1% or 3% O2 compared to air-stored fruit. Exogenous application of 5 mm ACC stimulated at 2-fold increase in ethylene production from 1% O2-stored fruit and a 4-fold increase in air-stored fruit. When 5 mm ACC, in combination with 0.05 mm cycloheximide (CHI), an inhibitor of protein synthesis, were supplied exogenously to disks cut from pears stored in air or 1% O2, the air-stored fruit produced 100 times more ethylene than 1% O2-stored fruit. Increased internal ethylene levels and accelerated softening during ripening of 1% or 3% O2-stored fruit suggests the need for rapid marketing of this fruit as compared to air-stored fruit. Chemical names used: 1-aminocyclopropane-l-carboxylic acid (ACC), 3-[2(3,5-dimethyl-2-oxocyclohexyl)-2-hydroxyethyl glutarimide (cycloheximide).
Girdling as a Means of Shortening the Juvenile Period of Avocado Seedlings
Authors: Lahav E. , Zamet D. , Gazit S. , Lavi U.
Published: September 2022

Shortening the juvenile period is highly important for fruit tree breeding projects. Four girdling dates were tested in an attempt to shorten the juvenile period in 9 crosses of 3-year-old avocado (Persea americana Mill.) seedlings. Early September girdling was more effective than later or no girdling. It increased flowering intensity significantly, increased the percentage of seedlings that set from 15% to 66%, and increased 7-fold the number of fruits harvested per seedling as compared with the ungirdled control.
Variance Components and Sampling Procedures for Fruit Size and Quality in Sour Cherry
Authors: Iezzoni A. F.
Published: September 2022

Fruit from 2 trees of each of 17 sour cherry cultivars were harvested in 1983 and 1984 and evaluated for 6 traits: fruit diameter and length, fruit firmness, soluble solids, and pit length and width. The amount and relative importance of the genetic and environmental variability were determined and used to develop a sampling scheme required for a specific level of genetic discrimination. Genetic differences accounted for the major component of the variability for fruit diameter and length and pit length and width. Soluble solids was the only trait with a significant year variation and year × cultivar interaction. In general, 5 fruit per tree and 2 trees per cultivar would detect the desired differences for fruit diameter and length and pit length and width, while a larger number of replications would be necessary to detect genetic differences for fruit firmness and soluble solids.
A Comparison of Two Methods for Measurement of Fruit Strength in Red Raspberry
Authors: Robbins JoAnn , Sjulin Tom
Published: September 2022

Fruit strength in red raspberry was measured using a cohesion method that determines the force required to pull a fruit apart. This method was compared to the compression method, which measures the force required to flatten the fruit. Fruit maturity significantly affected accuracy; the cohesion method was most variable for ripe fruit. A relatively low coefficient of variation across all maturity types indicates that the compression method is preferable for between-maturity comparisons, using a log transformation to produce variance homogeneity. With both methods, red ripe-stage raspberries showed significant differences between clones; the coefficients of variation for each method were similar within each clone. Variances were homogeneous using either method. The cohesion method gave relatively low absolute measurements that were highly correlated with those obtained using the compression method. Therefore, either method should be acceptable for measurements made within one maturity type.
‘Pontikis’ Pistachio
Authors: Pontikis C. A.
Published: September 2022

‘Pontikis’ is a high-yielding cultivar, with a high percentage of nuts with split shells.
Methods of Studying Root Systems in the Field
Authors: Taylor H. M.
Published: September 2022

Growing plants require photosynthetically active radiation (PAR), water, 15 to 20 elements (37), and the absence of lethal factors. Although most of the water and mineral elements used by plants is absorbed by roots, root systems have been studied in much less detail than plant tops. Part of this deficiency may be due to the “out of sight, out of mind” syndrome, but most of the deficiency occurs because root studies usually are much more time-consuming, more labor-intensive, and more costly than shoot studies. As one example, several related experiments were conducted during the 1979 growing season to obtain insight into the reason(s) why narrow-row soybeans (Glycine max L. Merr. ‘Wayne’) outyield soybeans grown in conventional meter-wide rows (2, 13, 16, 17, 21, 22, 25, 34). Much more data were collected above-ground than below the soil surface, but the above-ground measurements required only about one-half as much labor as the below-ground measurements.
Root Systems in Relation to Stress Tolerance
Authors: Miller D. E.
Published: September 2022

