scholarly journals Impact and Control of Powdery Mildew on Irrigated Soybean Varieties Grown in Southeast Australia

Agronomy ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 514 ◽  
Author(s):  
Mathew Dunn ◽  
Luke Gaynor
Keyword(s):  
Powdery Mildew ◽  
Grain Yield ◽  
Field Experiments ◽  
Effective Control ◽  
Yield Reduction ◽  
South Wales ◽  
Severity Of The Disease ◽  
High Level ◽  
Disease Pressure ◽  
And Control

Powdery mildew—caused by the fungus Erisyphe diffusa (syn. Microsphaera diffusa)—was first observed in commercial soybean crops in southern New South Wales (NSW), Australia, in 2011. Its detection raised concerns that soybean production might be constrained if the severity of the disease reached the levels observed in northern Australia. Field experiments were conducted over four consecutive seasons to examine the response of three soybean cultivars—Djakal, SnowyA and the breeding line N005A-80—to two fungicides and two fungicide application regimes. The cultivar Djakal was identified as having a high level of resistance to powdery mildew. The severity of infection symptoms varied between seasons. The most severe symptoms were observed during the 2014–2015 season which resulted in the largest grain yield reduction of 20% for the cultivar SnowyA. All fungicide treatments provided a significant reduction in the severity of symptoms, with the split application of tebuconazole and both the single and split applications of tebuconazole + prothioconazole providing the most effective control of the disease. Few other grain yield effects were found, even when strong disease control was achieved. This was a suspected result of the consistent late-in-the-season onset of the disease. Few differences were observed among the treatments in terms of lodging severity, date of physiological maturity, or grain oil and protein concentrations. It was concluded that both fungicides provided effective control of powdery mildew. However, when disease pressure is low, application might not be warranted in southern NSW.

Effect of time sowing and cultivar on the development and grain yield of irrigated wheat in the Macquarie Valley, New South Wales

1992 ◽  
Vol 32 (3) ◽  
pp. 345 ◽  
Author(s):  
JL Cooper
Keyword(s):  
Grain Yield ◽  
Field Experiments ◽  
New South ◽  
New South Wales ◽  
Moisture Stress ◽  
Frost Damage ◽  
Yield Reduction ◽  
Detectable Effect ◽  
South Wales ◽  
Wide Range

Field experiments over 2 seasons in the Macquarie Valley of central New South Wales compared yields under irrigation of 5 wheat varieties with a wide range of maturities sown from 8 April to 27 August.Early maturity wheats (Yecora and Avocet) sown prior to 6 May suffered frost damage, while the winter wheats (WW33G and Burgas) sown after 29 July were not fully vernalised and most tillers failed to produce heads. There was a curvilinear relation between time of sowing and grain yield. Excluding the treatments which suffered frost damage, the earliest time of sowing (8 April) produced the highest yield, with a 6.4% yield reduction between 8 April and 8 May. The yield reduction increased with later sowing date: 13.3, 19.3, and 26.5% during May, June, and July. Anthesis in mid September produced the highest yields for all varieties. Treatments which flowered earlier than mid September suffered frost damage. For each day later than 15 September that anthesis occurred, the mean yield fell by 1.3% or about 68 kg/ha.day. Date of anthesis had no detectable effect on the rate of individual grain growth (1.3 mg/grain.day), but the later anthesis occurred, the shorter the duration of grain development and the lower the final grain weight. Rising temperatures, not moisture stress, seems to be the factor causing the decline in yield with late sowing. This experiment was irrigated to eliminate moisture stress but the decline in yield was similar to that reported for dryland crops.

Yellow Nutsedge (Cyperus esculentus) Competition and Control in Corn (Zea mays)

Weed Science ◽  
1979 ◽  
Vol 27 (1) ◽  
pp. 32-37 ◽  
Author(s):  
E. W. Stoller ◽  
L. M. Wax ◽  
F. W. Slife
Keyword(s):  
Zea Mays ◽  
Control Measures ◽  
Effective Control ◽  
Yield Reduction ◽  
Cyperus Esculentus ◽  
Yellow Nutsedge ◽  
Effective Combination ◽  
Percentage Yield ◽  
Hand Weeding ◽  
And Control

Competition of yellow nutsedge (Cyperus esculentusL.) with corn (Zea maysL.) was evaluated in the field at various yellow nutsedge densities over a 3-yr period. A relationship between yellow nutsedge density (shoots/m2) and percentage yield reduction revealed an 8% yield reduction for every 100 shoots/m2. Two 3-yr studies were conducted to determine the most effective combination of preplant-incorporated, postemergence, or postemergence-directed treatments for yellow nutsedge control in corn. The preplant incorporated treatments were alachlor [2-chloro-2′,6′-diethyl-N-(methoxymethyl)acetanilide], EPTC (S-ethyl dipropylthiocarbamate), or nothing; postemergence treatments were bentazon [3-isopropyl-1H-2,1,3-benzothiadiazin-(4) 3H-one 2,2-dioxide], two cultivations, or nothing; and the postemergence-directed treatments were ametryn [2-(ethylamino)-4-(isopropylamino)-6-(methylthio)-s-triazine] or nothing. One preplant-incorporated treatment of EPTC or alachlor prevented yield reductions from yellow nutsedge competition. When no control was practiced, yields were reduced 17% in a moderate yellow nutsedge infestation (initially infested with 300 tubers/m2) and 41% in a heavy infestation (initially infested with 1200 tubers/m2). Yields were reduced 7 to 8% in the moderate infestation when no preplant-incorporated treatments were used regardless of whether postemergence or postemergence-directed treatments were also used. After 1 yr, all control measures resulted in less tuber density than no control measures, but all control treatments had essentially similar tuber densities. After the second year, several herbicide treatments were as effective as hand weeding in reducing tuber density. At least 2 yr of effective control treatments were required to reduce tubers to 20% of the original density, and 3 yr of treatment to reduce the density to 15% of the original density. No combination of treatments, including hand weeding, eliminated tubers after 3 yr.

