Relationship between scald (Rhynchosporium secalis) and losses in grain yield of barley in Western Australia

1985 ◽  
Vol 36 (5) ◽  
pp. 655 ◽  
Author(s):  
TN Khan ◽  
MF D'Antuono
Keyword(s):  
Grain Yield ◽  
Critical Point ◽  
Western Australia ◽  
Field Experiments ◽  
Yield Loss ◽  
Growth Stages ◽  
Point Model ◽  
Percentage Yield ◽  
The Mean ◽  
Ripe Stage

The three commonly used techniques, viz. critical point model, area under the curve and multiple linear regression, were applied to study the relationship between scald infection and grain yield in field experiments conducted during 1979-1983 in Western Australia. In the preliminary analysis leaf three from the top and the mean of the top three leaves were found to be best correlated with yield. The three models did not dilfer greatly, presumably owing to the high correlations between scald at the milky ripe stage and at the earlier growth stages. The critical point model was chosen because of its simplicity. Percentage yield loss in combined data from all experiments showed a significant correlation (P < 0.001) with scald at the milky ripe stage and defined percentage yield loss in cultivars Clipper and Stirling to be about one-third of the mean scald damage on leaves 1 (flag), 2 and 3 at g.s. 75. Due to the range of trials in this analysis, it was suggested that this relationship may be applied to estimate yield loss from survey data in other parts of southern Australia, where scald is endemic.

Tolerance and Selectivity of Cereal Species and Cultivars to Postemergence Weed Harrowing

Weed Science ◽  
2009 ◽  
Vol 57 (3) ◽  
pp. 338-345 ◽  
Author(s):  
Jesper Rasmussen ◽  
Helle H. Nielsen ◽  
Hanne Gundersen
Keyword(s):  
Grain Yield ◽  
Weed Control ◽  
Field Experiments ◽  
Yield Loss ◽  
Soil Cover ◽  
Crop Damage ◽  
Growth Stages ◽  
Crop Tolerance ◽  
Barley Cultivars ◽  
Cereal Species

POST weed harrowing and other cultivation methods to control weeds in early crop growth stages may result in crop damage due to low selectivity between crop and weeds. Crop tolerance to cultivation plays an important role but it has not been clearly defined and analyzed. We introduce a procedure for analyzing crop tolerance on the basis of digital image analysis. Crop tolerance is defined as the ability of the crop to avoid yield loss from cultivation in the absence of weeds, and it has two components: resistance and recovery. Resistance is the ability of the crop to resist soil covering and recovery is the ability to recover from it. Soil covering is the percentage of the crop that has been buried because of cultivation. We analyzed data from six field experiments, four experiments with species of small grains, barley, oat, wheat, and triticale, and two experiments with barley cultivars with different abilities to suppress weeds. The order of species' tolerance to weed harrowing was triticale > wheat > barley > oat and the differences were mainly caused by different abilities to recover from soil covering. At 25% soil covering, grain yield loss in triticale was 0.5%, in wheat 2.5%, in barley 3.7%, and in oat 6.5%. Tolerance, resistance, and recovery, however, were influenced by year, especially for oat and barley. There was no evidence of differences between barley cultivars in terms of tolerance indicating that differences among species are more important than differences among cultivars. Selectivity analysis made it possible to calculate the crop yield loss due to crop damage associated with a certain percentage of weed control. In triticale, 80% weed control was associated with 22% crop soil cover on average, which reduced grain yield 0.4% on average in the absence of weeds. Corresponding values for wheat, barley, and oat were 23, 21, and 20% crop soil cover and 2.3, 3.6, and 5.1% grain yield loss.

Residual value of molybdenum for wheat production on naturally acidic soils of Western Australia

2006 ◽  
Vol 46 (10) ◽  
pp. 1333 ◽  
Author(s):  
R. F. Brennan
Keyword(s):  
Grain Yield ◽  
Western Australia ◽  
Field Experiments ◽  
Relative Effectiveness ◽  
Growth Stages ◽  
Eastern Region ◽  
Residual Value ◽  
Wheat Roots ◽  
Agricultural Areas ◽  
Tissue Test