Roots anchor the plant in the soil, absorb and translocate water and nutrients, synthesize and transport growth regulators and other organic compounds, provide a sink for carbohydrates from the shoots, and in some species act as storage organs. Most research on roots has dealt with their role in absorption. Root characteristics that affect the area of absorbing surface are important, i.e., root length density, number and type of root hairs, and mycorrhizal relations. With nutrients that diffuse slowly in the soil, such as P and K, root density is especially important. Factors that reduce root growth may injure the plant by reducing the volume and intensity of soil exploration. Fortunately, plants produce more roots than are needed for normal growth–insurance that the plant can survive stresses, purchased at a cost of the increased photosynthate and other materials required for the extra root production.
Genetic Variability in Root Systems Associated with Nutrient Acquisition and Use
Authors: Gabelman W. H. , Gerloff G. C. , Schettini Terry , Coltman Robert
Published: September 2022

Variability within the plant kingdom for nutrient acquisition and use reflects differences in root morphology and differences in mechanisms that either aid or prevent ion movement into the root. This variability implies genetic variance, yet few genetic studies have been completed. Methods of studying acquisition and their application to genetic research and interpretation are presented for K, Ca, and P.
Vesicular-Arbuscular Mycorrhizae in Vegetable Crops
Authors: Miller J. Creighton , Rajapakse Sriyani , Garber Randall K.
Published: September 2022

Mycorrhiza refers to a mutualistic, symbiotic relationship formed between fungi (Gr. mukes) and living roots (Gr. rhiza) of higher plants. These associations are prevalent among most plant species and have been observed in most vegetables except the Cruciferae and Chenopodiaceae. In fact, some vegetables do not appear to grow or develop normally without mycorrhizae. In addition to their wide distribution in the plant kingdom, these nonpathogenic relationships are geographically ubiquitous. Thus, the mycorrhizal condition is the rule, as both host plant and fungus specificity is minimal and usually not observed.
Split-root Water Application to Highbush Blueberry Plants
Authors: Abbott John D. , Gough R. E.
Published: September 2022

Watered split-root portions of 2-year-old plants of ‘Bluecrop’ blueberry (Vaccinium corymbosum L.) exhibited significantly greater shoot dry weight, shoot thickness, shoot length, mean number of shoots, and leaf dry weight than nonwatered portions. Watered portions blossomed, produced fruit, and set new flower buds while existing flower buds died and no new flower buds formed on the nonwatered portions.
Resistance of Cucumber Lines to Rhizoctonia solani Damping-off: Not Related to Fruit Rot Resistance
Authors: Booy Gerdien , Wehner Todd C. , Jenkins Samuel F.
Published: September 2022

Seedlings of 35 cucumber (Cucumis sativus L.) lines were evaluated for resistance to damping-off caused by Rhizoctonia solani Kuhn. Five variables were measured, with the corrected disease rating (a rating for disease severity including a correction for seed vigor) being the most useful. Differences in resistance occurred among the lines, with ratings varying from 1.5 to 5.9 on a 0 (no disease) to 9 (plant dead) scale. The ratings for damping-off resistance were compared with ratings collected previously for rhizoctonia fruit rot resistance. The correlations were low and nonsignificant (r = −0.19 to −0.10). Thus, the damping-off test would not be a good substitute for the fruit rot test.
Seedling Screening Techniques to Select High-yielding Genotypes of Sweet Potato
Authors: Bouwkamp J. C. , McArdle R. N.
Published: September 2022

Selection of seedlings for early development of storage roots, either directly or indirectly using cold temperature (7°-10°C), increased the proportion of high-yielding genotypes in subsequent populations. Although both techniques described are somewhat inefficient, retaining some low- and high-yielding genotypes, they may be useful in selection at the seedling stage, permitting the breeder to evaluate a larger number of seedlings.
A Hypothesis for Inheritance of Resistance to Cane Botrytis in Red Raspberry
Authors: Daubeny Hugh A.
Published: September 2022

Reaction to cane Botrytis was determined for 43 red raspberry cultivars and selections and for seedlings of 25 progenies. Although there were some variations in relative reactions, it was possible to class the cultivars and selections as resistant or susceptible after examinations in at least two years. Segregations in the seedling populations suggested that two gene pairs might be involved in the reaction to the disease with the presence of at least two dominant genes necessary to give a resistant reaction. Postulated genotypes should be of predictive value in the choice of parents.
An Automated Apparatus for Measuring Root Length
Authors: Barnett C. E. , White R. A. , Petrovic A. M. , Good G. L.
Published: September 2022

