Impact of solar UV-B radiation on seedling emergence, chlorophyll fluorescence, and growth and yield of radish (Raphanus sativus)

2002 ◽  
Vol 29 (7) ◽  
pp. 797 ◽  
Author(s):  
Jorge Alberto Zavala ◽  
Javier Francisco Botto

We report the impact of present-day solar UV-B radiation on seedling emergence, its association with the accumulation of UV-absorbing compounds, and the growth and yield of radish (Raphanus sativus L.). Two field experiments were conducted at intermediate latitudes in South America (Buenos Aires, Argentina) using two cultivars of radish (`Scarlet Globe' and `Sparkler National'). Solar UV-B reduced the emergence of seedlings by nearly 20% for the Scarlet radish cultivar, and delayed emergence for both cultivars by least one day. Using a chlorophyll fluorescence method to estimate the degree of UV penetration into photosynthetic tissue, we found significant differences in the levels of UV-B-absorbing compounds between seedlings grown under contrasting levels of solar UV-B. The increase of specific UV-absorbing compounds in the cotyledons required an initial lag period of 4 d after the emergence of seedlings. We could not detect any relationship between the accumulation of UV-B-screening compounds in cotyledons and leaves of the same plant, suggesting that solar UV-B induced a localized response in green tissues. Ambient UV-B affected the biomass partitioned to tubers, resulting in an increase of at least 17% in tuber diameter and 26% in tuber fresh weight at the end of the life cycle. Our results indicate that the early effects of UV-B on seedling development involve a cost for young plants, but it appears to be advantageous to increase the carbon partitioning to the tubers at harvest. These findings suggest ways to improve the yield of radish crops.

2006 ◽  
Vol 57 (11) ◽  
pp. 1203 ◽  
Author(s):  
S. E. Bruce ◽  
M. H. Ryan ◽  
J. A. Kirkegaard ◽  
J. Pratley

Four field experiments investigated strategies to reduce the negative effects of surface-retained wheat stubble on the emergence, growth, and yield of canola. All experiments compared 3 stubble treatments: (1) no stubble (stubble removed or burnt); (2) stubble-spread (6 t/ha wheat stubble evenly distributed on the surface); and (3) stubble-inter-row (6 t/ha stubble distributed on the inter-rows only). Seedling emergence was reduced in the presence of evenly spread stubble compared with no stubble, and the emerged seedlings had longer hypocotyls, reduced leaf number, and reduced biomass. Reduced shoot growth was not associated with lower shoot N concentration. These early effects on shoot growth persisted at 3 of the 4 sites, resulting in average yield reductions of 26% (range 0–59%) in the stubble-spread treatments compared with no stubble. Restricting stubble to the inter-rows resulted in an initial reduction in seedling growth compared with no stubble, but this difference had diminished by flowering. The yield for the stubble inter-row treatment was similar to no stubble at 2 sites and intermediate between no stubble and stubble-spread at the other 2 sites, with an overall yield reduction of 5.3% compared with no stubble. The results indicate that the negative effects on canola performance of surface-retained wheat stubble can be largely eliminated by adopting sowing techniques that push wheat stubble away from the seeding row and onto the inter-row. This provides a viable option to stubble burning and maintains the benefits of stubble retention.


2019 ◽  
pp. 62-64
Author(s):  
S. R. Gasanov ◽  
S. A. Mammadova

The study of the dynamics of plant growth and yield of vegetable crops (carrot variety Absheron winter (Daucus carota subsp. sativus (Hoffm.) Schьbl.) and radish variety Virovsky white (Raphanus sativus var.radicula Pers.)) was conducted in the field conditions after presowing exposure to different temperatures: I option – sowing of seeds exposed to low temperatures (for 15 days the swollen for 24 hours seeds were kept at a temperature of 0±1°С); Option II - sowing of seeds exposed to variable temperatures (for 5 days, the swollen for 24 hours seeds were exposed to variable temperatures of + 20°C (8 hours) and 0±1°C (16 hours) and then 10 days at a temperature of 0±1°C; K1 – sowing dry seeds; K2 – sowing soaked seeds. The impact on the seeds of low and variable temperatures caused an increase in growth processes, both in radish and carrot. Both studied crops showed a tendency to increase the yield to a greater extent when exposed to swollen seeds with variable temperatures. Thus, the average weight of radish crops exceeded the control variant by 47.1% and carrots by 27.6%. The yield of root crops per m2increased by 36.4% for radish and 30.0% for carrot. To increase the productivity of vegetable crops, we recommend using the studied methods of pre-sowing seed treatment in practice.


