scholarly journals Exogenous Gibberellic Acid Advances Reproductive Phenology and Increases Early-Season Yield in Subtropical Blackberry Production

Agronomy ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1317
Author(s):  
Syuan-You Lin ◽  
Shinsuke Agehara

Inadequate winter chill causes poor and erratic budbreak in blackberry (Rubus L. subgenus Rubus Watson), limiting the commercial production in subtropical climates. We examined the effects of exogenous gibberellic acid (GA3) on the reproductive phenology, fruit number, yield, and fruit quality of three blackberry cultivars (‘Natchez’, ‘Navaho’, and ‘Ouachita’) grown under subtropical climatic conditions in two consecutive growing seasons. A single spray application of GA3 at 0 or 49 g·ha−1 was performed when plants were dormant in late December to late January. Exogenous GA3 advanced the onset of budbreak by 12 to 82 days, flowering by four to 20 days, and fruit ripening by 0 to 15 days. When pooling across the cultivars, it also increased early-season yield by 83% to 276% in two consecutive growing seasons and total-season yield by 60% in the second growing season. Among the cultivars, the yield responses to GA3 were most consistent in ‘Ouachita’, with early-season yield increasing by up to 499%. The average berry weight and soluble solids concentration were slightly reduced by GA3, but these reductions were not consistent in the two growing seasons and the impact on overall fruit marketability was small. These results suggest that exogenous GA3 is an effective bud dormancy breaking compound for blackberry, and it could be an important adaptation tool for subtropical blackberry production.

HortScience ◽  
2020 ◽  
pp. 1-7
Author(s):  
Syuan-You Lin ◽  
Shinsuke Agehara

In subtropical blackberry (Rubus L. subgenus Rubus Watson) production, inadequate winter chill causes poor and erratic budbreak, whereas high temperatures and heavy rainfall deteriorate late-season fruit quality. We examined the effects of four defoliants [zinc sulfate (ZS), potassium thiosulfate (KTS), urea, and lime sulfur (LS)] on defoliation, budbreak, yield, and fruit quality of ‘Natchez’ blackberry grown under inadequate chilling conditions in two consecutive growing seasons. Plants were treated with defoliants at 187 kg·ha−1 via spray application (1870 L·ha−1) at the beginning of chill accumulation (late December). A nonionic surfactant (Agri-Dex) was added at 0.5% (v/v) to all treatments including the water control. Cumulative chilling hours (<7.2 °C) at the experiment site were 209 and 134 in the first and second growing seasons, respectively. Defoliation was only 40.2% to 55.5% in the control, but it was induced moderately by LS (69.7% to 84.7%) and severely by the other defoliants (81.7% to 94.7%). Budbreak was induced most rapidly by urea application, followed by LS, KTS, and ZS, advancing by 17 to 66 days compared with the control. Consequently, urea, KTS, LS, and ZS increased early season yield by 2.79, 2.55, 0.87, and 0.31 t·ha−1, respectively, compared with the control (0.12 t·ha−1). By contrast, the final percentage of budbreak and total-season yield did not show significant treatment effects. KTS caused cane dieback and increased bud mortality, resulting in the lowest total-season yield among the treatments. Importantly, defoliants had no negative impact on berry size and soluble solids concentration. These results suggest that urea, LS, and ZS are effective bud dormancy-breaking agents for blackberry and that they could be an important adaptation tool for subtropical blackberry production. Among the three defoliants, urea appears to be the ideal chemical option because of its consistent efficacy, favorable safety profile, and low application cost.


Author(s):  
Syuan-You Lin ◽  
Shinsuke Agehara

AbstractInadequate winter chill causes poor budbreak in blackberry (Rubus L. subgenus Rubus Watson), limiting the commercial production in the subtropics. In ‘Natchez’ blackberry, our previous study found that, under inadequate chilling conditions, urea and lime sulfur (LS) applied as defoliants before chill accumulation advanced budbreak but did not improve final budbreak. In this study, we applied the two defoliants at the end of chill accumulation and examined their effectiveness in breaking dormancy, with a hypothesis that it can be enhanced with increased exposure to chilling. Field experiments were conducted over two growing seasons under subtropical climatic conditions. ‘Natchez’ blackberry was sprayed with urea or LS at 10%. Both defoliants were effective in both advancing and maximizing budbreak. Final budbreak reached 42.6% to 76.8% in the defoliant treatments, compared with 27.1% to 31.6% in the control. Advanced budbreak by defoliants increased early season yield by 35% to 88%. Although not statistically significant, defoliants increased total-season yield by 19% to 56%, compared with the control. Phytohormone profiling revealed no changes in abscisic acid and gibberellic acid 4, but increasing trends in jasmonic acid and indole-3-acetic acid (IAA) during budbreak. The LS treatment increased IAA accumulation by up to 377% compared with the control. These results suggest that urea and LS are highly effective dormancy-breaking agents for blackberry when applied after winter chill accumulation. These defoliants could be an important adaptation tool for subtropical blackberry production. Furthermore, increased IAA accumulation appears to be, at least in part, the mode of action for LS-induced budbreak.


