Effectiveness of incomplete resistance to Pyrenophora tritici-repentis in wheat

1989 ◽  
Vol 40 (1) ◽  
pp. 43 ◽  
Author(s):  
RG Rees ◽  
GJ Platz
Keyword(s):  
Grain Size ◽  
Grain Yield ◽  
Yield Loss ◽  
Yellow Spot ◽  
Yield Losses ◽  
Pyrenophora Tritici Repentis ◽  
Incomplete Resistance ◽  
Disease Pressure ◽  
Moderate Yield

Severe epidemics of yellow spot (Pyrenophora tritici-repentis) reduced grain yield by c. 60% in the highly susceptible wheat cv. Banks in two experiments. About two-thirds of the yield loss was associated with reduced grain size. Milder epidemics developed in cultivars with incomplete resistance and resulted in substantially smaller effects on grain yield. The value of the resistance in a high-yielding background was illustrated by yield advantages over Banks of c. 230% for Genaro 8 1 and c. 190% for Vicam 7 1, under heavy disease pressure. Lines selected from crosses of Genaro 81/2*Banks and Vicam 7!/2*Banks had less disease than Banks and only small to moderate yield losses occurred in the best selections under heavy disease pressure. This illustrates that the resistance from these sources can be transferred readily into adapted Australian wheats and should greatly reduce yield losses from yellow spot.

Yield losses in wheat from yellow spot: a disease-loss relationship derived from single tillers

1981 ◽  
Vol 32 (6) ◽  
pp. 851 ◽  
Author(s):  
RG Rees ◽  
RJ Mayer ◽  
GJ Platz
Keyword(s):  
Grain Yield ◽  
Harvest Index ◽  
Wheat Yield ◽  
Yellow Spot ◽  
Disease Development ◽  
Yield Losses ◽  
Grain Development ◽  
Pyrenophora Tritici Repentis ◽  
Percentage Loss ◽  
Average Loss

The effect of yellow spot (Pyrenophora tritici-repentis) on wheat yield has been examined with a single-tiller technique. The disease was assessed on c. 1000 tagged main stems in each of five wheat crops. Grain yield, its components, and harvest index were measured on each tiller. In most cases these response variables were significantly correlated with yellow spot levels. The disease-loss relationship, L = 0.26X, was developed where L is the percentage loss in grain yield per main head and X is the average level of yellow spot on the top two leaves at around the milk stage of grain development. From four of the crops examined, an average loss of 12.7 % in grain yield per main head was estimated. Under environmental conditions which particularly favour disease development, the losses derived from this relationship are probably underestimated.

Yield losses in wheat from yellow spot: comparison of estimates derived from single tillers and plots

1982 ◽  
Vol 33 (6) ◽  
pp. 899 ◽  
Author(s):  
RG Rees ◽  
GJ Platz ◽  
RJ Mayer
Keyword(s):  
Grain Yield ◽  
Disease Severity ◽  
Yield Loss ◽  
Wheat Yield ◽  
Sprinkler Irrigation ◽  
Yellow Spot ◽  
Grain Number ◽  
Pyrenophora Tritici Repentis ◽  
Wheat Stubble ◽  
The Relationship

Losses in wheat yield associated with yellow spot (Pyrenophora tritici-repentis) have been examined in a field experiment where development of crop and disease were promoted with sprinkler irrigation. Different amounts of infected wheat stubble were applied to initiate epidemics in four treatments, while fungicide sprays were used to reduce the severity of yellow spot in a fifth treatment. The relationship between severity of yellow spot and the amount of infected stubble at first appeared to be linear but became more noticeably logarithmic as the epidemics progressed. Under conditions favouring disease development, a loss in grain yield of c. 49% was measured in the most severely diseased treatment relative to the sprayed treatment, with grain number per unit area and grain size both being reduced. The percentage loss in grain yield was less for main stems than for later heads. Regression analyses of disease severity with grain yield and its components using 50 main stems in each plot gave different estimates of yield loss, depending on the growth stage at which disease severity was assessed. These estimates of yield loss and those provided by a previously developed disease-loss relationship severely underestimated the overall loss in grain yield. However, there was better agreement between estimates derived from the regressions and loss in grain yield on main stems. Possible reasons for the discrepancies in estimates of loss in grain yield are discussed.

scholarly journals The impact of cultivar resistance and fungicide treatment on mycotoxin content in grain and yield losses caused by Fusarium head blight in wheat

2010 ◽  
Vol 46 (No. 1) ◽  
pp. 21-26 ◽  
Author(s):  
V. Šíp ◽  
J. Chrpová ◽  
O. Veškrna ◽  
L. Bobková
Keyword(s):  
Grain Yield ◽  
Fusarium Head Blight ◽  
Field Experiments ◽  
Yield Loss ◽  
Joint Effect ◽  
Yield Losses ◽  
Cultivar Resistance ◽  
Head Blight ◽  
Fungicide Treatment ◽  
The Impact

