Effects Of Prohexadione-calcium Research Articles

Influence of prohexadione-calcium on temperate fruit crops – A Review

Plant growth retardants have great potential to maintain a balance between vegetative and reproductive growth of the plants. Prohexadione-calcium is reported as a novel plant growth retardant that inhibits late stages of gibberellins (GAs) biosynthesis in plants. It is emerged as one of an important management tool that an orchardist has available to control vegetative growth in plants and can enhance flowering and fruit quality. Currently, prohexadione-calcium is considered as a reduced risk compound, since it exhibits negligible toxicological effects and has been reported to degrade in higher plants with a halflife of a few weeks and in soil with a halflife of less than a week. The available literature on the effect of prohexadionecalcium on vegetative growth, fruit set, fruit yield, fruit quality and return bloom have been reviewed in this paper.

Effect of prohexadione calcium on vegetative growth, yield and scab development on ‘Sinap Orlovskii’ apple trees

There are many apple orchards in the Russian Federation where trees were trained with volumetric canopies; the vigor of these canopies must be suppressed. Prohexadione calcium (calcium 3-hydroxy-5-oxo-4-propionyl-cyclohex-3-enecarboxylate) was developed to inhibit the gibberellins biosynthesis to reduce vegetative growth. The study was done in the commercial orchard of “Planeta sadov” LLC in Michurinck district of Tambov Region (53°02’11.9 “N 40°29’29.9 “E). This research was aimed to evaluate the influence of prohexadione calcium on the length of one-year shoot growth, yield, and scab development on trees of vigorous apple cultivar ‘Sinap Orlovskii,’ planted 6 x 4 m (418 tr. ha-1). After 1.25 + 1.25 g ha-1 prohexadione calcium double treatment, the length of one-year shoots was 1.96 (2019) and 1.60 (2020) times less than Control 1 (without prohexadione calcium application and hand pruning) and 2,00 times less than in hand pruning treatment. The application of prohexadione calcium inhibited apple tree height and reduced the average height growth rate by 10.7% (2019) and 17.0% (2020). Growth retardant treatments stimulated significant yield increases and improved the commercial value of fruits. The enhance of scab protection improved under the influence of prohexadione calcium treatments. The application of growth retardant increased the alternate bearing index.

Effects of prohexadione-calcium on photosynthetic characteristics and protective enzyme activity of soy?bean seedlings under saline-alkali stress

Effects of prohexadione-calcium on photosynthetic characteristics and protective enzyme activity of soy?bean seedlings under saline-alkali stress

Use of Prohexadione Calcium on Grass Species Development

ABSTRACT: This study has aimed to evaluate the effect of prohexadione-calcium as a plant growth regulator on growth and quality of Japanese lawn grass, Broadleaf carpet grass and Bermudagrass. The treatments and doses of the prohexadione-calcium tested with two three reapplications were 27.5, 55.0, 110.0, 165.0 and 165.0 g a.i. ha-1, and a control without application of a growth regulator. Visual injury evaluations were performed using a scale of scores and plant height and chipping dry matter were determined. We have evaluated the total thickness of the sod grass, root length and dry matter of this material at the end of the experimental period. The study was arranged in a completely randomized design with four replications. The results were submitted to analysis of variance by F-test and the averages of the treatments were compared by t test at 5% probability. The prohexadione-calcium plant growth regulator was visually selective and reduced shoot growth of the three species of grass and can thus be used in the management of lawns in gardens and sports areas. As for the production of sod grass, the prohexadione-calcium can be recommended for Japanese lawn grass and Broadleaf sod grass, especially doses 165.0+165.0 and 55.0+55.0+55.0 respectively, because they have provided a better quality sod grass. For Bermudagrass, the effect of the treatments was harmful for the quality of sod grass and is not recommended for production purposes.