1974 ◽  
Vol 83 (1) ◽  
pp. 125-133 ◽  
Author(s):  
P. C. Longden ◽  
R. K. Scott ◽  
D. W. Wood

SUMMARYFrom monogerm sugar-beet seed as harvested non-viable fruits have to be eliminated, multigerm ones rejected and the size made sufficiently uniform for use in precision drills. Seed which had been gently rubbed to remove some of the cortex was graded for diameter, thickness and by aspiration, either singly or in combination. Effects of grading were determined by laboratory germination tests, radiography and field sowings in which seedling emergence and crop growth and yield were recorded.Grading by thickness was effective in removing multigerm fruits. Grading by aspiration and diameter rejected non-viable seed and reduced the variation in size. By combining all three grading methods, samples of seed of 80% germination and 90% monogermity were produced, provided the seed lot as threshed gave at least 50% germination. True seed weight increased with fruit diameter but only the first aspiration was effective in removing light true seeds. Radiography showed that both aspiration and, to a less extent, grading by diameter were effective in removing most empty fruits but neither eliminated those with shrivelled seed. The field experiments confirmed that increase in fruit diameter or aspiration gave more seedlings. Even at uniform, high plant density, sugar yields were less from the smallest (less than 3 mm diameter) than from the other grades of seed. The initial aspiration also improved sugar yield but further aspiration decreased yield.


Plant Disease ◽  
2005 ◽  
Vol 89 (5) ◽  
pp. 515-520 ◽  
Author(s):  
H. M. Booker ◽  
P. Umaharan ◽  
C. R. McDavid

Field experiments were carried out in St. Augustine, Trinidad & Tobago, West Indies to determine the effects of time of inoculation of Cowpea severe mosaic virus (CPSMV) and cultivar on crop growth and yield in cowpea (Vigna unguiculata). Crop growth and yield loss were investigated through growth analysis and yield component analysis on three cultivars in two seasons (wet and dry). Time of inoculation had the most profound impact on yield. Inoculations during the early log phase (seedling stage), 12 days after seeding (DAS), consistently had the greatest impact (50 to 85% yield loss) compared with those inoculated during the exponential growth phase (24 DAS; 22 to 66% yield loss) or linear growth phase (35 DAS; 2 to 36% yield loss). The effects were particularly pronounced in the dry season and in the more determinate cultivar, H8-8-27. Reduction in maximum leaf area index, leaf area duration, or maximum vegetative dry matter explained reductions in yield. Yield reductions resulted primarily from reduced pod number per plant and, to a lesser extent, from reduced average pod dry weight. The results show that CPSMV control measures should be aimed at delaying infection by CPSMV to minimize the impact on cowpea yield.


Author(s):  
Yesica C Menendez ◽  
Diego H Sanchez ◽  
Rod J Snowdon ◽  
Deborah P Rondanini ◽  
Javier F Botto

Abstract Plant density defines vegetative architecture and competition for light between individuals. Brassica napus (canola), as a model system of indeterminate growth, presents a radically different plant architecture compared to traditional crops commonly cultivated at high density. Using a panel of 152 spring-type canola accessions and a double haploid (DH) population of 99 lines from a cross between Lynx and Monty, we performed Genome-Wide-Analysis-Studies (GWAS) and Quantitative Trait Locus (QTL) mapping for 12 growth and yield traits at two contrasting plant densities (15 and 60 plants m -2). We revealed mostly novel associations by GWAS (19) and QTLs (11) for growth and yield traits being the most significant for flowering, biomass, rosette height, silique and seed number, and grain yield; often representing density-independent signals although we also uncovered some density-dependent associations typically mapping at low density. Further RNA-seq transcriptomics revealed distinctive latent gene regulatory responses to simulated shade between Lynx and Monty. Given the phylogenetic relatedness, we additionally used Arabidopsis thaliana aiming at testing genes to validate density effects of homologous counterparts mapping into relevant rapeseed QTLs. Our results suggest that TCP1 may promote the growth independently of plant neighbors, while HY5 could increase biomass and seed yield specifically at high plant density. For flowering time, the observations in tested mutants suggested that the corresponding genes may plausibly contribute to promote flowering in plant-density dependent (i.e., PIN) and independent (i.e., FT, HY5 and TCP1) manner. This work underscores the advantages of using agronomic field experiments together with genetic and transcriptomic approaches to decipher quantitative complex traits that potentially mediate superior crop productivity.