2020 ◽  
Vol 24 (2) ◽  
Author(s):  
Ádám Esztergályos ◽  
Zsolt Polgár

The length of tuber dormancy of potato varieties is an important factor in the profitability of the potato sector. Under temperate climatic conditions longer dormancy is more advantageous. However, in case of multiple planting within one growing season, in seed multiplication programs or during rapid post-harvest disease testing, breaking or shortening of dormancy is often needed. Numerous ways for chemical regulation of dormancy period were developed, but the efficiency of such methods is strongly genotype dependent. Recently a comparative study of chemical treatments for breaking tuber dormancy of some new Hungarian potato varieties was carried out. Continuing this work, here we report about the effects of chemical treatments used for breaking dormancy on the number of stems and tubers of progeny plants. The experiment was conducted in three consecutive vegetation period, with three varieties having different maturity type and different dormancy period: Balatoni rózsa, Botond and Démon. Treatments were performed using gibberellic-acid, benzyl-adenine and Rindite in different concentrations and combinations. After the dormancy period, tubers were planted into pots and grown under controlled conditions. Number of developed stems and tubers was counted. According to the results, applied treatments had a large effect on the number of developing stems and tubers of the progeny plants. Combined treatments of Rindite+gibberellic-acid, and gibberellic-acid at 100 ppm increased significantly the number of stems and tubers. Correlation between the efficiency of dormancy breaking and the number of developed tubers was found. Based on our data, Rindite and gibberellic-acid have an important role not only in breaking dormancy, but also in increasing the tuber number/plant. This positive effect could be utilized in seed potato production.


HortScience ◽  
2009 ◽  
Vol 44 (6) ◽  
pp. 1637-1640 ◽  
Author(s):  
Valeria Sigal Escalada ◽  
Douglas D. Archbold

The impact of heat plus aminoethoxyvinylglycine (AVG) treatments alone or in combination on ripening of four apple cultivars has been studied. A solution of AVG was applied to ‘Lodi’, ‘Senshu’, ‘Redchief Delicious’, and ‘Red Fuji’ apple trees ≈4 weeks before normal harvest at 124 g·ha−1 a.i. After harvest, half of each group of control and AVG-treated fruit was heated at 38 °C for 4 days and then stored at 4 °C for 30 days. After cold storage, AVG and heat individually suppressed ethylene production of ‘Senshu’ and ‘Redchief Delicious’ but not of ‘Lodi’ or ‘Red Fuji’. The combination of AVG with heat treatment reduced ethylene production the most consistently in each cultivar except ‘Lodi’, suggesting some additive effect of the treatments. The respiration rate after cold storage was not consistently affected by any treatment. AVG alone and with heat maintained firmness of ‘Lodi’, AVG plus heat maintained it in ‘Senshu’, but neither ‘Redchief Delicious’ nor ‘Red Fuji’ firmness responded to the treatments. AVG-treated ‘Lodi’ and ’Redchief Delicious’ fruit, heated fruit of all cultivars, and AVG plus heat in all had lower titratable acidity than controls after cold storage. Although there were no effects of any treatment on fruit soluble solids concentration, the combined treatment increased the soluble solids:titratable acidity ratio of all cultivars, although heat or AVG alone had no consistent effects. Total ester production by ‘Redchief Delicious’ peel tissue after cold storage was reduced 44% by AVG and 70% or more by heat and AVG plus heat. There were no differences in peel alcohol acyltransferase activity among the treatments, supporting the hypothesis that substrate availability was the limiting factor for ester synthesis in treated fruit. Overall, heat plus AVG treatment did not provide any advantage over each alone for maintaining apple fruit quality during short-term cold storage.


