bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Photochemical Air Pollutants on Zinfandel Grapes1
Authors: Thompson C. R. , Hensel E. , Kats G.
Published: August 2022

The formation of ozone in Los Angeles type (photochemical) smog was recognized by Haagen-Smit et al (1) in 1952. It soon became apparent that this compound could cause plant lesions identical to those which were seen on economic crops growing in many areas of the Los Angeles Basin. A “stipple” of grape leaves which occurred in midsummer in the field and which became progressively more severe with the season, was shown by Richards et al (4) to be very similar to lesions produced by ozone fumigation. Additional work with conifers (5) showed that a severe needle mottle of Pinus ponderosa and related species was caused by ozone in photochemical smog. Peroxy-acyl nitrates and oxides of nitrogen axe present in this mixture and are toxic to plants, but the separate effects of these pollutants have not been studied on grapes in detail.
Mechanized Growing and Harvesting of Vegetable Crops in the Eastern United States
Authors: Warren G. F.
Published: August 2022

Although there are several ways to discuss mechanization of crop production, I have chosen the evolutionary approach. Mechanization goes through evolutionary stages. As new crops are mechanized, the intermediate steps could be by-passed if the evolutionary pattern is understood. Let us examine some of the steps taken in mechanization with various vegetable crops.
The Influence of Mechanization on Processing of Fruits and Vegetables
Authors: Allewelt William F.
Published: August 2022

I greatly appreciate your invitation to participate in this symposium. As a layman involved in the workings of the canning industry, my principal contribution will be to provide a further dimension for your deliberations. I will attempt to describe the social and economic environments which have caused us to appeal to you for accelerated development of mechanical equipment for the production and processing of fruits and vegetables.
Response of ‘McIntosh’ Apple Trees to Soil Injections of Lime1
Authors: Michelson L. F. , Lord W. J. , Drake M. , Baker J. H.
Published: August 2022

Hydrated dolomitic limestone as a slurry was injected under pressure to soil depths of 3 feet under apple trees growing in acid loamy sand soil. Comparisons of: 1) dripline vs. near bole placement, 2) spring vs. fall application and 3) trees having high leaf magnesium vs. trees having lower leaf magnesium were made. Near bole treatment appeared superior to dripline placement; the response of trees to spring applications were immediate, exceeding the response to fall application, and trees having a higher original leaf magnesium content were more responsive than those of lower leaf magnesium.
Performance of Muscadine Grapes (Vitis rotundifolia Mich.) in Central Florida1
Authors: Balerdi C. F. , Mortensen J. A.
Published: August 2022

Some people consider muscadines as the most satisfactory of all fruits for the home garden in the south (1). An increasing interest in muscadine culture in Florida is indicated by growers who have planted them for commercial production, and by others who plan vineyards for the near future. Therefore, information on the performance of muscadine varieties in central Florida is valuable for potential growers, and for research and extension personnel.
Horticulture’s Issues in Education, Science, Communication, Philosophy, Politics, and Human Welfare
Authors: Frazier W. A.
Published: August 2022

William Alan Frazier (Tex), like his predecessor, Neil Stuart, was born in 1908 and received his graduate degrees from the University of Maryland in the 30‘s. He graduated with honors from Texas A & M in 1930 with a BS in Horticulture.
The Effect of Light Types on Leaf and Flower Bud Burst of Excised Peach Shoots1,2
Authors: Lavee S. , Erez A.
Published: August 2022

Peach leaf and flower buds showed different light requirements for opening. Leaf bud opening required light, the active range for the process was 600 - 690 m. Flower bud opening was relatively light independent. Green light or low light intensities slightly promoted it, while red and white light or high intensities caused some inhibition.
Influence of 2,3,5-trnodobenzoic Acid, Gibberellin and Row Spacing on Yield and Growth Parameters of Southern Peas
Authors: Hipp Billy W. , Cowley W. R.
Published: August 2022

Once-over harvest with a mechanical harvester is becoming more important in the production of many crops. This is particularly true for southern peas because a major item of expense in production of the crop is harvesting if hand harvested. Recently, research was reported concerning the use of 2,3,5-triiodobenzoic acid (TIBA) for increasing adaptability of southern peas for mechanical harvest (3). The work by Hipp and Cowley (3) indicated better plant geometry for mechanical harvest but only a slight increase in yield when peas were grown on 38-inch beds. Prevatt and Lundy (4) reported smaller, more compact pea plants with the application of TIBA to southern peas. The use of TIBA on soybeans also results in small compact plants but yield increases are generally small when plants are grown on conventional 38-inch rows. Variations in row spacing appears to be the most logical method of increasing yield of peas since TIBA application generally results in reduced plant size (1,2,3,4,5). Experiments were conducted at the Texas A&M University Agricultural Research and Extension Center at Weslaco to evaluate the influence of TIBA and Gibberellin on the yield and growth parameters of California Blackeye No. 5 peas.
Pre-harvest Defoliation of Apple Nursery Stock using Ethrel1,2
Authors: Cummins J. N. , Fiorino P.
Published: August 2022

Two-year-old apple trees growing in the nursery row were effectively defoliated by sprays of Ethrel at concentrations of 2000, 3750, and 5000 ppm. Retarded shoot growth and polarity reversal indicated that a 5000 ppm concentration was supraoptimal.