Reactions to artificial infection with Fusarium graminearum isolates and a new fungicide Swing Top were studied in nine winter wheat cultivars evaluated in field experiments at two sites for three years for expression of symptoms, deoxynivalenol (DON) content in grain and grain yield. The results demonstrate a pronounced and relatively stable effect of cultivar resistance on reducing head blight, grain yield losses and contamination of grain by the mycotoxin DON. It is advantageous that the moderate level of resistance to Fusarium head blight (FHB) was detected also in two commonly grown Czech cultivars Sakura and Simila. Average fungicide efficacy for DON was 49.5% and 63.9% for a reduction in yield loss, however, it was found highly variable in different years and sites. The joint effect of cultivar resistance and fungicide treatment was 86.5% for DON and even 95.4% for reducing the yield loss. A very high risk was documented for susceptible cultivars and also the effects of medium responsive cultivars were found to be highly variable in different environments and therefore not guaranteeing sufficient protection against FHB under different conditions.

Tolerances of wheat cultivars to pre-emergence herbicides

1985 ◽  
Vol 25 (4) ◽  
pp. 922 ◽  
Author(s):  
D Lemerle ◽  
AR Leys ◽  
RB Hinkley ◽  
JA Fisher
Keyword(s):  
Grain Yield ◽  
Spring Wheat ◽  
Yield Loss ◽  
New South ◽  
New South Wales ◽  
Yield Reduction ◽  
Wheat Cultivars ◽  
Yield Losses ◽  
South Wales

Twelve spring wheat cultivars were tested in southern New South Wales for their tolerances to the recommended rates and three times the recommended rates of trifluralin, pendimethalin, tri-allate and chlorsulfuron. Recommended rates of these herbicides did not affect the emergence or grain yield of any cultivar. However, differences between cultivars in their tolerances to trifluralin, pendimethalin and chlorsulfuron at three times the recommended rate were identified. The extent of the reduction in emergence and/or grain yield varied with herbicide and season, and there was also a herbicidexseason interaction. Durati, Songlen and Tincurrin were the most susceptible cultivars to trifluralin, and Teal was the most tolerant. Yield losses from trifluralin were more severe in 1979 than in 1980 or 1981. The differential between cultivars treated with pendimethalin was smaller and more variable; Tincurrin was the only cultivar with a yield reduction in more than one season. Durati, Songlen and Shortim were the only cultivars affected by chlorsulfuron. A reduction in crop emergence of a cultivar treated with trifluralin or pendimethalin did not correlate consistently with any grain yield loss, and reductions in emergence were always greater than yield loss.

scholarly journals Yield Loss in Cereals, Caused by Fusarium culmorum and F. pseudograminearum, Is Related to Fungal DNA in Soil Prior to Planting, Rainfall, and Cereal Type

Plant Disease ◽  
2013 ◽  
Vol 97 (7) ◽  
pp. 977-982 ◽  
Author(s):  
G. J. Hollaway ◽  
M. L. Evans ◽  
H. Wallwork ◽  
C. B. Dyson ◽  
A. C. McKay
Keyword(s):  
Grain Yield ◽  
Durum Wheat ◽  
Bread Wheat ◽  
Yield Loss ◽  
Quantitative Polymerase Chain Reaction ◽  
Fusarium Culmorum ◽  
South Australia ◽  
Crown Rot ◽  
Wheat Bread ◽  
Yield Losses

In southeastern Australia, Fusarium crown rot, caused by Fusarium culmorum or F. pseudograminearum, is an increasingly important disease of cereals. Because in-crop control options are limited, it is important for growers to know prior to planting which fields are at risk of yield loss from crown rot. Understanding the relationships between crown rot inoculum and yield loss would assist in assessing the risk of yield loss from crown rot in fields prior to planting. Thirty-five data sets from crown rot management experiments conducted in the states of South Australia and Victoria during the years 2005 to 2010 were examined. Relationships between Fusarium spp. DNA concentrations (inoculum) in soil samples taken prior to planting and disease development and grain yield were evaluated in seasons with contrasting seasonal rainfall. F. culmorum and F. pseudograminearum DNA concentrations in soil prior to planting were found to be positively related to crown rot expression (stem browning and whiteheads) and negatively related to grain yield of durum wheat, bread wheat, and barley. Losses from crown rot were greatest when rainfall during September and October (crop maturation) was below the long-term average. Losses from crown rot were greater in durum wheat than bread wheat and least in barley. Yield losses from F. pseudograminearum were similar to yield losses from F. culmorum. Yield loss patterns were consistent across experiments and between states; therefore, it is reasonable to expect that similar relationships will occur over broad geographic areas. This suggests that quantitative polymerase chain reaction technology and soil sampling could be powerful tools for assessing crown rot inoculum concentrations prior to planting and predicting the risk of yield loss from crown rot wherever this disease is an issue.

