Effects of Timing and Intensity of Summer Pruning on Vegetative Traits of Two Southern Highbush Blueberry Cultivars

Pruning is a recommended practice for blueberry (Vaccinium spp.) production and is usually done in the summer in warm subtropical climates with long growing seasons. Summer pruning promotes healthy vegetative growth during the remainder of the growing season; however, research-based recommendations for summer pruning strategies are lacking. The objective of this study was to determine effects of summer pruning timing and intensity on vegetative growth in ‘Jewel’ and ‘Emerald’ southern highbush blueberry (V. corymbosum-interspecific hybrid), two cultivars of the primary species grown in subtropical areas. To determine effects of pruning time, 30% of the canopy was removed in June or July. To determine pruning intensity effects, either 30% or 60% of the canopy was removed in June, both followed by shoot tipping in July. Both timing and intensity treatments were compared with a non-pruned control. Lack of pruning in the first year had no negative effects on growth; however, lack of pruning for two or more seasons decreased regrowth volume and shoot length of both cultivars. By the third season, canopy regrowth volume in both cultivars decreased in the non-pruned control compared with the 30% and 60% pruning treatments and compared with the June pruning treatment. Disease infection in ‘Jewel’ was also increased in the non-pruned control compared with these pruning treatments. Summer pruning, regardless of timing or intensity, generally increased vigor of vegetative growth for both cultivars and decreased incidence of leaf disease in ‘Jewel’.

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Vegetative Growth of Three Southern Highbush Blueberry Cultivars Obtained from Micropropagation and Softwood Cuttings in Two Florida Locations

HortScience ◽

10.21273/hortsci.49.5.556 ◽

2014 ◽

Vol 49 (5) ◽

pp. 556-561 ◽

Cited By ~ 8

Author(s):

Silvia R. Marino ◽

Jeffrey G. Williamson ◽

James W. Olmstead ◽

Philip F. Harmon

Keyword(s):

Tissue Culture ◽

Plant Height ◽

Growing Season ◽

Vaccinium Corymbosum ◽

Highbush Blueberry ◽

Plant Canopy ◽

Growing Seasons ◽

Canopy Volume ◽

Shoot Number ◽

Southern Highbush

Field performance of southern highbush blueberry (Vaccinium corymbosum L. interspecific hybrids) cultivars Emerald, Jewel, and Primadonna derived from softwood cuttings (SW) and tissue culture (TC) was evaluated in Citra and Haines City, FL, in 2010–12. Both fields were planted in Apr. 2010 on sandy soil amended with pine bark. Plant height and width were recorded at both locations, from which plant canopy volume was calculated. Additionally, whole plants were harvested at planting and after the first growing season, after the first fruit harvest, and after the second growing season. Average plant height and width, number of major canes, and total shoot number were determined at each sampling date. Dry weights for roots, crowns, canes, shoots, and leaves were obtained. Although propagation method affected plant canopy volume during the first season, no effects were observed by the end of the second growing season. At planting and after the first and second growing seasons, TC plants of the three cultivars had more major canes. Total shoot number per plant was greater for TC ‘Jewel’ at all dates but ‘Emerald’ TC plants had more shoots only at planting and after the first growing and harvest seasons. Tissue culture resulted in increased plant dry weights of ‘Jewel’ and ‘Emerald’ after the first and second growing seasons. There were no significant differences in total number of shoots or plant dry weight between TC and SW-derived ‘Primadonna’ plants at any point during the study.

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Facilitation Effects of Haloxylon salicornicum Shrubs on Associated Understory Annuals, and a Modified “Stress-Gradient” Hypothesis for Droughty Times

Plants ◽

10.3390/plants9121726 ◽

2020 ◽

Vol 9 (12) ◽

pp. 1726

Author(s):

Nasr H. Gomaa ◽

Ahmad K. Hegazy ◽

Arafat Abdel Hamed Abdel Latef

Keyword(s):

