scholarly journals Infection Efficiency of Venturia inaequalis Ascospores as Affected by Apple Flower Bud Developmental Stage

Plant Disease ◽  
1997 ◽  
Vol 81 (6) ◽  
pp. 661-663 ◽  
Author(s):  
S. Sanogo ◽  
D. E. Aylor
Keyword(s):  
Developmental Stage ◽  
Venturia Inaequalis ◽  
Growth Stages ◽  
Vegetative Shoot ◽  
Flower Buds ◽  
Flower Bud ◽  
Infection Efficiency ◽  
Tight Cluster ◽  
Bud Growth

The average infection efficiency of ascospores of Venturia inaequalis deposited on cluster leaves of apple flower buds was 6 to 16%, 3 to 9%, and 0.4 to 0.6% at tight cluster, first pink, and full pink-to-bloom, respectively. No lesions were observed on flower bud cluster leaves at petal fall. However, the leaves on the vegetative shoot emerging from the flower bud were highly susceptible; the average infection efficiency of ascospores on these leaves was 6 to 21%. The infection efficiency was more variable on young cluster and vegetative shoot leaves than on developing and mature cluster leaves. Results from this study indicate that differences in infection efficiency of V. inaequalis ascospores could be identified by apple bud growth stages.

scholarly journals UAV-Based Heating Requirement Determination for Frost Management in Apple Orchard

2021 ◽  
Vol 13 (2) ◽  
pp. 273
Author(s):  
Wenan Yuan ◽  
Daeun Choi
Keyword(s):  
Apple Orchard ◽  
Growth Stages ◽  
Flower Bud ◽  
Critical Temperatures ◽  
Mapping Algorithm ◽  
Aerial Vehicle ◽  
Bud Growth ◽  
Frost Protection ◽  
Map Resolution ◽  
Temperature Maps

Frost is a natural disaster that can cause catastrophic damages in agriculture, while traditional temperature monitoring in orchards has disadvantages such as being imprecise and laborious, which can lead to inadequate or wasteful frost protection treatments. In this article, we presented a heating requirement assessment methodology for frost protection in an apple orchard utilizing unmanned aerial vehicle (UAV)-based thermal and RGB cameras. A thermal image stitching algorithm using the BRISK feature was developed for creating georeferenced orchard temperature maps, which attained a sub-centimeter map resolution and a stitching speed of 100 thermal images within 30 s. YOLOv4 classifiers for six apple flower bud growth stages in various network sizes were trained based on 5040 RGB images, and the best model achieved a 71.57% mAP for a test dataset consisted of 360 images. A flower bud mapping algorithm was developed to map classifier detection results into dense growth stage maps utilizing RGB image geoinformation. Heating requirement maps were created using artificial flower bud critical temperatures to simulate orchard heating demands during frost events. The results demonstrated the feasibility of the proposed orchard heating requirement determination methodology, which has the potential to be a critical component of an autonomous, precise frost management system in future studies.

Leaf absorption, withdrawal and remobilization of autumn-applied urea-N in apple

2004 ◽  
Vol 84 (1) ◽  
pp. 259-264 ◽  
Author(s):  
S. Guak ◽  
D. Neilsen ◽  
P. Millard ◽  
N. E. Looney
Keyword(s):  
Malus Domestica ◽  
Low Temperatures ◽  
Fruit Set ◽  
Urea Solution ◽  
Flower Buds ◽  
Flower Bud ◽  
Flower Opening ◽  
Total N ◽  
Bud Growth ◽  
Flower Quality

Six-year-old well-nourished Jonagold/M9 apple (Malus domestica) trees were sprayed 7 d after harvest with a 2% urea solution enriched with 9.9% atom 15N. Through 3 d of the absorption period, leaves absorbed 19.2% of the intercepted urea 15N. This low absorption could be in part due to unfavourable conditions, i.e., low temperatures (daily mean ≈5°C) and windy conditions following treatment. During leaf senescence, 48% of the urea 15N absorbed was withdrawn from leaves and most of that (95%) remained in the treated branch section. Of this portion, 65% of the urea 15N was found in dormant bark, 29% in wood, and 6% in flower buds. In the following spring, 46% of the stored urea 15N was remobilized for growth of the flower buds when sampled at the “pink” stage of bud development. This accounted for 3.8% of total N in these tissues. This contribution did not influence flower quality, estimated by the length of the period between flower opening and petal fall and the level of fruit set. Key words: Malus × domestica, urea-15N, flower bud growth, fruit set

scholarly journals Timing and Concentration of Hydrogen Cyanamide Affect Blueberry Bud Development and Flower Mortality