Biology ◽  
2022 ◽  
Vol 11 (1) ◽  
pp. 115
Author(s):  
Alaa I. B. Abou-Sreea ◽  
Marwa Kamal ◽  
Dalia M. El Sowfy ◽  
Mostafa M. Rady ◽  
Gamal F. Mohamed ◽  
...  

Phosphorus (P) is an essential macronutrient necessary for plant growth, development, and reproduction. Two field experiments were carried out in 2018/2019 and 2019/2020 on P-deficient soil to evaluate the impact of foliar fertilization with nanophosphorus (nP) on growth, yield, and physio-biochemical indices, as well as trigonelline content of fenugreek plants under deficient irrigation (dI) stress (a deficit of 20 and 40% of crop evapotranspiration; dI-20 and dI-40). The growth and yield traits, leaf integrity (relative water content and membrane stability index), photosynthetic pigment contents, leaf and seed P contents, and stem and leaf anatomical features significantly decreased under dI-20, with greater reductions recorded under dI-40. In contrast, water-use efficiency, osmoprotective compounds, including free amino acids, soluble sugars, proline, and trigonelline, along with antioxidant contents (ascorbate, glutathione, phenolics, and flavonoids) and their activity increased significantly under both dI-20 and dI-40. However, foliar feeding with nano-P considerably increased plant growth and yield traits, leaf integrity, photosynthetic pigments contents, leaf and seed P contents, and anatomical features. Besides, water-use efficiency, osmoprotectant contents, and antioxidant content and activity were further increased under both dI-20 and dI-40. The positive effects were more pronounced with the smaller nP (25 nm) than the larger nP (50 nm). The results of this study backed up the idea of using foliar nourishment with nP, which can be effective in modulating fenugreek plant growth and seed production.


2008 ◽  
Vol 88 (4) ◽  
pp. 799-809 ◽  
Author(s):  
K. F. Chang ◽  
S. F. Hwang ◽  
B. D. Gossen ◽  
G. D. Turnbull ◽  
H. Wang ◽  
...  

Rhizoctonia solani causes seedling blight and root rot in lentil, which reduces plant populations and the vigour and yield of surviving plants. Factors in the seedling environment, such as inoculum density, temperature, seeding depth, seeding date, and fungicidal seed treatment were studied to determine the degree to which they affect the impact of R. solani on lentil seedlings. Survival of lentil plants was evaluated after planting into soil artificially inoculated with various concentrations of a highly aggressive isolate of R. solani (AG-4). Emergence, seedling survival and shoot dry matter production decreased with increasing inoculum density, but these declines varied with temperature. Low soil temperatures delayed the emergence of lentil seedlings in non-inoculated soil, but in inoculated soils, emergence was inhibited with increasing temperatures. Depth of seeding did not affect seedling establishment, but root rot severity increased with depth of seeding in a growth cabinet trial. Root nodulation was reduced as root rot severity increased. In field experiments carried out over 3 station years, seeding date had a substantial effect on seedling emergence and yield of inoculated treatments, but the trends were not consistent between sites. In field assessments of fungicide efficacy, treatment of seed with thiabendazole plus carbathiin (Crown) and carbathiin plus thiram (Vitaflo 280) improved seedling establishment relative to the inoculated control. Key words: Lens culinaris, damping-off, root rot, seeding date, fungicide seed treatment depth of seeding, thiabendazole, carbathiin, thiram


Author(s):  
Shahbaz Khan ◽  
Atif Rasool ◽  
Sohail Irshad ◽  
Muhammad Bilal Hafeez ◽  
Madad Ali ◽  
...  