Species Richness ◽

Water Availability ◽

Stress Gradient ◽

Growing Season ◽

Annual Species ◽

Negative Effects ◽

Growing Seasons ◽

Dry Seasons ◽

The Impact ◽

Haloxylon Salicornicum

Perennial shrub-annual plant interactions play key roles in desert regions influencing the structure and dynamics of plant communities there. In the present study, carried out in northwestern Saudi Arabia, we examined the effect of Haloxylon salicornicum shrubs on their associated understory annual species across four consecutive growing seasons, along with a record of the seasonal rainfall patterns. We measured density and species richness of all the annual species in permanent quadrats located beneath individual shrubs, as well as in the spaces between shrubs. During wet growing season H. salicornicum shrubs significantly enhanced the density and species richness of sub-canopy species, whereas in the relatively dry seasons they exerted negative effects on the associated species. In all growing seasons, the presence of shrubs was associated with enhanced soil properties, including increased organic carbon content, silt + clay, and levels of nutrients (N, P and K). Shrubs improved soil moisture content beneath their canopies in the wet growing season, while in the dry seasons they had negative effects on water availability. Differences in effects of H. salicornicum on understory plants between growing seasons seem due to the temporal changes in the impact of shrubs on water availability. Our results suggest the facilitative effects of shrubs on sub-canopy annuals in arid ecosystems may switch to negative effects with increasing drought stress. We discuss the study in light of recent refinements of the well-known “stress-gradient hypothesis”.

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The Effect of Mycorrhizal Inoculum and Phosphorus Treatment on Growth and Flowering of Ajania (Ajania pacifica (Nakai) Bremer et Humphries) Plant

Horticulturae ◽

10.3390/horticulturae7070178 ◽

2021 ◽

Vol 7 (7) ◽

pp. 178

Author(s):

Matej Vosnjak ◽

Matevz Likar ◽

Gregor Osterc

Keyword(s):

Arbuscular Mycorrhizal Fungi ◽

Flowering Time ◽

Endophytic Fungi ◽

Mycorrhizal Fungi ◽

Arbuscular Mycorrhizal ◽

Growing Season ◽

Shoot Length ◽

Available Phosphorus ◽

Growing Seasons ◽

Number Of Shoots

The influence of mycorrhizal inoculum in combination with different phosphorus treatments on growth and flowering parameters of Ajania (Ajania pacifica (Nakai) Bremer et Humphries) plants was investigated in two growing seasons (2015 and 2016). Plants of the cultivar ‘Silver and Gold’ were transplanted into pots either with added mycorrhizal inoculum or without inoculum and assigned to four phosphorus treatments. Mycorrhizal colonization was assessed by evaluating the frequency of colonization, intensity of colonization and density of fungal structures (arbuscules, vesicles, coils and microsclerotia) in the roots. During the growing season, the content of plant available phosphorus in the soil was analyzed, and shoot length, number of shoots, number of inflorescences, number of flowers and flowering time were evaluated. Inoculated Ajania plants were successfully colonized with arbuscular mycorrhizal fungi and dark septate endophytic fungi. In the root segments, hyphae were mainly observed, as well as vesicles, coils, arbuscules and microsclerotia, but in lower density. The density of fungal structures did not differ among phosphorus treatments, but did differ between years, with a higher density of fungal structures in 2016. Mycorrhizal plants developed higher number of shoots in 2016, higher number of inflorescences, higher number of flowers, and they flowered longer compared to uninoculated plants.

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The onset in spring and the end in autumn of the thermal and vegetative growing season affect calving time and reproductive success in reindeer

Current Zoology ◽

10.1093/cz/zoz032 ◽

2019 ◽

Vol 66 (2) ◽

pp. 123-134 ◽

Cited By ~ 4

Author(s):

Amélie Paoli ◽

Robert B Weladji ◽

Øystein Holand ◽

Jouko Kumpula

Keyword(s):

Reproductive Success ◽

Time Lag ◽

Growing Season ◽

Plant Phenology ◽

Negative Effects ◽

Main Hypothesis ◽

Vegetation Growth ◽

Growing Seasons ◽

Finnish Lapland ◽

Reindeer Population

Abstract A developing trophic mismatch between the peak of energy demands by reproducing animals and the peak of forage availability has caused many species’ reproductive success to decrease. The match–mismatch hypothesis (MMH) is an appealing concept that can be used to assess such fitness consequences. However, concerns have been raised on applying the MMH on capital breeders such as reindeer because the reliance on maternal capita rather than dietary income may mitigate negative effects of changing phenologies. Using a long-term dataset of reindeer calving dates recorded since 1970 in a semidomesticated reindeer population in Finnish Lapland and proxies of plant phenology; we tested the main hypothesis that the time lag between calving date and the plant phenology in autumn when females store nutrient reserves to finance reproduction would lead to consequences on reproductive success, as the time lag with spring conditions would. As predicted, the reproductive success of females of the Kutuharju reindeer population was affected by both the onset of spring green-up and vegetative senescence in autumn as calves were born heavier and with a higher first-summer survival when the onset of the vegetation growth was earlier and the end of the thermal growing season the previous year was earlier as well. Our results demonstrated that longer plant growing seasons might be detrimental to reindeer’s reproductive success if a later end is accompanied by a reduced abundance of mushrooms.

