Effects of Gibberellic Acid on Dormant Seeds and Subsequent Crops of Pigeonpeas (Cajanus cajan)

1969 ◽  
Vol 44 (1) ◽  
pp. 21-27
Author(s):  
Raúl Abrams

Seed of the commercial pigeonpea varieties Kaki, Saragateado, and Florido were soaked overnight in solutions of gibberellic acid containing 0, 20, 30, 40, and 50 p.p.m., in order to determine the effect of the acid on plant height, flowering period, and yield of this crop. The following results were obtained: 1. There were no significant differences in plant height between the three commercial varieties that could be attributed to the gibberellic acid treatments. 2. Varieties differed in their flowering periods, but this could not be attributed to the gibberellic acid treatments, as such differences are of genetic origin. 3. Gibberellic acid had no effect on the yield of green peas.

2014 ◽  
Vol 32 (1) ◽  
pp. 13-18
Author(s):  
Gary J. Keever ◽  
J. Raymond Kessler ◽  
James C. Stephenson

Staggered starting dates for night-interrupted lighting (NIL) were evaluated for accelerated sequential flowering of herbaceous perennials with different photoperiod requirements outdoors in a southern nursery setting. Plants evaluated were black-eyed Susan (Rudbeckia fulgida ‘Goldsturm’), an obligate long-day (LD) plant; obedient plant (Physostegia virginiana ‘Miss Manners’), a facultative LD plant; and Stokes' aster (Stokesia laevis ‘Peachie's Pick’), a facultative intermediate-day plant. With all species, the dates of first flower and maximum flower number occurred sooner under LDs from incandescent (INC) and fluorescent (FLU) lamps than under natural photoperiod (NP). Mean and maximum flower numbers were greater under NIL than under NP for black-eyed Susan and Stokes' aster but not for obedient plant. Time in flower increased in Stokes' aster, but either decreased or was not affected by NIL for black-eyed Susan and obedient plant. Flowering periods of black-eyed Susan and obedient plant exposed to different NIL timings overlapped extensively while leaving a gap in flowering between plants exposed to NIL and those under NP. This gap in flowering suggests that the intervals between NIL start dates could be longer to lessen the flowering overlap of plants under NIL, and that the interval between the start of the last NIL treatment and the onset of an inductive photoperiod be reduced to maintain sequential peak flowering until the natural flowering period. With Stokes' aster, flowering overlapped for plants in the different NIL timings and under NP, resulting in continuous sequential blooms from first flowering of plants under NIL until the plants' natural flowering period under NP in late May. Flowering periods of Stokes' aster exposed to NIL beginning on different dates overlapped extensively, suggesting that at least one NIL start date could be omitted and the intervals between the start of NIL increased without sacrificing continuous sequential peak flowering. NIL from INC and FLU lamps promoted growth in plant height compared to that of plants under NP, although the increase in plant height was less under FLU lamps.


2010 ◽  
pp. 132-140 ◽  
Author(s):  
MA Islam ◽  
MH Reza ◽  
SMAHM Kamal ◽  
MA Wazed ◽  
KM Islam

An experiment was conducted with a local cultivar of garlic to study the effects of planting date and gibberellic acid on the growth and yield of garlic at the field laboratory of the Department of Crop Botany, Bangladesh Agricultural University, Mymensingh during November 2001 to April 2002. Early planting influenced the plant height, leaf number, bulb diameter and total dry matter. With the delay in planting time starting from November 7, the yield was chronologically reduced in later plantings. Significantly the highest bulb yield (2.67 t/ha) was recorded when planting was done on November 7 and lowest yield (0.92 t/ha) was obtained from December 22 planted crop. Bulb yield was higher in control plants than those of GA3 treated plants. The interaction effects of planting date and different concentrations of GA3 differed significantly in respect of plant height, number of leaves, bulb diameter and dry weight of roots, leaves and bulbs and yield of garlic.


