VEGETATIVE AND REPRODUCTIVE GROWTH OF DETERMINATE TOMATOES AS INFLUENCED BY APPLICATIONS OF ETHEPHON, DCIB, NAA AND SADH AT THE SIX-CLUSTER STAGE

1974 ◽  
Vol 54 (4) ◽  
pp. 777-782 ◽  
Author(s):  
J. A. VELIATH ◽  
A. C. FERGUSON
Keyword(s):  
Lycopersicon Esculentum ◽  
Phosphonic Acid ◽  
Fruit Set ◽  
Total Yield ◽  
Fruit Size ◽  
Normal Growth ◽  
Reproductive Growth ◽  
Vegetative And Reproductive Growth ◽  
Potential Use ◽  
Fruit Load

In an attempt to control fruit set and thereby increase fruit size, 2-(chloroethyl) phosphonic acid (ethephon), sodium 2,3-dichloroisobutyrate (DCIB), naphthaleueacetic acid (NAA) and N-dimethylaminosuccinamic acid (SADH) were applied as sprays to plants of the determinate tomato Lycopersicon esculentum Mill. ’Summit’ when fruit was set on six clusters. In comparison, one set of plants was deblossomed manually after the six-cluster stage, and another untreated. Although none of the chemicals provided perfect control of fruit load, NAA (100 ppm), SADH (4,000 ppm) + NAA (100 ppm), DCIB (4,000 ppm) + ethephon (500 ppm) and DCIB (6,000 ppm) were approximately 81, 77, 75 and 73% effective, respectively, in reducing fruit load. However, decreases in fruit load were not accompanied by corresponding increases in fruit size. In all probability, this was due to the impairment of normal growth by the chemicals. Several of the treatments produced substantial increases in early and total yield, by maturing a greater number of fruits and thus may be of potential use to commercial growers.

Thinning response of ‘Redhaven’ peaches to 1-aminocyclopropane carboxylic acid (ACC)

2020 ◽  
pp. 1-13
Author(s):  
John A. Cline ◽  
Catherine J. Bakker ◽  
Amanda Beneff
Keyword(s):  
Carboxylic Acid ◽  
Fruit Set ◽  
Total Yield ◽  
Fruit Size ◽  
Fruit Weight ◽  
Full Bloom ◽  
Fruit Thinning ◽  
Leaf Yellowing ◽  
Peach Trees ◽  
Fruit Load

Peach trees bear an abundance of flowers which produce a surplus of fruit that the tree is unable to support. A self-regulatory mechanism enhances the abscission of immature fruitlets leading to a reduced fruit load, but this is often insufficient to achieve fruit of marketable size. Supplementary manual fruit thinning is typically required to optimize economic fruit load. This 2-yr study investigated the response of ‘Redhaven’ peach trees to sprays of 300 and 600 mg L−1 1-aminocyclopropane carboxylic acid (ACC) during the phenological stages of full bloom, shuck split, and ∼20 mm fruitlet diameter. The objective was to determine the efficacy of ACC on fruit set, fruit size, and yield at harvest and the amount of hand-thinning required at “June drop”. Although the response to ACC varied between the 2 yr, 600 mg L−1 ACC spray at full bloom (2018) and at ∼20 mm fruit size (2019) reduced fruit set, the need for hand-thinning by 59%–66%, and crop load. Treatments also had varying but significant effects on leaf yellowing and leaf drop when measured shortly after application. ACC reduced total yield and number of fruit per tree in both study years and increased fruit weight in 2019. Overall, peaches were responsive to ACC at a range of timings from bloom to ∼20 mm fruit size. This study enhances our understanding of ACC on fruitlet abscission of peaches and is one of few studies to demonstrate the effectiveness of a chemical fruitlet thinner for peaches.

