scholarly journals Effect of Temperature Regimes on Morphological Development of Selected Canola (Brassica napus) Genotypes

Author(s):  
J. S. Nwogha ◽  
G. A. Agenbag ◽  
J. E. Obidiegwu ◽  
C. O. Amadi

Seven canola genotypes selected from early and mid-maturing groups of canola genotypes presently planted in the Western Cape canola production area were grown in 3 litre plastic bags filled with a mixture of sand and compost at ratio of 1:1 and irrigated with fully balanced nutrient solution at EC=2.0 in two glasshouses at night/day temperature regimes of 10/15˚C and 15/20˚C. Plant heights were measured at 14 days interval from 28 to 84 days after planting (DAP). Plants were sampled for leaf area (LA) and above ground dry mass (DM) at budding, flowering and seed physiological maturity stages. Plant growth rates (PGR) from planting to budding, from budding to flowering and from flowering to physiological maturity growth stages were calculated. Relative growth rates (RGR) and net assimilation rates (NAR) from budding to flowering and from flowering to physiological maturity stages were also calculated. Days after planting, GDD and PTU at budding, flowering and physiological maturity were correlated with leaf area, dry mass, number of pods plant-1   and pod dry mass plant-1 at budding, flowering and physiological maturity stages to determine whether there were relationships between the variables. The study showed that by increasing night/day temperature from 10/15˚C to 15/20˚C plant height, number of leaves plant-1 at budding stage, leaf area at budding , plant growth rate (PGR) from planting to budding stage and relative growth rate (RGR) from budding to flowering stage were increased. However, PGR from budding to physiological maturity, RGR from flowering to physiological maturity, net assimilation rate (NAR) from budding to flowering stage, leaf area at flowering and physiological maturity stages, as well as  number of flower stems, number of pods  plant-1, above ground total dry mass at flowering and physiological maturity  stages were  decreased. Pod dry mass at physiological maturity decreased by 22.24% to 40.35% for different genotypes which clearly demonstrated the variations in sensitivity of canola genotypes to increasing night/day temperatures and also indicates that canola crop can be genetically improved for heat tolerance.

Author(s):  
Parthvee Rupsinh Damor ◽  
Arvind D. Patel

Background: Among the pulse crops mungbean is one of the richest sources of protein. There is great loss in the yield of mungbean due to various reasons may be biotic or abiotic constraints. To overcome the yield loss various physiological activities are studied. Physiological activities of the plant are greatly influenced by the source manipulation, plant growth regulators and chemical in mungbean. In correspondence to this, an experiment was conducted to study the physiological parameters in greengram.Methods: A factorial randomized block design in two respective years, i.e. 2016 and 2017 to study the response of source manipulation (nipping, 25% defoliation and 50% defoliation), plant growth regulators (GA3 and NAA at 25 and 50mg/l respectively) and chemical (Thiourea 500 and 1000mg/l) on the physiological parameters like Crop Growth Rate (CGR), Relative Growth Rate (RGR), Net Assimilation Rate (NAR) and Leaf Area (LA) in greengram at 30, 45, 60 and 75 DAS/harvest at Regional Research Station, Anand Agricultural University, Anand. Result: From the obtained results it can be proposed that the physiological parameters like crop growth rate, relative growth rate and net assimilation rate increased with the increasing phase and decreased at harvesting stage. While leaf area increased significantly at each growth phase. The treatment of nipping M2 was noted significantly higher value for CGR i.e., 8.42, 16.17 and 11.48 g/cm2/day/10, for RGR i.e., 0.544, 2.967 and 1.290 g/day, for NAR i.e., 0.466, 2.959 and 1.484 mg/cm2/day and for LA i.e. 96.87, 218.94, 381.88 and 588.78 cm2. While the treatment S2 GA3 25 mg/l was noted significantly higher value for CGR i.e, 8.60, 16.67 and 11.69 g/cm2/day/10, for RGR i.e., 0.568, 2.938 and 1.202 g/day, for NAR i.e., 0.372, 3.043 and 1.529 mg/cm2/day and for LA i.e., 96.61, 224.75, 382.20 and 580.42 cm2 contributing to the higher seed yield under M2 nipping treatment i.e., (1719.7 kg/ha) and S2 treatment i.e., GA3 25 mg/l (1714.1 kg/ha). Thus, GAM-5 had a better source-sink partitioning efficiency.


Author(s):  
Hossein Jahantigh ◽  
Seyed Reza Amiri

Drought stress is one of the most important environmental factors which can limit the lentil production. To evaluate the effect of drought stress at flowering and pod filling stages on growth indices of lentil cultivar Kimiya (a new high yielding lentil cultivar for moderate cold and semi warm climate of Iran), an experiment was conducted at the research greenhouse of Higher Educational Complex of Saravan in completely randomized design with four replications. The drought stress was applied by withholding irrigation until the soil moisture reached to 20% of field capacity at stages of flowering and pod filling. In this experiment, we measured grain yield per plant, growth indices including plant leaf area (PLA), relative growth rate (RGR), plant growth rate (PGR), and net assimilation rate (NAR). Results showed that the flowering stage in lentil plant is more sensitive to drought as exhibited significant decline in PLA, RGR, PGR and NAR. PGR declined at the end of growing season when vegetative growth stop, senescence of leaves, the reduction of NAR, and the allocation of assimilate to the seeds.


2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Evy Latifah ◽  
Amik Krismawati ◽  
Mohammad Saeri ◽  
Zainal Arifin ◽  
Bas Warsiati ◽  
...  