Effect of Prohexadione calcium, 6-benzyl amino purine and 6-furfuryladenine on vegetative growth and fruit quality in apple

It is well established that the climatic change is altering yield in fruit trees. This adversity reflects, among others, extreme temperature modifications in northern Mexico. This effect modifies negatively the physiology of apple trees (<i>Malus domestica</i> Borkh.), originating excessive shoot growth and a decrease in flower bud formation. In this study, Prohexadione-Ca (P-Ca), 6-benzyl amino purine (BAP) and N6-furfuryladenine (kinetin) were evaluated on shoot and reproductive growth in Golden Delicious apple trees in Arteaga Coah., Mexico. A completely randomized design with 12 treatments was used. These were: Control, Prohexadione calcium (Ca-P) at doses of 150, 300 and 450 mg/L, cytokinins (CK) [6-benzylaminopurine (BAP) + N6-furfuryladenine (kinetin)] at concentrations of 150 and 300 mg/L, and combinations of these bioregulators to the doses mentioned. The experimental unit consisted of two trees per treatment. Variables evaluated were: shoot growth, fresh weight, vitamin C, and carotenoid concentration in fruit and return bloom. P-Ca drastically reduced shoot growth and increased return bloom. Carotenoids and vitamin C concentrations were increased in fruits with this retardant. Cytokinins applied individually or in combination with P-Ca caused increments on flower bud formation, fruit weight, and carotenoid and vitamin C concentrations in harvested fruits.

Effect of prohexadione calcium on vegetative growth, seed maturity and seed yield of the Kabuli chickpea cultivar CDC Frontier

Lokuruge, P., Tar'an, B., Harms, T., Howard, R. and Bandara, M. 2015. Effect of prohexadione calcium on vegetative growth, seed maturity and seed yield of the Kabuli chickpea cultivar CDC Frontier. Can. J. Plant Sci. 95: 571–578. In the western Canadian semi-arid prairies, chickpea maturity is often delayed by the presence of cool and wet, growing conditions, particularly during the late growth stages of the crop. This results in reduced seed yield and quality, by increasing vegetative growth and delaying seed maturity. A field study was conducted in 2010 and 2011 at Brooks and Bow Island in Alberta to evaluate the potential use of prohexadione calcium (PC) to control secondary vegetative growth of Kabuli chickpea cultivar CDC Frontier. PC was foliar-applied at 750, 1500, 3000 and 4500 mg (a.i.) L−1 to CDC Frontier chickpeas at 10, 20 and 30 d after first flower appearance. Results indicated that PC had no significant impact on plant height at the late reproductive stages, mainly due to the resumption of ...

Effects of prohexadione-calcium on sweet potato vegetative growth as influenced by cultivar and nitrogen

The sweet potato (Ipomoea batatas Lam.) under high nitrogen produces excess vines at the expense of storage root. Prohexadione-Ca has been used to reduce vegetative growth and increase harvest efficiency and yield in many fruit and row crops. Using Prohexadione-Ca to reduce vegetative growth in sweet potato may enhance storage root yield and harvest efficiency. This study examined the effects of Prohexadione-Ca on sweet potato vegetative growth. In 2010 and 2011, two week-old plants of the sweet potato cv. O’ Henry and SC1149-19 were sprayed with 0 and 810 mg a.i. L-1 Prohexadione-Ca over N levels of 0, 2.7 and 5.3 g plant-1in the greenhouse. Vine length was significantly (P≤0.05) reduced by Pro-Ca. The reduction in vine length was not affected by cultivar or N. Internode length was significantly (P≤0.05) reduced by Pro-Ca. Prohexadione-Ca treated plants had significantly higher leaf thickness and vine diameter compared to untreated plants. However, leaf area and vines plant-1 were unaffected by Prohexadione-Ca. Data from this study indicated that Pro-Ca has the potential of being used to manipulate source-sink relationship for higher storage root yield in sweet potato. Key words: Prohexadione-calcium, sweet potato, vegetative growth, growth inhibitors, gibberellins, cultivar, nitrogen.

Immediate and residual effects of prohexadione-calcium, with or without ethephon, applied in a low-pH solution on vegetative and reproductive growth in sweet cherry trees (Prunus avium L.)

SummaryA single application of either prohexadione-calcium (Ca) at 250 mg l–1, or of prohexadione-Ca at 250 mg l–1 plus ethephon at 180 mg l–1, dissolved in water acidified with 1.0 g l–1 citric acid was applied to young ‘Burlat’ sweet cherry trees (Prunus avium L.). In the year of application, both chemicals provided effective growth control over the entire season, with prohexadione-Ca plus ethephon being more restrictive to growth than prohexadione-Ca alone. This pattern of growth suppression was observed in the dynamics of shoot elongation, mean shoot length, internode length, and total shoot extension. Both chemical treatments increased flower bud set on previous-season shoots. Residual effects (i.e., in the year following treatment, with no additional chemical application) were produced by prohexadione-Ca plus ethephon, which reduced the mean shoot length to 56.6% of untreated control trees, and by both treatments significantly limiting the length of all internodes relative to the controls. No residual effects were observed on the numbers of flower buds in year-2.