Irrigation of greenhouse tomatoes grown in "Harrow" peat-bags

1991 ◽  
Vol 71 (3) ◽  
pp. 947-949 ◽  
Author(s):  
Athanasios P. Papadopoulos ◽  
Chin S. Tan
Keyword(s):  
Lycopersicon Esculentum ◽  
Key Words ◽  
Environmental Conditions ◽  
Total Yield ◽  
Fruit Size ◽  
Irrigation Frequency ◽  
Marketable Yield ◽  
Greenhouse Tomato ◽  
Greenhouse Tomatoes ◽  
Fertilizer Solution

Three spring and two fall crops of greenhouse tomato (Lycopersicon esculentum L. Mill; various cultivars) grown in "Harrow" peat bags were irrigated 1, 4, 8 or 16 times daily. All plants received the same volume of fertilizer solution which varied with time from 0.2 to 1.0 L plant−1 d−1 according to crop and environmental conditions. The results showed little or no effect of irrigation frequency on early or total yield, number of grade no. 1 fruit, or fruit size. Key words: Lycopersicon esculentum, marketable yield

scholarly journals Efficacy of ethrel (2-chloroethyl phosphonic acid) as a chemical hybridizing agent in red pepper (Capsicum annuum L. var. Pusa jwala)

2007 ◽  
Vol 13 (4) ◽  
pp. 41-44
Author(s):  
D. K. Agnihotri ◽  
S. V. S. Chauhan
Keyword(s):  
Capsicum Annuum ◽  
Phosphonic Acid ◽  
Total Yield ◽  
Fruit Size ◽  
Pollen Sterility ◽  
F1 Hybrids ◽  
Male Sterile ◽  
Yield Parameters ◽  
Size Number ◽  
Number Of Seeds

A field experiment was conducted during 2003-2004 and 2004-2005 to study the effect of foliar sprays of ethrel or ethephon (2- chloroethyl phosphonic acid) on pollen sterility and yield parameters in Capsicum annuum var. Pusa jwala. Effect of treatments was also studied in F1 hybrids raised from treated male sterile plants crossed with the control plants. Plants sprayed with 0.1, 0.2 and 0.3% (v/v) ethrel exhibited 93.1-100% pollen sterility. This was associated with significant reduction in yield parameters (number of flowers, fruits/plant, fruit size, number of seeds/fruit and total yield/plant). However, the plants sprayed only once with 0.1% ethrel at pre-meiotic stage showed 93.1% pollen sterility without any significant reduction in yield parameter. The F1 hybrids obtained by crossing the 100% male sterile treated plants with the pollen of untreated (control) plants exhibited only insignificant reduction in the number of flowers/ plant, fruits/plant, fruit size, number of seeds/fruit and total yield/plant. However, these parameters in F1 hybrids were significantly higher over the treated plants.

scholarly journals Impact of Repeated Yearly Applications of Prohexadione-Calcium On Vegetative and Reproductive Growth of ‘Golden Delicious’/M.9 Apple Trees

2017 ◽  
Vol 25 (1) ◽  
pp. 47-54 ◽  
Author(s):  
A. Nilgün Atay ◽  
Fatma Koyuncu
Keyword(s):  
Fruit Quality ◽  
Vegetative Growth ◽  
Fruit Set ◽  
Negative Impact ◽  
Apple Trees ◽  
Reproductive Growth ◽  
Node Number ◽  
Golden Delicious ◽  
Vegetative And Reproductive Growth ◽  
Prohexadione Calcium

Abstract Growth retardants have great potential to balance between vegetative and reproductive growth. To assess the effects of prohexadione-calcium (Pro-Ca, Regalis) on reproductive and vegetative growth, return bloom, fruit set, and also fruit quality in ‘Golden Delicious’ apple grafted on M.9 rootstock, an experiment was performed during 2010-2012. The applications of 125 mg dm-3 Pro-Ca on the same trees in each year resulted in a 40-43% shoot length reducing. Internodes length decreased with Pro-Ca at about 30%, while total node number was unaffected. Results indicate that Pro-Ca applications have no effects on tree trunk growth, flowering, yield, fruit set and development. Pro-Ca also didn’t have any negative impact on fruit quality during the three consecutive years. Moreover, Pro-Ca resulted in higher fruit size compared to control in the third year of trial. The results of this experiment clearly suggest that fruit growers can use Pro- Ca for the control of vegetative growth without having any negative effects on fruit quality and yield parameters. Once a full canopy has been achieved, annual shoot growth can be suppressed in the range of 20 to 30 cm with 125 mg dm-3 Pro-Ca treatment in ‘Golden Delicious’ apple trees.