The 2000 ppm concentration somewhat delayed early spring growth, but not unacceptably so. Using this or a slightly lower level appears quite promising as a commercial practice. Development of visible root germs was greater on Ethrel treated plants.
Register of New Fruit and Nut Varieties List 241
Authors: Brooks Reid M. , Olmo H. P.
Published: August 2022

Blushing Golden.- - Plant pat. 2,835, Oct. 1, 1968, assigned to Stark Bros. Nurseries & Orchards Co., Louisiana, Missouri. Origin and description appeared in List 23.
Storage of Bananas in Polyethylene Bags with an Ethylene Absorbent1
Authors: Liu Fu-Wen
Published: August 2022

Storage of preclimacteric bananas in sealed polyethylene showed promise. After a reasonable period of storage the bags must be opened to allow normal ripening. Endogenous ethylene was a source of potential ripening in these sealed poly bags. Hence, an ethylene absorbent was usually essential. A commercial product, ‘Purafil’ was capable of absorbing this ethylene and extending the storage life of preclimacteric fruits.
Anthocyanins in Pears1
Authors: Francis F. J.
Published: August 2022

The introduction of colored mutants and their development into commercial varieties of red pears has attracted considerable attention since the fruit has a very attractive appearance (4,6). Dayton (1) reported that Starkcrimson, a mutation from Clapps Favorite, differed from all other red sports in having approximately 50% of cells in the outer hypodermal layer colored with anthocyanin. The Eureka variety had approximately 10% of epidermal cells colored. All other red sports had anthocyanin only in the second histogenic layer. The epidermis was colorless, together with one or two cell layers below this. Starkcrimson and, for example, Max-Red Bartlett, a sport of Bartlett, probably developed from different gene mutations. It was of interest to determine whether the anthocyanin pigments were identical in the two varieties.
Screening for Resistance to Lettuce Mosaic1
Authors: Ryder Edward J.
Published: August 2022

Since the publication of the list of lettuce lines and cultivars screened for resistance to common lettuce mosaic (2), many more materials have been screened. A second source of resistance was found and the screening technique was changed. This paper brings the list up to date and notes the changes.
The ASHS Educational Slide Collection1
Authors: Larsen Fenton E.
Published: August 2022

Color slides put more life into all forms of horticultural teaching, in the classroom, for industry and agricultural meetings, as a part of garden club programs, also on television, the largest audience of all. The ASHS Slide Collection is under way. Help develop it! Make use of it! The Education Committee suggests that a good slide set with narrative should be given the same administrative credit as any other form of publication.
A Rapid Stain for Plant Cell Nuclei1
Authors: Carmichael J. W. , Sherman W. B. , Schank S. C.
Published: August 2022

Recent studies in pollen germination, fertilization and embryo sac development have led to a search for a rapid nuclear stain. Pontacyl violet 6R3 (C.I. 16640) proved to be excellent in animal tissues (4) and was therefore tested for effectiveness with plant tissues.
Effect of Ethrel on Growth and Bulb Initiation in Onion1
Authors: Levy D. , Kedar N.
Published: August 2022

Young onion plants were grown in glass tubes under short daylength non-inductive for bulbing. Ethrel was added to the growth medium and caused swelling of leaf-bases, bulb initiation and a pronounced increase in the bulbing index. Swelling of leaf-bases was also observed in Ethrel treated plants of leek. In a replicated field experiment seedlings of 5 cultivars were sprayed once or several times with Ethrel at rates of 500, 1,000, 5,000 and 10,000 ppm. Except for one very early cultivar, which showed bulbing due to natural daylength, the treatments resulted in early bulb initiation and in a greatly increased rate of bulbing. Rates of 5,000 and 10,000 ppm Ethrel were more effective than lower concentrations but they also caused retarded leaf growth and a decrease in the final size of bulbs. The possible role of ethylene in bulbing of onion is discussed.
New Vegetable Varieties List XVII1
Authors: Barnes W. C.
Published: August 2022

Sixteen prior lists of new vegetable varieties introduced since 1936 were published in Vols. 63, 65, 67, 69, 70, 75, 77, 82, 84, 86, 88, 90, and 92 of Proceedings of the American Society for Horticultural Science, and Vol. 4 No. 1 of HortScience.
Dilution Technique for Calibration of Infrared Gas Analyzers for Use with Carbon Dioxide1
Authors: Tibbitts T. W. , Read M.
Published: August 2022

A simple dilution technique is described for the calibration of infrared gas analysers for use with carbon dioxide. The technique involves determining the exact volume of a closed loop system, which includes analyser, circulating pump and connecting tubing. Successive dilutions with either known volumes of nitrogen gas with no carbon dioxide or span gas with known concentrations of carbon dioxide, provide a range of calculable concentration points from which the calibration curve can be plotted.
Effect of Fall Application of 2-Chloroethylphosphonic Acid on Apple Trees1
Authors: Ketchie D. O. , Williams M. W.
Published: August 2022

Limb units and whole trees of ‘Delicious’ and ‘Golden Delicious’ sprayed in the fall with 250 ppm, 500 ppm and 1000 ppm Ethrel significantly decreased fruit set and vegetative growth the following season.
Injury to City Plants from Industrial Emissions of Herbicides1
Authors: Lanphear F. O. , Soule Oscar H.
Published: August 2022