Prohexadiona de cálcio e a redução do vigor, produtividade e qualidade da uva grano d'oro

A Prohexadiona de Cálcio é um regulador de crescimento que atua na inibição da biossíntese de giberelinas, reduzindo o crescimento vegetativo. O objetivo deste trabalho foi avaliar seu efeito na videira Grano d'Oro, mutação da variedade Bordô (Vitis labrusca L.), na redução do vigor, produtividade e qualidade dos frutos. Foi utilizado o produto Apogee®, na concentração de 250 mg L-1 de Prohexadiona de cálcio, em diferentes datas de aplicação. Os tratamentos foram uma aplicação na plena florada, uma aplicação 45 dias após a plena florada e testemunha (sem nenhuma aplicação). O delineamento experimental foi em blocos completamente casualizados, com 4 blocos e 20 plantas por parcela. Ramos marcados foram medidos para a determinação do seu crescimento, e na colheita foi determinado o número de cachos por planta, a produtividade (kg planta-1 e T ha-1), o peso de 50 pagas, o número de bagas por cacho, o teor de sólidos solúveis totais (°Brix), a acidez total titulável (meq L-1) e o pH. A aplicação de Prohexadiona de Cálcio na plena florada reduziu o crescimento dos ramos em 33%, aos 15 dias após a plena florada, diminuindo essa redução ao longo do ciclo, sendo que, aos 93 dias após a plena florada, chegou a 8% em relação aos outros dois tratamentos. A aplicação da Prohexadiona de Cálcio na plena florada causou as maiores reduções no vigor e o maior aumento na produtividade das plantas de Grano d'Oro. O aumento da produtividade e a redução do vigor foram acompanhados por uma redução nos teores de sólidos solúveis totais. A redução no vigor não eliminou a necessidade da realização do desponte.

EFFECTS OF PROHEXADIONE-CALCIUM ON GRAPE CLUSTER STRUCTURE AND SUSCEPTIBILITY TO BUNCH ROT (BOTRYTIS CINEREA) IN cv. GRÜNER VELTLINER

In Austria plant growth regulators have long been used on grapevines for induction of loose clusters and avoidance of Botrytis cinerea attacks. The purpose of this work was to examine the effect of a plant growth regulator containing prohexadione-calcium as active ingredient based on various parameters. The experiment was conducted on cv. Gruner Veltliner. Results were analysed on the basis of the following parameters, cluster weight and lenght, berry and seed weight, number of berries and seeds, evaluation of infestation severity by B. cinerea, and FTIR analysis. In addition, the bending index of the berries was recorded. which describes the suppleness of the clusters. The four main test variants were: (i) control, (ii) prohexadione-calcium alone, (iii) prohexadione-calcium with a botryticide and (iv) botryticide alone. Regarding the effect of prohexadione-calcium, results showed that there was a significant difference in cluster compactness. The increased number of small clusters additionally resulted in a significant increase in suppleness and reduced compactness. In 2009, B. cinerea infestation in the control was less than in the other treatments; in 2010, no significant difference was found. In 2010, the application of prohexadione-calcium led to increased must densities, compared with the control plots.

EFFECT OF GROWTH REGULATORS ON 'GALA' APPLE FRUCTIFICATION

Blooming is one of the most important events during the growing season of an apple tree because it determines the next harvest. At this time, environmental and physiological factors interact to define the next steps of the fructification. Under mild winter climates, such as those experienced in the Southern Brazilian apple growing area, it is common for blooming and vegetative growth to start together. In this situation, the vegetative growth strongly competes with the flowers for carbohydrates, negatively affecting the fruit set. Growth regulators that act as cytokinins, auxins or gibberellins may increase the fruit set. The effects of prohexadione calcium (PCa) at the rates of 0, 55, 110 and 220 mg L-1, sprayed alone or combined with thidiazuron (TDZ) 10 mg L-1 or with PromalinTM 0.5 L ha-1, were compared for their effects on the fructification and on the fruit characteristics of ‘Royal Gala’ apples. The treatments were applied between the pink bud and the full bloom stage. Applications of PCa at 55 mg L-1 plus TDZ at 10 mg L-1 increased the fruit set and the number of fruits per cluster, but did not differ from the treatment with only TDZ 10 mg L-1. When applied singly, the PCa treatments gave variable results, with a tendency to be better than the control. PCa plus Promalin reduced the fruit set. PCa 55 mg L-1 + TDZ 10 mg L-1 increased 132% the number of fruit per tree in comparison with untreated trees. The growth regulators PCa and TDZ were effective in increasing yield when there was lack of pollination.

