Nitrogen Stimulated Increases in Peach Yields Are Associated with Extended Fruit Development Period and Increased Fruit Sink Capacity

This study was designed to characterize the mechanisms of N-stimulated peach Prunus persica (L.) Batsch productivity. The effects of N fertilization on potential assimilate availability (source capacity) and on the growth capacity of individual fruit (sink capacity) were assessed. On heavily thinned trees, fertilization did not stimulate fruit growth rates relative to those on nonfertilized trees, suggesting that fruit growth rates were not assimilate-limited throughout the period of fruit development. However, N fertilization resulted in a longer fruit development period and increased the growth potential of individual fruit by 20% (fresh mass) and 15% (dry mass) vs. controls. In unthinned trees, N fertilization increased total fruit yield by 49% (fresh mass) and 40% (dry mass) compared to the unthinned, nonfertilized controls. N fertilization increased total fruit yield per tree in unthinned peach trees by extending the fruit development period and thus increasing the amount of assimilate accumulated for fruit growth. The fruit development period was prolonged both by assimilate deprivation associated with increasingly higher crop loads and by N fertilization. Thus, the prolongation of the peach fruit development period by N-fertilization appears inconsistent with the role of N in increasing assimilate availability for fruit growth. We conclude that N fertilization stimulates peach yields by increasing the period for fruits to use assimilates (sink capacity). The effect of N on assimilate availability was not directly evaluated. The timing of fertilizer N availability did not influence fruit growth potential.

Download Full-text

Prospects for Mechanical Harvest of Zucchini Squash

HortScience ◽

10.21273/hortsci.31.4.668g ◽

1996 ◽

Vol 31 (4) ◽

pp. 668g-668

Author(s):

Jim E. Wyatt

Keyword(s):

Growth Rates ◽

Fruit Development ◽

Plant Material ◽

Fruit Growth ◽

Fruit Yield ◽

Leaf Removal ◽

Harvest Efficiency ◽

Marketable Fruit ◽

Marketable Size

Removing a portion of the foliage of zucchini squash without reducing yield would increase the efficiency of mechanical harvest since less plant material would be passed through the harvester. Pruning 50% of the leaves and petioles at either first or second harvest had no effect on third harvest fruit yield. Primary or secondary fruit growth rates were not affected by leaf removal. Presence of a primary fruit reduced the number of secondary fruit developing to marketable size but the rate of secondary fruit development was similar on plants with one, two, or three fruit. The maximum fruit to develop at one time in this planting was two per plant. Following one or two hand-harvests of zucchini squash, mechanical harvest efficiency will be increased after removal of 50% of the leaves and maturation of two marketable fruit per plant.

Download Full-text

Ethephon Alters the Physiology of Young Apple Fruits

HortScience ◽

10.21273/hortsci.33.3.497b ◽

1998 ◽

Vol 33 (3) ◽

pp. 497b-497

Author(s):

Daniel Ward ◽

Richard Marini

Keyword(s):

Water Potential ◽

Fruit Development ◽

Dry Mass ◽

Fruit Tree ◽

Fruit Growth ◽

Abscission Zone ◽

Starch Accumulation ◽

Control Fruit ◽

Apple Fruits ◽

Fruit Diameter

Methods are needed to quickly assess the efficacy of chemical thinning treatments, so, if needed, additional treatments can be applied. When fruit diameter averaged 19 mm, `Smoothee' trees were sprayed with Ethrel at the rate of 3.7 ml formulation/L to induce abscission of most fruits on the tree. The diameter of 10 fruit/tree were measured daily and fruits were sampled 2, 4, and 6 days after treatment (DAT) to evaluate fruit development. Fruit on nontreated trees increased in diameter at the rate of about 0.7 to 0.9 mm/day. Fruit growth on treated trees was normal for 1 day, slowed to 0.5 mm for 2 days, and grew <0.1 mm/day thereafter. Fruit water potential was less negative for treated trees 2 DAT. Fresh and dry mass of treated fruit ceased increasing after 4 DAT. Percent dry mass of control fruit declined on each sampling date, but did not decline for treated fruit after 4 DAT. Cellulase was active in the abscission zone 4 DAT for treated fruit, but not control fruit. Compared to control fruit 6 DAT, treated fruit had elevated respiration and less starch accumulation. Fruits began to abscise 6 DAT. Following Ethrel application. The first indication that a fruit is destined to abscise are reduced fruit growth and changes in water potential 2 DAT.

