scholarly journals Photosynthetic Heat Stability in Highbush Blueberries and the Possibility of Genetic Improvement

HortScience ◽  
1992 ◽  
Vol 27 (10) ◽  
pp. 1111-1112 ◽  
Author(s):  
J.F. Hancock ◽  
K. Haghighi ◽  
S.L. Krebs ◽  
J.A. Flore ◽  
A.D. Draper

Seven highbush blueberry (Vaccinium corymbosum L.) cultivars were evaluated for their photosynthetic heat stability. Ail showed significant reductions in CO2 assimilation rates (A) as leaf temperatures were raised from 20 to 30C, although `Blue-crop', `Jersey', `Elliot', and `Rubel' (22% to - 27%) were significantly less affected than Spartan', `Bluejay', and `Patriot' (-41% to -51%). To determine whether temperature adaptations of highbush types can be broadened through hybridization with native, heat-tolerant species, `Bluecrop' was crossed with the V. darrowi Camp. selection Florida 4B, and F2, BC1, and BC2, populations were generated. This approach showed promise as genotypes were identified in all the derivative populations that were more heat tolerant than `Bluecrop' and had a high A.

2012 ◽  
Vol 58 (No. 5) ◽  
pp. 236-241 ◽  
Author(s):  
S. Mihaljević ◽  
B. Salopek-Sondi

Auxins and their synthetic analogues are commonly used for rooting of cuttings, but their efficiency depends on experimental set-up and, even more importantly, on species or cultivar, and type of explants investigated. In attempt to improve rooting procedure for highbush blueberries (Vaccinium corymbosum L.), we investigated alanine conjugate of indole-3-butyric acid (IBA-Ala) as potential root-promoting compound and compared with commonly used auxins indole-3-butyric acid (IBA) and indole-3-acetic acid (IAA). The effect of different concentrations of auxins on the rooting of highbush blueberry stem cuttings (var. Bluecrop, Bluetta, Burlington and Jersey) and in vitro-derived microcuttings (var. Jersey) was investigated. Auxin treatments significantly promoted rooting of all four varieties in comparison to control. The most efficient rooting promoter in all varieties appeared IBA-Ala (provided up to 83%, and 93% of the rooted cuttings and microcuttings, respectively). Furthermore, IBA-Ala caused a vigorous, well-branched root system that resulted in better acclimatization and survival of plants. Results suggest the application of IBA-Ala may be beneficial for rooting of difficult-to-root varieties of blueberry and related species and their practical application in the nursery industry.  


HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 582a-582
Author(s):  
Jane Beggs

Deformed or damaged berries reduce the grade of frozen highbush blueberries (Vaccinium corymbosum L.). Before berries are frozen, immature fruit are commonly removed by density sorting in water tanks. Three studies were conducted to determine if the firmness or quality of highbush blueberries could be improved by the addition of CaCl2 to sorting tank water. `Bluecrop' and `Jersey' berries were dipped in CaCl2 solutions (0.0-4.0%) for periods of 0.5-8.0 minutes. The effect of rinsing the fruit after treatment was also studied. Berries were held at 2C for several days before evaluation. A 61.5 cm length of PVC pipe (4.0 cm. I.D.) was filled to a depth of 50 cm. with berries and dropped 4 times on to a hard surface from a height of 10 cm. The compression of the column of berries was measured and berries were removed and visually sorted according to the degree of damage. The amount of compression and number of damaged berries were inversely related to the CaCl2 concentration. Rinsing berries immediately after dips negated the effects of CaCl2. Treatment with CaCl2 may result in objectionable flavors.


HortScience ◽  
1993 ◽  
Vol 28 (1) ◽  
pp. 33-35 ◽  
Author(s):  
C.B. Ely ◽  
R.E. Frans ◽  
T.L. Lavy ◽  
R.E. Talbert ◽  
J.D. Mattice

