scholarly journals RICE SEEDLING PERFORMANCE TREATED WITH GIBBERELLIC ACID AT DIFFERENT TEMPERATURES

2020 ◽  
Vol 22 (2) ◽  
pp. 84-90
Author(s):  
Luis Osmar Braga Schuch ◽  
Ivan Ricardo Carvalho ◽  
Cristian Troyjack ◽  
João Roberto Pimentel ◽  
Nata Balsan Moura ◽  
...  

This work aimed to evaluate the initial performance of seedlings originated from seeds of rice cultivars treated with gibberellic acid and exposed to different growth temperatures. The cultivars SCS - 112, BRS 7-TAIM, BR IRGA 410 and IRGA 417 were used, soaked in concentrations of gibberellic acid of 0; 150; 300; 450; 600 and 750 mg L-1 and taken into germinator under temperatures of 15; 20 and 25oC. The evaluations were performed in relation to shoot and root of rice seedlings at 3; 7 and 21 days after sowing. The cultivars showed different dry matter production of shoot and root as gibberellic acid concentration, temperature and time of evaluation. The better initial performance of seedlings exposed to gibberellic acid shows the higher expression of the rice seeds vigor and demonstrates the superiority in efficiency of different physiological processes involved in the resumption of growth the embryo. Thus, gibberellic acid favors the growth of the rice seedlings over time.

2004 ◽  
Vol 142 (2) ◽  
pp. 141-151 ◽  
Author(s):  
J. ERIKSEN ◽  
F. P. VINTHER ◽  
K. SØEGAARD

Grass-legume associations may offer a way of improving the N efficiency of dairy farming, but may also have an adverse impact on the environment by increasing leaching losses. Nitrate leaching from four cropping sequences with different grassland frequency and management (long-term grazed, long-term cut, cereals followed by 1 and 2-year grazed leys) were investigated on a loamy sand in central Jutland for both unfertilized grass-clover (perennial ryegrass (Lolium perenne L.)/white clover (Trifolium repens L.)) and fertilized perennial ryegrass (300 kg N/ha) swards during 1997–2002. Furthermore, 1 year (2001) of N2 fixation in 1-, 2- and 8-year-old grass-clover pastures was determined. Nitrate leaching from grazed unfertilized grass-clover was always considerably lower than from grazed fertilized ryegrass. The effect of grassland age on nitrate leaching was insignificant in grass-clover but clear in grazed ryegrass, where levels increased dramatically with sward age. In production years 6–8, leaching from grass-clover was only 9–13% of the comparable losses from ryegrass. Under the cutting regime grass-clover showed a significant reduction in both yield and N-removal with increasing sward age, whereas for ryegrass these figures did not show any decreasing trend. N2 fixation was lower in 8-year-old swards compared with fully established 2-year-old swards as a consequence of lower dry matter production, lower clover content and a lower proportion of clover-N derived from the atmosphere. The results from the present study indicate that the higher leaching losses observed in fertilized grass compared with unfertilized grass-clover systems were caused by (1) a reduction in N2-fixation in grass-clover over time and (2) a reduction in dry matter production in grass-clover over time, lowering the grazing intensity and the recycling of grassland N via animal excreta.


1968 ◽  
Vol 19 (2) ◽  
pp. 221 ◽  
Author(s):  
DG Morgan

Single plants of Festuca arundinacea (cv. S170) were treated with gibberellic acid (GA) and the sequence of effects on the growth of the whole plant and of various organs followed by means of growth analysis. The first effect of GA was to change the distribution of dry matter between shoot and root and between tillers within the shoot without affecting total plant weight. Shoot growth was increased and resulted in a larger amount of photosynthetic tissue with a higher net assimilation rate; total plant weight increased as a consequence of these effects. The significance of these results in interpreting previous work on the effects of GA on dry matter production in grasses and other plants is discussed.