This study aimed to examine plant growth of tomato grafted onto different eggplant rootstocks. We applied a randomized block design comprising twelve treatments with three replicates. Three varieties of tomato—Cervo, Karina, and Timoty—and three rootstocks—Gelatik, EG203 line, and Solanum torvum—were selected for this study. Nongrafted tomato plants of the same varieties were used as controls. The variables recorded were the number of branches, the diameter of scions and rootstocks, root length, and root dry weight at 4, 6, 8, and 10 weeks after planting (WAT) and relative growth rate, specific leaf area, and net assimilation rate at 4, 8, and 12 WAT. Grafted tomato plants demonstrated better growth than controls. There was a significant relationship between yield, plant growth parameters, and photosynthetic organs, expressed by higher production, greater scion diameter, longer roots, and increased relative growth rate, leaf area ratio, and net assimilation rate of grafted plants, compared to the controls.


2016 ◽  
Vol 40 (2) ◽  
pp. 199-205 ◽  
Author(s):  
Saiful Islam ◽  
Nargis Jahan

An investigation was made to see the effect of different concentrations (10, 20, 30 and 40 ppm) of 2, 3, 5- triiodobenzoic acid (TIBA) on leaf area index (LAI), leaf area duration (LAD), crop growth rate (CGR), relative growth rate (RGR) and net assimilation rate (NAR) of a cultivar of chickpea (Cicer arietinum L.) grown during rabi season of 2015 - 2016. Results revealed that LAI and LAD showed a positive response from flowering stage to maturity (66 - 110 DAS) due to 30 ppm TIBA application with maximum LAI and LAD occurring at the flowering stage. At 66 - 83 and 83 - 97 DAS, CGR was highest with the application of 30 ppm TIBA, while RGR was highest due to 10 ppm TIBA. Peak CGR was recorded at the time of pod setting to pod filling stage (8 - 97) and increased over control by 29.64%. Irrespective of the treatments, NAR was recorded maximum during flowering stage to pod setting (66 - 83 DAS) and thereafter decreased till maturity. At 66 - 83 and 83 - 97 DAS, maximum NAR values were recorded due to 30 ppm TIBA and the increases were 9.09 and 32.69% higher over the control, respectively.Journal of Bangladesh Academy of Sciences, Vol. 40, No. 2, 199-205, 2016


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.


2019 ◽  
Vol 4 (1) ◽  
pp. 1-7
Author(s):  
N. Nurmuliana ◽  
Muh. Akhsan Akib

AbstractThe growth of jack bean (Canavalia ensiformis L) is affected by genetic and environmental factors.  One of the environmental factors involved is growing space. Growing space related to each plant of areas occupied is stated by the distance between plants. A Research has been conducted as long three months in dry season with average daily temperature of 25 to 31OC on altitude of 25 to 500 meter, to determine the timing of the application of cutback technology based on an analysis of growth of jack bean plants (Canavalia ensiformis L) in different growth spaces.  The research was conducted in the trial form using a randomized block design. Variables of plants growth analysis observed is leaf area index (LAI), leaf area is computed by gravimetric method; net assimilation rate (NAR), and relative growth rate (RGR) is determined based on the dry weight of plants; in all three rooms grew, namely 75 cm x 100 cm (control), 75 cm × 75 cm and 75 cm × 50 cm, each repeated three times. The result shows that the trend of leaf area index increased at net assimilation rate (g-1.cm-2.week-1) and relative growth rate (g-1.g-1.minggu-1) decreasing at the time the plant to the age 8 weeks after planting.  The best time for the application of reduction technology to jack bean plants (Canavalia ensiformis L) in all tested growing spaces, is recommended when plants are between 7 and 8 weeks after planting


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.


2009 ◽  
Vol 66 (6) ◽  
pp. 733-741 ◽  
Author(s):  
Alessandra Aparecida Giacomini ◽  
Sila Carneiro da Silva ◽  
Daniel Oliveira de Lucena Sarmento ◽  
Cauê Varesqui Zeferino ◽  
Salim Jacaúna Souza Júnior ◽  
...  

Grazing strategies alter sward leaf area patterns of growth, affecting herbage accumulation and utilisation. The objective of this experiment was to evaluate the growth of marandu palisadegrass (Brachiaria brizantha cv. Marandu) swards subjected to strategies of intermittent stocking. The experiment was carried out in Piracicaba, São Paulo, Brazil, from October/2004 to September/2005. Swards were grazed at 95 and 100% canopy light interception (LI) to post-grazing heights of 10 and 15 cm, following a 2 × 2 factorial arrangement with four replications in a randomised complete block design. The response variables evaluated were: crop growth rate, relative growth rate, net assimilation rate, leaf area ratio and leaf weight ratio. In early and late spring, the highest crop growth rate was recorded for treatment 95/15 (11.2 and 10.1 g m-2 day-1, respectively), along with high values of net assimilation rate (4.4 and 6.9 g m-2 day-1, respectively), leaf area ratio (0.0095 and 0.0103 m-2 g-1, respectively) and leaf weight ratio (0.56 and 0.56 g g-1, respectively). To compensate reductions in net assimilation rate plants made some morphological and physiological adjustments increasing leaf area and leaf weight ratio. Relative growth rate and net assimilation rate were 26 and 50% higher, respectively, on swards grazed at 95% than at 100% LI. In early spring treatments 100/10 and 95/15 resulted in the highest relative growth rate (0.086 and 0.059 g m-2 day-1, respectively). Treatment 95/15 resulted in the most favourable pattern of growth (crop growth rate, relative growth rate, net assimilation rate), particularly during the transition period between winter and spring.


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