Download Full-text

PHENOLOGY OF LOW-CHILL `FLORDAPRINCE' PEACH

HortScience ◽

10.21273/hortsci.27.6.669a ◽

1992 ◽

Vol 27 (6) ◽

pp. 669a-669

Author(s):

Peter Allan ◽

Alan George ◽

Robert Nissen

Keyword(s):

Fruit Development ◽

Shoot Growth ◽

Dry Mass ◽

Fruit Growth ◽

Extension Growth ◽

Seed Growth ◽

Peach Trees ◽

Subtropical Australia ◽

Leaf N

Low chill `Flordaprince' peach trees were grown in subtropical Australia, either following paclobutrazol application to dwarf the trees, or extra nitrogen to invigorate them. Fruits were thinned uniformly. Paclobutrazol significantly reduced the competing spring shoot growth and gave earlier maturity of larger, better quality fruits. It reduced the spring, but increased the autumn root flush. Stage 2 of fruit growth was slightly longer in vigorous trees, resulting in delayed seed growth and greater dry mass of the embryos. Starch reserves were greatest in the roots, followed by the trunk, shoots and leaves. The reserves were lowest during the second half of fruit development, but rose again after the end of shoot extension growth. Leaf N, P, and K levels decreased through the season while Ca and Mg increased. There were significantly lower K and higher Ca and Mg levels in dwarfed trees.

Download Full-text

Evaluation of Zeolite-based Soilless Root Media for Potted Chrysanthemum Production

HortScience ◽

10.21273/hortsci.33.3.465e ◽

1998 ◽

Vol 33 (3) ◽

pp. 465e-465

Author(s):

Janet L. Carlino ◽

Kimberly A. Williams ◽

Earl R. Allen

Keyword(s):

Crop Production ◽

Dry Mass ◽

Nutrient Leaching ◽

Fresh Mass ◽

Production Cycle ◽

Control Medium ◽

Fertilizer Rate ◽

Innovative Technologies ◽

Root Media ◽

Soluble Fertilizer

Chrysanthemum growth and nutrient leaching of three clinoptilolite-based root media, which were formulated and provided by Boulder Innovative Technologies, Inc. and ZeoponiX, Inc., were compared to the performance of control plants grown in Sunshine Mix #2 (3 peat: 1 perlite, v/v). The control received 210 mg·L–1 N from an 18N–4P–15K soluble fertilizer at each irrigation. The experimental zeolite-based medium NZ, which contained untreated zeolite and received the same soluble fertilizer as the control, leached lower concentrations of NH4-N, K, and PO4-P for most of the production cycle compared to the control. Medium EZ1 was formulated to provide N, P, and K as fertilizer nutrients and produced plants similar to the control based on ratings, height, width, and dry mass, but not fresh mass, at harvest when the fertilizer rate was half of that applied to the control, 105 mg·L–1 N. Medium EZ2, which did not receive P or K from soluble fertilizer, produced plants similar to the control based on rating, height, and dry mass, but not width or fresh mass, with soluble fertilizer input reduced to only N. Tissue N, P, and K concentrations of plants grown in media EZ1 and EZ2 were lower than those of control plants. With further refinements, these zeolite-based products show promise for decreasing nutrient leaching during crop production and allowing for application of lower rates of soluble fertilizers.

Download Full-text

Fruit yield and composition in orange trees cv. 'Lane Late' in response to nitrogen fertilization in Sandy Typic Hapludalf soil

Ciência Rural ◽

10.1590/0103-8478cr20140869 ◽

2017 ◽

Vol 47 (3) ◽

Author(s):

Gustavo Brunetto ◽

◽

Cesar Cella ◽

Alcione Miotto ◽

Eduardo Girotto ◽

...

Keyword(s):

Fruit Juice ◽

Organic Matter Content ◽

Titratable Acidity ◽

N Fertilization ◽

Fruit Yield ◽

Soluble Solids ◽

Total N ◽

Total Titratable Acidity ◽

Orange Trees ◽

The Impact

ABSTRACT: Little is known about the impact of N fertilization on fruit production and composition in orange groves grown in soils with low or medium organic matter content in Rio Grande do Sul (RS). This study aimed to evaluate how N fertilization of orange trees cv. 'Lane Late' in a sandy soil may interfere in fruit yield and composition of fruit and juice. The experiment was conducted with orange trees cv. 'Lane Late' growing in Sandy Typic Hapludalf soil, in Rosário do Sul (RS). The plants received applications of 0, 20, 40, 60, 80, 100, 120, 140 and 160kg N ha-1. Total N in leaves, number of fruits per plant, yield, fresh weight, fruit diameter, peel thickness, percentage of fruit juice, peel color, juice color, ascorbic acid content, total soluble solids (TSS) and total titratable acidity were evaluated in 2010/2011 and 2011/2012 crops. In the first crop, especially yield, number of fruits per plant, TSS content in fruit juice and ratio decreased with increasing N rate applied. However, in the second crop, the total titratable acidity of the fruit juice prominently increased with the dose of N applied. In both crops, results were highly influenced by rainfall distribution, which affect the plant physiology, soil N dynamics and, consequently, probability of response to N applied and the loss of mineral N in the soil.

Download Full-text

NONLINEAR AGROMETEOROLOGICAL MODELS FOR ESTIMATING LYCHEE FRUIT GROWTH

Revista Brasileira de Fruticultura ◽

10.1590/0100-29452017169 ◽

2017 ◽

Vol 39 (2) ◽

Author(s):

LUCAS EDUARDO DE OLIVEIRA APARECIDO ◽

RAFAEL BIBIANO FERREIRA ◽

GLAUCO DE SOUZA ROLIM ◽

BIANCA SARZI DE SOUZA ◽

PAULO SERGIO DE SOUZA

Keyword(s):

Fruit Development ◽

Dry Matter ◽

Potential Evapotranspiration ◽

Climatic Conditions ◽

Fruit Growth ◽

Multivariate Models ◽

Degree Days ◽

Fresh Matter ◽

Meteorological Elements ◽

Fruit Diameter

ABSTRACT The influence of climate on the development of lychee fruit is complex, but few studies have discussed the problem. We developed agrometeorological models for simulating the development of fruit fresh matter (FM), fruit dry matter (DM), fruit length (LE), fruit diameter (DI), fruit volume (VO), and fruit number per cluster (FN) of the “Bengal” lychee cultivar as functions of climatic conditions. We conducted three analyses: (a) the influence of mean meteorological elements on the rates of fruit growth, (b) estimation of fruit development by the agrometeorological models using sigmoidal adjustments, and (c) simulation of fruit development using multiple nonlinear regression of two meteorological elements to improve the accuracy. A rate of water deficit (WD) near 5 mm d-1 maximised FM, DM, LE, DI, and VO. Increases in potential evapotranspiration (PET), degree days (DD), and actual evapotranspiration (AET) were correlated with increases in VO and decreases in LE and NF. Models estimating fruit development indicated that the accumulation of WD, PET, AET, and DD had sigmoidal relationships with all variables of fruit growth except FN. FN decreased as WD, PET, AET, and DD increased. The adjusted multivariate models were accurate, with the largest error of 6.45 cm3 (VO). The best models were: FM = f(SWD, DD), LE = f(SAET, DD), DI = f(SWD, DD), VO = f(SWD, DD), and FN = f(SAET, WD).

Download Full-text

Individual and Interactive Temporal Implications of UV-B Radiation and Elevated CO2 on the Morphology of Basil (Ocimum basilicum L.)

Horticulturae ◽

10.3390/horticulturae7110474 ◽

2021 ◽

Vol 7 (11) ◽

pp. 474

Author(s):

T. Casey Barickman ◽

Skyler Brazel ◽

Akanksha Sehgal ◽

C. Hunt Walne ◽

Wei Gao ◽

...

Keyword(s):

Elevated Co2 ◽

Plant Morphology ◽

Dry Mass ◽

Root Surface ◽

Morphological Features ◽

Fresh Mass ◽

Interactive Effects ◽

Root Surface Area ◽

Surface Wax ◽

Radiation Treatments

Temporal and spatial variations in ozone levels and temporal changes in solar radiation greatly influence ultraviolet radiation incidence to crops throughout their growth, yet the interactive effects of CO2 and UV-B radiation on Basil production under sunlight environmental conditions has not been studied. Basil ‘Genovese’ plants grown under sunlit plant growth chambers were subjected to a combination of supplemental UV-B (0 and 10 kJ m−2d−1) and ambient (420 ppm) and elevated (720 ppm) CO2 treatments for 38 days after 14 days of germination. UV-B radiation treatments caused a decrease in basil stem branching, fresh mass, and stem dry mass under both CO2 treatments when harvested after 17 and 38 days of treatment. There was also an increase in basil leaf surface wax under UV-B (10 kJ m−2d−1) treatment compared to controls (0 kJ m−2d−1). Elevated CO2 treatments caused a decrease in morphological features, including specific leaf area and fresh mass. Interactive effects between UV-B and CO2 treatments existed for some morphological features, including plant height, root surface area, and average root diameter. Understanding the impacts that CO2 and UV-B radiation treatments have on basilcan improve existing varieties for increased tolerance while simultaneously improving yield, plant morphology, and physiology.

Download Full-text

Hydroponics growth of Eucalyptus saligna Sm. on salt-stress mediated by sodium chloride

Journal of Biotechnology and Biodiversity ◽

10.20873/jbb.uft.cemaf.v3n4.lopessilva ◽

2012 ◽

Vol 3 (4) ◽

pp. 213-218 ◽

Cited By ~ 1

Author(s):

André Luís Lopes da Silva ◽

Yohana de Oliveira ◽

Roberson Dibax ◽

Jefferson da Luz Costa ◽

Gessiel Newton Scheidt ◽

...

Keyword(s):

Salt Stress ◽

Aerial Part ◽

Dry Mass ◽

Hydroponic Culture ◽

Fresh Mass ◽

Root Number ◽

Eucalyptus Saligna ◽

Volume Number ◽

Micropropagated Plants ◽

Fresh And Dry Mass

The aim of this work was to evaluate the growth of two clones of Eucalyptus saligna on salt-stress mediated by NaCl in hydroponics. Micropropagated plants of the clones p0 and p1 were acclimatizated and cultivated in hydroponics at 0 and 300 mM NaCl levels. The total length, volume, number, fresh mass and dry mass of the roots, the height, fresh and dry mass of the aerial part and the fresh and dry mass of the complete plant were evaluated to the 14 days of hydroponic culture with NaCl. There were significant differences among the clones. The clone p0 was superior to the clone p1 in relation to volume of the roots, root number, root fresh mass and total fresh mass of the root. Regards the effect of the salinity on the plants, significant reduction was observed in the height of the aerial part, fresh mass of the aerial part and the total fresh mass. Even so, the interaction between the clones and the concentrations of NaCl was significant for the total fresh mass. In the period of 14 days of hydroponic culture on 300 mM NaCl was possible to discriminate these two clones in relation to the tolerance and susceptibility to the salt stress. The clone p0 presented higher growth and larger tolerance to the salinity than clone p1.

Download Full-text

Use of the QTL approach to the study of soybean trait relationships in two populations of recombinant inbred lines at the F7 and F8 generations

Brazilian Journal of Plant Physiology ◽

10.1590/s1677-04202006000200004 ◽

2006 ◽

Vol 18 (2) ◽

pp. 281-290 ◽

Cited By ~ 18

Author(s):

Antonio José Dias Vieira ◽

Dario Alves de Oliveira ◽

Taís Cristina Bastos Soares ◽

Ivan Schuster ◽

Newton Deniz Piovesan ◽

...

Keyword(s):

Leaf Area ◽

Recombinant Inbred ◽

Recombinant Inbred Lines ◽

Dry Mass ◽

Inbred Lines ◽

Leaf Nitrogen ◽

Fresh Mass ◽

Net Assimilation ◽

Two Populations ◽

Pod Number

This work aimed to identify the quantitative trait loci (QTL) associated with photosynthesis and growth and productivity traits of soybean and to study possible associations between these traits by the analysis of coincidence of QTL in linkage groups (LGs). Thus, populations of recombinant inbred lines (RILs) of the F7 and F8 generations derived from the cross between the varieties BARC-8 and Garimpo were used. The traits evaluated were net assimilation rate of CO2 under saturating light (Asat), potential photosynthesis rate (Pmax), leaf area (A), specific leaf area (SLA), specific leaf nitrogen (N); root (W R), nodule (W N), stem (W ST), leaf (W L), pod (W P) and plant dry mass (W T); nodule (nN), seed (n s), and pod number (nP); seed fresh mass per plant (W S), one-hundred seed fresh mass (W HS) and seed protein percentage (P%). It was possible to identify the following QTL associated with the following soybean traits: SLA, Asat, N, W R, W ST, W L, W T, W P, W HS, n s and nP, indicating that the RIL population has a great potential for mapping loci associated with quantitative traits of the soybean crop. The correlations between the soybean traits were partially confirmed by coincidence of QTL.

Download Full-text