Root lengths of an adventitious root system (creeping bentgrass, Agrostis palustris Huds.) and a woody plant fiberous root system (Hetz juniper, Juniperus chinensis L. ‘Hetzii’) were estimated using an automated method employing a video camera and an area/length meter to count scanning line and root intersections. A grid method of root length estimation was used for comparison. Under- and overestimation was random when the automated method was used for creeping bentgrass samples (<80 cm) and the shorter group of juniper root samples (150-550 cm). However, these estimates were much closer to the actual root length, in the ranges evaluated, than the estimates from the grid method. The lengths of long juniper root samples (600-3000 cm) were underestimated consistently with the automated method. The magnitude of this underestimation increased with increasing length. However, the relationship between estimated and actual root length remained linear and was about 76% of the actual length. For the ranges of root length evaluated, this method was found to be useful for root length estimation.
GARDPLAN—an Integrated Data Base Program for Vegetable Gardening in North Dakota
Authors: Smith R. C. , Askew R. G. , Egeberg R. , Franklund D.
Published: September 2022

Vegetable garden planning software for personal computers is gaining in popularity (3). The program described herein (GARD-PLAN) provides a listing of vegetable crops from which the user makes selections. Cultural recommendations are made, and yields are projected based on the selections made in the program. A 3-year study to determine the dollar value of vegetable gardens in the 40 counties in North Dakota showed that the average value per garden was about $400, with the highest-valued garden at over $1200 (1). Therefore, vegetable gardening can result in significant savings relative to fresh produce purchased during the growing season.
‘Sumor’, A Multi-use Sweet Potato
Authors: Dukes P. D. , Hamilton M. G. , Jones Alfred , Schalk J. M.
Published: September 2022

‘Sumor’, a multi-use sweet potato [Ipomoea batatas (L.) Lam.], was developed jointly by the Agricultural Research Service, U.S. Department of Agriculture, U.S. Vegetable Laboratory, and Clemson Univ., South Carolina Agricultural Experiment Station, Edisto Research and Education Center. This cultivar has potential as a high dry matter type for ethanol production and as a white-fleshed garden potato.
‘Chippewa’ and ‘Huron’ Viburnum
Authors: Egolf Donald R.
Published: September 2022

Viburnum japonicum (Thunb.) Spreng. × Viburnum dilatatum Thunb. ‘Chippewa’ and Viburnum lobophyllum Graebn. × V. japonicum ‘Huron’ are the first two semi-evergreen cultivars introduced that combine the heavy red fruiting of deciduous species with the evergreen characteristics of V. japonicum. Although the two cultivars have different parental species, the growth habits, flowering, fruiting, and foliage characteristics are similar. The most obvious difference is that ‘Chippewa’ (Fig. 1) has a broad obovate, lustrous leaf; whereas ‘Huron’ (Fig. 2) has a dull, more elliptic obovate leaf. ‘Chippewa’ and ‘Huron’ are the 16th and 17th Viburnum cultivar introductions from the U.S. National Arboretum shrub breeding project (1-7).
Soil Matric Potential, Plant Water Relations, and Growth in Asparagus
Authors: Wilcox-Lee Darlene
Published: September 2022

Soil moisture treatments were initiated in a greenhouse study using 14-weekold asparagus (Asparagus officinalis L. cv. Jersey Giant) seedlings. Treatments consisted of drying pots to a minimum soil matric potential ranging from –0 .0 5 to –1 .5 MPa prior to rewatering. After 10 weeks, root and fern dry weights, fern height, and shoot number were reduced by reducing soil moisture, with the largest decreases occurring between soil matric potentials of –0 .0 5 and –0 .1 MPa. Root : shoot ratios increased with decreasing soil moisture. In a growth chamber study, 4-month-old seedlings were watered to pot capacity and allowed to dry to a soil matric potential of —1.5 MPa. Xylem potential, relative water content (RWC), and shoot growth were measured daily as soil dried from field capacity to —1.5 MPa. Xylem potential was correlated with growth or RWC. Shoot growth ceased at a fern xylem potential of —1.8 MPa. RWC was reduced from ≈95% at pot capacity to 80% at a soil matric potential of — 1.5 MPa. These data indicate that asparagus exhibits characteristics of drought-tolerance. However, despite its apparent drought-tolerance, maximum growth occurs in young asparagus plants when soil water potential is close to field capacity, indicating that consistent irrigation would be beneficial in newly established plantings.
Increased Yield in Slicing Cucumbers with Vertical Training of Plants and Reduced Plant Spacing
Authors: Hanna H. Y. , Adams A. J. , Story R. N.
Published: September 2022