HortScience ◽  
2001 ◽  
Vol 36 (5) ◽  
pp. 922-924 ◽  
Author(s):  
J.G. Williamson ◽  
B.E. Maust ◽  
D.S. NeSmith
Keyword(s):  
Growth Stages ◽  
Flower Bud ◽  
Time Intervals ◽  
Vaccinium Ashei ◽  
Hydrogen Cyanamide ◽  
Bud Development ◽  
Mild Winter ◽  
Fruit Maturity ◽  
Bud Growth ◽  
Southern Highbush

The effects of hydrogen cyanamide (H2CN2) sprays on vegetative and reproductive bud growth and development were evaluated for `Climax' rabbiteye (Vaccinium ashei Reade) and `Misty' southern highbush blueberry (V. corymbosum L. hybrid). `Climax' plants were sprayed with 0% or 1% H2CN2 (v/v) at each of several time intervals or flower bud growth stages following either 270 or 600 hours of artificial chilling. `Misty' plants were sprayed with 0%, 1%, or 2% H2CN2 (v/v) immediately after exposure to 0, 150, or 300 hours of artificial chilling. H2CN2 application to `Climax' plants at 3 days after forcing (DAF) and at 10% to 30% stage 3 flower bud development dramatically accelerated leafing, and only minimal flower bud damage was observed at these application times. For `Misty', vegetative budbreak was increased and advanced by both H2CN2 spray concentrations, regardless of pretreatment chilling levels; the number of vegetative budbreaks per plant increased with increased concentration. Timing of anthesis did not appear to be affected by H2CN2, but fruit maturity was hastened. Increased pretreatment chilling also hastened fruit development. This effect on maturity appears to be due primarily to increased and accelerated vegetative budbreak, which probably increased leaf: fruit ratios. Greater flower bud mortality from H2CN2 occurred in nonchilled plants than in those chilled for 150 or 300 hours, especially at 2% H2CN2. These results indicate that H2CN2 has potential value in stimulating vegetative bud development, which potentially hastens maturity in blueberries grown under the mild winter conditions of the Southeast. However, spray concentration and timing of application will be critical to successful use of this compound.

scholarly journals Ethephon Prolongs Dormancy and Enhances Supercooling in Peach Flower Buds

1991 ◽  
Vol 116 (3) ◽  
pp. 500-506 ◽  
Author(s):  
Edward F. Durner ◽  
Thomas J. Gianfagna
Keyword(s):  
Prunus Persica ◽  
Storage Period ◽  
Bud Dormancy ◽  
Late Winter ◽  
Flower Buds ◽  
Flower Bud ◽  
Ethephon Treatment ◽  
Bud Growth ◽  
Peach Trees ◽  
Heat Requirement

The heat requirement for flower bud growth of container-grown peach trees [Prunus persica (L.) Batsch. cvs. Redhaven and Springold] in the greenhouse varied inversely and linearly with the length of the cold-storage period (SC) provided to break bud dormancy. Ethephon reduced the rest-breaking effectiveness of the 5C treatment. Buds from ethephon-treated trees grew more slowly than buds from untreated trees upon exposure to 20 to 25C, resulting in later bloom dates. The effect of ethephon on flower bud hardiness in field-grown trees of `Jerseydawn' and `Jerseyglo' was studied using exotherm analysis after deacclimation treatments. Bud deacclimation varied with reacclimating temperature (7 or 21 C), cultivar, ethephon treatment, and sampling date. All buds were more susceptible to injury in March than in January or February. Buds reacclimated more rapidly at 21C than at 7C. `Jerseyglo' reacclimated more rapidly than `Jerseydawn'. Untreated buds were less hardy and also reacclimated more rapidly than treated buds. Ethephon enhanced flower bud hardiness in three distinct ways: 1) it decreased the mean low-temperature exotherm of pistils, 2) it increased the number of buds that supercooled after exposure to reacclimating temperatures, and 3) it decreased the rate of deacclimation, especially at 21C. Ethephon prolongs flower bud dormancy by increasing the chilling requirement. The rate at which flower buds become increasingly sensitive to moderate temperatures in late winter and spring is thus reduced by ethephon. Thus, ethephon delays deacclimation during winter and delays bloom in the spring. Chemical name used: (2-chloroethyl) phosphoric acid (ethephon).