Two-year-old highbush blueberry bushes (Vaccinium corymbosum L. `Collins') were treated in Mar. 1985 with diuron or simazine at 2.2 or 4.5 kg a.i./ha. No residues were detected by reverse-phase high-performance liquid chromatography-ultraviolet absorbance detection (HPLC-UV) from treated berries that were harvested in June. Methiocarb was applied in May 1986 at 0.84 and 3 kg·ha-1 over the top of 3-year-old `Collins' when the berries began to ripen. Reverse-phase HPLC-UV of berries treated with methiocarb at 3 kg·ha-1 had combined residues of methiocarb and its sulfone and sulfoxide metabolites of 13.1 ppm from unrinsed and 7 ppm from rinsed berries harvested on the day of treatment; 4.9 ppm from unrinsed and 4 ppm from rinsed berries harvested 4 days after treatment; and 2.4 ppm from unrinsed and 2.5 ppm from rinsed berries harvested 8 days after treatment. Unrinsed berries treated with methiocarb at 0.84 kg·ha-1 had 5.7 ppm residue on the day of treatment and 1 ppm 8 days later. Residues from berries treated with methiocarb at 0.84 or 3 kg·ha-1 were below the legal tolerance level of 5 ppm after the required 7-day waiting period. Chemical names used: n'-(3,4-dichlorophenyl)-N,N -dimethylurea (diuron); 6-chloro- N,N' -diethyl-1,3,5-triazine-2,4-diamine (simazine); 3,5-dimethyl-4-(methylthio)phenol methylcarbamate (methiocarb).


2000 ◽  
Vol 10 (2) ◽  
pp. 308-314 ◽  
Author(s):  
Sridhar Polavarapu

A common practice in highbush blueberry (Vaccinium corymbosum L.) culture is to use combinations of insecticides and fungicides to reduce the number and cost of pesticide applications. In response to apparent phytotoxicity observed in commercial fields that were treated with combinations of diazinon and captan formulations, phytotoxicity of two formulations of diazinon (Diazinon AG600 and Diazinon 50W) and captan (Captan 80WP and Captec 4L) was investigated on highbush blueberries during 1997 and 1998. Phytotoxicity injury similar to injury observed in commercial fields was reproduced in treatments with diazinon and captan mixtures in all experiments. The Diazinon AG600 and Captec 4L mixture was the most severe and caused significantly more phytotoxic-ity to fruit and leaves than individual treatments of Diazinon AG600, Captec 4L or untreated control. Separation of diazinon and captan applications by 8 h significantly reduced phytotoxicity compared to mixture treatments. Injured fruit and leaves recovered over time and most treatments showed only a mild injury at the time of harvest. Phytotoxicity on fruit and leaves caused by Diazinon AG600 and Captec 4L mixture was significantly affected by application date with the earliest application causing the greatest injury. These data indicate that diazinon and captan mixtures cause phytotoxicity on highbush blueberries and therefore the two should not be applied in combination.


HortScience ◽  
1996 ◽  
Vol 31 (6) ◽  
pp. 981-983 ◽  
Author(s):  
W.O. Cline

The effects of inoculum, surface wetness, and stem scar on postharvest fungal infection of highbush blueberry (Vaccinium corymbosum L.) fruit were evaluated by exposing berries of the cultivars Bluechip (small, dry stem scar) and Blueray (large, wet stem scar) to infested and noninfested surfaces under wet or dry conditions. Rots caused by Colletotrichum gloeosporioides (Penz.) Penz. & Sacc. in Penz. and Alternaria tenuissima (Kunze:Fr.) Wiltshire were evaluated. Field-harvested berries stored for 7 days at 21 °C resulted in baseline infection levels of 1.5% (`Bluechip') and 18.7% (`Blueray') for C. gloeosporioides, and 10.1% vs. 28.9%, respectively, for A. tenuissima. Wet stem scars, infestation of handling surfaces, and addition of moisture were all responsible for increasing postharvest rots; however, most of the significant increases in rots occurred with a combination of two or more of these factors.


1999 ◽  
Vol 131 (6) ◽  
pp. 757-768 ◽  
Author(s):  
Margriet H. Dogterom ◽  
Mark L. Winston

AbstractWe investigated pollen and nectar foraging of honey bees, Apis mellifera L., from pollen-poor and pollen-rich, small and large colonies in blooming highbush blueberry, Vaccinium corymbosum L. cv. Bluecrop fields. The proportion of pollen foragers differed significantly between pollen-rich and pollen-poor colonies after storage levels were manipulated, but foraging and pollen stores returned to similar levels within a week. No differences were found in small colonies, although the proportion of pollen foragers was high (46% and 45% from pollen-rich and pollen-poor colonies, respectively). Only 7.6% of pollen foragers carried Vaccinium sp. pollen in their loads independent of treatment, day, and colony size, whereas 60.8% of nectar foragers carried up to 100 tetrads of Vaccinium sp. pollen on their bodies. The average proportion of Vaccinium sp. pollen carried by nectar and pollen foragers per day and treatment was less than 10%. Our research indicates that when colonies are placed in fields of blooming blueberry flowers, pollen foraging is stimulated in large colonies with stores that are pollen poor, but predominantly for pollen types other than blueberry. This research indicates that nectar foragers are the major visitor of highbush blueberry cv. Bluecrop and suggests that increasing the number of nectar foragers rather than pollen foragers would result in more honey bees foraging on highbush blueberry, in particular cv. Bluecrop.