Naturally acidic sandplain soils in the lower rainfall (<350 mm annual average) eastern region of the agricultural areas of south-western Australia are deficient in molybdenum (Mo) for grain production of wheat. Liming soils ameliorates Mo deficiency, but it is not an economic option for these soils because they are naturally acidic at soil depths commonly explored by wheat roots. Consequently, Mo fertiliser, usually as Mo trioxide, needs to be applied to wheat on these soils. The residual value of the Mo fertiliser for these soils was not known, so was measured using grain yield of wheat in 2 long-term field experiments. The Mo fertiliser treatments were applied once only in different years to plots not treated with Mo in a previous year. In both experiments, the residual value of the fertiliser was measured in 1993. Thus, it was possible to determine the effectiveness of the fertiliser applied once only 1–11 years previously (previous Mo) relative to freshly applied (current) Mo applied in 1993. At both sites, a continuous decline in the effectiveness of previous Mo relative to current Mo was related to time of Mo–soil contact. In experiment 1, the effectiveness of previous Mo relative to current Mo decreased by about 40, 50, 60 and 70% when applied 2, 5, 7 and 11 years previously. In experiment 2, on a more acidic soil with a larger capacity to sorb Mo, the relative effectiveness of previous Mo decreased by about 60 and 80% for Mo applied 2 and 6 years previously. The concentration of Mo measured in youngest emerged leaf blades was related to 90% of the maximum shoot yield at the time of sampling (diagnostic critical tissue test value) and to 90% of the maximum grain yield (prognostic critical tissue test value). Irrespective of the growth stage of wheat, both critical diagnostic and prognostic values were about 0.07 mg Mo/kg. The concentration of Mo in grain that was related to 90% of the maximum grain yield was 0.02 mg/kg. The reapplication of Mo fertiliser to naturally acidic sands can be made with knowledge of the residual value and use of tissue testing for Mo, particularly when sampled at early growth stages of wheat.

A re-evaluation of chlormequat application to wheat in Western Australia

1986 ◽  
Vol 26 (3) ◽  
pp. 361
Author(s):  
MW Perry ◽  
DJ Miers
Keyword(s):  
Grain Yield ◽  
Western Australia ◽  
Field Experiments ◽  
Leaf Growth ◽  
Maximum Yield ◽  
Growth Stages ◽  
Time Of Application ◽  
Natural Rainfall ◽  
Application Rates ◽  
Yield Responses

The effect of chlormequat on the grain yield of wheat was investigated in 24 field experiments between 1981 and 1983. Two times of application (at the 3.5- and 6-leaf growth stages-Zadoks decimal score 13.5 and 16.0) and rates of application up to 0.75 kg/ha a.i. were tested with two chlormequat formulations, Cycocel 750 and Bettaquat. Chlormequat application reduced crop height in all trials, but crop lodging did not occur in any trial. Statistically significant yield responses to rate of application alone were obtained in only three of 24 trials, with maximum yield occurring at 0.19-0.37 kg/ha a.i. and with some indication of a yield depression at 0.75 kg/ha a.i. A significant effect of time of application was observed in only two trials, but the results conflicted. In one trial there was a significant interaction between rate and time, with a response to rate of chlormequat only at the 6-leaf stage. No differences were detected between chlormequat formulations. In individual trials, the mean grain yield from the chlormequat treatments ranged from 92.9 to 116.5% of the control. However, averaging over all trials in each year, chlormequat treatments yielded 102.5, 99.3 and 100.0% of the control, respectively, in the three years. Our results confirm that low application rates of chlormequat, applied early in crop development, can increase grain yield. However, over the 24 trials, the effects of chlormequat were too small and inconsistent to warrant its use to increase wheat grain yields under natural rainfall in south-western Australia.

Effect of spot-type net blotch (Drechslera teres (Sacc.) Shoem) infection on barley yield in short season environment of northern cereal belt of Western Australia

1989 ◽  
Vol 40 (4) ◽  
pp. 745 ◽  
Author(s):  
TN Khan
Keyword(s):  
Western Australia ◽  
Field Experiments ◽  
Yield Loss ◽  
Yield Response ◽  
Net Blotch ◽  
Drechslera Teres ◽  
Percentage Yield ◽  
Negative Effect ◽  
Short Season ◽  
Spot Type

The effect of spot-type net blotch (Drechslera teres (Sacc.) Shoem.) on yield was studied in fourteen field experiments located at two sites over seven years in the area where the disease occurs; the northern cereal belt of south-west Western Australia. An overall reduction of 26% in grain yield occurred associated with spot-type net blotch infection. The yield losses varied depending upon season, date of sowing and cultivar. Disease was found to reduce 100 grain weight and number of ears/m2, but number of grains/ear were not affected. Regression analysis supported the above negative effect of disease on yield in general, but in a few cases disease and yield were positively correlated. The Area Under Curve (AUC) model was considered most appropriate and percentage yield loss (L) was estimated as L = 0.0233 AUC. Using this relationship, potential losses in yields of cvv. Beeeher and O'Connor were estimated to be 34% and 29%, respectively. The application of this relationship is suggested to be limited to short season environments similar to the northern cereal belt of Western Australia. A need to understand factors which modify the yield response to this disease is highlighted.