Injury typical of the phenoxyacetic acid herbicides 2,4-D and 2,4,5-T was observed in a large area of St. Louis in the spring of 1969. Screening of chemicals from a local manufacturer of these herbicides revealed that at least 7 chemicals involved in the production of these herbicides produce symptoms similar to those observed in the field. Injury occurred from aqueous concn as low as 1 ppm as well as from vapors of the isobutyl ester of 2,4-D. The uniqueness of plant injury due to industrial emissions of herbicides demonstrates the need for using biological parameters in assessing air quality.
Defoliation of Snap Beans with Preharvest Treatments of 2-Chloroethylphosphonic Acid1
Authors: Palevitch Dan
Published: August 2022

2-chloroethylphosphonic acid (Ethrel) applied to snap bean plants (cv. ‘Tenderette’) at 250-4000 ppm as a preharvest treatment caused considerable leaf abscission. A reduction in yield per plant resulted from yellowing and abscission of the pods. Much less damage occurred with the lower concentrations and/or by postponing the treatment close to the anticipated harvest time. The effectiveness of Ethrel as a leaf abscission promotor was greater in the summer than in the autumn season. The possible use of Ethrel as an aid for mechanical harvesting of snap beans is discussed.
Inheritance of Mottle-Leaf in Cucurbita moschata Poir.1
Authors: Coyne Dermot P.
Published: August 2022

Segregation in squash (Cucurbita moschata Poir.) crosses between a ‘Crookneck Butternut’ selection (green-leaf) × ‘Golden Cushaw’ (mottle-leaf) and ‘New Hampshire Butternut’ (green-leaf) × ‘Hercules’ (mottle-leaf) indicated that the mottle-leaf trait was primarily controlled by an incompletely dominant gene (M).
The Effects of Horticultural Practices on Man and his Environment
Authors: Walker Kenneth C.
Published: August 2022

It is recognized that the practice of horticultural science is not necessarily synonymous with the general practice of agriculture. Webster’s New International Dictionary defines horticulture as “the cultivation of a garden or orchard, the science and art of growing fruits, vegetables, and flowers and ornamental plants; one of the main divisions of agriculture.” You may or may not agree with this definition or there may be a more accurate and up-to-date one. Nevertheless, the definition does establish certain limits or boundaries of your science. However, the impact of horticultural practices on man and his environment are not as well defined.
Modifying the Environment
Authors: Feder William A.
Published: August 2022

We are living in an age which is witness to unparalleled technological development. However, in the headlong rush towards technological sophistication and mechanized living, we have not been able to, or have not chosen, to forsee the large scale evnironmental alterations which would necessarily result from these vast and diverse activities.
Thiabendazole and Benomyl for the Control of Postharvest Decay of Apples1
Authors: Cargo C. A. , Dewey D. H.
Published: August 2022

Postharvest treatment with thiabendazole (TBZ) or benomyl reduced the incidence of soft rot or blue mold disease caused by Penicillium expansum Thorn in ‘Mcintosh’ apple fruits. Both materials were significantly effective during cold storage or simulated marketing tests in which the apples were artificially punctured and then dipped in solutions containing rot inoculum and the chemical. All concentrations tested, 250, 500 and 1000 ppm TBZ and 75, 140, and 300 ppm benomyl, yielded rot control without affecting the respiratory activity of the apples.
Accumulation of Simazine in Mulch Residue under Apple Trees and its Effect on Apple Rootstocks and Soil Microorganisms1
Authors: Lord W. J. , Gunner H. B. , Robinson D. E.
Published: August 2022

Simazine, especially from granular application, accumulated in hay mulch residue under apple trees and reduced soil contamination from this herbicide.

No marked build-up of simazine occurred in the soil. Simazine residues in soil ana mulch caused injury or death of EM VII rootstock, particularly after application in granular form.

Simazine in mulch had little influence on microbial populations. In soil, granular simazine increased numbers of bacteria, fungi and actinomycetes in the spring.
Annual Weed Control in Young Prunes1
Authors: Elmore C. L. , Lange A. H. , Buschmann L. L. , Chaney D. H.
Published: August 2022

The control of annual weeds in young prune orchards increased growth. The degree of foliar expressed phytotoxicity did not result in decreased tree growth. Simazine gave long lasting weed control and the most foliar symptoms on prunes, but superior tree growth. Simazine and dichlobenil produced more foliar symptoms than diphenamid, but less indication of growth reduction.
Effect of 2-Chloroethylphosphonic Acid and Cycloheximide on Abscission and Ripening of ‘Bartlett’ Pears1
Authors: Griggs William H. , Iwakiri Ben T. , Fridley Robert B. , Mehlschau James
Published: August 2022

Branch units of 20 ‘Bartlett’ pear trees were sprayed with 2-chloroethylphosphonic acid (Ethrel) at 250, 500, or 1000 ppm or with cycloheximide (beta-[2-(3,5-dimethyl-2-oxocyclohexyl)-2-hydroxyethyl] glutarimide) at 3, 5, or 20 ppm a wk before the beginning of normal harvest to weaken the abscission layer to facilitate mechanical harvest. Half the trees had been sprayed with naphthaleneacetic acid (NAA) to prevent preharvest drop. Nine days after application, Ethrel at 1000 ppm had significantly reduced the fruit removal force (FRF) on trees that had received no NAA. In contrast, the presence of NAA evidently nullified the abscission-promoting effect of Ethrel. All other treatments failed to reduce FRF significantly. None of the sprays caused discernible phytotoxic effects or hastened fruit maturity. However, after storage for 50 days at 0°C, 17% to 50% of the fruits that received Ethrel at 500 or 1000 ppm, broke down during ripening. Cycloheximide caused no breakdown, but 20% to 80% of the fruits aprayed with 5 or 20 ppm had necrotic spots at the calyx end.
Preharvest Sprays with 2-Chloroethylphosphonic Acid to Degreen ‘Robinson’ and ‘Lee’ Tangerine Fruits
Authors: Young Roger , Jahn Otto , Cooper W. C. , Smoot J. J.
Published: August 2022

