scholarly journals Field assessment of corn yield losses and compensatory yield for infested plants by Lepidopteran stem borers in different sowing dates at El-Behiera governorate, Egypt.

2020 ◽  
Vol 13 ◽  
pp. 31-40
Author(s):  
Al-Eryan M. A. S ◽  
Abu- Shall Amany M. H. ◽  
Ibrahiem H. K. ◽  
Huessein Hanaa S.
Keyword(s):  
Total Yield ◽  
Maize Yield ◽  
Simple Linear Regression ◽  
Yield Losses ◽  
Stem Borers ◽  
Yellow Corn ◽  
Maize Varieties ◽  
Increase Rate ◽  
Economic Injury

Whenever the determination of yield loss and economic injury levels are essential tools for initiating integrated pest management (IPM) programs in the maize field, the assessment of compensatory yield is very important for determinate the accurate losses in the field and the recovery power for the maize verity. The present study aimed to estimate the yield losses of three maize varieties due to Sesamia critica and Ostrinia nubilalis, infestation; regression between maize yield losses and percent of infestation and determine the compensatory yield arising in intact plants as a result of absence or dead (caused by infestation) of adjacent plants under field conditions in El-Behiera governorate. The present results showed that yield losses resulting from S. cretica infestation in early sowed maize ranged from 5.29 – 32.17%. In case of maize that sowed in recommended date “June”, yield losses due to S. cretica was slightly decreased, and it accompanied with O. nubilalis infestation in two fields, which increased the total yield losses. A simple linear regression turned out between the percentage of infestation of S. cretica or O. nubilalis and percentage of yield losses, with R2 values 0.84 and 0.45, respectively. The yellow corn was more tolerant to stem borers infestation than white corn with percentages of increase rate in compensatory yield 27.07 %.  Whenever the determination of yield loss and economic injury levels are essential tools for initiating integrated pest management (IPM) programs in the maize field, the assessment of compensatory yield is very important for determinate the accurate losses in the field and the recovery power for the maize verity. The present study aimed to estimate the yield losses of three maize varieties due to Sesamia critica and Ostrinia nubilalis, infestation; regression between maize yield losses and percent of infestation and determine the compensatory yield arising in intact plants as a result of absence or dead (caused by infestation) of adjacent plants under field conditions in El-Behiera governorate. The present results showed that yield losses resulting from S. cretica infestation in early sowed maize ranged from 5.29 – 32.17%. In case of maize that sowed in recommended date “June”, yield losses due to S. cretica was slightly decreased, and it accompanied with O. nubilalis infestation in two fields, which increased the total yield losses. A simple linear regression turned out between the percentage of infestation of S. cretica or O. nubilalis and percentage of yield losses, with R2 values 0.84 and 0.45, respectively. The yellow corn was more tolerant to stem borers infestation than white corn with percentages of increase rate in compensatory yield 27.07 %.  

scholarly journals Uncertainties In The Effectiveness of Biological Control of Stem Borers Under Different Climate Change Scenarios In Eastern Africa

2021 ◽  
Author(s):  
Ines Gwendolyn Jendritzki ◽  
Henri E. Z. Tonnang ◽  
Paul-André Calatayud ◽  
Christian Borgemeister ◽  
Tino Johansson ◽  
...  
Keyword(s):  
Climate Change ◽  
Biological Control ◽  
Insect Pests ◽  
Maize Yield ◽  
Stem Borer ◽  
Eastern Africa ◽  
Climate Change Scenarios ◽  
Agricultural Crop ◽  
Yield Losses ◽  
Stem Borers

Abstract Climate change (CC) is expected to significantly affect biodiversity and ecosystem services. Adverse impacts from CC in the Global South are likely to be exacerbated by limited capacities to take adequate adaptation measures and existing developmental challenges. Insect pests today are already causing considerable yield losses in agricultural crop production in East Africa. Studies have shown that insects are strongly responding to CC by proliferation, shift in distribution or by altering their phenology, which is why an impact on agriculture can also be expected. Biological control (BC) has been proposed as an alternative measure to sustainably contain insect pests but few studies predict its efficacy under future CC. Using the species distribution modelling approach Maxent, we predict the current and future distribution of three important lepidopteran stem borer pests of maize in eastern Africa, i.e., Busseola fusca (Fuller, 1901), Chilo partellus (Swinhoe, 1885) and Sesamia calamistis (Hampson, 1910), and two of their parasitoids that are currently used for BC, i.e., Cotesia flavipes (Cameron, 1891) and Cotesia sesamiae (Cameron, 1906) . Based on these potential distributions and data collected during household surveys with local farmers in Kenya and Tanzania, future maize yield losses are predicted for a business-as-usual scenario and a sustainable development scenario. Accordingly, we found that BC of the three stem borer pests by C. flavipes and C. sesamiae will be less effective under more severe CC resulting in a reduced ability to curb maize yield losses caused by the stem borers. These results highlight the need to adapt BC measures to future CC to maintain its potential for environmentally-friendly pest management strategies. The findings of this research are thus of particular relevance to policy makers, extension officers and farmers in the region and will aid the adaptation of smallholder agricultural practices to current and future impacts of CC.