Abstract Wheat is the main crop in the world ranks after rice and the largest grain source of Pakistan. Among several reasons for diminishing wheat yield in Pakistan, water stress throughout the growing season decreases crop production because of the short life span. Two years (2015–16 and 2016–17) field experiments were conducted to assess the impact of various water regimes (full irrigation, irrigation at 45, 60, and 75 mm potential soil moisture deficit (PSMD)) on the growth and yield of wheat. Maximum crop growth rate was recorded by application of irrigation at 45 mm PSMD. Application of irrigation at 45 mm PSMD ensured maximum radiation use efficiency regarding total dry matter production and grain yield. The maximum number of productive tillers, spike length, and grain yield were recorded under 45 mm PSDM treatment. The present results show that the effect of water is more pronounced regarding the growth and productivity of wheat. Application of irrigation at 45 mm PSMD ensures higher economical yield.


2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Samuel Y. Agbaglo ◽  
Seloame T. Nyaku ◽  
Hannah D. Vigbedor ◽  
Eric W. Cornelius

The interaction of the fungus, Fusarium oxysporum f. sp. vasinfectum (FOV), and the nematode, Meloidogyne incognita, on wilt disease on “Essoumtem” and Clemson spineless okra varieties, was examined in pot and field experiments from September 2016 to June 2017, in the University of Ghana farms. Four-week-old “Essoumtem” and Clemson spineless seedlings for pot experiment and one-week-old “Essoumtem” and Clemson spineless seedlings for field experiment were inoculated with fungus, Fusarium oxysporum, and nematode, Meloidogyne incognita. The individual, simultaneous, and sequential inoculation of second stage juveniles (at 1000 J2/kg soil) of Meloidogyne incognita and Fusarium oxysporum (1.1 × 106 cells/kg soil) resulted in significant reduced plant growth parameters (plant height, plant girth, chlorophyll content, fresh and dry shoot weights, and fresh and dry root weights). Maximum suppression in plant growth parameters was observed in plants that received NF21 (Fusarium oxysporum inoculated 21 days after Meloidogyne incognita on okra) and F21 (fungus inoculated 21 days after seedling emergence) treatments for pot and field experiments, respectively. The least suppression of plant growth parameters was observed in separate inoculations of the two pathogens for both pot and field experiments. Maximum suppression in yield parameters was observed in okra plants that received NF21 and F21 treatments for pot and field experiments, respectively. Minimal yield suppression was observed for individual inoculations (N and F treatments) in both pot and field experiments. The highest severity of wilt disease was observed on okra plants that received NF21 and F21 treatment in both pot and field experiments. Plants in control plots had higher yields and the least wilt incidences (0.0%).


2021 ◽  
Vol 25 (8) ◽  
pp. 1435-1439
Author(s):  
B.P. Mshelmbula ◽  
E. Ogale ◽  
S. Bello ◽  
H.A. Kana ◽  
M.Y. Sulayman ◽  
...  

Cowpea (Vigna unguiculata) is one of the most ancient crops known to man and is grown across various climatic zones, most commonly in the dry savanna regions of sub-Saharan Africa. The objective of this work was therefore to investigate the impact of Gibberelic acid on the growth and yield of cowpea. Field experiments was conducted during the 2019 rainy season at the Botanical Garden of Federal University of Lafia. The cowpea accessions were submerged into various concentrations of GA3 (90mg/L, 120mg/L, and 150mg/L). The results showed varying response of the accessions in varying GA3 concentrations. Both Accessions (TVU-1 and TVU-4) recorded no significant difference across all treatments in the number of flowers. In TVU-1 accession, the least concentration, 90mg/L recorded the highest number of flowers (0.22) at 12(WAP); while in TVU-4, the seeds exposed to the highest concentration recorded the highest number of flowers. Similar result was observed in the number of pods of both accessions (TVU-1 and TVU-4) were there was no significant difference (P≤0.5) recorded. There was increase in the number of root nodules with increased in the growth hormone concentrations as treatment 150mg/L showed the highest number of root nodules in both accessions; even though no significant difference was recorded. It is therefore recommended that different accessions at different concentrations of gibberelic acid be tired to see their responses.


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