SEASONAL DYNAMICS OF THE SUNFLOWER STEM WEEVIL, CYLINDROCOPTURUS ADSPERSUS (LECONTE) (COLEOPTERA: CURCULIONIDAE), ON CULTIVATED SUNFLOWER IN THE NORTHERN GREAT PLAINS

1987 ◽  
Vol 119 (12) ◽  
pp. 1131-1137 ◽  
Author(s):  
Laurence D. Charlet
Keyword(s):  
South Dakota ◽  
Great Plains ◽  
Northern Great Plains ◽  
Growth Stages ◽  
Regression Equations ◽  
Flower Bud ◽  
Bud Growth ◽  
Production Areas ◽  
North And South ◽  
Early Flower

AbstractThe sunflower stem weevil, Cylindrocopturus adspersus (LeConte), is a pest of cultivated sunflower in the major production areas of North and South Dakota, Minnesota, and Texas. Adults appeared in sunflower plots between 5 and 25 June in 1980–1985, when plants had 4–14 leaves. Oviposition began soon after adults were present and continued into late August. Peak densities of both eggs and adults occurred in mid-July. Larvae hatched between 6 and 11 July, when plants were in the early flower bud growth stages. Larvae fed in the sunflower stalk and moved to the stalk base or root crown to construct overwintering chambers. The seasonal patterns of the weevil’s life stages in 6 years were similar, but population densities varied. Regression equations were developed to predict larval numbers in stalks from number of adults to aid in making control decisions.

scholarly journals Peach Pistil Carbohydrate and Moisture Contents and Growth during Controlled Deacclimation following Ethephon Application

1991 ◽  
Vol 116 (3) ◽  
pp. 507-511 ◽  
Author(s):  
Edward F. Durner ◽  
Thomas J. Gianfagna
Keyword(s):  
Moisture Content ◽  
Phosphoric Acid ◽  
Prunus Persica ◽  
Carbohydrate Content ◽  
Flower Buds ◽  
Flower Bud ◽  
Moisture Contents ◽  
Ethephon Treatment ◽  
Bud Growth ◽  
Fall Application

Flower bud growth and carbohydrate content of pistils of two peach cultivars [Prunus persica (L.) Batsch. cvs. Jerseydawn and Jerseyglo] was studied during controlled postrest deacclimation in February and March at 7 and 21C following an application of ethephon (100 mg·liter-1, in October. Ethephon-treated pistils contained more sorbitol and sucrose than untreated pistils, and levels of both sugars decreased during deacclimation. Sorbitol content decreased more rapidly at 21C than at 7C in February, but no difference was detected in March. Fructose content increased during deacclimation in February and was not affected by cultivar, ethephon treatment, or deacclimation temperature. In March, fructose increased in untreated `Jerseydawn' pistils during deacclimation, but not in ethephontreated pistils. In `Jerseyglo', fructose was detected in all samples and declined during deacclimation. Glucose was not detected in treated pistils in February. In untreated pistils, glucose increased during deacclimation. In March, glucose was not detected in `Jerseydawn' pistils reacclimated at 7C. At 21C, glucose was detected only in untreated pistils after 2, 3, or 4 days of deacclimation. In `Jerseyglo', glucose was detected in all pistils. Moisture content of ethephon-treated pistils was lower than untreated pistils in both February and March. Pistil moisture content during deacclimation increased more slowly in ethephon-treated pistils than in untreated pistils in February, but not in March. Pistils sampled in March had a lower moisture content when reacclimated at 7C than at 21C. Pistil growth at 21C was slower in ethephon-treated buds than in untreated buds, but no difference was detected at 7C. The effects of a fall application of ethephon on the carbohydrate content of flower buds in relation to both winter deacclimation and growth in the spring are discussed. Chemical names used: (2-chloroethyl) phosphoric acid (ethephon).

scholarly journals Management Of Thrips Infesting Mung Bean Using Pesticides

2020 ◽  
Vol 17 (2) ◽  
pp. 43-52
Author(s):  
S Yasmin ◽  
MA Latif ◽  
M Ali ◽  
MM Rahman
Keyword(s):  
Mung Bean ◽  
Untreated Control ◽  
Seed Weight ◽  
Growth Stages ◽  
Flower Buds ◽  
Flower Bud ◽  
Thrips Palmi ◽  
Thrips Species ◽  
Vegetative And Reproductive Growth ◽  
Thrips Population

The study was conducted to evaluate the effect of bio-pesticides and chemical insecticides namely Novastar 56EC, Stargate 48SC, Confidor 70WG, Actara 25aWG, Tracer 45SC, Ecomec 1.8EC, Bioneem plus 1EC to control thrips infesting mung bean in the experimental field of Sher-e- Bangla Agricultural University during November 2017 to February 2018. An untreated control observation was also evaluated. Efficacy of the treatments differed significantly and showed effective results in reduction of thrips population and infestation on mung bean at vegetative and reproductive growth stages of the plant. Stargate 48SC (clothianidin) was the most effective insecticide against the thrips species Megalurothrips usitatus and Thrips palmi with the highest reduction of population on top trifoliate leaves and terminal shoots (100.00 and 89.40%, respectively) at vegetative stage and reduction on flower buds and flowers (86.04 and 85.95%, respectively) at reproductive stage of mung bean. The lowest flower bud and flower infestation (7.22 and 3.41%, respectively) and shedding (4.21 and 1.06%, respectively) by thrips with the highest number of pod (23.80 plant-1), seed (10.20 pod-1), 1000 seed weight (48.40 g) and yield (1026.91 kg ha-1) were also found in Stargate 48SC treated plots followed by Confidor 70WG and Actara 25WG treatments. SAARC J. Agri., 17(2): 43-52 (2019)

scholarly journals Genotype, Temperature, and Fall-applied Ethephon Affect Plum Flower Bud Development and Ovule Longevity