1973 ◽  
Vol 53 (3) ◽  
pp. 571-577 ◽  
Author(s):  
L. R. TOWNSEND

In a 6-yr field study with highbush blueberries (Vaccinium corymbosum L.) the incorporation of raw sawdust or peat with the soil, plus surface-applied fertilizer, did not increase yields, bush size, or vigor. Control bushes were more vigorous, produced higher yields with larger fruit, and usually had lower levels of all nutrients, Ca excepted, than those receiving the other treatments even though the differences were not generally significant at the 5% level. Regression equations revealed that leaf Ca, bush size, and winter injury were the most important variables associated with yields, whereas fruit size was most closely related to leaf Ca, Mg, and N.


HortScience ◽  
2007 ◽  
Vol 42 (7) ◽  
pp. 1612-1615 ◽  
Author(s):  
Jeffrey G. Williamson ◽  
D. Scott NeSmith

Greenhouse and field experiments were conducted to determine the effects of the growth regulator N-(2-chloro-4-pyridyl)-N′-phenylurea (CPPU) on fruit set, berry size, and yield of southern highbush blueberry (Vaccinium corymbosum hybrids). The experiments were conducted over a period of several years in Georgia and Florida. CPPU sprays were capable of increasing fruit set and berry weight of southern highbush blueberry, although the responses to CPPU treatment were variable and appeared to be influenced by factors such as rate, spray timing, and cultivar. In Florida, high natural fruit set may have prevented increased fruit set from CPPU. A slight delay in berry maturity was noted in several experiments. Spray burn occurred on several occasions and may be related to factors such as cultivar, rate, spray volume, and use of surfactant.


HortScience ◽  
1993 ◽  
Vol 28 (12) ◽  
pp. 1162-1163 ◽  
Author(s):  
James N. Moore ◽  
Maurus V. Brown ◽  
Bruce P. Bordelon

The influence of in-row plant spacing on the yield and fruit size of `Blueray' (erect growing) and `Bluecrop' (spreading) highbush blueberry (Vaccinium corymbosum L.) was studied. Plants of both cultivars, spaced at 0.61 m within the row, had significantly higher yields per hectare than plants grown at wider spacings (0.92 and 1.22 m) in each of five harvest years. On a per-plant basis, however, plants spaced at 1.22 m had higher yields in the last two harvest years of the experiment than plants spaced more closely, which indicated that interplant competition reduced per-plant yields of closely spaced plants as plants grew larger. Over the 5-year harvest period, plots with 0.61-m plant spacing produced a cumulative total yield of 17.24 t·ha more than plots with the conventional 1.22-m spacing. Plant spacing did not affect fruit size in this experiment.


2001 ◽  
Vol 10 (2) ◽  
pp. 113-119 ◽  
Author(s):  
A. KASURINEN ◽  
T. HOLOPAINEN ◽  
S. ANTTONEN

Transmission electromicroscopy, trypan blue staining in combination with stereomicroscope analysis and biochemical ergosterol assay were used to study the mycorrhizal symbionts in wild bilberry (Vaccinium myrtillus), bog whortleberry (Vaccinium uliginosum) and highbush blueberry (Vaccinium corymbosum) roots. TEM-analysis showed that in all species ericoid mycorrhizas formed hyphae coil inside the epidermal root cells. In stereomicroscopic viewing the highest mycorrhizal colonisation was observed in the roots of wild bilberries (51%), whereas according to the ergosterol assay the highest total fungal biomass of roots was found in bog whortleberries (209 mg g-1 of root d. wt). Both ergosterol and microscopical method showed that the mycorrhizal associations in blueberry cultivars and their wild relatives growing on natural soil medium are frequent, although ericoid mycorrhiza formation of highbush blueberries was somewhat weaker than that of wild bilberries and bog whortleberries.


Sign in / Sign up

Export Citation Format

Share Document