Relative resistance, associated yield losses and phyto-oestrogen production from fungal foliar diseases in new and old annual Medicago cultivars

1995 ◽  
Vol 46 (2) ◽  
pp. 441 ◽  
Author(s):  
MJ Barbetti

The relative resistance, associated herbage and seed yield losses and phyto-oestrogen production from fungal foliar diseases in two new annual Medicago cultivars, viz. M. sphaerocarpos cv. Orion and M. truncatula cv. Caliph, were compared with those of four old cultivars, viz. M. murex cv. Zodiac, M. polymorpha var. brevispina cw. Santiago and Circle Valley, and M. truncatula cv. Cyprus. Orion was much more resistant to Phoma stem disease than Circle Valley and Santiago, but was more susceptible than Zodiac. However, Orion was the most susceptible cultivar to Phoma leaf disease. Orion and Caliph were susceptible to Leptosphaerulina stem disease, resembling Santiago, but much more susceptible than Circle Valley and Zodiac. Caliph was comparable with Cyprus with moderate susceptibility to both Phoma and Leptosphaerulina on stems. Both Caliph and Cyprus were resistant to Pseudopeziza. In mid-October and early November, foliar diseases reduced overall herbage yield of the six varieties by 16.2 and 20.3% respectively, compared with the fungicide-treated plots of the same cultivars. Foliar diseases reduced seed yield by 37.3%, and mean seed weight by 13- 7% compared with fungicide treated plots. Foliar disease in the disease block increased the content of the phyto-oestrogen coumestrol in stems from 230 to 500 ppm and in pods from 30 to 130 ppm, compared with the fungicide block. There was a positive correlation between the severity of Phoma on stems and leaves and the level of coumestrol in stems and pods. Orion produced large amounts of coumestrol in stems and pods in response to foliar diseases (e.g. 470 ppm in stems) but less than Zodiac. Caliph also produced large amounts of coumestrol in stems and pods in response to foliar diseases (e.g. 230 ppm in stems), and was similar to Cyprus but had less coumestrol than all other cultivars tested (stems) or Zodiac, Circle Valley and Santiago (pods). Orion carried the highest level of P. medicaginis seed contamination (28%), followed by Santiago (15%), Cyprus (11%), Circle Valley (l0%), Zodiac (10%) and Caliph (6%).


2004 ◽  
Vol 44 (1) ◽  
pp. 57 ◽  
Author(s):  
L. J. Latham ◽  
R. A. C. Jones ◽  
B. A. Coutts

Field experiments provided quantitative information on the yield losses caused by virus infection within 4 different combinations of non-persistently aphid-transmitted virus and cool-season crop legume: Alfalfa mosaic virus (AMV) in chickpea, faba bean and lentil, and Cucumber mosaic virus (CMV) in lentil. Virus infection foci were introduced into plots and naturally occurring aphids spread infection from these to the other plants. Plants were tagged individually when typical virus symptoms first appeared during the growing period. Paired plant comparisons between symptomatic and asymptomatic plants were made to measure different yield loss parameters. Late infection with AMV in faba bean cv. Fiord diminished shoot dry weight by 41% and seed yield by 45%, but plants infected earlier recovered sufficiently from their initial shock reaction not to produce significant yield losses. In plants of lentil cv. Matilda first showing symptoms at different times, infection with AMV decreased shoot dry weight by 74–76%, seed yield by 81–87% and individual seed weight by 10–21%, while CMV diminished shoot dry weight by 72–81%, seed yield by 80–90% and individual seed yield by 17–25%. Early infection with AMV killed plants of chickpea cv. Tyson while later infection decreased shoot dry weight by 50%, seed yield by 98% and individual seed weight by 90%. The first tentative evidence for seed transmission of AMV in faba bean is reported with a transmission rate of 0.04%.



1979 ◽  
Vol 30 (5) ◽  
pp. 883 ◽  
Author(s):  
HJ Ogle ◽  
DE Byth ◽  
R McLean

In a field trial conducted at the University of Queensland Research Farm, Redland Bay in 1976, plots of soybeans were protected from rust, Phakopsora pachyrhizi, with mancozeb sprays for varying periods after sowing. Seed yield losses were 60–70% in the most severely rusted plots. In a glasshouse trial, rust inoculations were commenced at regular intervals during growth, and yield was reduced by 95% in plants inoculated immediately prior to flowering. In both trials, reduced yield was associated with reductions in the number of filled pods per plant, the number of filled seeds per plant and seed weight. The oil but not the protein content of the seed was also reduced in the more severely rusted treatments in the field trial.