Effects of Prohexadione Calcium on growth and gibberellins contents of Chrysanthemum morifolium R. cv Monalisa White

The effect of Prohexadione Calcium (Pro-Ca) and daminozide was observed on the growth characteristics and endogenous gibberellin contents of Chrysanthemum morifolium R. cv Monalisa White. Three concentrations viz. 100, 200 and 400 ppm of Pro-Ca and a single concentration of daminozide (800 ppm) were applied three times with 7 days interval on three weeks old plant under greenhouse condition. Pro-Ca suppressed the plant length up to 30.7% while daminozide inhibited up to 27.12% at optimum concentration. The chlorophyll contents and stem diameter were higher than control, while the fresh weight and flower number insignificantly reduced with such treatments. Gibberellin (GA) analysis showed that Pro-Ca and daminozide application significantly lowered bioactive GA 1 content, although the amount of its immediate precursor GA 20 was fractionally higher. Bioactive GA 4 content was slightly higher than the control while significant difference in GA 9 was found between the plants treated with Pro-Ca and daminozide. Current study showed that both early C13 hydroxylation and non-C13 hydroxylation pathways of GA biosynthesis are operational in C. morifolium.

Differential effects of prohexadione-calcium on red colour development in ‘Royal Gala’ and ‘Fuji’ apples

SummaryTwo different spray programmes for split application of prohexadione-calcium (ProCa) were tested on ‘Royal Gala’ and ‘Fuji’ apple trees (Malus domestica Borkh.) to evaluate their effect on red colour development in the fruit. Applications of ProCa split into two sprays at full-bloom and 60 d after full-bloom (DAFB) were sufficient to control shoot growth in these cultivars. A third application (95 DAFB) did not result in any additional beneficial effects. In addition to obtaining significant reductions in shoot elongation, reductions in leaf area were also noted. No effects on yield or on various fruit quality parameters resulted from the ProCa treatments, with one important exception, fruits from ‘Fuji’, a late-season cultivar, displayed a greater percentage of fruit surface with red colour. Simultaneously, a deeper red colour was recorded on the blushed side of the fruit, resulting from greater concentrations of anthocyanins and carotenoids. In contrast, fruits of ‘Royal Gala’, a mid-season cultivar, did not show differences in fruit colouration following treatment with ProCa.

Prohexadione-calcium effects on the quality of ‘Royal Gala’ apple fruits

SummaryTo study the effects of prohexadione-calcium (Pro-Ca) on fruit quality, an experiment was performed in 2002 in which trees were treated with two different concentrations of Pro-Ca and left with different crop-loads. Increasing levels of thinning resulted in smaller yields, but greater fruit sizes, which followed a curvilinear pattern when plotted against crop-load. The soluble solids content and titratable acidity of fruits decreased linearly with increasing crop-load. Fruit skin chromaticity values also changed. Luminescence increased, while a* values decreased linearly with increasing crop-load, indicating more reddish and darker coloured fruits on trees subjected to very heavy thinning. In addition, the concentrations of soluble sugars in fruits changed with the level of cropping; fructose and glucose concentrations increased with crop-load, while sorbitol and sucrose decreased. The application of Pro-Ca shortly after full-bloom inhibited shoot elongation growth, but did not result in changes in yield or in any of the fruit quality parameters analysed.

Effect of prohexadionecalcium on nectar composition of pomaceous flowers and on bacterial growth

Prohexadionecalcium is an acylcyclohexanedione that reduces incidence of fire blight caused by Erwinia amylovora To determine whether prohexadionecalcium can be used in conjunction with biological control agents its effect on the secretion and composition of nectar from apple and pear flowers was evaluated Plants treated with prohexadionecalcium produced more nectar but the sugar concentration of the nectar was lower The ability of E amylovora and of two biological control agents of fire blight Pantoea agglomerans and Pseudomonas fluorescens to grow in a sugar solution corresponding to the composition of nectar from treated or untreated plants was determined in the laboratory All bacteria including E amylovora grew better in the sugar solution corresponding to the nectar from treated plants The concentration of sugar in the nontreated flowers may be too high for bacterial growth These results also suggest that prohexadionecalcium can be used alongside biological control agents for reduction of fire blight incidence