Effect of sowing rate on grain yield, kernel weight, and grain protein percentage of barley (Hordeum vulgare L.) in northern New South Wales

1992 ◽  
Vol 32 (4) ◽  
pp. 465 ◽  
Author(s):  
AD Doyle ◽  
RW Kingston
Keyword(s):  
Hordeum Vulgare ◽  
Grain Yield ◽  
Field Experiments ◽  
New South ◽  
New South Wales ◽  
Kernel Weight ◽  
Grain Protein ◽  
Hordeum Vulgare L ◽  
Protein Percentage ◽  
South Wales

The effect of sowing rate (10-110 kg/ha) on the grain yield of barley (Hordeum vulgare L.) was determined from a total of 20 field experiments conducted in northern New South Wales from 1983 to 1986. Effects of sowing rate on kernel weight and grain protein percentage were also determined from 12 experiments conducted in 1985 and 1986. Two barley varieties were tested each year. In all years fallow plus winter rainfall was equal to or greater than average. Grain yield increased with higher sowing rates in most experiments, with the response curve reaching a plateau above 60-70 kg/ha. For 13 of the 40 variety x year combinations, grain yield fell at the highest sowing rates. Only in an experiment where lodging increased substantially with higher sowing rates was there a reduction in yield at a sowing rate of 60 kg/ha. The average sowing rate for which 5 kg grain was produced per kg of seed sown was 63 kg/ha. Grain protein percentage usually fell, and kernel weight invariably fell, with increasing sowing rate. Increasing sowing rates from the normal commercial rate of 35 kg/ha to a rate of 60 kg/ha typically increased grain yields by 100-400 kg/ha, decreased kernel weight by 0.4-2.0 mg, and decreased grain protein by up to 0.5 percentage points. In no case was the grain weight reduced to below malting specifications. It was concluded that sowing rates for barley in northern New South Wales should be increased to about 60 kg/ha.

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 Split Applications of Copper Fungicides Improve Control of Melanose on Grapefruit in Florida

Plant Disease ◽  
1998 ◽  
Vol 82 (9) ◽  
pp. 983-986 ◽  
Author(s):  
L. W. Timmer ◽  
S. E. Zitko ◽  
L. G. Albrigo
Keyword(s):  
Field Experiments ◽  
Metallic Copper ◽  
Effective Control ◽  
Control Analysis ◽  
Fresh Market ◽  
Copper Fungicides ◽  
Net Returns ◽  
The One ◽  
Disease Pressure ◽  
Application Programs

Citrus melanose, caused by Diaporthe citri, is a major disease of fresh market grapefruit which is controlled primarily by preventive applications of copper fungicides. The goal of this research was to improve melanose control without increasing the total amount of metallic copper utilized. Disease control was assessed in field experiments for 3 years using one, two, three, or four applications of copper fungicides in which the same total amount of metallic copper was applied per season in each program. Melanose was severe in 1995 and 1997, and the four-application schedule provided better control than the one-, two-, or three-application programs. In 1996, disease pressure was low and all programs and fungicides provided equally effective control. Analysis of copper residues on the fruit indicated that loss of protection was attributable more to increase in fruit surface area when fruit were growing rapidly than to removal of copper by weathering. On larger, slower-growing fruit, loss of copper residues was apparently due to both factors. Economic evaluation of improved packouts of fresh market fruit and additional application costs indicated that net returns would be increased by $650 to $1,250 per hectare during years in which melanose was severe when the four-spray program was compared to a single spray.

