Growth Regulator Prohexadione Calcium Research Articles

Effect of Prohexadione Calcium Application Timing and Rate on Peanut (Arachis hypogaea) Growth and Yield in Mississippi

Excessive vegetative growth in peanut can lead to decreased harvest efficiency. Peanut vegetative growth is often managed with the plant growth regulator prohexadione calcium. Although application of prohexadione calcium is recommended at 50% and 100% canopy closure (CC) as defined by lateral vines touching, research on the optimal application timing and rate has been minimal. The objective of this research was to evaluate the effect of prohexadione calcium application timing and rate based on percent canopy closure. Experiments were conducted at 6 different sites in Mississippi over 2 years. Treatments in 2020 included prohexadione calcium applied at 50% CC + one application at 100% CC (recommended by product label), two applications in one week at 100% CC, and three applications in one week at 100% CC. In 2020, all prohexadione calcium applications were made at 140 g a.i./ha. Treatments in 2021 included application timings at 50% and 100% CC and multiple application rates at each timing including 70 g a.i./ha, 140 g a.i./ha, and 280 g a.i./ha. Peanut response was evaluated based on pod weight after digging, pod count after digging, dry plant weight, pod loss, and peanut yield. Dry plant weight, pod loss, and pod weight were unaffected by prohexadione calcium application. Peanut yield ranged from 6200 kg/ha to 7300 kg/ha across years, locations, and prohexadione calcium treatments. Yields following all prohexadione calcium application timings and rates were similar to those following applications at the recommended timings and rate. With the exception of two applications in one week at 100% CC, yield response following prohexadione application was similar to that of the untreated check. Therefore, prohexadione calcium application timings and rates are likely more flexible than the labelled recommendation with respect to vegetation management; however, yield enhancement following application was inconsistent.

Effects of Prohexadione Calcium Applications on Growth and Yield Characteristics of Cucumber (Cucumis sativus L.)

This study was conducted to determine the effects of growth regulator prohexadione calcium (Pro-Ca) and inhibitor gibberellic acid on some parameters (yield, pigment levels of leaves, nutrient contents, proline, enzyme activities and fruit quality) when applied at different doses (0, 15, 30, 45, and 60 mg L-1). Chemicals were applied after transplanting seedlings. A total of 12 plots including 3 plants for each dose were used in randomised plot experimental design. Although it has a positive effect on leaf proline content and enzyme activities, 45, and 60 mg L-1 doses of Pro-Ca had negative effects on morphological parameters (excluding stem diameter), yield, leaf pigment (excluding chlorophyll a) and nutrient contents compared to control. High Pro-Ca doses generally affected the fruit quality properties positively while 15 mg L-1 of Pro-Ca did not affect other parameters, except decreasing fruit yield. A 30 mg L-1 of Pro-Ca dose was the most positive effective dose on the examined parameters. The highest vegetative development, yield, nutrient uptake and proline content were obtained from the plants subjected to 30 mg L-1 of Pro-Ca dose. Moreover, this dose increased fruit firmness, TSS, EC values and enzyme activities compared to control. Being an important quality criterion in cucumber storage after harvest, the weight loss rate 29.4% was lower in fruits obtained from the plant having 30 mg L-1 of Pro-Ca dose compared to that of the control plants. Therefore, 30 mg L-1 of Pro-Ca application, beside its positive effects on plant growth, yield and fruit quality, can be suggested for also increase shelf life of fruits in cucumber cultivation in greenhouse.

RTK GPS and Automatic Steeringfor Peanut Digging

<abstract><title><italic>Abstract. </italic></title> Peanut harvesting is a two-stage process. In the first stage, a digger-shaker-inverter implement is used to plow peanut from the ground. In the second stage, a combine is used to thresh peanut pods from the vines. Yield loss can be significant, especially during the digging stage where the implement may not be properly aligned over the rows of peanut. In this study, RTK-based automatic steering was compared to manual steering to determine the potential for reduced yield losses. In addition, peanut response to the plant growth regulator prohexadione calcium was compared to a non-treated peanut to determine if reduced yield losses were obtainable. Prohexadione calcium regulator did not improve yield significantly. However, use of RTK based automatic steering was significant, increasing harvested yield by 510Â kg/ha or 11%.