2-Chloroethylphosphonic acid (Ethrel) applied at 50 to 200 ppm as a preharvest spray, showed considerable promise in degreening ‘Robinson’ and ‘Lee’ tangerine fruit. The preharvest degreening resulted in less postharvest degreening time required for acceptable color and less fruit decay during storage. Ethrel concn between 100 and 200 ppm caused abscission of some old leaves, but had no apparent effect on external appearance other than color.
Indicator of Freezing in Citrus Seedlings1
Authors: Yelenosky G. , Horanic G. , Galena F.
Published: August 2022

Studies show electrical potential (Millivoltage output) generated by citrus seedlings is useful as an indication of freezing in hardened seedlings or where freeze rates are 1° hr-1 or less. Needle-sharp probes of a gold-amalgam wire attached to a strip chart recorder with a variable millivolt supply were used to detect mv changes in seedlings exposed to freeze conditions in an artificial environment room. An abrupt increase of 2 to 6 mv in the mv signal indicated the onset of freezing in the seedlings as checked by the heat of crystallization measured with thermocouples, visual signs of freezing, and subsequent physical damage studies.
Effect of Temperature on Flower Bud and Leaf Anthocyanin Formation in the Lowbush Blueberry1
Authors: Hall I. V. , Forsyth F. R. , Newbery R. J.
Published: August 2022

Lowbush blueberry plants had greater flower bud formation with more primordial meristems and more advanced floret primordia and lower concentration of anthocyanins in leaves at warmer temperatures than at cooler temperatures.
Fruit Development in Short and Long Cycle Blueberries1
Authors: Edwards T. W. , Sherman W. B. , Sharpe R. H.
Published: August 2022

Growth cycle studies of blueberry fruit were investigated for 3 Florida selections ‘4-15’, ‘4-71’ and ‘Bluegem’ (‘6-164’) which differed in the length of time from an thesis to maturity. The 3 stages of fruit development were exemplified by a double-sigmoid curve. Fruit size increase in stage I was due primarily to cell division and in stage III to cell enlargement. Delayed growth rate in stage II was accompanied by rapid development of the embryo and endosperm. Duration of individual stages varied with the clone and temperature and the length of each growth stage was important in determining the time required from anthesis to fruit maturity.
Pesticides and Pollution
Authors: Paul Larsen R.
Published: August 2022

No domestic issue since the depression of the 1930‘s has generated so much concern and emotion as “pollution. ” Like it or not, we as horticulturists are being swept along in an accelerating tide of public opinion against anything which may seem to add another gram of contamination to our earthly environment. In the public mind, pollution and pesticides have become synonymous. That is, pesticides are environmental poisons regardless of form, use or purpose. This unfortunate fear has been very effectively promoted by certain special interest groups who believe in strict protection and preservation of the environment, but only in accordance with their viewpoint.
The Detection of Ethylene in the Internal Atmosphere of Bulbs1
Authors: Staby G. L. , De Hertogh A. A.
Published: August 2022

Ethylene was detected in the internal atmosphere of 5 bulb species. Some, if not all, of the determined ethylene concn are of physiological significance. Experiments using methyl l-(butylcarbamoyl)-2-benzimi-dazole carbamate, a protective fungicide, indicate that fungi normally associated with tulip bulbs are at least partially responsible for the gas.
Cold Injury as Related to Cultural Management and Possible Protective Devices for Dormant Peach Trees
Authors: Savage Earl F.
Published: August 2022

In the peach growing areas of southeastern United States, it is only occasionally that peach trees are cold injured in early winter. The fruit is harvested in July, and there are nearly 3-1/2 months during which the leaves remain active on the trees, replenishing carbohydrate reserves. The fall months are warm with little rainfall so that the trees enter the dormant season in a non-vigorous condition. In the normal season, sufficient hours of cold below 45°F have accumulated, usually by late January, to break the rest period of most peach varieties and during warm periods in late winter the trees gradually resume growth and become susceptible to injury from low temperature. Thus, cold injury to immature tissues in the Southeast usually occurs during late winter whereas cold injury in the northern states, unless it results from extremely low temperature, occurs in early winter.
The Horticultural Crops Research Program of the Federal Experiment Station in Puerto Rico
Authors: Gaskins M. H.
Published: August 2022

The Federal Experiment Station in Puerto Rico is maintained at Mayaguez for crops investigations requiring a tropical environment. When established in 1902, the station was the only institution for agricultural research on the island. The research program included all of the diverse investigations such as animal husbandry, entomology, and forestry, in addition to crops studies, required for improvement of agriculture in Puerto Rico. Today, the Agricultural Experiment Station of the University of Puerto Rico is responsible for studies related entirely to insular agriculture. Research projects at the Federal station are selected for applicability, not only in Puerto Rico, but in other tropical areas as well. The Federal station also maintains projects with temperate-zone crops when these are needed to supplement investigations at locations on the mainland. Since 1961, the station has been part of the Crops Research Division of the Agricultural Research Service, and joint projects have been maintained with various other research units in the Division.
Rating of Pear Cultivars for Resistance to Fire Blight1
Authors: Oitto W. A. , van der Zwet T. , Brooks H. J.
Published: August 2022