1991 ◽  
Vol 31 (2) ◽  
pp. 225 ◽  
Author(s):  
MJ Barbetti ◽  
PGH Nichols

Studies were conducted to determine the herbage and seed yield losses caused by rust (Uromyces trifolii-repentis Liro) in field plots of 6 subterranean clover varieties. By early October (mid spring), rust caused large reductions in herbage production in varieties Green Range (25.9%), Mount Barker (24.8%), Woogenellup (20.3%), Mulwala (18.7%) and Karridale (15.2%). By the beginning of November (late spring), herbage yield losses were greater in Mulwala (50.5%), Green Range (49.4%), Woogenellup (36.9%) and Mount Barker (34.1%). Rust also caused large reductions in seed yield in Green Range (89.4%), Mulwala (84.8%), Karridale (70.2%), Woogenellup (67.2%) and Mount Barker (39.5%). The variety Larisa was highly resistant to rust, with no significant (P>0.05) reduction in herbage or seed yield.



1996 ◽  
Vol 76 (4) ◽  
pp. 933-935 ◽  
Author(s):  
T. D. Warkentin ◽  
K. Y. Rashid ◽  
A. G. Xue

The efficacy of sulfur (Kumulus S) and myclobutanil (Nova 40W) fungicides for control of powdery mildew (Erysiphe pisi Syd) in field pea (Pisum sativum L.) was investigated in field trials at two locations in Manitoba in 1994 and 1995. Both fungicides were effective in reducing disease seventy and increasing seed yield and seed weight of the susceptible cultivar Radley. Fungicide treatments were economically beneficial when disease pressure was high. Key words: Field pea, Pisum sativum L., powdery mildew, Erysiphe pisi Syd., sulfur, myclobutanil



1964 ◽  
Vol 44 (1) ◽  
pp. 96-99
Author(s):  
J. L. Dobb ◽  
C. R. Elliott

Pasture sampling cages placed on creeping red fescue (Festuca rubra L.) in early May and removed in early August of 1961 and 1962 caused 65 and 41% reductions in seed yield and 14 and 15% reductions in herbage yield, respectively. The reduction in seed yield was attributed primarily to a reduction in the number of seed-bearing culms but also to small reductions in the number of seeds per head and the 1000-seed weight. Components of herbage yield were not studied.The cages reduced light intensity. They often reduced wind velocity, lowered air temperature, and reduced the vapor-pressure deficit, although not consistently.



1995 ◽  
Vol 35 (1) ◽  
pp. 73 ◽  
Author(s):  
MJ Barbetti ◽  
PGH Nichols

A field study was conducted to quantify the effect of rust on the herbage production and seed yield of 4 new midseason cultivars of Trifolium subterraneum (Denmark, Gosse, Goulburn, Leura) and to compare their performance with 8 current commercial cultivars. Leura, Gosse, and Goulburn were all resistant to rust, with Leura most resistant. Denmark was not resistant to rust, but was much less susceptible than Green Range and marginally less susceptible than Mt Barker. By the end of the season, rust had reduced herbage yield in Green Range, Junee, Karridale, and Seaton Park (32, 23, 22, 18%, respectively) but did not affect any new cultivar. Rust reduced the seed yields of all cultivars except Goulburn, Larisa, and Leura. Seed yields of Green Range, Woogenellup, Mt Barker, Seaton Park, Denmark, Esperance, Karridale, Gosse, and Junee were reduced by 75, 70, 58, 55, 49, 47, 40, 40, and 38%, respectively. Rust also reduced the size of seed in all cultivars except Goulburn.



2017 ◽  
Vol 23 (1) ◽  
Author(s):  
A. B. SAGADE

The study of the effect of three well known mutagens, ethyl methane sulphonate (EMS), methyl methane sulphonate (MMS) and gamma rays (GR) on the yield contributing traits of the urdbean variety TPU-4 were carried out in the M3 generation. Effect of selected mutagenic treatments/doses of EMS (0.02, 0.03 and 0.04 M), MMS (0.0025, 0.05 and 0.01 M) and (GR) (30, 40 and 50 KR) on different yield contributing traits like plant height, plant spread, number of pods per plant, pod length, number of seeds per pod, seed yield per plant and 100 seed weight were analyzed in the M3 populations of the variety TPU-4. Seeds of M2 plants and control were harvested separately and sown to raise M3 population.. Genetic variabilty in the mutagen administered M3 progeny of the urdbean variety TPU-4 was analyzed by employing statistical methods. Data on mean values and shift in the mean of seven quantitative traits was evaluated on individual plant basis. The experimental findings revealed that concentrations / dose of the all these mutagens showed inhibitory effect on plant height, number of pods per plant, pod length and number of seeds per pod. Lower concentrations of mutagens exerted a promotory effect on plant spread, 100 seed weight and seed yield per plant while higher concentrations of these mutagens inhibited them to different extent.