Effect of Cluster Thinning and Prohexadione Calcium Applications on Phenolic Composition and Sensory Properties of Red Wines

The overall objective of this study was to investigate the effect of manual cluster thinning (CT) and the application of the growth regulator Prohexadione calcium (ProCa) on the phenolic composition and the sensory profile of Tempranillo and Grenache wines produced from treated vines in La Rioja (Spain). ProCa was applied at preblooming and CT was carried out at veraison in two consecutive years. Different physicochemical parameters and analyses of phenolic compounds were carried out in control, CT and ProCa grapes and wines and wine sensory was performed. Thinning treatments decreased crop yield, besides ProCa application reduced berry size, and berry weight. Color and phenolic composition of Grenache and Tempranillo wines in general were affected by thinning treatments, with an increase in anthocyanin, flavanol and flavonol concentrations. In sensory analysis, wines obtained from thinned vines presented higher values for several aromatic (e.g., white and yellow fruits, fresh flowers) and taste attributes (i.e., astringency, bitternes, persistence). CT and ProCa treatments resulted in an improvement in wine quality. In general, similar results in phenolic composition, sensory properties and quality of wines were obtained by manual and chemical cluster thinning. ProCa as a growth regulator may be an option for a quality vitiviniculture.

Treatment of grapevines with prohexadione calcium as a growth regulator. The influence on production, winemaking and sensory characteristics of wines

&lt;p style="text-align: justify;"&gt;&lt;strong&gt;Aims&lt;/strong&gt;: The overall objective of this study was to investigate the effect of the growth regulator Prohexadione Calcium (ProCa) on the production of Tempranillo vines in La Rioja, the vinification and the sensory profile of wines obtained from treated grapes.&lt;/p&gt;&lt;p style="text-align: justify;"&gt;&lt;strong&gt;Methods and results&lt;/strong&gt;: Prohexadione calcium was applied to Tempranillo vines from Rioja Baja at preblooming in years 2004 and 2005. A number of rows were not treated and they were used as controls. Vinification was carried out at an experimental winery. Oenological parameters were determined. A sensory analysis was performed on the obtained wines. The results showed that crop yield was reduced in treated vines. As regards the fermentation process, slight differences were observed in the case of the treated Tempranillo grapes in comparison to the control. The sensory analysis revealed different organoleptic characteristics in the wines obtained from treated grapes in comparison to those produced from the untreated ones.&lt;/p&gt;&lt;p style="text-align: justify;"&gt;&lt;strong&gt;Conclusion&lt;/strong&gt;: The growth regulator Prohexadione calcium can be used as an alternative to bunch thinning. Improved sanitary conditions of grapes are observed. The treatment at preblooming produces a reduction in berry size and weight. An improvement in sensory characteristics and wine quality is observed, as a consequence of reduced production.&lt;/p&gt;&lt;p style="text-align: justify;"&gt;&lt;strong&gt;Significance and impact of study&lt;/strong&gt;: ProCa as a growth regulator may be an option for a quality vitiviniculture. No previous studies have been published on applications of ProCa in grapevines in either Europe or in cv. Tempranillo. Additionally, studies with other varieties have not demonstrated sensory improvements in wines obtained from treated vines.&lt;/p&gt;

Yield and Plant Growth Response of Peanut to Midseason Forage Harvest

Harvesting of peanut (Arachis hypogaea L.) foliage during the growing season may increase farm revenue through the sale of peanut hay; however, it is unknown how the peanut plant will respond to forage removal with respect to plant characteristics, pod yield, quality, and revenue. This experiment was a randomized complete block design where peanut foliage was harvested or sprayed with a plant growth regulator prohexadione calcium (PHDC; Ca salt of 3, 5‐dioxo‐4‐propionylcyclohexanecarboxylic acid). There were nine treatments replicated five times. Peanut ‘Georgia Green’ was planted in twin rows during 2005 and 2006 on Tifton loamy sand. Peanut foliage was harvested at 20‐cm height at 60, 90, and 120 days after planting (DAP). The PHDC was applied at recommended rates and timing. Leaf density was higher for peanut plants treated with PHDC compared with plants cut for forage. Leaf‐to‐stem ratios were higher with plants harvested early (60 DAP) compared with those harvested later (120 DAP). Total forage mass was lowest at 60 DAP and increased with single or multiple harvests. Total forage removed with one single midseason harvest was not different from an associated multiple harvest. Peanut pod yield decreased about 12% for each harvest. Peanut grade (total sound mature kernels, TSMK) decreased as the number of harvests increased, conversely, other kernels (OK) increased as the number of harvests increased. Pod and forage revenue was highest for the nonharvest and single‐harvest treatments and decreased with the multiple harvests.