A comparison of tri-allate formulations for control of wild oats in wheat in northern New South Wales

1989 ◽  
Vol 29 (2) ◽  
pp. 215
Author(s):  
RJ Martin ◽  
WL Felton ◽  
AJ Somervaille
Keyword(s):  
Grain Yield ◽  
Field Experiments ◽  
Crop Residues ◽  
New South ◽  
New South Wales ◽  
Liquid Formulation ◽  
Wheat Grain ◽  
Wild Oats ◽  
South Wales ◽  
Glasshouse Experiment

Three field trials and a glasshouse experiment were carried out in northern New South Wales to determine the effects of reduced mechanical incorporation and the presence of crop residues on the efficacy of liquid and granular formulations of triallate [S-(2,3,3-trichioroallyl) diisopropylthiocarbamate] for control of wild oats (Avena fatua and A. sterilis ssp. ludoviciana) in wheat. In field experiments, fallow management practices with surface crop residues ranging from nil to complete retention from the previous wheat crop, did not affect the performance of tri-allate (incorporated by sowing) in terms of control of wild oats and wheat grain yield response. Application of a granular formulation resulted in lower than expected wheat grain yields in 2 of the field experiments and phytotoxicity to the crop was suspected as the reason. Although soil incorporation improved the performance of tri-allate at the recommended rate of 0.8 kg/ha, satisfactory control of wild oats and profitable increases in wheat grain yield were obtained with tri-allate at 1.2 kg/ha when incorporated by sowing into seedbeds containing up to 2 t/ha of crop residue. We conclude that tri-allate as the liquid formulation at 1.2 kg/ha gives economic control of wild oats in no-tillage and stubble-mulched seedbeds when incorporated by sowing provided that the weed-free wheat grain yield potential is not less than 1.5 t/ha. Results from the glasshouse experiment, farmer experience and published literature support the practice of incorporating tri-allate into dry soil with subsequent activation by sowing rain. The potential use of the granular formulation is limited by the greater risk of crop damage compared with the liquid formulation.

scholarly journals Source capacity during flowering affects grain yield of amaranth (Amaranthus sp.)

2013 ◽  
Vol 59 (No. 10) ◽  
pp. 472-477 ◽  
Author(s):  
B. Roitner-Schobesberger ◽  
Kaul H-P
Keyword(s):  
Grain Yield ◽  
Dry Matter ◽  
Field Experiments ◽  
Growth Conditions ◽  
Yield Reduction ◽  
Sources And Sinks ◽  
Yield Level ◽  
Eastern Austria ◽  
Source Sink ◽  
Yield Formation

Amaranth is a promising C4-crop. However, for a wider spread of the crop a better understanding of factors that are influencing yield formation is crucial for optimizing the plant phenotype and enhancing yield. The present study wanted to clarify the effects of assimilate sources and sinks on yield formation by artificially altering source or sink size. Field experiments were conducted in Eastern Austria during three years with three genotypes, applying source-sink manipulation treatments at mid flowering (control, 50% of inflorescence removed, 50% or 100% of leaves removed). At maturity we measured shoot, inflorescence and grain dry matter, thousand kernel mass and number of seeds per plant. An average grain yield level of about 3.5 t/ha dry matter on control plots indicated favorable growth conditions for amaranth in general. The removal of all leaves had a strong detrimental effect on all parameters, but severity of yield reduction due to defoliation differed between genotypes, ranging from –49% to –73%. Contrastingly, 50% flower reduction did not have any significant effects. Also with 50% defoliation no significant yield reduction was observed. We conclude that source strength of amaranth during flowering is more yield limiting than its sink capacity.

Agronomic Evaluation of Performance of Sesame Varieties in Maize-based Intercropping System in the Southern Guinean Savanna of Nigeria

2019 ◽  
pp. 1-10
Author(s):  
A. T. Ajibola ◽  
G. O. Kolawole
Keyword(s):  
Grain Yield ◽  
Field Experiments ◽  
Block Design ◽  
Yield Reduction ◽  
K Value ◽  
Land Equivalent Ratio ◽  
Sesame Seeds ◽  
Evaluation Of Performance ◽  
Percentage Yield ◽  
Cropping Seasons

Aims: Field experiments were conducted to determine compatibility of sesame varieties for intercropping with maize. Study Design: The experiment was a randomized complete block design with three replications. Place and Duration of Study: Teaching and Research Farm, LAUTECH, Ogbomoso, southern guinea savanna area of Nigeria during the 2010 and 2011 cropping seasons. Methodology: The treatments included Sole maize (Oba Super 1 variety), five sole sesame varieties (E-8, O3l, O1m, O2 m, Exotic-Sudan) and their intercrops, making a total of eleven treatments.  Sole maize was planted at a spacing of 75 cm x 25 cm. For intercrops, maize was planted at a spacing of 100 cm x 25  cm and sesame seeds were planted at a spacing of 100 cm x 10 cm such that sesame row alternated maize row. Maize was planted first and sesame was introduced two weeks after. Results: Intercropping maize with sesame varieties significantly (P = 0.05) reduced number of pods and grain yield of sesame varieties in both years. However, variety O2m produced grain yield in the intercrop similar to the mono crop. Generally, Intercropping sesame with maize significantly reduced the grain yield of maize by 36% compared to the sole crop. Exotic-Sudan varieties caused the highest percentage yield reduction (52%). Sesame varieties O2m and O3l were the only varieties whose yield advantage in intercropping with maize had land equivalent ratio (LER) of 1.28 and 1.18 while other varieties had values less than 1 indicating yield advantage of O2m and O3l with maize. The relative crowding coefficient (K) value of maize (4.98) was higher than sesame (0.44) thus indicating its dominance in the mixture. Conclusion: It is concluded that the prospective sesame farmers could grow varieties O2m and O3l in place of the popular E-8 because intercropping with maize did not affect their performances in both years.

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.

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