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The effects of nitrogen and irrigation on timothy (Phleum pratense) grown for production of seed: I. Vegetative growth

The Journal of Agricultural Science ◽

10.1017/s0021859600018621 ◽

1967 ◽

Vol 69 (2) ◽

pp. 225-230 ◽

Cited By ~ 3

Author(s):

D. A. Lambert

Keyword(s):

Vegetative Growth ◽

Irrigation Treatment ◽

Phleum Pratense ◽

First Year ◽

Positive Effects ◽

The Third ◽

The Mean ◽

Second Year ◽

Additional Nitrogen ◽

Applied Nitrogen

1. Plants of S.48 timothy were established on a 1 ft square pattern for production of seed. Two series of plots, one irrigated and one not irrigated, were treated with three levels of applied nitrogen: 0 (NO), 87 (Nl) and 261 (N2) lb N per acre (0, 97·5 and 292·5 kg N/ha) per annum, for 3 years. In this, the first of two papers, only vegetative aspects of growth are considered. Since the irrigation treatment started only 2 weeks before most of the data were recorded, effects of irrigation on vegetative growth were generally small.2. The number of tillers per plant was increased by application of nitrogen; the lower increment was more effective than the additional nitrogen in the higher dose.3. The weight of tillers per plant was increased by nitrogen at both levels of application. The mean weight of each tiller was increased by nitrogen after the first year, predominantly in the N 2 treatment. In the second year, irrigation also increased the weight per tiller.4. The weight of roots per plant was significantly affected by application of nitrogen. In the first year, the weight was increased by nitrogen in irrigated plots; in the second year the roots were significantly heavier in the Nl treatment than in N0 and N2 treatments, where weights were similar; the same situation existed in irrigated plots in the third year, but in non-irrigated plots the weights of roots were similar in N1 and N2 treatments and were heavier than in the N0 treatment. Irrigation had positive effects on the weight of roots in the first and second years.

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Budset and Growth of Eastern White Pine Following Application of 6-Benzylaminopurine to Seedlings Fertilized with Different Levels of Nitrogen

Journal of Environmental Horticulture ◽

10.24266/0738-2898-6.2.42 ◽

1988 ◽

Vol 6 (2) ◽

pp. 42-45

Author(s):

L. Eric Hinesley ◽

Robert D. Wright

Keyword(s):

Irrigation Water ◽

Pinus Strobus ◽

Dry Weight ◽

Growing Season ◽

First Year ◽

White Pine ◽

Eastern White Pine ◽

Growing Seasons ◽

One Year ◽

Different Levels

Eastern white pine (Pinus strobus L.) were potted and solution fed once weekly during 2 growing seasons with 5 levels of N in the irrigation water: 50, 100, 200, 300 and 400 ppm. Leaders were treated with 750 ppm 6-benzylaminopurine (BA) in late June of the first year. The higher N levels resulted in greater stem diameter, greater foliage dry weight, longer and heavier needle fascicles, better foliage color, greater budset after application of BA, and more and longer branches on the BA-treated leader the second growing season. BA should be applied to trees with N concentration ≥ 1.5% in one-year-old foliage.

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Growth of Three Shade Tree Genera as Influenced by Irrigation and Nitrogen Rates

Journal of Environmental Horticulture ◽

10.24266/0738-2898-1.1.5 ◽

1983 ◽

Vol 1 (1) ◽

pp. 5-6

Author(s):

R.D. Wright ◽

E.B. Hale

Keyword(s):

Shoot Growth ◽

Acer Rubrum ◽

Tree Height ◽

First Year ◽

Red Maple ◽

Trunk Diameter ◽

The Third ◽

Growing Seasons ◽

N Rates ◽

Nitrogen Rates

The influence of N rates and irrigation on shoot growth and trunk diameter were evaluated for red maple (Acer rubrum, L. ‘October Glory’), pin oak (Quercus palustris Muenchh) and dogwood (Cornus florida L. ‘Barton’). Irrigation increased shoot growth and trunk diameter for all 3 species during the first 2 growing seasons. Tree height and trunk diameter at the end of the third growing season were also greater for irrigated trees. Increasing the N levels from 168 to 329 Kg N/ha (150 to 300 lb N/A) resulted in a decrease in trunk diameter the first year and a decrease in shoot growth the second year in ‘October Glory’ maple. No significant differences in oak growth due to N rate were observed. Shoot growth and trunk diameter for dogwood were greater at 329 kg N/ha (300 lb N/A) than at 168 kg N/ha (150 lb N/A) only the first year. Neither height or trunk diameter at end of the third year were significantly increased from applying the higher level of N for any of the genera.