Peanut (Arachis Hypogaea L.) Cultivar Response to Prohexadione Calcium

Abstract Peanut digging efficiency is often reduced due to excessive vine growth. The plant growth regulator prohexadione calcium retards vegetative growth and improves row visibility by inhibiting internode elongation resulting in improved digging efficiency and in some instances increases in pod yield. The objective of this research was to determine the effects of prohexadione calcium on row visibility and pod yield of newly released and commercially available cultivars AT VC-2, Brantley, CHAMPS, Georgia Green, Gregory, Perry, Phillips, NC-V 11, NC 12C, Tamspan 90, and VA 98R and the breeding lines N02006, N01013T, and VT 976133. Although differences in row visibility were noted among cultivars, prohexadione calcium improved row visibility in almost every experiment regardless of cultivar. The cultivars NC 12C and Perry were more responsive to prohexadione calcium in terms of pod yield than NC-V 11 or VA 98R. Response of these cultivars was independent of digging date. In other experiments, prohexadione calcium improved row visibility of the cultivars AT VC-2, Gregory, NC-V 11, Perry, VA 98R, and Wilson, but did not increase yield when compared with non-treated peanut. In a final experiment, prohexadione calcium improved row visibility of the Virginia market type cultivars Brantley, CHAMPS, Gregory, and Phillips and the experimental lines N02006, N01013T, and VT 976133. Row visibility for the experimental line N01013T was improved at 2 of 4 sites by prohexadione calcium. In a final experiment, prohexadione calcium increased row visibility of Georgia Green, Gregory, and Tamspan 90 but did not affect pod yield of these cultivars.

Effects of the plant growth regulator prohexadione-calcium and the SAR-inducer acibenzolar-S-methyl on the quality of apples at harvest

SummaryAn experiment was conducted over two consecutive years (2002 and 2003) in an apple orchard planted with Malus domestica cv. ‘Mitchgla’ to study the impact of treatments with acibenzolar-S-methyl or prohexadione-calcium on different characteristics of fruit quality at harvest. Parameters measured included: quantity of marketable apples, harvest maturity, organoleptic attributes, and amount of PR-10 gene products encoding potential allergens. Our results highlighted the fact that application of acibenzolar-S-methyl during the 2003 growing season led to a reduction in the red colour of the skin and to a reduction in the sugar content of the apples, whereas prohexadione-calcium had no measurable effect on these parameters. The application of prohexadione-calcium induced an increase in the accumulation of PR-10 transcripts in fruits compared to control or acibenzolar-S-methyl treatments. An analysis of the expression of two members of the APb gene sub-class, AP2 (Ypr10*Md.a) and AP3 (Ypr10*Md.c), which are homologous to the major apple allergen Mal d 1, revealed a higher abundance of transcripts in apples after the application of prohexadione-calcium compared to the acibenzolar-S-methyl treatment. These experimental data have implications for the quality attributes of marketable fruits, since the use of acibenzolar-S-methyl may modify some harvest maturity parameters related to consumer preferences, while prohexadione-calcium could increase the major allergen content of apples.