Helia ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Khaled Mohamed Aboelkassem ◽  
Asmaa Abd-EL-Halime Ahmed ◽  
Mohamed Ali Abdelsatar

Abstract The present investigation was carried out to evaluate agronomic performance and oil quality of seven sunflower genotypes at Shandaweel Research Station, Agricultural Research Center, Sohag, Egypt during 2018 and 2019 summer seasons. These genetic materials were sown in a randomized complete block design having three replications. Significant genetic variations among evaluated sunflower genotypes for agronomic traits and oil quality were observed. The superior sunflower genotypes were Line 120 for seed yield per hectare (3102.38 kg), Sakha 53 for seed oil content (44.63 %) and Line 125 for oil quality where it contained the highest proportion of unsaturated fatty acids (89.20 %). The phenotypic coefficients of variation were slightly higher than genotypic coefficients of variation for all studied traits. High heritability (exceeded 60%) and genetic advance as percent of mean (ranged from medium to high, exceeded 10%) was observed for most studied traits. Seed yield per plant positively correlated with plant height, stem diameter, head diameter, and 100-seed weight and most chemical traits at phenotypic and genotypic levels. Maximum phenotypic direct effects on seed yield per plant were observed for 100-seed weight, head diameter and total unsaturated fatty acids. While, the highest genotypic direct effect on seed yield per plant was observed for head diameter. Hence, most studied traits could be employed as selection criteria for improving evaluated sunflower genotypes.



1993 ◽  
Vol 73 (4) ◽  
pp. 985-994 ◽  
Author(s):  
G. Saindon ◽  
G. B. Schaalje

Genotype × environment (GE) effects in regional registration trials for dry beans in western Canada were studied to determine whether geographic distribution of sites could be rationalized. The structure of the GE effects on the maturity, seed weight and seed yield of seven dry bean check cultivars grown at eight locations during 4 yr was investigated using GE mean squares decomposition, cluster analysis and the additive main effect and multiplicative interaction (AMMI) method. The analyses revealed a high level of redundancy in the locations which suggested that most GE effects can be captured with fewer testing sites. The partition of the GE mean squares demonstrated the possibility of reproducing the GE structure of the entire data sets with as few as three sites; however, more locations may be needed to compensate for unpredictable environmental effects. Based on biological interpretation of groupings and visual assessment of the AMMI displays, a five-location set fully represented the GE effects on maturity, seed weight and seed yield and accounted for the inconsistent clustering of the Brooks site for the three traits. Also, the set should allow for site losses due to unpredictable environmental events. The dry bean industry in western Canada is expanding to non-traditional growing areas and the establishment of trials in these areas should be considered as they may create GE effects not considered to date. Key words: Phaseolus vulgaris L., genotype × environment interactions, cluster analysis, AMMI analysis



1976 ◽  
Vol 56 (2) ◽  
pp. 275-280
Author(s):  
T. LAWRENCE

Progenies from a five-genotype diallel cross in Russian wild ryegrass, Elymus junceus Fisch., were studied to assess the pattern of genetic control for F1 seed weight and a number of seedling and adult plant characters. Variation in F1 seed weight was largely determined by the maternal parent, but some control by the pollen parent was apparent. Of the seedling characters, days to emerge, rate of leaf appearance, rate of tiller appearance, and seedling dry matter yield, only days to emerge showed additive variance which is amenable to direct selection. The other three characters could be most easily exploited by a recurrent selection program. The adult plant characters, date of inflorescence appearance, P content of the forage, and organic matter digestibility indicated strong additive control which is amenable to direct selection. Dry matter yield and seed yield also showed strong additive control which was accompanied by specific combining ability and weak maternal effects suggesting good progress should be possible by direct selection methods but crossing the selections in a diallel fashion prior to formation of synthetics might be desirable. The seedling characters, rate of leaf and tiller appearance and seedling dry matter yield were interrelated and associated with adult plant yield, thus offering the possibility of screening seedlings for these characters in a recurrent selection program for improved forage or seed yield.



Sign in / Sign up

Export Citation Format

Share Document