Gibberellic acid induced growth acceleration in Populus hybrids

1984 ◽  
Vol 14 (6) ◽  
pp. 850-854 ◽  
Author(s):  
S. B. Rood ◽  
G. Daicos ◽  
T. J. Blake

Weekly applications of 0.4 mg gibberellic acid (GA) in 8 μL 95% ethanol micropipetted onto shoots of rooted cuttings increased Populuseuramericana (Dode) Guinier height growth by 54% and shoot dry weight by 25% after 21 days. Total leaf area increased by 21% as a result of more rapid leaf production and slightly larger leaf sizes. Root growth was unaffected by GA treatment. The observed GA-induced acceleration resulted from an increase in relative growth rate while mean net assimilation rate was unaffected. Owing to a substantial increase in the number and size of leaves, the leaf area ratio, representing the ratio of photosynthesizing to respiring material, increased. While direct micropipette application of GA promoted height growth and primary shoot dry weight accumulation, GA application through either foliar spray or soil drench also promoted the growth of secondary shoots. Application of GA to shoots was more effective in promoting shoot growth than application through the roots. Direct GA application also promoted the growth of P. alba L. × P. grandidentata Michx. and P. × canescens (Ait.) Smith × P. alba × P. grandidentata. Thus, GA can be used for hastening early growth of these trees under winter greenhouse conditions.

HortScience ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 1053E-1054
Author(s):  
Yun-Chan Huh ◽  
Du-Hyun Kim ◽  
Sang-Gyu Lee ◽  
Kyoung-Sub Park ◽  
Dong-Kum Park ◽  
...  

Growth response of `Sambok Honey' watermelon grafted onto different rootstocks, including four Citrullus rootstocks and three other cucurbitaceous rootstocks, was evaluated at low and normal temperature regimes. Marked reduction in plant growth rate was observed in plants grown at low temperatures as compared to those grown at normal or optimal temperatures. Relative growth reduction rates were 40% to 48% for vine length, 39% to 51% for total leaf area, 37% to 60% for shoot fresh weight, and 50% to 79% for shoot dry weight, respectively. Watermelon rootstock PI 482322 showed comparable plant growth as the most popular rootstock (Shintozwa pumpkin) even at low temperatures. `Sambok Honey' watermelon grafted onto watermelon hybrids `PI 271969 × PI 296341' and `PI 271769 × Calhoun Gray', showed comparable plant growth as FR Dantos bottle gourd rootstock. Index of growth ability at low temperature (IGALT), which was calculated on the basis of reduced rate of vine length, dry weight, and leaf area, was comparatively high in C. martinezii, Shintozwa, PI 482322, and `PI 271769 × PI 296341' rootstocks (50% or higher) and lowest in own-rooted `Sambok Honey' or in watermelon plants on `Knight' rootstock. Watermelon hybrids `PI 271969 × PI 296341' and `PI 271769 × Calhoun Gray' exhibited better or at least comparable growth at low temperatures as compared to `FR Dantos', thus confirming the feasibility of using watermelon rootstocks even in winter greenhouse conditions.


1962 ◽  
Vol 58 (2) ◽  
pp. 235-241 ◽  
Author(s):  
W. W. Fletcher ◽  
D. J. Martin

1. Gibberellic acid had no effect on the germination of six species of small-seeded legumes.2. Seven varieties of Trifolium repens L. plants were treated with gibberellic acid and their responses determined. All varieties showed an increase in petiole length and individual leaf area due to an increase in cell numbers; a decrease in stolon numbers and length was also noted. The total leaf area per plant remained unchanged. Total dry weight, shoot dry weight and root dry weight were each significantly reduced.3. The stolons lost their normal diageotropic response and became negatively geotropic and it is postulated that the stoloniferous habit may be due to a gibberellic acid/indole-acetic acid interaction.4. Because treated plants of Wild white clover closely resembled untreated plants of Ladino clover it is postulated that endogenous levels of gibberellins may play an important part in the development of varieties and in the evolutionary process as a whole.


1989 ◽  
Vol 40 (2) ◽  
pp. 293 ◽  
Author(s):  
DR Eagling ◽  
RJ Sward ◽  
GM Halloran

Measurements were made on the effect of barley yellow dwarf virus (BYDV) infection on the early growth of four commercial cultivars of ryegrass (Lolium spp.) under two different temperatures (24�C and 16�C). At 24'C, BYDV infection was associated with reduced root dry weight (30-40%) in all cultivars; the effect of infection on shoot dry weight and leaf area was variable. At 16�C, the effect of BYDV infection was variable, being associated with increases in root dry weight, shoot dry weight, and leaf area in one cultivar (Grasslands Ariki) and decreases in another (Victorian). In two other cultivars, root dry weight, shoot dry weight and leaf area were not significantly affected (P>0.05) by infection with BYDV.At 24�C, the reductions in root dry weight associated with BYDV infection were not concomitant with reductions in the root relative growth rates. Up to at least 28 days after inoculation (46-50 days after germination) reductions in root dry weight were associated with both aphid-feeding damage and virus infection. Experiments with the cultivar Victorian, showed that shoot dry weight was not significantly affected (P>0.05) by feeding with viruliferous (BYDV) or non-viruliferous aphids (Rhopalosiphum padi L.). At 16�C, changes in root and shoot dry weight were associated with changes in the root and shoot relative growth rates.