Natural infections of fire blight following 2 years of epiphytotic conditions caused severe blight damage in the pear cultivar collection at Beltsville, Maryland. Of 522 cultivars rated with the USDA fire blight scoring system, 88% were highly susceptible, 2% were moderately susceptible, 4% were moderately resistant, 5% were highly resistant, and 2% had no blight symptoms. Names of pear cultivars in each resistance class are listed.
Thiabendazole Control of Postharvest Apple Decay1
Authors: Blanpied G. D. , Purnasiri Apithai
Published: August 2022

2-(4-Thiazolyl) benzimidazole (thiabendazole or TBZ) applied as a postharvest treatment (1000-2000 ppm) significantly reduced decay of apples: intact (not skin punctured); skin punctured before or after TBZ treatment; mechanically harvested; waxed after TBZ treatment. TBZ was active against Penicillium expansum, Botrytis sp., but not Alternaria sp. New skin punctures were more susceptible to infection than old punctures.
Teaching and Research Training for Tropical Overseas Horticulture
Authors: Krezdorn A. H.
Published: August 2022

Almost one quarter of the land surface of the world and one third of the population is found within the area limited by the Tropic of Cancer and the Tropic of Capricorn, which geographically constitutes the tropics. None of the continental United States lies within this area.
Repetitive Flowering from a Single Floral Axis in Camellia1
Authors: Ackerman W. L.
Published: August 2022

An unusual flowering phenomenon has been observed for 4 consecutive years on an unnamed Camellia japonica clone, PI 276119. While many faded blossoms dropped from the plants, others remained firmly attached. The inner portion of the tightly folded center of each persistant faded blossom remained pinkish-white. These centers expanded and were similar to emerging flower buds except they did not have bud scales. Elongation of the old flower axis placed the new bud slightly above the old flower. Following a resting stage of 6 weeks to about 4 months, new blossoms developed on the same axis and directly above the old flowers. During the 1970 season as many as 3 successive blooms were observed one upon the other.

The physiological aspects of this phenomenon are contrary to normal flower bud development in camellia. Repetitive flowering from a single floral axis appears to violate the principle of determinate growth of flower buds.
Fruit and Vegetative Responses of the Highbush Blueberry to Gibberellic Acid under Greenhouse Conditions1
Authors: Mainland C. M. , Eck P.
Published: August 2022

Gibberellic acid (GA) at 0, 5, 50, 200 and 500 ppm was applied to the highbush blueberry, var. ‘Coville,’ for 3 consecutive fruiting periods in the greenhouse. Application to the flower was a prerequisite for parthenocarpic fruit set and development. No significant differences were found in the number of shoots formed, shoot length, and stem or trunk diameter. GA caused a significant reduction in the number of flower buds formed for the next crop.
Effects of Ethylene on Morphology and Flowering of Chrysanthemum morifolium Ramat1
Authors: Tjia Benny O. S. , Rogers Marlin N. , Hartley David E.
Published: August 2022

Chrysanthemum, ‘#3 Indianapolis White’, subjected continuously to atmospheres containing 1-4 ppm ethylene failed to initiate and develop flower buds under short day conditions. The plants showed typical epinastic symptoms, shortening of internodes, thickening of stems and loss of apical dominance. The plants developed many short axillary shoots, each with a few small leaves. The top leaves on the plant became smaller and smaller and were less dissected than the controls. Subjecting plants alternatively to ethylene containing and normal atmospheres generally prevented flowering also, but occasionally crown budding occurred. Bioassay of endogenous auxins showed that these growth promoting substances were maintained at high levels in the ethylene treated plants, which may account for their failure to flower. In addition, ethylene also seemed to affect the polar auxin transport system of the plant.
Effect of Rootstock on Bloom Periods of Pear Trees1
Authors: Griggs W. H. , Iwakiri Ben T.
Published: August 2022

A 4-year study of the bloom periods of pear trees with different types of rootstocks indicates that, under the range of chilling conditions characteristic of California’s major pear districts, rootstock has little or no influence on scion chilling requirements.
Environmentally Induced Variations of Sweet Corn Characteristics as They Relate to the Time Required for Development
Authors: Arnold Charles Y.
Published: August 2022

Exposure to warm and cool temperatures in the period from planting to the 4tli leaf stage had no effect on the total number of leaves produced by ‘Golden Cross Bantam’ sweet corn. The same treatments in the period from the 4th to the 9th leaf stage resulted in a 3-leaf difference with the warm treated plants having the greater number. Exposure to warm temperatures suppressed the elongation of the lower internodes regardless of whether the exposure was in the planting to the 4th leaf or to the 9th leaf period. Exposure to warm and cool temperatures in the periods from the 5th leaf stage to tassel initiation, tassel initiation to ear initiation, and ear initiation to row initiation resulted in a complex situation in which the time of pollen shed or silk appearance was influenced not only by the time of tassel, ear, or row initiation but also by the number of leaves still to be developed to the point of visibility. Exposure of 5 varieties of sweet corn to 10, 13, and 16 hr photoperiods up to the time of tassel initiation supported the observations in the literature that varieties adapted to tropical or subtropical regions are more likely to respond to photoperiod than those adapted to temperate regions.
Photoperiod, Temperature and Genotype Interactions Affecting Time of Flowering in Beans, Phaseolus vulgaris L.1
Authors: Padda Darshan S. , Munger Henry M.
Published: August 2022

Temperature and photoperiod affected time of flowering in ‘Red Kidney’ and ‘Great Northern UI 1’ varieties of dry beans. ‘Great Northern-1’ was delayed in flowering under 18-hr photoperiod and the low temperature of 60°F night and 70° day. However, at higher temperatures it flowered normally under all photoperiods. ‘Red Kidney’ on the other hand was delayed under 18-hr photoperiod and high temperatures, above 85° day and night temperatures 70° or higher. It was relatively insensitive to photoperiod under the low temperature, and under the medium temperature of 70° night and 80° day.