Interactions of Clethodim and Sethoxydim with Selected Agrichemicals Applied to Peanut

Experiments were conducted in North Carolina during 2002 and 2003 to evaluate broadleaf signalgrass and large crabgrass control by clethodim and sethoxydim applied in two-, three-, or four-way mixtures with fungicides, insecticides, and foliar fertilizer–plant growth regulator treatments. Broadleaf signalgrass and large crabgrass control by clethodim and sethoxydim was not reduced by the insecticides esfenvalerate, indoxacarb, or lambda-cyhalothrin. The fungicides azoxystrobin, chlorothalonil, pyraclostrobin, and tebuconazole reduced large crabgrass control by clethodim or sethoxydim in one or more of three experiments for each herbicide. Disodium octaborate and the plant growth regulator prohexadione calcium plus urea ammonium nitrate (UAN) mixed with clethodim and fungicides improved large crabgrass control in some experiments. In contrast, prohexadione calcium plus UAN and disodium octaborate did not affect broadleaf signalgrass or large crabgrass control by sethoxydim.

Response of Four Virginia-Type Peanut Cultivars to Prohexadione Calcium as Affected by Cultivar and Planting Pattern

Abstract An experiment at Suffolk, VA in 2001 and 2002 evaluated the response of virginia-type peanut (Arachis hypogaea L.) to the growth regulator prohexadione calcium as affected by cultivar and ...

MANIPULATING TRANSPLANT MORPHOLOGY TO ADVANCE AND ENHANCE FRUIT YIELD IN STRAWBERRY

Strawberry plants are vegetatively propagated in northern nurseries to supply fruit production farms in the southern United States of America. Digging actively growing plants in the fall from northern nurseries, and transplanting them into southern fields at a time of seasonally high temperatures makes it difficult for transplants to re-establish. Tall transplants are prone to leaf damage during shipping, and excessive leaf area causes more wilting after transplanting, leading to plant death in the southern fields. Improving strawberry plant morphology in the northern nurseries can produce more robust transplants, resulting in better post-transplant growth, higher fruit yields and earlier fruit production. Experiments to alter plant morphology used two methods: mechanical leaf removal by mowing, and chemical control using the growth regulator prohexadione-calcium. Two cultivars, 'Sweet Charlie' and 'Camarosa', were mowed in a nursery field in Nova Scotia (45° 26' N, 63° 27' W) on one of four dates (Aug. 22, Sept. 7, Sept. 22 and Oct. 5) during the growing season in 2000. Plants were dug on October 5, and transplanted in Dover, Florida (28° 00' N, 82° 22' W). Fruits were collected twice weekly from late November, 2000 to mid-February, 2001. Mowing reduced plant height and total leaf area. At time of digging, plants which were mowed later were shorter than those mowed earlier. By the end of December 'Camarosa' plants mowed on Sept. 7, had produced 51 % more fruit by weight than the unmowed controls; total yield (to mid-February) was increased by 20%. Plants of 'Sweet Charlie' treated with prohexadione-calcium on Sept. 7 in Nova Scotia were more compact, and in turn produced 29 % more fruit by weight by the end of December, and greater total fruit yield (18 %) relative to non-treated transplants in Florida.

Peanut Response to Prohexadione Calcium as Affected by Cultivar and Digging Date

Abstract An experiment at two locations in 1995 and two locations in 1996 evaluated virginia-type peanut (Arachis hypogaea L.) response to the growth regulator prohexadione calcium (calcium salt of 3,5-dioxo-4-propionylcyclohexanecarboxylic acid) as affected by cultivars and digging dates. Prohexadione calcium at 140 g ai/ha was applied at row closure and again 3 wk later in 1995 or 140 g/ha at row closure and 70 g/ha 3 and 6 wk later in 1996. The cultivars AgraTech (AT) VC-1, NC 9, NC 10C, NC 12C, NC-V11, and VA-C92R were dug on three separate dates approximately 11d apart. Response to prohexadione calcium was independent of digging dates. Prohexadione calcium altered canopy architecture and increased row visibility at harvest for all cultivars although the response was greatest with NC-V 11 and least with NC 9. Prohexadione calcium hastened pod maturity, increased percentages of extra large kernels, total sound mature kernels, and fancy pods, and increased peanut value/kg irrespective of cultivars and digging dates. Yield response to prohexadione calcium was cultivar dependent. NC 9 was most responsive, with yield increased 7 to 16% at all locations. Yields of ATVC-1, NC 10C, NC 12C, and NC-V 11 were increased 9 to 15% at two locations and unaffected at two locations. VA-C 92R was the least responsive, with yield increased 5% at two locations and decreased 8% at two locations.