scholarly journals The Potential Use of Metamitron as a Chemical Fruit-thinning Agent in Mandarin

2018 ◽  
Vol 28 (1) ◽  
pp. 28-34 ◽  
Author(s):  
Ockert P.J. Stander ◽  
Johané Botes ◽  
Cornelius Krogscheepers
Keyword(s):  
Fruit Set ◽  
Fruit Size ◽  
Fruit Trees ◽  
Fruit Yield ◽  
Citrus Reticulata ◽  
Alternate Bearing ◽  
Fruit Thinning ◽  
Total Carbohydrates ◽  
Leaf Carbohydrates ◽  
Potential Use

Under conditions of profuse flowering and excessive fruit set, citrus (Citrus sp.) fruit need to be thinned to increase the size of remaining fruit, reduce the intensity of alternate bearing, or both. Metamitron was recently developed as a chemical fruit-thinning agent for apple (Malus ×domestica) and pear (Pyrus communis), and it inhibits photosynthesis and is thought to transiently reduce the carbohydrate pool in fruit trees. Citrus trees are sensitive to carbohydrate stress during and immediately after flowering, but the response of citrus to foliar treatment with a photosynthesis inhibitor, such as metamitron, is unknown. The purpose of this study was to evaluate metamitron for its effects on leaf carbohydrates and its ability to chemically thin citrus fruitlets. Significant fruit-thinning effects were found in all the experiments conducted over two seasons. A 300 mg·L−1 metamitron treatment reduced leaf sugars and leaf total carbohydrates, and consistently reduced the total number of fruit per tree in both seasons in ‘Nadorcott’ mandarin (Citrus reticulata), irrespective of the timing of application. In the second season, a reduction in fruit yield was reported with an increase in metamitron concentration, both in mass and number of fruit per tree. A 150 mg·L−1 metamitron treatment in November had no fruit-thinning effects, and fruit yield was not different from the control. The application of metamitron did not increase the fruit size of ‘Nadorcott’ mandarin and had no direct effect on other fruit quality attributes in either season. Metamitron can be used as a chemical fruit-thinning agent to reduce fruit numbers in ‘Nadorcott’ mandarin, but an increase in fruit size or quality should not be expected.

scholarly journals Vegetative and Reproductive Growth and Yield of Plukenetia volubilis Plants in Responses to Foliar Application of Plant Growth Regulators

HortScience ◽  
2016 ◽  
Vol 51 (8) ◽  
pp. 1020-1025 ◽  
Author(s):  
C. Yang ◽  
D.Y. Jiao ◽  
Z.Q. Cai ◽  
H.D. Gong ◽  
G.Y. Li
Keyword(s):  
Plant Growth ◽  
Plant Growth Regulators ◽  
Growth Regulators ◽  
Seed Oil ◽  
Fruit Set ◽  
Growth And Yield ◽  
Oil Yield ◽  
Reproductive Growth ◽  
Plukenetia Volubilis ◽  
Vegetative And Reproductive Growth