1988 ◽  
Vol 18 (1) ◽  
pp. 131-134
Author(s):  
Daniel K. Struve ◽  
W. Timothy Rhodus

The basal 1 cm of taproot of dormant bareroot 1-0 red oak (Quercusrubra L.) seedlings were given a 3-s dip in 20, 40, or 80 mM concentrations of indole-3-butyric acid (IBA), phenyl indole-3-thiolobutyrate (P-ITB), or equal parts IBA and P-ITB at 20 or 40 mM concentrations. Sixty control seedlings were dipped in 95% ethanol, while 30 seedlings were used for each auxin treatment. Seedlings were potted on May 12, 1986, and grown outdoors. At the end of the 104-day study period, all concentrations of IBA and P-ITB significantly increased number of roots regenerated (from 5.3 with 20 mM IBA to 11.9 for 80 mM IBA) compared with control seedlings. However, P-ITB-treated seedlings produced significantly more leaves (20–24) and leaf area (320–472 cm2), and up to 10 g more dry weight than IBA and non-auxin-treated seedlings. P-ITB treated seedlings had higher relative growth and net assimilation rates and lower leaf area ratio than IBA-treated or control seedlings. Seedlings treated with 20 mM of equal parts IBA and P-ITB were similar to P-ITB-treated seedlings while seedlings treated with the 40 mM IBA and P-ITB combination were similar to IBA-treated seedlings.


Agronomy ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1859
Author(s):  
Saeid Hassanpour-bourkheili ◽  
Mahtab Heravi ◽  
Javid Gherekhloo ◽  
Ricardo Alcántara-de la Cruz ◽  
Rafael De Prado

Wild poinsettia (Euphorbia heterophylla L.) is a difficult-to-control weed in soybean production in Brazil that has developed resistance to herbicides, including acetolactate synthase inhibitors. We investigated the potential fitness cost associated to the Ser-653-Asn mutation that confers imazamox resistance in this weed. Plant height, leaf and stem dry weight, leaf area and seed production per plant as well as the growth indices of specific leaf area, leaf area ratio, relative growth rate and net assimilation in F2 homozygous resistant (R) and susceptible (S) wild poinsettia progenies were pairwise compared. S plants were superior in most of the traits studied. Plant heights for S and R biotypes, recorded at 95 days after planting (DAP), were 137 and 120 cm, respectively. Leaf areas were 742 and 1048 cm2 in the R and S biotypes, respectively. The dry weights of leaves and stems in the S plants were 30 and 35%, respectively, higher than in the R plants. In both biotypes, the leaves had a greater share in dry weight at early development stages, but from 50 DAP, the stem became the main contributor to the dry weight of the shoots. The R biotype produced 110 ± 4 seed plant−1, i.e., 12 ± 3% less seeds per plant than that of the S one (125 ± 7 seed plant−1). The growth indices leaf area ratio and specific leaf area were generally higher in the S biotype or similar between both biotypes; while the relative growth rate and net assimilation rate were punctually superior in the R biotype. These results demonstrate that the Ser-653-Asn mutation imposed a fitness cost in imazamox R wild poinsettia.


2021 ◽  
Vol 6 (1) ◽  
pp. 28
Author(s):  
Khavid Faozi ◽  
Prapto Yudono ◽  
Didik Indradewa ◽  
Azwar Ma'as

A coastal sandy land is a potential land used for soybean cultivation. The success in developing soybeans in coastal sandy land depends on the suitability of cultivars used and the cultivation technology applied. Therefore, this study aimed to analyze the growth of twelve soybean cultivars in coastal sandy land as affected by the application of banana pseudo-stem bokashi. The experiment was carried out in factorial randomized complete block design with three replications. The treatment factors consisted of rates of bokashi (0, 20, 40, and 60 ton.ha-1) and 12 soybean cultivars (Anjasmoro, Argomulyo, Burangrang, Demas 1, Dena 1, Devon 1, Gamasugen 1, Gema, Gepak Ijo, Grobogan, Kaba, and Slamet). The net assimilation rate, relative growth rate, and root and shoot dry weight were affected by the bokashi rates, with varying responses according to the soybean cultivar. Demas 1 cultivar was the most adaptive cultivar in coastal sandy land based on its ability to accumulate dry matter of plants. The accumulation of dry matter of roots and shoots increased with bokashi application and the optimum rate were 42.83 ton.ha-1 and 45.56 ton.ha-1, respectively.