scholarly journals Economic Threshold of Volunteer Corn GR® in Soybean as a Function of Emergence Time and Origin of Corn

2018 ◽  
Vol 36 (0) ◽  
Author(s):  
C. PIASECKI ◽  
M.A. RIZZARDI
Keyword(s):  
Field Experiments ◽  
Individual Plant ◽  
Yield Losses ◽  
Emergence Time ◽  
Economic Threshold ◽  
Control Cost ◽  
Soybean Yield ◽  
Volunteer Corn ◽  
Corn Plants

ABSTRACT: Volunteer corn is extremely competitive with soybean and the degree of interference varies with the corn density, time of emergence and origin. The objectives of this work were to determine the economic threshold (ET) of volunteer corn GR® F2 in soybean as a function of the time of emergence (same day and nine days after soybean) and origin (individual plants or clumps). Each clump was manually adjusted to have seven corn plants. Four field experiments were conducted in randomized blocks design with four replicates in Passo Fundo, RS, Brazil. The soybean yield losses (%) were calculated and adjusted to the model of the rectangular hyperbola and generated the parameters for the determination of the ET, that was calculated based on the volunteer corn control costs (US$ ha-1), efficiency of control (%), price paid for soybean (US$ kg-1) and soybean yield (kg ha-1). The ET mean was 0.3 and 0.48 for individual corn plants m-2 emerged together and nine days after soybean, and 0.08 and 0.03 m-2 for individual plants and clumps, respectively. Increases in grain yield and price paid for soybean, greater control efficiency of corn and lower control cost promote reduction in the ET of volunteer corn in soybean. The control of volunteer corn is justified in a density less than 0.5 individual plant m-2 and is close to zero when corn originates from clumps. Volunteer corn is one of the most competitive weed in soybean crops.

scholarly journals The Impact of Nitrogen Fertilization and the Use of Biostimulants on the Yield of Two Maize Varieties (Zea mays L.) Cultivated for Grain

Agronomy ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1408
Author(s):  
Krzysztof Kapela ◽  
Anna Sikorska ◽  
Marek Niewęgłowski ◽  
Ewa Krasnodębska ◽  
Krystyna Zarzecka ◽  
...  
Keyword(s):  
Nitrogen Fertilization ◽  
Control Object ◽  
Maize Yield ◽  
Family Farm ◽  
Maize Varieties ◽  
Maize Grain ◽  
Set Up ◽  
Hybrid Cultivar ◽  
The Impact

The field experiment was carried out in 2015–2017 on a family farm in Toczyski Czortki, in the Mazovia voivodeship in Poland. The experiment was set up in a split–split–plot system in three replications. The area of one plot was 30 m−2. The studied factors were: I—two maize varieties: PR38N86 (medium late hybrid cultivar 280 FAO), P8400 (medium early hybrid cultivar 240 FAO); II—four doses of nitrogen fertilization: 1. control object—without the use of nitrogen (0 kg N·ha−1), 2. nitrogen dose—80 kg N·ha−1 (applied once before sowing), 3. nitrogen dose—120 kg N·ha−1 (applied once before sowing), 4. nitrogen dose—160 kg N·ha−1 (applied once before sowing); III—four types of biostimulants used: 1. control object—without using a biostimulant, 2. Asahi®SL biostimulant: I term—four-leaf phase (BBCH 14) at a dose of 0.60 dm3∙ha−1, II term—eight-leaf phase (BBCH 18) at a dose of 0.60 dm3∙ha−1, 3. Improver® biostimulant: I term—four-leaf phase (BBCH 14) at a dose of 1.00 dm3∙ha−1, II term—eight-leaf phase (BBCH 18) at a dose of 0.60 dm3∙ha−1, 4. Zeal® biostimulant: I term—six-leaf phase (BBCH 16) at a dose of 2.00 dm3∙ha−1. The aim of the study was to determine the effect of nitrogen fertilization and the use of biostimulants on the size and quality of yield of two varieties of maize grown for grain. Based on the conducted research, it was found that nitrogen doses influenced the amount of maize grain obtained. The highest yields were obtained using 120 kg N∙ha−1. Nitrogen doses significantly affected the studied maize yield components. The dose of 120 kg N∙ha−1 increased the number of grains in the cob, while the dose—160 kg N∙ha−1 exerted the best effect on obtaining the highest values of a thousand seeds. The biostimulants used in the experiment significantly affected the mass of one thousand seeds and the number of grains in the cob. In addition, Asahi®SL, Improver® and Zeal® biostimulants increased maize yield in each growing season studied.