Identification of Sources of Resistance and Yield Loss Assessment for Aerial Blight and Anthracnose/Pod Blight Diseases in Soybean

2021 ◽  
Author(s):  
Pawan K. Amrate ◽  
M.K. Shrivastava ◽  
Gyanendra Singh
Keyword(s):  
Yield Loss ◽  
Pressure Field ◽  
Yield Losses ◽  
Loss Assessment ◽  
Sources Of Resistance ◽  
Yield Loss Assessment ◽  
Soybean Genotypes ◽  
Cent Disease ◽  
Disease Pressure ◽  
Soybean Diseases

Background: Aerial blight (Rhizoctonia solani Kuhn) and Anthracnose/pod blight (Colletotrichum truncatum) are important soybean diseases, affect most of the present varieties with varying intensity, in India. There are also few reports of resistance against both the diseases. Methods: To identify resistance, a set of 121 diverse soybean genotypes including six susceptible checks i.e. JS 93-05, JS 335, JS 72-280, Punjab 1, RKS 18 and VLS 58 were evaluated under high disease pressure field conditions during 2017, 2018 and 2019. Moreover, assessment of yield losses due to these diseases were also worked out in highly infected plants of susceptible checks.Result: It was observed that aerial blight (0.0-46.8 per cent) and anthracnose/pod blight (0.0-56.2 per cent) were affected soybean genotypes from R1 to R7 and V3 to R7 stages, respectively. The genotypes responded differently and showed absolute resistance to susceptible reaction. Out of 121 genotypes, only five genotypes i.e. JS 20-57, JSM 222, MACS 1407, PS 1611 and Cat 2126 B were found to be highly resistant against both the diseases. Per cent pod and yield losses were significantly correlated with varying severity of aerial blight (0.966** and 0.995**) and anthracnose/pod blight (0.957** and 0.995**), respectively. However, the highest yield loss of 41.0 and 64.8 per cent were recorded on 55.6 and 75.2 per cent disease index (at 90 days) of aerial blight and anthracnose/pod blight, respectively.

THE EFFECT OF HAIL DAMAGE ON BARLEY

1979 ◽  
Vol 59 (4) ◽  
pp. 1147-1152 ◽  
Author(s):  
K. M. GILBERTSON ◽  
E. A. HOCKETT
Keyword(s):  
Hordeum Vulgare ◽  
Grain Yield ◽  
Yield Loss ◽  
Heading Date ◽  
Yield Losses ◽  
Heading Time ◽  
Hordeum Vulgare L ◽  
Positive Correlation ◽  
Hail Damage ◽  
Final Yield

After a severe hailstorm at Fort Ellis, Montana, an experienced hail insurance adjuster estimated 90–100% damage in replicated yield plots of barley (Hordeum vulgare L.). After harvest, grain yield losses for all 66 entries in the nursery were found to range from 26 to 84%. A group of 11 cultivars selected for further study averaged 55% less than normal yield with a range of 29–82%. Yield and heading date were significantly (P < 0.05) correlated for all cultivars (r = 0.39*, n = 42), within six-rowed cultivars (r = 0.79*, n = 7), and for the 11 selected cultivars (r = 0.62*, n = 11). Although there was no significant correlation between yield and heading date within two-rowed cultivars, a group of two-rowed early isogenics was significantly reduced in grain yield compared to their late counterparts. The number of days between heading and time of hail damage was a better indicator of final yield loss than number of culms remaining (the criterion used for hail-adjuster estimates of damage). Regrowth is more likely to occur in barley if the hail damage is near or before heading time rather than 5–15 days after heading. Therefore, the positive correlation in this test between late heading date and yield is because the later entries had just headed out when the hail came, while the low yielding entries headed 10–15 days before the hailstorm.

scholarly journals Sowing date reduces the incidence of wheat blast disease

2016 ◽  
Vol 51 (5) ◽  
pp. 631-637 ◽  
Author(s):  
Maurício Antônio de Oliveira Coelho ◽  
Gisele Abigail Montan Torres ◽  
Paulo Roberto Cecon ◽  
Flávio Martins Santana
Keyword(s):  
Grain Yield ◽  
Sowing Date ◽  
Minas Gerais ◽  
Blast Disease ◽  
Yield Losses ◽  
Potential Yield ◽  
Wheat Blast ◽  
Sowing Dates ◽  
Severity Of The Disease ◽  
Disease Pressure