Studies of the flowering response of parental and hybrid populations under 18-hr photoperiod and the high, medium and low temperature conditions indicated that ‘Red Kidney’ and ‘Great Northern-1’ differ by 2 major temperature-sensitive genes. ‘Red Kidney’ has a dominant gene Ht which causes delayed flowering at temperatures above 85° and long photoperiod while ‘Great Northern-1’ has a dominant gene Lt which causes delayed flowering at temperatures below 75° and long photoperiod. The F1 Htht Ltlt is delayed at all temperatures under long photoperiod.

Anatomical studies indicated that flower initiation had occurred under all photoperiod and temperature conditions but further development of floral primordia into flowers was delayed or completely inhibited under the conditions responsible for delay.
Effects of Kinetin, Salt Concentration, and Temperature on Germination and Early Seedling Growth of Lactuca sativa L.1
Authors: Odegbaro O. A. , Smith O. E.
Published: August 2022

The effect of salinity (0 to 0.12 M NaCl) and temperature (20-30°C) on germination of ‘Phoenix’ lettuce seed was studied. Increasing levels of both factors inhibited germination and reduced fresh weight of young seedlings. The salinity by tempertaure interaction was found to be statistically significant in the inhibition of germination. Although the mechanism of this interaction is not known, it was found that osmotic inhibition was reduced at lower temperatures. Kinetin largely overcomes both temperature and osmotic inhibition of germination, but its effect on early seedling development varies with temperature. At 15° no significant effect was observed, but at higher temperatures (23° and 25°) it increased fresh weight at higher salinity levels but had no effect at lower salinity levels.
Degree of Resistance Among Pear Species to the Woolly Pear Aphid, Eriosoma pyricola1
Authors: Westwood M. N. , Westigard P. H.
Published: August 2022

Roots of most of the primitive Pynus species were infested with pear root aphid Eriosoma pyricola Bak. and David., and increase or decrease in number noted 30 days later. Although seedling populations varied somewhat, P. amygdaliformis, P. elaeagrifolia, P. syriaca, P. betulaefolia, P. calleryana, P. koehnei, P. ussuriensis, and P. nivalis can be considered resistant. P. communis, P. cordata, P. gharbiana, P. pashia, P. Fauriei, and P. pyrifolia were either susceptible or very variable in resistance. Only P. bucharica, P. dimorphophylla, and P. mamorensis had no resistant seedlings in the lots tested. Interspecific hybrid populations were predictable though variable in resistance.
Determination of Gibberellins in Ovaries and Young Fruits of Navel Oranges and their Correlation with Fruit Growth1
Authors: Wiltbank W. J. , Krezdorn A. H.
Published: August 2022

After refinement, a fluorometric technique was found adequate for quantitatively determining certain gibberellins in the flowers and young fruits of navel sweet oranges. Using this method, significant changes in gibberellins were shown to occur, both in tissue concentrations and total amounts per fruit, in samples collected during the bloom and early period of fruit growth.

Two relationships, a correlation between gibberellin concentration and rate of fruit growth, and an effect of total gibberellins per fruit on cumulative fruit growth, were found. These data indicated a cause and effect relationship between endogenous gibberellins and the early stages of fruit growth of the navel orange.
The Simultaneous Measurement of Apparent Photosynthesis and Transpiration of Citrus Seedlings at Different Soil Moisture Levels1
Authors: Bielorai H. , Mendel K.
Published: August 2022

Diurnal rates of photosynthesis and transpiration of sour orange and sweet lime seedlings were measured continuously and simultaneously under 4 different soil moisture regimes, using an infra-red gas analyzer and hygrosensors. Photosynthesis and transpiration rates were found to decrease gradually as the soil moisture dropped from 17% to 9% (equivalent to tensions of 0.2 to 3 atm). A sharp reduction in both processes was observed for both rootstocks when the soil moisture was in the wilting range. At the high moisture content, photosynthesis and transpiration rates of sweet lime were higher than those for sour orange plants. Conversely, at the low moisture content (in the wilting range), the rates were greater for the sour orange seedlings. The high soil moisture tensions had a relatively greater effect on photosynthesis than on transpiration.
Identification of Cucumis species by Paper Chromatography of Flavonoids1
Authors: Brown G. B. , Deakin J. R. , Wood M. B.
Published: August 2022

Paper chromatography of flavonoids from leaf extracts of 21 Cucumis species produced patterns which were species specific. Some morphologically similar species produced chromatographic patterns which were similar to each other, while others failed to do so. Certain morphologically different species also produced chromatograms which were similar to each other. Although the individual species can be identified by their chromatographic patterns, a chromatographic grouping of related species often fails to conform with groupings made on a morphological basis.
Distinguishing Characteristics of the Jonathan Spot and Lenticel Spot Disorders in the ‘Jonathan’ Apple Fruit1
Authors: Richmond A. E. , Dewey D. H.
Published: August 2022

The disorder known as Jonathan spot commonly observed on ‘Jonathan’ apples actually consists of 2 spot types which must be distinguished in order to define the affecting factors and to resolve the confusing and contradictory evidence in the literature. The spots which occur in the epidermal tissues without definite relation to lenticels are considered as Jonathan spot. Those which occur directly around the lenticels are defined as lenticel spots.