1992 ◽  
Vol 117 (1) ◽  
pp. 14-21 ◽  
Author(s):  
Yerko M. Morenol ◽  
Anita Nina Miller-Azarenko ◽  
William Potts
Keyword(s):  
Mineral Content ◽  
Boron Content ◽  
Dry Weight ◽  
Full Bloom ◽  
Flower Buds ◽  
Flower Bud ◽  
Terminal Flower ◽  
Ethephon Treatment ◽  
Bud Growth ◽  
Growth Chambers

Flower bud growth and ovule longevity of plum (Prunus domestics L.) cultivars Italian and Brooks and the effects of fall-applied ethephon and of temperature were studied. Fresh and dry weights of terminal flower buds were measured at l-week intervals from 50 days to 1 day before bloom in 1988. Buds were also analyzed for N, P, K, Ca, and B. After bloom, ovule longevity was determined using a fluorescence method after staining with aniline blue. Ovule longevity was determined in 1990 using shoots excised at full bloom from untreated and ethephon-treated trees of both cultivars and held in growth chambers for 18 days at 5, 10, 15, or 20C. `Brooks' flower buds showed a higher accumulation of fresh and dry weight than `Italian', and ethephon reduced bud weights in both cultivars. Ethephon did not affect mineral content of flower buds of `Brooks', but `Italian' flower buds contained a higher concentration of Ca and a lower concentration of P when treated with ethephon. Boron content was higher in the ethephon-treated buds of `Italian' trees on some sampling dates. Ovule longevity was higher for `Brooks' than for `Italian' in both years. Ethephon treatment delayed ovule senescence in `Italian' flowers, but had little or no effect on `Brooks' flowers. Increasing temperatures induced faster ovule senescence in both cultivars. Chemical name used. 2-chloroethylphosphonic acid (ethephon).

scholarly journals ELONGATION OF LILIUM LONGIFLORUM BUDS AND PEDICELS IS LOCALIZED AT THE BUD BASE REGION

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1063b-1063
Author(s):  
Della Carbonaro ◽  
William B. Miller
Keyword(s):  
Time Course ◽  
Lilium Longiflorum ◽  
Growth Patterns ◽  
Flower Buds ◽  
Flower Bud ◽  
Adequate Knowledge ◽  
Easter Lily ◽  
Time Course Experiment ◽  
Seasonal Flowering ◽  
Bud Growth

Success in the production of seasonal flowering plants requires adequate knowledge of plant growth patterns and rates. In Easter lilies, pedicel growth is one the components of final plant height. Flower bud growth rates are important from the standpoint of timing of anthesis. To learn more about the localization of growth in Easter lily flower buds and pedicels, we conducted a time course experiment. Buds and pedicels were marked at 1.2 mm intervals using an inked bolt. Distances between ink marks were determined at 3 day intervals. Results indicate that 30 mm flower buds elongate almost exclusively from basal regions of the bud. The basal 1.2 mm segment elongated 16 mm in 20 days, while the apical 1.2 mm segment elongated 0.75 mm in the same period. Larger buds (initially 90 mm) gave similar results, although bud tip growth rate increased to some degree just prior to flowering. Pedicel elongation occurred almost exclusively at the apical end of the pedicel, adjacent to the region of greatest bud growth.

scholarly journals Adjusting Growth Stage Values to Develop a Linear Scale for Apricot Flower Bud Phenology

HortScience ◽  
1998 ◽  
Vol 33 (7) ◽  
pp. 1141-1144 ◽  
Author(s):  
Paul T. Austin ◽  
Errol W. Hewett ◽  
Dominique Noiton ◽  
Julie A. Plummer
Keyword(s):  
Growth Stage ◽  
Simple Technique ◽  
Prunus Armeniaca ◽  
Growth Stages ◽  
Flower Bud ◽  
Continuous Scale ◽  
Assessment Period ◽  
Bud Phenology ◽  
Bud Growth ◽  
Stage Class

Integer values used to represent apricot (Prunus armeniaca L.) flower bud growth stages in a phenological scale were adjusted by a simple technique based on cumulative counts of bud observations. Adjusted stage values on a new continuous scale were calculated so that differences between consecutive values were proportional to the frequency with which buds were observed in each growth stage class during the entire assessment period. This meant that adjusted scale values were linearly related to bud development rate at 20 °C. The method was applied to a scale describing flower development from budbreak to petal fall for three cultivars of apricot growing under orchard conditions.

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