In field experiments conducted during 2 years, substantial yield increases were obtained with vertically trained (staked) cucumber plants (Cucumis sativus L.) over vining plants (unstaked). The marketable yield was doubled in some instances, and fruit rot was reduced significantly. More female flowers set and developed into marketable fruits on vertically trained plants than on vining plants. The fresh weight, length, and width of the leaves on the main stem of the staked plants prior to the first harvest were also greater than on unstaked plants. The staked plant fresh weight prior to the first harvest and after the last harvest was significantly greater than that of unstaked plants, but both had the same number of female flowers. Reducing within- row plant spacing from 30 to 15 cm significantly increased yield. Weekly foliar fertilization with 1.5N-0.4P-0.6K (kg·ha−1) for 8 weeks did not increase yield.
Use of a Phenological Model to Time Acceleration of Pollinizer Bloom
Authors: Seeley Schuyler D. , Seeley Earl J. , Richardson E. Arlo
Published: September 2022

A pear anthesis phenology model was used to determine timing of placement of reflector boards near ‘Seckel’ pear trees, or polyethylene hotcaps over them to accelerate their bloom for optimum pollination of ‘Anjou’. The normal full bloom date of ‘Anjou’ was predicted from the Utah chill unit (CU) and growing degree hour (GDH) models. ‘Bartlett’ pear phenology and historical bloom divergence of ‘Seckel’ and ‘Anjou’ were used in the absence of ‘Seckel’ and ‘Anjou’ phenology to determine the timing and amount of supplemental thermal accumulation. Bloom-accelerating techniques were placed on the pollinizer trees at an intermediate anthesis stage. Polyethylene hotcaps accelerated bloom effectively.
Injury, Growth, and Flowering Response of Azaleas to Two Formulations of Fluazifop-butyl
Authors: Gilliam C. H. , Wehtje G. R. , Fare D. C.
Published: September 2022

Phytotoxicity associated with application of 0.28 kg·ha−1 a.i. of the 4E formulation of fluazifop-butyl to Rhododendron ‘Hino-crimson’ was characterized by plant response similar to the response to chemical pinching. Flowering the following spring increased with fluazifop-butyl treatment. In a separate study, application of 1E PP005 (a formulation containing only the active isomer fluazifop-butyl) produced effects similar to the 4E formulation at one-half the rate (0.14 kg·ha−1). Chemical name used: butyl (±)-2-[4-[[5-(trifluoromethyl)-2-pyridinyl]oxy]phenoxy]propanoic acid (fluazifop-butyl).
The Effect of Cadmium on Growth and Acetylene Reduction (N2 Fixation) by Alnus glutinosa
Authors: Hensley David L. , Carpenter Philip L.
Published: September 2022

Effects of Cd accumulation on dry weight accumulation and acetylene reduction (N2 fixation) of 1-year Alnus glutinosa (L.) Gaertn. exposed to 0, 1, 2, 4, or 8 ppm Cd as CdCl2·2½ H2O were determined. After 6 months of greenhouse sand culture, significant amounts of Cd accumulated in the nodules and roots, but not in shoot tissues. There were no significant differences on root, nodule, or shoot dry matter accumulation or on C2H2 reduction (N2 fixation) due to CdCl2 treatments.
Comparison of Pinching Methods on Selected Species of Columnea, Kalanchoe, and Crassula
Authors: Lyons R. E. , Hale C. L.
Published: September 2022

Mechanical and chemical methods for improving the branching of Crassula argentea Thunb., Kalanchoe tomentosa Bak., and Columnea microphylla Klotzsch and Hanst. ex Orst. were examined. C. argentea did not respond to hand-pinching, atrinal, or BA treatments. K. tomentosa produced 44% more branches when treated with 50 ppm BA but were relatively unaffected by atrinal or hand-pinching. C. microphylla typically branched only from the basal nodes; however, 59% more branching was observed when treated with 500 ppm atrinal. Hand-pinching or BA did not affect branching of Columnea. Atrinal also retarded stem elongation of C. microphylla; the inhibitory effect of 500 ppm was comparable to the reduction in stem length caused by hand-pinching. Chemical names used: (2,3:4,6 bis-O-(1-methylethylidene)-O-L-xylo-2-hexulofuranosonic acid, dikegulac sodium, atrinal), N-(phenylmethyl)-2H-purin-6-amine (BA).
Dormancy Terminology
Authors: Denney James O.
Published: September 2022