Histologically, the epidermal tissues afflicted with Jonathan spot showed a significant radial compression of the collenchyma cells in the 4 to 7 subepidermal tiers; whereas, such modification was not always apparent in tissues affected with lenticel spot. For the latter, some degree of rupture of the epidermis and the 3 to 5 subepidermal collenchyma tiers was usually noted. Jonathan spot development was inhibited by high temperature (70°F). It was favored by delayed harvest, yet none was observed until the fruit was stored at low temperature for several months. Conversely, lenticel spot often was present at harvest time and its development was accelerated at high temperature and inhibited at low temperature. High relative humidity (90%) enhanced lenticel spot development, whereas, humidity level had no effect on Jonathan spot.
Pollen Analysis of Two Highbush Blueberry Varieties Vactinium corymbosum1
Authors: Brewer J. W. , Dobson R. C.
Published: August 2022

A significantly higher percentage of blueberry pollen germinated from the variety ‘Rubel’ than from ‘Jersey’. Germination of pollen from both varieties decreased with blossom age. The ‘Rubel’ variety had a longer optimum period of germination than did the ‘Jersey’. The number of pollen grains released by the ‘Rubel’ blossoms also appeared to be greater than that of the ‘Jersey’. Differences in pollen germination and production may explain differences in fruit production under conditions of low pollinator levels. Multiple germination tubes were produced by both varieties of blueberry pollen.
Vernalization of Globe Artichoke, Cynara scolymus L.1
Authors: Gerakis P. A. , Markarian D. , Honma S.
Published: August 2022

The effect of seed environment and stage of germination during vernalization on flower induction in globe artichoke was investigated. Soaking the seed in water for 48 hr at 70° F prior to vernalization at 35° to 45° for 15 days with adequate moisture and oxygen, resulted in a higher percentage of bolters. Air temperatures above 65° immediately after sowing the vernalized seed caused devernalization, while a week of 50° to 65° had no effect. Seed treatment with chloro-choline chloride inhibited vernalization. Gibberellic acid sprays substituted successfully for vernalization with a large percentage of plants. A minimum of 10 leaves were required for bud initiation with all effective vernalizing treatments. Through vernalization and by subsequently growing the plants at an optimum temperature and light environment, the normal biennial reproductive cycle of artichoke was reduced to 6.5 months.
Evaluating Resistance to Monilinia laxa (Aderh. & Ruhl.) Honey of Varieties and Hybrids of Apricots and Almonds using Mean Growth Rate of Cankers on Young Branches as a Criterion of Susceptibility1
Authors: Crossa-Raynaud P. H.
Published: August 2022

Comparative susceptibility of apricot and almond varieties to brown rot due to Monilinia laxa (Aderh. & Ruhl.) Honey was determined by inoculating longitudinal slits 2 cm long on selected branch cuttings with M. laxa conidia. After 3 weeks the resulting cankers were measured. The resistance ratings obtained were closely correlated with ratings obtained from observations made during the past several years in Tunisian orchards.

This method, applied to apricot hybrids, suggests that the resistance is polygenic and that the ‘Hamidi’ variety of apricots is a good source of resistance.
Timing of Olive Oil Application and Its Probable Role in Hastening Maturation of Fig Fruits1
Authors: Saad Faisal A. , Crane Julian C. , Maxie E. C.
Published: August 2022

Olive oil application during an approximate 10-day period following the time at which all drupelets within ‘Mission’ fig fruits had turned red was effective in stimulating fruit growth and maturity. Olive oil was found to yield ethylene, particularly when exposed to solar irradiation, and it is this degradation product that undoubtedly is the stimulative agent.
Seasonal Development of External Color and Carotenoid Content in the Peel of Ripening ‘Shamouti’ Oranges12
Authors: Eilati S. K. , Monselise S. P. , Budowski P.
Published: August 2022

External peel color and the content of chlorophyll, total carotenoids, carotenes and xanthophylls in the flavedo of ‘Shamouti’ orange fruits were studied during their development from the young to the overripe fruit stages.