1991 ◽  
Vol 74 (4) ◽  
pp. 570 ◽  
Author(s):  
P. D. Greany ◽  
R. E. McDonald ◽  
W. J. Schroeder ◽  
P. E. Shaw

2016 ◽  
Vol 1 (01) ◽  
pp. 92-96
Author(s):  
Sachin Kumar ◽  
Jitendra Kumar ◽  
Himanshu Kaushik ◽  
Rajbeer .

A field experiment was conducted at the Horticulture Research Farm Department of Horticulture, CCS University, Meerut during the year 2011-12 with 2 factors and 9 treatments, P1B0 (Gibberellic acid@ 200ppm at 30 DAP),P0B1 (Azotobacter @ 0.14ml/ liter water (corm treatment), P1B2 (Gibberellic acid @ 200ppm at 30 DAP + Azotobacter @ 0.14ml./m2 (soil application), P2B0 (Gibberellic acid @ 200ppm at 60 DAP), P2B1 (Gibberellic acid @ 200ppm at 60 DAP + Azotobacter @ 0.14ml/liter water (Corm treatment)), P2B2 (Gibberellic acid @ 200ppm at 60 DAP + Azotobacter @ 0.14ml./m2 (soil application)),P0B1 (Azotobacter @ 0.14ml/ liter water (corm treatment)), P0B2 (Azotobacter @ 0.14ml./m2 (soil application)),P0B0 (control). Maximum result were found of days for opening of first floret, plant height, number of florets per spike, spike length and length of rachis at the treatment combination P2B2 (Gibberellic acid @ 200ppm at 60 DAP + Azotobacter @ 0.14ml./m2 (soil application)),while the appearance of initial spike, width of leaf and diameter of florets were found in P2 B1 (Gibberellic acid @ 200ppm at 60 DAP + Azotobacter @ 0.14ml/ liter water (corm treatment)) expect number of days for corm sprouting and number of leaves per plant.


2016 ◽  
Vol 50 (3) ◽  
Author(s):  
R. S. Singh ◽  
M. N. Singh

The six generations (P<sub>1</sub>, P<sub>2</sub>, F<sub>1</sub>, F<sub>2</sub>, BC<sub>1</sub> and BC<sub>2</sub>) of twelve cross combinations of pigeonpea (<italic>Cajanus cajan</italic> L.) were studied during 2003-2006 for days to 50 % flowering, days to maturity, plant height, number of primary branches, number of secondary branches, pods per plant, pod length, number of seeds per pod, 100-seed weight, harvest index and seed yield per plant. The means of six generations were subjected to detect main gene effects and interactions. The estimates of six parameter model revealed that both additive and dominant gene effects were important in all the crosses for almost all the traits. However, the relative contribution of dominant gene effects was much higher than additive gene effects for plant height, pods per plant and seed yield per plant. Higher frequency of duplicate type of epistasis also confirms the prevalence of dominance gene effects for above traits except for seed yield per plant.


1993 ◽  
Vol 44 (1) ◽  
pp. 81-83 ◽  
Author(s):  
Tridip Goswami ◽  
T.C. Sarma ◽  
D.N. Bordoloi ◽  
C.M. Sarmah

2000 ◽  
Vol 51 (2) ◽  
pp. 235 ◽  
Author(s):  
G. J. Rebetzke ◽  
R. A. Richards