2002 ◽  
Vol 71 (1) ◽  
pp. 28-35 ◽  
Author(s):  
Yoshiharu WADA ◽  
San-Iku YUN ◽  
Hiroki SASAKI ◽  
Tadanobu MAEDA ◽  
Kunio MIURA ◽  
...  

Author(s):  
G.V. Venkataravana Nayaka ◽  
G. Prabhakara Reddy ◽  
R. Mahender Kumar

Background: Growth and yield characteristics of genotypes depend on genetic and environmental factors. Among the different production factors, varietal selection at any location plays an important role. Proper crop management depends on the growth characteristics of various varieties to get maximum benefit from new genetic material. Among the different water- saving irrigation methods in rice, the most widely adopted is alternate wetting and drying (AWD). Many of the rice cultivars vary in their performance under different systems of cultivation.Methods: A field experiment was conducted on a clay loam soil at Indian Institute of Rice Research (IIRR) Rajendranagar, Hyderabad, Telangana during the kharif seasons of 2017 and 2018. to study the “productivity and water use efficiency of rice cultivars under different irrigation regimes and systems of cultivation” The treatments consisted of two irrigation regimes Alternate wetting and drying and Saturation as main plot treatments, three establishment methods System of Rice Intensification (SRI), Drum Seeding (DS) and Normal transplanting (NTP) as sub plot treatments and four Cultivars namely DRR Dhan 42, DRR Dhan 43, MTU-1010 and NLR-34449 as sub-sub plot treatments summing up to 24 treatment combinations laid out in split-split plot design with three replications.Result: At 60, 90 DAS/DAT and harvest significantly dry matter production (DMP) was recorded with DRR Dhan 43 cultivar (607, 4320 and 11548 kg ha-1 respectively in pooled means of both 2017 and 2018) than other cultivars. Whereas MTU-1010 and NLR-34449 recorded on par dry matter production values at all the crop growth stages during both the years of study. However, DRR Dhan 42 produced the lowest dry matter production compared to other genotypes. DRR Dhan 43 recorded higher dry matter accumulation (g m-2) in root, stem and leaves at all the crop growth stages, during both the years of the study over other cultivars. Alternative wetting and drying method of irrigation recorded significantly higher DMP at all the growth stages of rice (60, 90 DAS/DAT and at harvest) except at 30 DAS/DAT during both 2017 and 2018 as compared to saturation. SRI recorded significantly higher DMP as compared to normal transplanting; however, it was comparably at par with drum seeding at all the growth stages.


1970 ◽  
Vol 34 (2) ◽  
pp. 313-322 ◽  
Author(s):  
MA Razzaque ◽  
MM Haque ◽  
MA Hamid ◽  
QA Khaliq ◽  
ARM Solaiman

A pot experiment was conducted at Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur during the year 2003 to find out the dry matter production and yield of rice cultivars under different nitrogen levels and growing conditions. Thirty-day old single seedlings were transplanted in pot and were placed in 3 growing conditions, such as i) Open top chamber (OTC) with elevated CO2 (570 ± 50 ppm), ii) OTC with ambient CO2 (360 ± 50 ppm), and iii) open field condition. The three nitrogen levels used were, i) control, ii) optimum dose, and iii) supra optimum dose. Three rice cultivars used in the experiment were, i) BRRI dhan 39, ii) Khashkani, and iii) Shakkarkhora. Rice yield and dry matter production respond significantly to different environments. Increasing atmospheric CO2 increased grain yield. Stem dry weight, leaf dry weight, leaf sheath dry weight and root dry weight were increased in elevated CO2 than ambient CO2 and field condition. BRRI dhan 39 gave highest yield (50.82 g/plant) at supra optimum N level in elevated CO2. Local variety gave similar result under elevated CO2 in optimum and supra optimum N levels. The lowest yield (15.09 g/plant) was produced by Shakkorkhora in field condition with no nitrogen application. Key Words: Nitrogen; elevated CO2; yield; dry matter.DOI: 10.3329/bjar.v34i2.5804Bangladesh J. Agril. Res. 34(2): 313-322, June 2009


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