Abstract: The objective of this work was to assess the effect of sowing date on the intensity of wheat blast disease, as well as the yield losses caused by this disease in different wheat (Triticum aestivum) genotypes. The experiments were conducted in 2013 at the Sertãozinho experimental station of Empresa de Pesquisa Agropecuária de Minas Gerais (Epamig), in the municipality of Patos de Minas, in the state of Minas Gerais, Brazil. Fourteen wheat genotypes and two sowing dates were evaluated. The experimental design was a randomized complete block with three replicates. The evaluated variables were: incidence, severity, thousand grain weight (TGW), grain yield, and yield losses. A disease index (DI) was calculated, based both on the incidence and the severity of the disease, to measure blast intensity in wheat. The sowing date significantly affected DI, TGW, and grain yield. Significant linear correlations were observed between DI and yield losses (0.89), between losses and TGW (-0.85), and between losses and grain yield (-0.93). For wheat blast, DIs greater than or equal to 0.5 indicate potential yield losses equal to or greater than 70%. The EP063030 line and the MGS Brilhante and BRS 264 cultivars are the most tolerant to blast, when exposed to high disease pressure.

scholarly journals Interference of Broadleaf Buttonweed and White-Eye in Soybean

2020 ◽  
Vol 38 ◽  
Author(s):  
F. DIESEL ◽  
M.M. TREZZI ◽  
M. GALLON ◽  
P.H.F. MIZERSKI ◽  
S.C. BATISTEL ◽  
...  
Keyword(s):  
Grain Yield ◽  
Yield Loss ◽  
Block Design ◽  
Grain Weight ◽  
Weed Competition ◽  
Yield Losses ◽  
Weed Species ◽  
Randomized Block Design ◽  
Crop Weed Competition ◽  
1000 Grain Weight

ABSTRACT: Weed species is one of the factors contributing to grain yield losses due to crop-weed competition. Two of the most common weeds of soybean fields in Brazil are from the Rubiaceae family: Borreria latifolia and Richardia brasiliensis. This study aimed to evaluate the effects of B. latifolia and R. brasiliensis on plant development, yield components, and soybean productivity. Two assays were conducted in a randomized block design with four replications, using a two-level factorial design, in which the first factor consisted of the species B. latifolia and R. brasiliensis and the second factor consisted of the densities 0, 2, 4, 6, 8, 10, and 12 plants m-2. Plant height, leaf area and total chlorophyll in the V6 and R5 stages, number of pods per plant, number of grains per pod, 1000-grain weight, and grain yield loss were evaluated in both cultivars. Grain yield of both soybean cultivars was negatively affected by the interference with B. latifolia and R. brasiliensis. The species B. latifolia was more competitive with soybean when compared to R. brasiliensis, causing higher reductions for all variables. Each B. latifolia plant per square meter is able to reduce the yield of soybean by 3 a 4.4%, while each R.brasiliensis plant reduces yield by 2 a 2.6%. For both species, the reduction in soybean yield due to competition was caused by a decrease in the number of pods per plant, number of grains per pod, and 1000-grain weight.

Assessment of yield loss caused by common root rot in wheat cultivars in Queensland

1992 ◽  
Vol 43 (1) ◽  
pp. 43 ◽  
Author(s):  
GB Wildermuth ◽  
RD Tinline ◽  
RB McNamara
Keyword(s):  
Grain Yield ◽  
Disease Severity ◽  
Root Rot ◽  
Yield Loss ◽  
Grain Weight ◽  
The Other ◽  
Regression Equations ◽  
Yield Losses ◽  
Common Root ◽  
Common Root Rot

The effects of common root rot (CRR) caused by Bipolaris sorokiniana on grain yield, number of tillers, number of grains and grain weight of wheat plants were determined in four field experiments. Sites with different soil populations of B. sorokiniana were selected and inoculum of the fungus added to some plots. Disease and yield measurements were made on eight cultivars and lines differing in susceptibility to CRR. Timgalen, Songlen and Hartog were susceptible whereas Kite, 1008 C16, 141-4 and ISWYN 32 were partially resistant to CRR. Grain yield, tiller and grain number, but not grain weight decreased as disease severity increased. Diseased plants had lower tiller numbers than healthy ones and as a consequence a reduced number of grains and grain yield per plant. Five methods were compared for estimating yield loss caused by the disease. Polynomial regression equations for each cultivar between yield and disease rating of sub-crown internodes or multiple regression equations between yield and disease parameters of sub-crown internodes or tiller bases were established. A third method involved the projection of yield losses from one cultivar to other cultivars and in a fourth method yield losses were estimated from actual yields. In addition, an equation Yield loss (%) = 3 46 + 0.23 disease severity) (%) was established in one experiment and used as a fifth method in the other experiments. Yield losses estimated by methods 1 and 2 were similar and higher than those from the other methods. In areas where disease severity is high, methods 1 and 5 appear to be the most suitable for determining yield losses. Losses in a susceptible cultivar, Timgalen, varied between 13.9 and 23.9% whereas those in a partially resistant cultivar, 1008 C16, varied between 6.8 and 13.6%.

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