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Response of Micropropagated Apple Trees to Field Establishment Procedures

HortScience ◽

10.21273/hortsci.26.11.1364 ◽

1991 ◽

Vol 26 (11) ◽

pp. 1364-1365 ◽

Cited By ~ 1

Author(s):

Richard H. Zimmerman

Keyword(s):

Cold Storage ◽

Vegetative Growth ◽

Shoot Growth ◽

Cultural Practices ◽

Growing Season ◽

First Year ◽

Sectional Area ◽

Apple Trees ◽

Cross Sectional ◽

Terminal Shoot

Growth, flowering, and fruiting of micropropagated `Jonathan' apple trees (Malus domestica Borkh.) transferred in Spring 1983 to the field from either a nursery, cold storage, or greenhouse were compared. First-year shoot and trunk growth was greatest for trees transplanted from the nursery and least for trees that were held in the greenhouse before being transferred to the field. Trees pruned low (35 cm) at planting time had more terminal shoot growth and less trunk cross-sectional area after the first growing season than those pruned high (90 cm). The effect of preplanting cultural practices on vegetative growth diminished in the 2nd year and disappeared by the end of the 3rd year in the orchard. Flowering began in 1985 and was only slightly affected by preplanting cultural practices and pruning treatments. Fruiting was not affected by the treatments.

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Hydrogen Cyanamide Stimulates Early Foliation of `Misty' Southern Highbush Blueberry

HortScience ◽

10.21273/hortsci.32.3.537c ◽

1997 ◽

Vol 32 (3) ◽

pp. 537C-537

Author(s):

J.G. Williamson ◽

R.L. Darnell

Keyword(s):

Vegetative Growth ◽

Fruit Set ◽

Small Diameter ◽

Highbush Blueberry ◽

Full Bloom ◽

Flower Buds ◽

Flower Bud ◽

Hydrogen Cyanamide ◽

Southern Highbush ◽

Chilling Treatment

Two-year-old, container-grown `Misty' southern highbush blueberry plants were sprayed to drip with two concentrations of hydrogen cyanamide (HCN) (20.4 g·L–1 and 10.2 g·L–1) after exposure to 0, 150, or 300 hr of continuous chilling at 5.6°C. All plants were sprayed immediately after chilling and placed in a greenhouse for several weeks. The plants were moved outdoors during flowering to increase cross-pollination from nearby `Sharpblue' blueberry plants. HCN sprays killed some of the more advanced flower buds on shoot terminals and on small-diameter wood from the previous spring growth flush. Significantly greater flower bud mortality occurred for the 20.4 g·L–1 HCN sprays than for the 10.2 g·L–1 sprays. Flower buds subjected to 0 hr of chilling were more susceptible to spray burn than flower buds receiving 150 or 300 hr of chilling. Very little flower bud death occurred with the 10.2 g·L–1 HCN rate on plants receiving 300 hr of chilling. Vegetative budbreak was advanced for both HCN treatments compared to controls, regardless of chilling treatment. HCN-treated plants were heavily foliated at full bloom, while non-treated plants had very few to no leaves during bloom. HCN may be useful for stimulating vegetative growth in some southern highbush blueberry cultivars that suffer from poor foliation during flowering and fruit set.

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Grapevine culture in trenches. 2. Reproductive characteristics and interactions with vegetative growth

OENO One ◽

10.20870/oeno-one.2003.37.2.947 ◽

2003 ◽

Vol 37 (2) ◽

pp. 85

Author(s):

Christophe Zapata ◽

Jean-Claude Audran ◽

Christian Magné

Keyword(s):

Biomass Production ◽

Vegetative Growth ◽

Fruit Set ◽

Reproductive Development ◽

Growing Season ◽

Pinot Noir ◽

Inflorescence Development ◽

The Third ◽

Controlled Conditions ◽

Berry Size

<p style="text-align: justify;">In order to assess the consequence of a strong vegetative growth on inflorescence development and berry setting, two grapevine cultivars differing in their rate of fruit set were grown for 3 years in a greenhouse under semi-controlled conditions. Merlot (low % fruit set) and Pinot noir (high % fruit set) vines produced well-developed clusters in year 3 after planting, thus allowing the study of interactions between vegetative growth and reproductive development over the third growing season. Progress in development of both cultivars was simultaneous until pea berry size and biomass production was similar throughout the season. However, biomass production was negatively correlated to flower differentiation (number of flowers/inflorescence) in Merlot whereas not in P. noir. Possible causes of this interaction are discussed.</p>

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