2020 ◽  
pp. 1-6
Author(s):  
Nikola Arsenijevic ◽  
Matheus de Avellar ◽  
Liberty Butts ◽  
Nicholas John Arneson ◽  
Rodrigo Werle

Abstract The use of photosystem II (PSII)-inhibitor and/or protoporphyrinogen oxidase (PPO)-inhibitor PRE herbicides in soybean may, under adverse environmental conditions, result in early season crop injury. A field study was conducted near Brule and North Platte, Nebraska, during the 2016 and 2017 growing seasons with the objective to evaluate the impact of PRE herbicides metribuzin (PSII-inhibitor) and sulfentrazone (PPO-inhibitor) on early season soybean development, final plant stand, and yield using 22 soybean varieties adapted to southwestern Nebraska. Herbicide treatments consisted of metribuzin (560 g ai ha−1) and sulfentrazone (280 g ai ha−1) applied within 3 d after planting and a nontreated control (NTC). Sulfentrazone reduced green canopy vegetation at the V2 growth stage by 22% and final plant stand at physiological maturity by 10% compared with the NTC. The number of pods per plant was 16% higher for sulfentrazone and the number of seeds per plant was 15% and 4% higher for sulfentrazone and metribuzin compared with the NTC, respectively. Sulfentrazone and metribuzin resulted in a slightly higher yield (3%) compared with the NTC, thus no yield reduction from PRE herbicides was observed in this study. These results support other findings that sulfentrazone and metribuzin have potential to cause early-season crop injury; however, when applied according to their label recommendations and following regional agronomic management practices, this impact may not translate into soybean yield reduction while such herbicides provide effective soil residual weed control.


2005 ◽  
Vol 15 (4) ◽  
pp. 886-895 ◽  
Author(s):  
S.S. Miller ◽  
R.W. McNew ◽  
B.H. Barritt ◽  
L. Berkett ◽  
S.K. Brown ◽  
...  

Cultivar and planting site are two factors that often receive minimal attention, but can have a significant impact on the quality of apple (Malus ×domestica) produced. A regional project, NE-183 The Multidisciplinary Evaluation of New Apple Cultivars, was initiated in 1995 to systematically evaluate 20 newer apple cultivars on Malling.9 (M.9) rootstock across 19 sites in North America. This paper describes the effect of cultivar and site on fruit quality and sensory attributes at a number of the planting sites for the 1998 through 2000 growing seasons. Fruit quality attributes measured included fruit weight, length: diameter ratio, soluble solids concentration (SSC), titratable acidity (TA), flesh firmness, red overcolor, and russet. Fruit sensory characteristics rated included crispness, sweetness, and juiciness, based on a unipolar intensity scale (where 1 = least and 5 = most), and acidity, flavor, attractiveness, and desirability based on a bipolar hedonic scale (where 1 = dislike and 5 = like extremely). All fruit quality and sensory variables measured were affected by cultivar. The two-way interaction of cultivar and planting site was significant for all response variables except SSC, TA, russet, crispness, and sweetness ratings. The SSC: TA ratio was strongly correlated with sweetness and acidity sensory rating, but was weakly correlated with flavor rating. The results demonstrate that no one cultivar is ideally suited for all planting sites and no planting site is ideal for maximizing the quality of all apple cultivars.


2020 ◽  
Vol 10 (1) ◽  
pp. 181-192
Author(s):  
Rafael Piva ◽  
Renato Vasconcelos Botelho ◽  
Patrícia Carla Giloni de Lima ◽  
Adamo Domenico Rombolà

The biodynamic cultivation method consists of seeing the farm as an agricultural organism; its main goal is soil fertility, along with a rich diversity and biological activity. The objective of this work was to evaluate the growth, the physiology and the yield of grapevines cv. BRS Carmem, comparing organic and biodynamic production systems. The experiment was conducted under field conditions in Guarapuava, Paraná State, Southern Brazil planted in September 2013 and evaluated until June 2017. The experimental design was a randomized block with two treatments and six replications. In the plots of biodynamic treatment the following biodynamic preparations were applied: silica horn (501), manure horn (500), 508 (Equisetum hyemale L.) and Fladen. All plants were fertilized with the same organic compost, however, those from the biodynamic treatment received the preparations 502 (Achillea millefolium), 503 (Chamomilla officinalis), 504 (Urtica dioica), 505 (Quercus robus), 506 (Taraxacum officinale) And 507 (Valeriana officinalis). During three consecutive growing seasons the following variables were evaluated: enzyme activity (EC 3.2.1.39) β 1,3 glucanase and (EC 3.2.1.14) chitinase, mildew severity Plasmopara viticola, leaf water potential, gas exchange, chlorophyll fluorescence, SPAD index, Measurements of length and diameter of the canes, trunk diameter, weight of the pruning material, number of clusters, cluster length, berry diameter and soluble solids concentration. Biodynamic treatment promoted at least one year greater growth of plants (length and diameter of canes trunk diameter and SPAD index), better physiological response (leaf photosynthetic activity, Rubisco enzyme efficiency, maximum quantum yield of PSII), biochemistry (ß 1,3 glucanases and chitinase enzymes) and consequently greater resistance to disease and productivity.


HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 438c-438
Author(s):  
Richard P. Marini ◽  
Douglas G. Pfeiffer

`Campbell Redchief Delicious' trees were treated with a factorial combination of five European red mite (ERM) populations (range = 0 to 3000 cumulative mite-days per leaf (CMD)), and four crop densities (CD) (range = 2 to 12 fruit · cm-2 trunk cross sectional-area) during two growing seasons. Yield was related positively to CD and negatively to CMD. In general, fruit weight, fruit surface red color, and fruit soluble solids concentration declined with increasing levels of CMD and CD. For most response variables, there was a significant CMD by CD interaction. Fruit were graded into six size categories and crop value was calculated. Crop value generally increased with increasing CD and declined with increasing CMD, mite feeding reduced crop value most at high CD. Crop value estimates were used to calculate economic injury levels. We propose economic injury levels of 1000, 500, and 300 CMD, respectively for spur `Delicious' trees with light, moderate, and heavy crop loads.


HortScience ◽  
2002 ◽  
Vol 37 (6) ◽  
pp. 867-870
Author(s):  
R. Keith Striegler ◽  
Chris B. Lake ◽  
Justin R. Morris ◽  
Renee T. Threlfall ◽  
Gary L. Main ◽  
...  

'Sunbelt' is a juice grape cultivar developed by the Univ. of Arkansas. This cultivar produces 'Concord'-type juice and is adapted to warm climatic conditions of the southern United States. Preliminary evaluation showed that 'Sunbelt' has potential to produce high-quality juice under the hot climatic conditions of the San Joaquin Valley. A study was conducted during the 1998 and 1999 growing seasons to further evaluate the adaptation of 'Sunbelt' to the San Joaquin Valley and determine the response of this cultivar to selected pruning methods. Vines were grown for two seasons without use of insecticides, fungicides, or herbicides. Vines were subjected to four pruning treatments: severe hand pruning (60-80 nodes retained/vine); moderate hand pruning (120-160 nodes retained/vine); machine pruning with hand follow-up (160-180 nodes retained/vine); and minimal pruning (200-400 nodes retained/vine). Vines were trained to a Geneva Double Curtain trellis system. Yield, components of yield, and juice quality were significantly impacted by pruning treatment. In both seasons, mechanized systems of pruning (machine and minimal) produced higher yield than hand pruning. Minimal pruning resulted in the highest yield (42 t·ha-1) in 1998, while yield from the machine-pruned vines was highest (29 t·ha-1) in 1999. Minimally pruned vines had the highest clusters/vine and lowest cluster weight among the treatments. The extremely high yields obtained for the minimal pruning treatments produced fruit that was less mature resulting in juice with lower soluble solids than the other treatments in 1998. However, in 1999 the juice from minimally pruned vines had the highest soluble solids. Sensory analysis of juice produced in 1999 showed that the juice from the machine-pruned treatment had the least color intensity. Sensory analysis showed that minimal and severe hand pruning were ranked higher for sweetness than machine and moderate hand pruning. In the second year of the study, the juice from the minimal-pruned and severe hand-pruned treatment were preferred over the moderate hand-pruned treatment or the machine-pruned treatment.


2019 ◽  
Vol 41 (4) ◽  
Author(s):  
Pricila Santos da Silva ◽  
Marines Batalha Moreno Kirinus ◽  
Caroline Farias Barreto ◽  
Carlos Sebastián Pérez Lamela ◽  
Marcelo Barbosa Malgarim ◽  
...  

Abstract The ripening of grapes is impaired by climatic conditions due to the prolonged rainy season and thus facilitates the proliferation of diseases such as grape clusters rotting, caused by the fungus Botrytis cinerea, even before the ideal harvesting point. The aim of the study was to evaluate the effect of gibberellic acid (GA3) on rot and on physical-chemical quality of ‘Sauvignon Blanc’ grapevine. The experiment was carried out in the production season of 2016 and 2017 in Campanha region in Rio Grande do Sul, Brazil. The GA3 treatments were at the doses of 0 (control); 2; 4; 6 and 8 mg L-1 of GA3. The percentage of clusters rotting and maturation index decreased, however, the titratable acidity increased with GA3 doses. The cluster and rachis length increased with application of GA3. The cluster width; cluster, rachis and berry mass and the soluble solids were not influenced by application of GA3. In ‘Sauvignon Blanc’ grapevine, GA3 reduced the percentage of clusters rotting and improved the cluster and rachis length characteristics and titrable acidity.


Sign in / Sign up

Export Citation Format

Share Document