Plukenetia volubilis Linneo, a tropical recurrent woody oilseed plant native to South America, was successfully introduced in China. A field experiment was conducted to determine the effect of the dry-season foliar sprays once every 2 weeks with 50 μm water or five different plant growth regulators (PGRs) viz., gibberellic acid (GA3), kinetin (KIN), indole-3-acetic acid (IAA), abscisic acid (ABA), and salicylic acid (SA) on the growth and yield of P. volubilis plants in Xishuangbanna, southwest China. Results showed that PGRs affected the leaf stomatal conductance (gS) and water-use efficiency (WUEi), rather than the net photosynthetic rate (PN). The phenological development of P. volubilis plants, including the time of flowering and maturity, and the dynamic pattern of fruit ripening, was not altered by PGR treatments. ABA and SA resulted in highest fruit set, seed oil content, and total fruit or seed oil yield, whereas GA3, IAA, and KIN were effective in increasing seed size. The nonstructural carbohydrates (NSC) are related to subsequent abscission or retention of the developing fruit, which was indicated by the positive relationship between carbohydrate concentration and fruit set across PGR treatments. The positive influences of PGRs on the total fruit yield (increased 4.3% to 15.2%) and total seed oil yield (increased 4.9% to 24.9%) per unit area throughout a growing season were found when compared with the control, depending to a great extent on the balance between vegetative and reproductive growth during the reproductive stage. This study suggests that PGRs, especially for ABA and SA, can become a valuable tool for promoting the seed oil yield of P. volubilis plants while maintaining high seed quality in the field.

scholarly journals Effect of Sterol-demethylation Inhibiting Fungicides on Apple Fruit Set, Fruit Size, Total Yield, and Gross Returns

HortScience ◽  
2003 ◽  
Vol 38 (4) ◽  
pp. 601-604 ◽  
Author(s):  
D.A. Rosenberger ◽  
T.L. Robinson ◽  
J.R. Schupp ◽  
C.A. Engle-Ahlers ◽  
F.W. Meyer
Keyword(s):  
Plant Growth Regulator ◽  
Fruit Set ◽  
Total Yield ◽  
Apple Scab ◽  
Fruit Size ◽  
Apple Fruit ◽  
Fruit Weight ◽  
Dmi Fungicides ◽  
Apple Production ◽  
Fruit Size And Shape

Effects of three sterol-demethylation inhibiting (DMI) fungicides and a contact fungicide were compared over two years at each of two locations to determine if fungicide treatments had differential effects on productivity, fruit size and shape, or gross returns for `Empire' apples (Malus ×domestica Borkh.). Treatments were applied four to five times per year during the primary apple scab season. Effects of treatments were assessed by comparing fruit set efficiencies, number of fruit per tree, total harvested fruit weight, and fruit length: diameter ratios at harvest. No significant differences were noted among individual treatments in any of the four trials. However, when treatments were contrasted by grouping individual treatments, significantly larger fruit size was noted for triflumizole treatments vs. combined fenarimol and myclobutanil treatments in one of the four trials and for captan or mancozeb compared to fenarimol and myclobutanil treatments in two trials. None of the DMI fungicides compared in these trials had any consistent adverse affect on fruit size, total yield, or estimated gross return per hectare. We conclude that the plant growth regulator effects of DMI fungicides are inconsistent and are unlikely to have significant economic impact on commercial apple production.

scholarly journals `Empire' Apple Responses to Fruit-thinning Chemicals

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 765E-765 ◽  
Author(s):  
Warren C. Stiles
Keyword(s):  
Size Distribution ◽  
Fruit Set ◽  
Total Yield ◽  
Fruit Size ◽  
Diameter Ratio ◽  
Time Of Application ◽  
Fruit Thinning ◽  
Small Fruit

Effects of NAA at 5, 10, and 15 ppm, Accel at 50, 75, and 100 ppm, NAA at 7.5 ppm plus carbaryl at 600 ppm, and a nontreated control on fruit set, fruit size, length–diameter ratio, seed numbers per fruit, and total yield of fruit were evaluated during the 1994 season. All treatments were applied to 10-year-old `Empire'/M.9/MM.111 trees as dilute sprays at a rate of 935 liters·ha–1 with an airblast sprayer on 3 June. King fruit measured 9–11 mm in diameter at time of application. Fruit set (fruits per 100 blossom clusters) was reduced significantly by Accel at 50 ppm (17%) and by NAA plus carbaryl (26%) in comparison with the nontreated control. Total yield of fruit was increased by all treatments; however, fruit from trees treated with NAA plus carbaryl was significantly larger than that from all other treatments. Percentages of small fruit, <108 g, were reduced by all treatments. Percentage of fruit ≥ 153 g was increased significantly only by NAA plus carbaryl. Length–diameter ratios and numbers of fully developed seeds per fruit were not influenced significantly by treatments. NAA at rates of 5, 10, and 15 ppm, or Accel at 50, 75, or 100 ppm, were less effective than a combination of NAA at 7.5 ppm plus carbaryl at 600 ppm in reducing fruit set and in affecting fruit size or fruit size distribution.

scholarly journals Earliness and Yield of Tropical Winter Squash Improved by Transplants, Plastic Mulch, and Row Cover

HortScience ◽  
2003 ◽  
Vol 38 (2) ◽  
pp. 203-206 ◽  
Author(s):  
Matthew T. Rulevich ◽  
Francis X. Mangan ◽  
Anne K. Carter
Keyword(s):  
Fruit Set ◽  
Total Yield ◽  
Fruit Size ◽  
Bare Soil ◽  
Direct Seeding ◽  
Wet Season ◽  
Plastic Mulch ◽  
Direct Seeded ◽  
Winter Squash ◽  
Polyethylene Mulch

Field studies were conducted in 1998 and 1999 in Massachusetts to assess the effects of transplants, black polyethylene mulch, and polyester spun-bonded row cover on early fruit set and total yield of two squash (Cucurbita moschata Duchesne) cultivars: `C42 × La Segunda' calabaza and `Waltham' butternut. Treatment comparisons included direct-seeded or transplanted squash, with or without black polyethylene mulch, and with or without the addition of a row cover in all combinations. The use of transplants was more effective at stimulating early fruit set and highest total yield than the use of mulch and row cover. The initiation of fruit set using transplants was advanced 9 days relative to direct-seeding. Mulch and row cover treatments significantly advanced early fruit set by 7 and 5 days, respectively, but only in 1998. Yields for both winter squash were 45% higher using transplants compared to direct seeding, 19% higher using mulch compared to bare soil, and 16% higher using row cover compared to no row cover. Total yields were higher for both cultivars in 1999 (warm, dry season) than in 1998 (cool, wet season). Use of transplants with plastic and row cover compared to the use of direct seed with neither plastic nor row cover increased yield of calabaza by 100% in both 1998 and 1999. Only the direct seeded plus plastic plus row cover treatment had yields that were similar to any of the transplanted treatments. Transplant treatments also increased number of fruit per plant and fruit size for both calabaza and butternut.

scholarly journals Planting Method and Irrigation Rate Influence Vegetative and Reproductive Growth of Peach Planted at High Density

1990 ◽  
Vol 115 (2) ◽  
pp. 207-212 ◽  
Author(s):  
J.G. Williamson ◽  
D.C. Coston
Keyword(s):  
Vegetative Growth ◽  
Fruit Size ◽  
High Density ◽  
Flower Bud ◽  
Reproductive Growth ◽  
Yield Efficiency ◽  
Irrigation Rate ◽  
Growing Seasons ◽  
Planting Method ◽  
Vegetative And Reproductive Growth

Several planting treatments modified vegetative and reproductive growth of young, own-rooted peach (Prums persica) trees evaluated at two levels of irrigation in a high-density orchard (5000 trees/ha). Trees planted in auger holes, narrow herbicide strips, and in fabric-lined trenches, but not those from raised beds, were smaller than control trees set in holes dug with a shovel. After two growing seasons, trees planted in the fabric-lined trenches were smaller and had more flowers per node and greater flower bud densities than trees in other planting treatments. Yield efficiency was greatest for this treatment, although fruit size was small throughout the orchard. Irrigation rates did not affect fruit yield or size. The effects of irrigation rate on vegetative growth were small compared to differences among planting treatments.

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