The points raised in my previous letter (HortScience 21:1096, Oct. 1986) have been discussed with Greg Lang and his colleagues in correspondence and at the XXII International Horticultural Congress (Aug. 1986) in Davis, Calif.
Effects of Calcium and Auxin on Russet Spotting and Phenylalanine Ammonia-lyase Activity in Iceberg Lettuce
Authors: Ke Dangyang , Saltveit Mikal E.
Published: September 2022

In the article “Effects of Calcium and Auxin on Russet Spotting and Phenylalanine Ammonialyase Activity in Iceberg Lettuce” by Dangyang Ke and Mikal E. Saltveit, Jr. (HortScience 21:1169–1171, Oct. 1986), Dangyang Ke's name was spelled incorrectly.
‘AU-Jubilant’ and ‘AU-Producer’ Watermelons
Authors: Norton J. D. , Cosper R. D. , Smith D. A. , Rymal K. S.
Published: September 2022

In the article “AU-Jubilant' and ‘AU–Producer’ Watermelons“ by J.D. Norton, R.D. Cosper, D.A. Smith, and K.S. Rymal (HortScience 21:1460–1461, Dec. 1986), the following corrections should be noted: The legends to Figs. 3 and 4 were reversed. The legend to Fig. 3 should read “Fruit of ‘AUProducer’ watermelon.”; the legend to Fig. 4 should read “Fruit of ‘AU–Jubilant’ watermelon.” In the legend to Fig. 1, the word should be “Pedigree”. In the literature citations, ref. 1 should read J. Amer. Soc. Hort Sci. instead of HortScience, and, in ref. 7, the volume number should read 105 instead of 195.
Pistillate Flower Abscission of the Persian Walnut
Authors: Catlin P. B. , Ramos D. E. , Sibbett G. S. , Olson W. H. , Olsson E. A.
Published: September 2022

The pistillate flower of walnut is a complex structure (10, 13, 14) and is referred to as a pistil for simplicity. Pistils emerge terminally on shoot or spurs after different degrees of vegetative extension from mixed buds (9, 14). Such growth can range from essentially nil to about 1 m. Pistils are borne on a short peduncle (Fig. 1). Two pistils per peduncle are most common, but one or three, or (rarely) more, can occur. Flowers are wind-pollinated and all cultivars are considered to be cross- and self-fruitful (9, 14). Pistils become receptive very shortly after emergence from the shoot apex when the two stigma lobes begin to separate. Fertilization of ovules is necessary for nut development to maturity, but pollination and fertilization are not required for early growth of the ovary (14). Ovaries of nonpollinated flowers will enlarge at rates similar to those of fertilized ones for several weeks before abscising, when about 1 to 2 cm in diameter.
Chemical Fruit Thinning Response of Spur ‘Delicious’ Apple as Influenced by Light Intensity and Soil Moisture
Authors: Lehman L. J. , Unrath C. R. , Young E.
Published: September 2022

Percent fruit set and crop density of mature ‘Starkrimson Delicious’ apple trees (Malus domestica Borkh.) were reduced by a whole tree airblast spray of 450 ppm ethephon plus 1200 ppm carbaryl applied 16 days after petal fall (DAPF). Irrigation regimes consisting of half-normal, normal, and twice normal rainfall had no effect on nonchemically or chemically induced fruit drop. Individual limbs within each tree received 30% shade from 0 to 16 DAPF, 73% shade from 0 to 16 DAPF, 73% shade from 17 to 35 DAPF, or no shade. At 16 DAPF, both early shade treatments reduced fruit size and set, but neither influenced nonchemically induced fruit drop occurring from 16 to 35 DAPF. Only heavy shade imposed from 0 to 16 DAPF decreased chemically induced fruit drop. Heavy shading from 17 to 35 DAPF without chemical thinner application doubled fruit drop. Excessive fruit drop occurred when heavy shading followed chemical thinner application, but thinner efficacy was not different from the unshaded, chemically thinned control. Chemical names used: (2-chloro-ethyl)phosphonic acid (ethephon); 1-naphthalenyl methylcarbamate (carbaryl).
Time of Flower Bud Initiation in Peach Cultivars Differing in Chilling Requirement
Authors: Raseira Maria C. B. , Moore J. N.
Published: September 2022