Maize Yield Losses Caused by Southern Corn Rust 1

Crop Science ◽  
1980 ◽  
Vol 20 (6) ◽  
pp. 812-814 ◽  
Author(s):  
Roduel Rodriguez‐Ardon ◽  
Gene E. Scott ◽  
Stanley B. King
Keyword(s):  
Maize Yield ◽  
Yield Losses ◽  
Southern Corn Rust

scholarly journals Mitigating Striga hermonthica parasitism and damage in maize using soybean rotation, nitrogen application, and Striga-resistant varieties in the Nigerian savannas

2020 ◽  
Vol 56 (4) ◽  
pp. 620-632
Author(s):  
Alpha Y. Kamara ◽  
Abebe Menkir ◽  
David Chikoye ◽  
Abdullahi I. Tofa ◽  
Aminu A. Fagge ◽  
...  
Keyword(s):  
Integrated Management ◽  
Maize Yield ◽  
Striga Hermonthica ◽  
Nitrogen Application ◽  
N Application ◽  
Resistant Varieties ◽  
Moisture Deficit ◽  
Maize Varieties ◽  
Control Technologies ◽  
On Farm

AbstractStriga hermonthica infestation causes significant losses of maize yield in the Nigerian savannas and several technologies have been developed and promoted to control Striga in maize. However, since no single technology has been found to be effective against Striga, integrated management is needed to achieve satisfactory and sustainable Striga control. Both on-station and on-farm trials were undertaken from 2013 to 2015 in Bauchi and Kano States of Nigeria to evaluate the performance of integrated Striga control technologies. In the on-station trials, a soybean–maize rotation did not suppress Striga in maize in either location. However, nitrogen application suppressed and reduced Striga infection, except in Bauchi in 2014. The soybean–maize rotation accompanied by N application reduced Striga damage in both locations. On farmers’ fields, rotating soybean with maize significantly reduced Striga infection. At the same time, the use of maize varieties with a combined tolerance to drought and resistance to Striga parasitism also increased maize grain yield on farmers’ fields, probably due to three factors: a reduction in Striga infection, reduced effects of a mid-season moisture deficit, and increased uptake of nutrients from the soil. We concluded that the use of Striga-resistant maize varieties in combination with the application of N fertilizer and rotation with soybean could increase the productivity of maize in Striga-infested fields in the Nigerian savannas.

Determination of Zearalenone in Corn: Collaborative Study

1976 ◽  
Vol 59 (3) ◽  
pp. 666-670
Author(s):  
Odette L Shotwell ◽  
Marion L Goulden ◽  
Glenn A Bennett
Keyword(s):  
Statistical Analysis ◽  
Thin Layer ◽  
Coefficient Of Variation ◽  
Collaborative Study ◽  
Corn Sample ◽  
Yellow Corn ◽  
Coefficients Of Variation ◽  
The Mean

Abstract Corn samples spiked at levels of 100, 300, 1000, and 2000 μg zearalenone/kg were sent to 22 collaborators for analysis by the Eppley method. All samples were yellow corn except one white corn sample spiked at 2000 μg/kg. Results from 16 collaborators were statistically analyzed. Only 4 of 16 collaborators detected zearalenone in the sample containing 100 μg/kg, but 11 detected the toxin in the sample containing 300 μg/kg. Average recoveries from all samples were 129% at 300 μg/kg, 101% at 1000 μg/kg, and 88% at 2000 μg/kg. The between-laboratory coefficients of variation were 53.0% at 300 μg/kg, 38.2% at 1000 μg/kg, and 27.0% at 2000 μg/kg. Five naturally contaminated corn samples, one in triplicate, were also provided. The mean level of zearalenone in the naturally contaminated samples ranged from 431 to 7622 μg/kg. The mean coefficient of variation for all samples was 40.5%. Two collaborators measured quantities of zearalenone on thin layer chromatographic plates densitometrically. Their results were not included in the statistical analysis, but the results indicated that densitometric measurement, given proper dilutions of solutions, could be used. The method has been adopted as official first action.

Relative Sowing Time and Density of Component Crops in a Maize/Cowpea Intercrop System

1987 ◽  
Vol 23 (1) ◽  
pp. 41-52 ◽  
Author(s):  
Francis Ofori ◽  
W. R. Stern
Keyword(s):  
Seed Protein ◽  
Total Yield ◽  
Maize Yield ◽  
Protein Yield ