Reappraisal of seasonal apple fruit growth

1993 ◽  
Vol 73 (2) ◽  
pp. 549-556 ◽  
Author(s):  
I. Schechter ◽  
J. T. A. Proctor ◽  
D. C. Elfving

Three apple cultivars (McIntosh, Delicious and Empire) were used in 1989 to study seasonal fruit growth. Fruit fresh weight (FW), dry weight (DW), dry matter concentration (DMC) and relative growth rate (RGR) were regressed against days after full bloom (DAFB) while partitioning the fruit growth curve into either two or three linear phases. Linear phases in fruit DW and FW development were evident throughout most of the growing season. However, cultivars differed in seasonal FW and DW accumulation totals and daily rates. Fruit RGR gradually declined until 75–80 DAFB, when it reached a low and constant rate until harvest. The DMC of fruitlets at about 30–35 DAFB was about half that at full bloom. After an additional 20–30 d during which DMC increased, fruits maintained a relatively stable DMC level to the end of the season. Key words: Malus domestica Borkh., fresh and dry weight, dry matter concentration, relative growth rate

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1180a-1180
Author(s):  
Theodore M. DeJong

The growth and development patterns of fruit have been studied for many years and it has become traditional to think of peaches as having a double sigmoid pattern with three main stages fruit growth. This concept is primarily based on analyses of fruit absolute growth rates An alternative approach is to express growth on a relative growth rate (RGR) basis which is simply the weight increase perg of fruit weight per day. This analysis applied to dry-weight peach fruit growth results in a two-phase curve that is known mathematically as a Gompertz function. During the first growth phase the RGR decreases logarithmically and during the second phase the RGR remains relatively stable. Expressing fruit growth on a RGR basis is advantageous for fruit growth carbon budget modelling because RGR is directly related to respiration rates and for physiological studies because most analyses for physiologically active substances are expressed on a weight basis. There is obviously not only one “right” way to express fruit growth but it may be instructive to use the RGR approach particularly when studying factors that may be associated with “sink” activity.


Author(s):  
E. A. Effa ◽  
A. A. J. Mofunanya ◽  
B. A. Ngele

Background: Soil pH is one of the most important factors that contribute to crop growth and productivity. The present research was designed to assess the influence of soil amendment using organic manure and agricultural lime on the relative growth rate (RGR) and net assimilation rate (NAR) of Phaseolus vulgaris and Vigna aconitifolia grown on soils from different locations. Methodology: The three locations were: Akamkpa, Calabar Municipality and Odukpani. The pH for the three soil locations were 4.0, 7.0 and 9.0, respectively. The treatments were; control (0 g), OM1 (100 g organic manure), OM2 (200 g organic manure), AL1 (100 g agricultural lime), AL2 (200 g agricultural lime), OM1 + AL1 (50 g organic manure + 50 g agricultural lime) and OM2 +AL2 (100 g organic manure and 100 g agricultural lime). Results: Results obtained on the RGR of the leaf dry weight of P. vulgaris treated with OM2 was the highest (0.50 g/wk) followed by OM1 (0.41 g/wk). OM1 + AL1 had the highest RGR of the stem dry weight of P. vulgaris grown on soil from Calabar Municipality. In the RGR of the root dry weight, OM2 had the highest mean value in both plants grown on Akamkpa soil. Results obtained at 4 weeks after planting (WAP) revealed that there was significant (P<0.05) increase in NAR of plants grown on soil from Akamkpa. The highest NAR was obtained for V. aconitifolia treated with OM2 (0.0447 g/wk) followed by OM2 + AL2 (0.0057 g/wk) for both V. aconitifolia and P. vulgaris. P. vulgaris grown on Akamkpa and Odukpani soils treated with AL2 (0.0032 g/wk), OM1 + AL1 (0.0041 g/wk) and OM2+ AL2 (0.0062 g/wk) had the highest NAR at 8 WAP. Conclusion: The RGR and NAR of the two bean varieties were improved following treatments with organic manure and agricultural lime.


Sensors ◽  
2020 ◽  
Vol 20 (22) ◽  
pp. 6501
Author(s):  
Mohammad Ajlouni ◽  
Audrey Kruse ◽  
Jorge A. Condori-Apfata ◽  
Maria Valderrama Valencia ◽  
Chris Hoagland ◽  
...  

Crop growth analysis is used for the assessment of crop yield potential and stress tolerance. Capturing continuous plant growth has been a goal since the early 20th century; however, this requires a large number of replicates and multiple destructive measurements. The use of machine vision techniques holds promise as a fast, reliable, and non-destructive method to analyze crop growth based on surrogates for plant traits and growth parameters. We used machine vision to infer plant size along with destructive measurements at multiple time points to analyze growth parameters of spring wheat genotypes. We measured side-projected area by machine vision and RGB imaging. Three traits, i.e., biomass (BIO), leaf dry weight (LDW), and leaf area (LA), were measured using low-throughput techniques. However, RGB imaging was used to produce side projected area (SPA) as the high throughput trait. Significant effects of time point and genotype on BIO, LDW, LA, and SPA were observed. SPA was a robust predictor of leaf area, leaf dry weight, and biomass. Relative growth rate estimated using SPA was a robust predictor of the relative growth rate measured using biomass and leaf dry weight. Large numbers of entries can be assessed by this method for genetic mapping projects to produce a continuous growth curve with fewer replicates.


2012 ◽  
Vol 30 (2) ◽  
pp. 317-325 ◽  
Author(s):  
R.C. Souza ◽  
A.C. Dias ◽  
M.R.A. Figueiredo ◽  
F.E.B. Obara ◽  
P.J Christoffoleti

The aim of this research paper was to compare the growth of D. ciliaris and D. nuda crabgrass species under non-competitive conditions. To this end, two experiments were conducted, one from March - July 2010 and the other from February - June 2011. The experimental design of both trials was completely randomized making a factorial (2 seasons x 2 species crabgrass x 12 evaluation periods) with four replications. Assessments began at 15 days after sowing (DAS), and repeated weekly until 92 DAS. The variables evaluated were total dry matter (roots+leaves+stems), leaf area, leaf number and tiller. The results were submitted to analysis of variance and the absolute growth rate, relative growth rate and leaf area ratio were calculated using the means, which were adjusted regression models. The crabgrass species were significantly different in leaf area, leaf number, tiller number and dry matter per plant. D. ciliaris for all variables was statistically higher than D. nuda. Regarding the speed at which the growth of the species occurred, the absolute growth rate and relative growth rate of D. ciliaris was also greater than D. nuda. In addition, D. ciliaris also had a lower leaf area ratio indicating greater efficiency in converting light energy into carbohydrates. It can be concluded that D. ciliaris has a higher growth rate in conditions where there is no limitation of nutrients and water availability in relation to D. nuda, mainly due to D. ciliaris have greater leaf area, number of leaves and dry matter accumulation per plant.


2013 ◽  
Vol 19 (1) ◽  
pp. 13-21
Author(s):  
MSI Mollah ◽  
MH Rashid ◽  
MS Hossain ◽  
M Khalekuzzaman

The experiments are conducted in the experimental field of the Department of Botany, Rajshahi University during the winter season of 2005-2006 to study the effects of soil moisture and NPK fertilizers on grain growth of four barley varieties (Hordeum vulgare L.) following split-split plot design. The highest grain growth parameters like, spikelet number, spike dry weight, grain number and grain dry weight, spike relative growth rate and grain relative growth rate were observed in the I2 treatment at different days after anthesis. F3 treatment produced the highest spikelet number, spike dry weight, grain number, grain dry weight, spike relative growth rate and grain relative growth rate but the control produced the lowest values. BHL-3 produced higher spikelet number and grain relative growth rate. BL-1 produced higher spike dry weight, grain number, grain dry weight and spike relative growth rate.DOI: http://dx.doi.org/10.3329/pa.v19i1.16985 Progress. Agric. 19(1): 13 - 21, 2008 


1988 ◽  
Vol 39 (5) ◽  
pp. 807 ◽  
Author(s):  
RH Chisholm ◽  
GJ Blair

Two solution culture experiments were conducted to compare the efficiency of phosphorus use and indicies for measuring it in a tropical and a temperate pasture legume. The species chosen were Stylosanthes hamata cv. 'Verano' (Caribbean stylo) and Trifolium repens cv. 'Ladino' (white clover).The first experiment used two solution P concentrations (2, 16 8M) to investigate differences between species in the rate and extent of P uptake. The second experiment used five solution P concentrations (1, 2, 4, 8, 16 8M ) to evaluate differences between species in internal efficiency of P utilization.There was no difference between white clover and stylo in the capacity to remove P from the same solution P concentrations. However, in both species the extent of depletion of solutions by plants grown at high P was not as great as that plants grown at low P. The ranking of species in terms of their internal efficiency or relative growth rate changed with time and P concentrations.Growth of white clover was better than stylo where there was a moderate deficiency of phosphorus. Alternatively, growth of stylo was better than white clover where phosphorus deficiency was more severe. The relative growth rate of stylo at low (2 8M ) P was maintained above 8% per day after prolonged P stress, whilst in white clover at the same P concentration RGR fell to less than 2% per day.Internal P efficiency or the amount of dry matter accumulated per unit P accumulated per unit time showed that white clover was more P efficient than stylo in the early stages of growth.


Author(s):  
A. Pagani ◽  
J. Molinari ◽  
E. Giardina ◽  
A. Di Benedetto

Pot ornamental plant productivity is related to the environmental growth facilities but negatively affected by the pot root restriction syndrome. Most ferns showed a lower relative growth rate and long production cycles (24 months or more) for which growers use small pots to increase yield per unit area of greenhouse. The aim of this work was to analyze growth changes in response to different pot volume in plants of A. nidus avis spore-propagated under the hypothesis that it would play a role as an abiotic stress which decrease commercial productivity. Our results showed that the use of big pots increased fresh and dry weight and frond area (the main aesthetic trait). When growth parameters were performed, a higher the frond appearance rate (RLA), the frond area expansion (RLAE) and the frond thickness (SLA) were found in 1500 cm3 pot as well as the relative growth rate (RGR) and the net assimilation rate. The use of biggest pot for fern cropping stimulated biomass accumulation through a higher capacity to initiate and expand fronds, to increase photosynthetic rates and change photo assimilate partitioning which favor shoots. From the grower´s point of view, our results suggested that higher yields of A. nidus avis fern would be reached decreasing root restriction, that is, to use the biggest pot volume from the early transplant from plug trays.


HortScience ◽  
1991 ◽  
Vol 26 (5) ◽  
pp. 590-592 ◽  
Author(s):  
Jean-Pierre Privé ◽  
J. Alan Sullivan

Growth rates for two types of tissue-cultured plant stock for `Heritage', `Ruby', and `Redwing' red raspberry (Rubus idaeus L.) were examined. Actively growing plantlets from the greenhouse (G) were compared to cold-treated (CT) plantlets from cold storage. The greatest differences between these two occurred during the first 6 weeks after planting. At 4 weeks, CT plants for all cultivars had longer canes and internodes, sometimes twice that of G plants. Although `Heritage' had greater total plant dry weights following chilling, `Ruby' and `Redwing' had less. Chilling had no effect on `Heritage' root growth but did reduce root dry weight for `Redwing' and `Ruby'. Relative growth rate (RGR) and leaf area ratio (L-AR) were more effective variables for analyzing growth as they considered differences in initial biomass and cane number and provided a better representation of the data during the initial 6 weeks of growth. All cultivars showed a greater total plant RGR and LAR for the CT plants at 6 weeks. During the first 4 weeks, the G plants were more efficient producers of root dry matter while the CT plants were more efficient producers of cane dry matter. By 6 weeks, the G plants had partitioned a greater percentage of their assimilates into cane growth while the leaves, canes, and roots of the CT plants contributed equally to total RGR. No difference in total or individual component RGR was observed after 6 weeks.


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