Time of flower bud initiation was determined for nine peach [Prunus persica (L.) Batsch.] cultivars, three in each of three chilling requirement groups (<500 hr, 500-750 hr, and 800-1050 hr below 7.2°C). Based on morphology of the apical dome, the first visible signs of flower bud initiation of all cultivars occurred between 15 July and 8 Aug. 1984, and between 1 and 20 July 1985. The earlier initiation period in 1985 may have been promoted by drought stress. Although significant differences occurred in time of flower bud initiation among chilling requirement groups in both years, they were not consistent from year to year, indicating that chilling requirement is not strongly associated with time of flower bud initiation. The rate of morphological development of flower primordia was not associated with earliness of flower bud initiation. ‘Diamante’, while early in flower bud initiation, showed a slow rate of subsequent flower development. No relationship was found between time of flower initiation and either time of bloom or time of fruit ripening of the cultivars.
Evapotranspiration Calculations For Young Peach Trees and Growth Responses to Irrigation Amount and Frequency
Authors: Renquist Richard
Published: September 2022

Peach tree [Prunus persica (L) Batsch, cv. Glohaven] growth responses to three irrigation regimes were compared during the first two seasons after planting. Weekly microsprinkler irrigation at two levels (1.0 and 1.5 times crop evapotranspiration, ETC) was compared to furrow irrigation (1.0 ETC) at 4-week intervals. Irrigation levels were based on Class A Pan evaporation, (Ep). Average trunk cross-sectional area (TCA) of furrow-irrigated trees was 42% and 64% less than microsprinkled trees after the first and second season, respectively. The bulk of the growth deficit was due to inadequate irrigation frequency rather than amount. However, better midsummer growth with microsprinkler irrigation at 1.5 ETC than 1.0 ETC supported previous reports that water use per unit canopy area is not linear—it is increased for small trees (partial canopies).
Influence of Polyethylene-covered Trenches on Yield of Bell Pepper
Authors: Dainello Frank J. , Heineman R. R.
Published: September 2022

The covered trench (CT) planting system was evaluated for increasing early yield of ‘Grande Rio 66’ bell pepper (Capsicum annum). Trenches covered with either one of three polyethylene materials (black, solid clear, or slitted clear) were compared to standard, raised flat-topped beds. Treatments were applied with a modified sled-type bed shaper and a conventional plastic mulch applicator. The slitted clear polyethylene CT treatment resulted in 45% of the total marketable fruit harvested in the first harvest as compared to 29% from the raised flat-topped beds. This treatment also increased total yield by ≈ 2000 kg·ha−1 over the standard, raised flat-topped beds.
Shoot Apex and Nodes Exposed Above-ground Influenced Growth of Sweet Potato Vine Cuttings
Authors: Hall Melvin R.
Published: September 2022

Pot-grown ‘Georgia Jet’ sweet potato [lpomoea batatas (L.) Lam.] vine cuttings, from which the primary shoot apex was removed, developed vines with fewer secondary laterals, but more tertiary laterals, and greater lengths of both secondary and tertiary laterals than were developed when the primary shoot apex was not removed. With eight nodes exposed aboveground, cuttings without the primary shoot apex developed a greater total length of secondary laterals due to longer internodes and greater total vine length than cuttings with the primary shoot apex. Dry weights of storage roots and lateral vines were increased, but dry weight of the primary vine was reduced from cuttings without the primary shoot apex. With four nodes exposed aboveground under field conditions, cuttings without the primary shoot apex developed fewer secondary laterals, less total vine length, and less yield of jumbo grade roots than those with the shoot apex. With eight nodes exposed aboveground under field conditions, cuttings with the primary shoot apex developed a greater number and length of tertiary laterals than those without the primary shoot apex, but the primary shoot apex did not affect secondary laterals, total vine length, or storage root yield significantly.
Bentgrass and Bermudagrass Putting Green Turf Tolerance to Postemergence Herbicides
Authors: Higgins J. M. , McCarty L. B. , Whitwell T. , Miller L. C.
Published: September 2022

Field experiments were conducted to evaluate response of ‘Penncross’ creeping bentgrass (Agrostis palustris Huds.) and ‘Tifgreen II bermudagrass [Cynodon dactylon (L.) Pers. × C. transvaalensis Burtt-Davy] to six postemergence herbicides. Fluazifop and sethoxydim were applied at 0.1, 0.2, and 0.3 kg ha−1. Fenoxaprop, haloxyfop, xylafop, and poppenate were evaluated at 0.07, 0.15, and 0.30 kg −1. Crop oil concentrate was added to each treatment at 2.4 liters·ha−1. Herbicides were applied in June 1985 to bentgrass, and in June and Aug. 1985 to bermudagrass. Bentgrass and bermudagrass had unacceptable color and density through 28 days after treatment (DAT) with all herbicides. Both species showed tolerance 28 DAT to fenoxaprop at 0.07 and 0.15 kg ha−1, but turf density was reduced compared to the untreated check. Bermudagrass quality at 42 and 49 DAT was not different from the untreated check with low and medium rates of fenoxaprop. All other herbicides reduced bentgrass and bermudagrass quality to unacceptable levels. Chemical names used: (±)-2-ethoxy-2,3-dihydro-3,3-dimethyl-5-benzofuranyl methanesulfonate (ethofumesate); (±)-2[4-[(6-chloro-2-benzoxazolyl)oxy]phenoxy]propanoate (fenoxaprop); (±)-2-[4-[[5-(trifluoromethyl)-2-pyridinyl]oxyl]phenoxy]propanoic acid (fluazifop); 2-[4-[[3-chloro-5-(trifluoromethyl)-2-pyridinyl]oxy]phenoxy]propanoic acid (haloxyfop); methyl-3-hydroxy-4[4-[[5-(trifluoromethyl)-2-pyridinyl]oxy]phenoxy]-pentanoate (poppenate); 2-[1-(ethoxyi-mino)butyl]-5-]2-(ethylthio)propyl]-3-hydroxy-2-cyclohexen-1-one (sethoxydim); 2-[4-[(6-chloro-2-quinoxalinyl)oxy]phenoxyl]propanoic acid (xylafop).
Ornamental Response to Two Methods of Oxadiazon Application
Authors: Glaze N. C. , Singh M. , Phatak S. C.
Published: September 2022

Oxadiazon was applied conventionally as a granular and compared to the emulsifiable concentrate injected into sprinkler irrigation system (chemigation) at 60- day intervals on 20 species of container-grown ornamentals. In general, phytotoxicity increased proportional to the number of applications and was most prevalent during cold weather. Moderate to severe phytotoxicity at 2 × and 4 × rates was observed on aucuba (Aucuba japonica Thunb.), azalea [Rhododendron (AZ) ‘Formosa’ and R. (AZ) ‘Fashionaire’], liriope [Liriope muscari (Decne) L. H. Bailey], pampas grass [Cortaderia selloana (Schult. & Schult. f.) Asch. & Graebn.], Japanese black pine (Pinus thunbergiana Franco), and red tip photinia (Photinia ‘Fraseri’ Dress). Increased injury was observed on aucuba, Japanese black pine, and azalea when oxadiazon was applied via chemigation. On the other species, the degree of phytotoxicity was proportional to the rate applied. Both monocots showed moderate (18%) to severe (45%) injury. The only cultivar with significant growth reductions after 8 months was the ‘Formosa’ azalea when chemigated. The only species with reduced marketability due to the herbicide was liriope. After the second application, the weight and number of weeds decreased proportional to the herbicide rate or number of applications. Chemical name used: 3-[2,4-dichloro-5-(1-methylethoxy)phenyl]-5-(1,1-dimethylethyl)-1,3,4-oxadiazol-2(3H)-one (oxadiazon).
In Situ Psychrometry For Measuring Cut Flower Water Status
Authors: Dixon Michael A.
Published: September 2022

Mature potted rose bushes and cut rose blooms (Rosa hybrida ‘Samantha’) were used to assess the reliability of in situ stem psychrometers for measuring the water potential of these plant systems. Concurrent measurements of adjacent leaf water potential using a pressure bomb were correlated with the psychrometer measurements. The plants were subjected to a series of drought and rehydration cycles in order to exhibit a wide range of water potential (— 0.1 to —1.8 MPa). The results closely followed a 1:1 correlation. The psychrometer installations on intact rose bush stems produced reliable measurements of stem water potential for up to 6 weeks. The technique described is a nondestructive means to monitor the water status of intact plants or cut flowers continuously in response to management practices, storage and shipping techniques, or methods to enhance keeping quality.