The Norin-10 dwarfing genes, Rht-B1b (Rht1) and Rht-D1b (Rht2), have been used to reduce plant height and increase grain yield in wheat breeding programs worldwide. Other dwarfing genes are available to reduce plant height of wheat but little is known of their effects on grain yield. A set of random, F5-derived wheat lines containing either minor genes for reduced plant height, or major gibberellic acid (GA) sensitive Rht8 and Rht9 dwarfing genes, were obtained from 3 different populations. Environment mean yields ranged from 2.5 to 4.6 t/ha. Genotypic variation was large and significant (P < 0.05) for plant height, grain yield and its components, and kernel number and size. Approximately 30% of lines were as short as variety Hartog, while kernel number per m2, harvest index, and grain yield of the shortest GA-sensitive lines were not significantly different (P < 0.05) from the commercial semidwarf checks Janz or Hartog. Furthermore, genotypic differences in plant height were genetically correlated (rg) with variation in kernel number (rg = −0.76*), harvest index (−0.71*), and grain yield (−0.62*). These correlated effects were confirmed with retrospective selection for height and were consistent with reported height effects of Rht-B1b and Rht-D1b dwarfing genes on kernel number and harvest index in wheat. Plant height differences among GA-sensitive lines were independent of variation in seedling characteristics (r2 = 0.01–0.02 n.s.), while a number of reduced-height lines produced 50% longer coleoptiles and greater seedling biomass than Janz. These studies demonstrate a correlation between the shorter height of GA-sensitive dwarfing genes and increased grain yield, and suggest their potential for improving wheat establishment through greater coleoptile length and early vigour.


2021 ◽  
Vol 4 (2) ◽  
pp. 134-147
Author(s):  
Samjhana Acharya ◽  
Bijay Ghimire ◽  
Suraj Gaihre ◽  
Krishna Aryal ◽  
Lal Bahadur Chhetri

A field experiment was conducted at Bangaun, Lamahi-3, Dang, Nepal to study the effect of GA3 on growth and flowering attributes of African marigold (Tagetes erecta) in Inner Terai of Nepal. The experiment consists of three replications and 8 treatments and laid out in a randomized complete block design- consisting of various concentrations of GA3 viz. 0ppm, 50ppm, 100ppm, 150ppm, 200ppm, 250ppm, 300ppm, and 350ppm. Kolkata local variety of African marigold was tested. The study revealed that among different concentrations of GA3, 300ppm showed the tallest plant height (72.93cm) and the highest basal diameter (1.49cm). Maximum numbers of primary branches (3.11) and the greatest plant spread (32.11cm) were obtained from 250ppm; similarly, maximum numbers of secondary branches (13.80) were recorded in 350ppm. In the case of floral parameters both 100ppm and 350ppm recorded earlier days to 50% flowering (44.00 days each), days for 100% flowering was recorded almost similar in every treatment that sticks around 54 and 55 days, maximum diameter (5.370cm) of flowers were obtained from 50ppm, the greatest fresh weight (6.180g) was recorded in 350ppm, 250ppm showed a maximum number of flower per plant (104.13), similarly, a longer duration of flowering (58 days) was recorded in 300ppm. Among all treatments, the 250ppm level of GA3 was found to be most suitable in terms of production perspective.


2021 ◽  
Vol 37 (6) ◽  
pp. 543-554
Author(s):  
Mun-Il Ahn ◽  
Sung Chul Yun

To preventively control fire blight in apple trees and determine policies regarding field monitoring, the Maryblyt ver. 7.1 model (MARYBLYT) was evaluated in the cities of Chungju, Jecheon, and Eumseong in Korea from 2015 to 2020. The number of blossom infection alerts was the highest in 2020 and the lowest in 2017 and 2018. And the common feature of MARYBLYT blossom infection risks during the flowering period was that the time of BIR-High or BIR-Infection alerts was the same regardless of location. The flowering periods of the trees required to operate the model varied according to the year and geographic location. The model predicts the risk of “Infection” during the flowering periods, and recommends the appropriate times to control blossom infection. In 2020, when flower blight was severe, the difference between the expected date of blossom blight symptoms presented by MARYBLYT and the date of actual symptom detection was only 1-3 days, implying that MARYBLYT is highly accurate. As the model was originally developed based on data obtained from the eastern region of the United States, which has a climate similar to that of Korea, this model can be used in Korea. To improve field utilization, however, the entire flowering period of multiple apple varieties needs to be considered when the model is applied. MARYBLYT is believed to be a useful tool for determining when to control and monitor apple cultivation areas that suffer from serious fire blight problems.


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