Relationship between net blotch (Drechslera teres) and losses in grain yield of barley in Western Australia

1987 ◽  
Vol 38 (4) ◽  
pp. 671 ◽  
Author(s):  
TN Khan
Keyword(s):  
Critical Point ◽  
Western Australia ◽  
Yield Loss ◽  
Yield Reduction ◽  
Multiple Point ◽  
Net Blotch ◽  
Drechslera Teres ◽  
Percentage Yield ◽  
The Relationship ◽  
Common Equation

Losses in the yield of cv. Dampier due to net blotch (Drechslera teres (Sacc.) Shoem.) were examined in six environments in Western Australia. Based on comparison between least diseased and most diseased treatments, there was an overall yield reduction of 21% (P < 0.05). Three models (Critical Point, Area Under Curve and Multiple Point) were used to study the relationship between net blotch infection and percentage yield loss. All models gave similar results. Because of its simplicity, the Critical Point Model based on mean net blotch infection on the top three leaves at GS 75 was chosen. The percentage yield loss in cv. Dampier was defined to be 37% of the mean diseased area on leaves 1 (flag), 2 and 3 at GS 75. This relationship is very similar to that developed earlier for scald, and a common equation for both scald and net blotch was suggested.

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.

The critical weed-free period in glyphosate-resistant soybean in Ontario is similar to previous estimates using glyphosate-susceptible soybean

2019 ◽  
Vol 99 (4) ◽  
pp. 437-443
Author(s):  
Nader Soltani ◽  
Robert E. Nurse ◽  
Amit J. Jhala ◽  
Peter H. Sikkema
Keyword(s):  
Growth Stage ◽  
Field Experiments ◽  
Yield Loss ◽  
Growth Stages ◽  
Weed Species ◽  
Weed Biomass ◽  
Weed Density ◽  
Weed Interference ◽  
Beginning Of Flowering ◽  
Minimal Reduction

A study consisting of 13 field experiments was conducted during 2014–2016 in southwestern Ontario and southcentral Nebraska (Clay Center) to determine the effect of late-emerging weeds on the yield of glyphosate-resistant soybean. Soybean was maintained weed-free with glyphosate (900 g ae ha−1) up to the VC (cotyledon), V1 (first trifoliate), V2 (second trifoliate), V3 (third trifoliate), V4 (fourth trifoliate), and R1 (beginning of flowering) growth stages, after which weeds were allowed to naturally infest the soybean plots. The total weed density was reduced to 24%, 63%, 67%, 72%, 76%, and 92% in Environment 1 (Exeter, Harrow, and Ridgetown) when soybean was maintained weed-free up to the VC, V1, V2, V3, V4, and R1 soybean growth stages, respectively. The total weed biomass was reduced by 33%, 82%, 95%, 97%, 97%, and 100% in Environment 1 (Exeter, Harrow, and Ridgetown) and 28%, 100%, 100%, 100%, 100%, and 100% in Environment 2 (Clay Center) when soybean was maintained weed-free up to the VC, V1, V2, V3, V4, and R1 stages, respectively. The critical weed-free periods for a 2.5%, 5%, and 10% yield loss in soybean were the V1–V2, VC–V1, and VC–V1 soybean stages in Environment 1 (Exeter, Harrow, and Ridgetown) and V2–V3, V2–V3, and V1–V2 soybean stages in Environment 2 (Clay Center), respectively. For the weed species evaluated, there was a minimal reduction in weed biomass (5% or less) when soybean was maintained weed-free beyond the V3 soybean growth stage. These results shows that soybean must be maintained weed-free up to the V3 growth stage to minimize yield loss due to weed interference.

Effect of fertiliser phosphorus and nitrogen on the concentrations of oil and protein in grain and the grain yield of canola (Brassica napus L.) grown in south-western Australia

2007 ◽  
Vol 47 (8) ◽  
pp. 984 ◽  
Author(s):  
R. F. Brennan ◽  
M. D. A. Bolland
Keyword(s):  
Brassica Napus ◽  
Grain Yield ◽  
Western Australia ◽  
Field Experiments ◽  
Grain Production ◽  
Brassica Napus L ◽  
Single Superphosphate ◽  
P Deficiency ◽  
Soil P ◽  
Soil P Testing

The effect of fertiliser phosphorus (P) and nitrogen (N) on seed (grain) yield and concentration of oil and protein in grain of canola (oil-seed rape; Brassica napus L.) was measured in two field experiments undertaken at eight sites from 1993–2005 in south-western Australia, on soils deficient in P and N. Six rates of P (0–40 kg P/ha as single superphosphate) and four rates of N (0–138 kg N/ha as urea) were applied. Significant grain yield increases (responses) to applied P occurred in both experiments and these responses increased as rates of applied N increased. For grain production, the P × N interaction was significant in all eight years and locations of the two experiments. Application of P had no effect on concentration of oil and protein in grain. Application of N always decreased the concentration of oil and increased the concentration of protein in grain. For canola grain production in the region, responses to applied N always occur whereas responses to applied P are rare, but if soil P testing indicates likely P deficiency, both P and N fertiliser need to be applied.