In the early stage, the main change consisted of a decrease in chlorophyll content, resulting in the initial yellowing of the peel. Later, concomitant with the appearance of the typical orange color (color break), total carotenoid content of flavedo, as well as its carotene/xanthophyll ratio increased rapidly. Such increase, however, continued after full color had been attained and until the fruit was decidedly overripe. The advantage of relating the pigment content to the flavedo layer rather than to the whole peel and the suitability of expressing the pigment concentration on a per cm2 basis are discussed briefly.
A New Male Sterility Gene in Capsicum annuum, L.1
Authors: Shifriss Chen , Frankel Rafael
Published: August 2022

Genetic male sterility was found in the Bell type pepper variety ‘All Big’. Breeding experiments suggest that the character is controlled by a single recessive gene in Bell type pepper varieties. This new source of male sterility appears to be superior to sources formerly reported by being highly stable and already present with a Bell type genetic background, and by the absence of undesirable pleiotropic effects. The usefulness of the character for hybrid seed production is discussed.
Effect of Short Photoperiods, Cycocel, and Gibberellic Acid upon Flower Bud Initiation and Development in Azalea ‘Hexe’1
Authors: Criley Richard A.
Published: August 2022

A technique using 2-branched rooted cuttings of azalea ‘Hexe’ was devised to provide uniform plant material for studying the effect of photoperiod and growth regulators on early stages of flower bud initiation and development. Flower initiation was most rapid under 8-hr daylengths, as a definite change of shape of apex was observed the 4th to 5th weeks. No change was observed on plants subjected to interrupted nights with 50 ft-c incandescent light supplied between 10 pm and 2 am.

Short days plus a drench of 0.4 g Cycocel, (2-chloro-ethyl) trimethylammonium chloride, accelerated initiation over short days alone. Gibberellic acid applied to Cycocel-treated plants at 3 and 4 weeks of short days delayed flower initiation. Gibberellic acid applied to short day plants during the 4th to 6th weeks was effective in preventing flower initiation in this cultivar.
Methods of Selecting Tomatoes for Drosophila Resistance1
Authors: Stoner Allan K. , Mason Horatio C.
Published: August 2022

Tomatoes can be screened for resistance to Drosophila by using a slit-fruit technique, or by trapping adult flies in jars containing sections of fruit of different varieties. These techniques can be used on a turntable to eliminate light effects, or by randomization in a greenhouse or an enclosed room with uniform light. Significant differences were found, both when Drosophila could choose between varieties and when they were restricted to cages containing fruit of only one variety. Due to the large amount of variation encountered when screening tomatoes for Drosophila resistance, large numbers of replications are necessary. The variation can be partially accounted for by differences in fruit maturity and differences between plants of a variety or line.
The Effect of 2-Chloroethanephosphonic Acid (Ethrel) on the Sex Expression and Yields of Cucumis sativus1
Authors: McMurray A. L. , Miller C. H.
Published: August 2022

The effect of 2-chloroethanepliosphonic acid (ethrel) on the sex expression of pickling cucumbers was studied. Tests to determine concentrations, effect on sex expression, and yield potential were conducted in greenhouse and field situations.

As many as 19 successive pistillate nodes were observed for the treated monoecious cultivar ‘SC 23’. The most effective concentrations of ethrel were 120, 180 and 240 ppm for these studies. These rates in single or multiple application resulted in the greatest number of continuous female nodes with the least shortening of internodes. A much lower concentration of 24 ppm had little effect as to stunting and only limited effect on sex conversion. Significant yield increases, as measured by value per acre, were obtained for 3 monoecious cultivars, ‘Model’, ‘SC 23’ and ‘Chipper’, treated with ethrel.
The Interaction of Resistant Rootstock to the Nitrogen, Weed Control, Pruning and Thinning Effects on the Productivity of Concord Grapevines1
Authors: Shaulis Nelson , Steel Robert G. D.
Published: August 2022

This reports a 1960-1964 study of the responses of ‘Concord’ grapevines, own-rooted as well as grafted on the phylloxera resistant rootstock ‘Couderc 3309’, to pruning severity, thinning of fruit, N fertilization and weed control in a factorial experiment at Fredonia, New York.

Although phylloxera were present, moderate size of vine and large yield were attained with own-rooted vines. Here, ‘3309’ rootstock did not have a unique effect on ‘Concord’.

As an initial response, in 1960, when the range in vine size was 1.8 to 3.0 lb. of cane prunings per vine, increases in vine size were associated with increased yield because fruitfulness was not then seriously depressed by the vine size increasing treatments of ‘3009’ rootstock, cultivation, and N fertilization.

As an equilibrium response in 1963-1964, in the range in vine size of 1.9-4.9 lb. of cane prunings per vine, when vine size was above 3.5 lb. of cane prunings, the decline in fruitfulness prevented a gain in yield, and there was either no increase or a decrease in fruit maturity.

A 1966 sequel, affording 8’ and 16’ of canopy length for each 8’ spaced vine, showed fruitfulness to be closely associated with node number per unit length of canopy. Where the canopy length is fixed, crowding was likely the basis for the declines in fruitfulness which accompanied increases in vine size and node number.

The effect of the resistant rootstock ‘3309’ was similar to that of the other vine-size increasing treatments in that it decreased fruitfulness and fruit maturity and had a small effect on yield and on soluble solids/vine.
Effects of 2-Chloroethane Phosphonic Acid and Its Interaction with Gibberellic Acid on Quality of ‘Early Italian’ Prunes1
Authors: Proebsting E. L. , Mills Harlan H.
Published: August 2022

The growth regulator, 2-chloroethane phosphonic acid (Ethrel) advanced color and soluble solids development by about 2 weeks, softening by 1 week when applied at 80 ppm 31/2 weeks before commercial maturity of untreated fruit. Lesser effects of a similar nature were produced by rates down to 10 ppm on the same date. Gibberellic acid (GA) delayed softening by 1 week, color and soluble solids development by 1 or 2 days when applied at 50 ppm 31/2 weeks before commercial maturity of untreated fruit. Internal browning was reduced. Ethrel combined with GA to produce better colored fruit with higher soluble solids and less internal browning than untreated checks.