Effects of Prohexadione-Calcium on Fruit Size and Return Bloom in Pear

The effects of prohexadione-calcium (P-Ca) on fruit size and return bloom in three pear cultivars were evaluated in Medford and Hood River, Ore., and in Cashmere, Wash. A variety of treatment dosages and timings was applied to 4- and 5-year-old trees in 2 years of study. Fruit weight of `Bosc' and `Red Anjou' pears was not affected by P-Ca treatments at any location in either year. However, decreased weight of `Bartlett' pear fruit was associated with all P-Ca treatments in 1999 in Medford except for 83 ppm applied at 2.5 to 6.0 cm shoot growth (first treatment) plus 2, 4, 6, and 8 weeks after first treatment (WAFT) and 125 ppm applied at 2.5 to 6.0 cm growth plus 4 WAFT. `Bartlett' fruit weight was reduced in Medford in 2000 by all treatments except 125 ppm applied at 2.5 to 6.0 cm growth plus 4, 8, and 12 WAFT. In Cashmere in 2000, mean weight of `Bartlett' and `d'Anjou' fruit was reduced by treatments with 83 or 125 ppm applied at 2.5 to 6.0 cm growth plus 2, 4, and 6 WAFT and of `Bosc' pear by all treatments that included more than a single application of P-Ca. Crop load was not significantly different among treatments at any location. Return bloom in the year following P-Ca treatment was reduced in `Bosc' pears by some to most treatments at all locations in both years. In contrast, return bloom was reduced in `Bartlett' and `Anjou' pears only in Hood River in 1999.

Effects of Prohexadione-calcium on Grape Yield Components and Fruit and Wine Composition

Prohexadione-calcium (prohexadione-Ca) was applied to field-grown Cabernet franc, Cabernet Sauvignon, Chardonnay, and Seyval to evaluate rates and timing effects on fruit yield components and on fruit and wine composition. Berries per cluster, berry weight, cluster weight, and clusters per shoot in the subsequent season were all decreased by multiple, prebloom plus postbloom, applications to Cabernet Sauvignon and Cabernet franc. Similar reductions in current season components of yield were observed with Seyval. Application (250 mg/L) to single clusters of Cabernet Sauvignon and Chardonnay at bloom, or in the one-to-two-week prebloom period decreased fruit set, whereas applications one to two weeks postbloom reduced berry weight, with no impact on fruit set. Berry weight reduction correlated to increased color intensity (420 nm + 520 nm), total anthocyanins, total phenols, and phenol-free glycosyl-glucose (PFGG) in Cabernet Sauvignon. In a separate experiment, prohexadione-Ca increased Cabernet franc must color intensity, total anthocyanins, and total phenols, despite having minimal effects on berry weight or crop yield. Aroma and flavor triangle difference tests did not distinguish treatment differences with young Cabernet franc wines. This study of prohexadione-Ca effects on grape reproductive development illustrated that berry set and berry weight were responsive to application timing, with the one-to-two-week period after bloom most sensitive to reductions in berry weight. The concurrent effects on fruit composition were generally positive, while the full impact on wine quality remains equivocal, but worthy of further evaluation.

EFFECTS OF PROHEXADIONE-CALCIUM (APOGEE¿) ON BLOSSOMING, PRODUCTION, AND FRUIT QUALITY IN PEAR

Prohexadione-Ca (Apogee™, BASF) was applied to several pear cultivars in Medford and Hood River, Oregon and Wenatchee, Washington, USA, in 1998 and 1999. Most trees received treatment at concentrations from 83 to 500 ppm at 2.5-6.0 cm of new shoot growth and some received subsequent applications according to various treatment schedules. Several treatments resulted in reduced fruit weight in unthinned 'Bartlett' pears at Medford in 1999, but not where fruit had been thinned. Other fruit characteristics were not detectably affected. Return bloom in 'Bosc' in 2000 was significantly reduced at all locations following several 1999 treatments, regardless of whether or not fruit had been thinned. Return bloom was also reduced in 'Anjou', 'Red Anjou', and 'Bartlett' at Hood River, and in 'Anjou' in Medford in 1999 (following 1998 treatments).