1968 ◽  
Vol 48 (3) ◽  
pp. 299-311 ◽  
Author(s):  
C. A. Campbell ◽  
D. W. L. Read

The response of Chinook wheat to light intensity, air temperature and soil moisture stress was studied under controlled environmental conditions in a 3 × 3 × 2 factorial experiment.Increasing day temperature from 21 to 27 °C or night temperature from 13 to 21 °C did not affect tillering, but the plants had shorter, slimmer culms with smaller individual leaves, less total leaf area, and less vegetative and grain dry matter. Temperature changes had little effect on leaf area ratios and their influence on net assimilation rate and relative growth rate was inconsistent. Percent grain protein was increased by temperature.A reduction of light intensity from 17 to 6 cals cm−2hr−1 did not change individual leaf size, but did produce shorter plants with fewer tillers and weak culms. Vegetative, root and grain dry matter were reduced. Shading reduced the translocation of leaf assimilates and lowered the cellulose content of the straw, but increased percent grain protein.Plants developed more tillers at the lower moisture stress, but this difference disappeared by heading time. The lower stress resulted in taller, thicker-stemmed culms with a greater total leaf area, and greater yields of straw and root. The effect of moisture on leaf area ratio was small and its influence on net assimilation rate and relative growth rate was small and inconsistent. Its influence on grain yield varied with temperature; the latter interaction was traced specifically to the influence of moisture stress on seed set. The effect of moisture on percent protein and carbohydrates in grain and on percent cellulose in the straw was inconsistent.


2013 ◽  
Vol 35 (1) ◽  
pp. 28-34 ◽  
Author(s):  
Lizandro Ciciliano Tavares ◽  
Cassyo de Araújo Rufino ◽  
André Pich Brunes ◽  
Felipe Freire Friedrich ◽  
Antonio Carlos Souza Albuquerque Barros ◽  
...  

The objective of this study was to evaluate the physiological performance of wheat seeds coated with micronutrients. The treatments were combinations of two products based on micronutrients, product "A": 780.0 g.L-1 of zinc and product "B": 182.4, 7.6 and 45.6 g.L-1 of zinc, boron and molybdenum, respectively, with five dosages of the products: 0, 1, 2, 3 and 4 mL. kg-1 seed, totaling 10 treatments with four replications. Physiological quality of the treated seed was evaluated from germination and vigor tests and the early plant growth from determinations of shoot dry weight, plant height and leaf area at 10, 20 and 30 days after emergence (DAE), as well as the rate of crop growth, relative and net assimilation. Seed yield and physiological quality were determined after harvest. It was concluded that coating wheat seeds with the product "A" , based on zinc and "B", consisting of zinc, boron and molybdenum, respectively, up to a dosage of 4 mL.kg-1 seed, did not adversely affect the physiological quality of the treated seeds or those produced. Both products tested resulted in increases in leaf area, plant height and shoot dry weight up to 30 DAE, as well as a higher seed yield.


1967 ◽  
Vol 45 (1) ◽  
pp. 117-131 ◽  
Author(s):  
D. J. C. Friend ◽  
V. A. Helson ◽  
J. E. Fisher

Leaf area per plant, total number of leaves and tillers, and total plant dry weight increased with increasing daylength over the range 8 to 24 h. The increase in the net assimilation rate and relative growth rate with increasing daily total radiation was similar to that obtained by raising the intensity of light given to plants grown under continuous illumination.During the vegetative phase of growth, the leaf area ratio decreased with increasing daylength, mostly because of an increased leaf thickness, again dependent on the level of total daily radiation. During the later stages of growth, earlier floral initiation at long daylengths caused an early decline in the leaf area ratio because of the rapid growth of the stem associated with inflorescence formation. This was a photoperiodic effect independent of the level of total daily radiation, as shown by supplementing an 8-h daylength with 8 h of low-intensity illumination.


Weed Science ◽  
1984 ◽  
Vol 32 (5) ◽  
pp. 655-663 ◽  
Author(s):  
Elizabeth P. Flint ◽  
David T. Patterson ◽  
David A. Mortensen ◽  
George H. Riechers ◽  
Jan L. Beyers

Sicklepod (Cassia obtusifoliaL. ♯6CASOB), hemp sesbania [Sesbania exaltata(Raf.) Cory ♯ SEBEX], and showy crotalaria (Crotalaria spectabilisRoth. ♯ CVTSP) were grown in controlled-environment greenhouses with day/night temperatures of 23/17, 26/20, 29/23, and 32/26 C. Plant height, leaf area, and total dry weight at 53 days after planting increased significantly with temperatures between 23/17 and 29/23 C in sicklepod and showy crotalaria, and between 23/17 and 32/26 C in hemp sesbania. In all species, leaves were produced more rapidly as temperature increased. Axillary branch leaf production was greatest at 29/23 C in sicklepod, and at 29/23 and 26/20 C in showy crotalaria; hemp sesbania showed little axillary branch development. Total dry-matter production in all species was closely correlated with leaf area duration, but not with net assimilation rate. Differences in total main stem leaf area in all species were primarily due to differences in leaf number rather than to differences in leaf size at maturity.


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