scholarly journals Development of Chlorophyll-Meter-Index-Based Dynamic Models for Evaluation of High-Yield Japonica Rice Production in Yangtze River Reaches

Agronomy ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 106 ◽  
Author(s):  
Ke Zhang ◽  
Xiaojun Liu ◽  
Syed Tahir Ata-Ul-Karim ◽  
Jingshan Lu ◽  
Brian Krienke ◽  
...  
Keyword(s):  
Grain Yield ◽  
Field Experiments ◽  
High Yield ◽  
Accurate Estimation ◽  
Growth Stages ◽  
Rice Grain ◽  
Japonica Rice ◽  
Ripening Period ◽  
The Third ◽  
Different Growth Stages

Accurate estimation of the nitrogen (N) spatial distribution of rice (Oryza sativa L.) is imperative when it is sought to maintain regional and global carbon balances. We systematically evaluated the normalized differences of the soil and plant analysis development (SPAD) index (the normalized difference SPAD indexes, NDSIs) between the upper (the first and second leaves from the top), and lower (the third and fourth leaves from the top) leaves of Japonica rice. Four multi-location, multi-N rate (0–390 kg ha−1) field experiments were conducted using seven Japonica rice cultivars (9915, 27123, Wuxiangjing14, Wunyunjing19, Wunyunjing24, Liangyou9, and Yongyou8). Growth analyses were performed at different growth stages ranging from tillering (TI) to the ripening period (RP). We measured leaf N concentration (LNC), the N nutrition index (NNI), the NDSI, and rice grain yield at maturity. The relationships among the NDSI, LNC, and NNI at different growth stages showed that the NDSI values of the third and fourth fully expanded leaves more reliably reflected the N nutritional status than those of the first and second fully expanded leaves (LNC: NDSIL3,4, R2 > 0.81; NDSIothers, 0.77 > R2 > 0.06; NNI: NDSIL3,4, R2 > 0.83; NDSIothers, 0.76 > R2 > 0.07; all p < 0.01). Two new diagnostic models based on the NDSIL3,4 (from the tillering to the ripening period) can be used for effective diagnosis of the LNC and NNI, which exhibited reasonable distributions of residuals (LNC: relative root mean square error (RRMSE) = 0.0683; NNI: RRMSE = 0.0688; p < 0.01). The relationship between grain yield, predicted yield, and NDSIL3,4 were established during critical growth stages (from the stem elongation to the heading stages; R2 = 0.53, p < 0.01, RRMSE = 0.106). An NDSIL3,4 high-yield change curve was drawn to describe critical NDSIL3,4 values for a high-yield target (10.28 t ha−1). Furthermore, dynamic-critical curve models based on the NDSIL3,4 allowed a precise description of rice N status, facilitating the timing of fertilization decisions to optimize yields in the intensive rice cropping systems of eastern China.

Field Pea and Lentil Tolerance to Interrow Cultivation

2017 ◽  
Vol 32 (2) ◽  
pp. 205-210 ◽  
Author(s):  
Katherine A. Stanley ◽  
Steven J. Shirtliffe ◽  
Dilshan Benaragama ◽  
Lena D. Syrovy ◽  
Hema S. N. Duddu
Keyword(s):  
Weed Control ◽  
Field Experiments ◽  
Yield Loss ◽  
Growing Season ◽  
Field Pea ◽  
Crop Damage ◽  
Growth Stages ◽  
Row Crops ◽  
Narrow Row ◽  
Mechanical Weed Control

AbstractInterrow cultivation is a selective, in-crop mechanical weed control tool that has the potential to control weeds later in the growing season with less crop damage compared with other in-crop mechanical weed control tools. To our knowledge, no previous research has been conducted on the tolerance of narrow-row crops to interrow cultivation. The objective of this experiment was to determine the tolerance of field pea and lentil to interrow cultivation. Replicated field experiments were conducted in Saskatchewan, Canada, in 2014 and 2015. Weekly cultivation treatments began at the 4-node stage of each crop, continuing for 6 wk. Field pea and lentil yield linearly declined with later crop stages of cultivation. Cultivating multiple times throughout the growing season reduced yield by 15% to 30% in both crops. Minimal yield loss occurred when interrow cultivation was conducted once at early growth stages of field pea and lentil; however, yield loss increased with delayed and more frequent cultivation events.

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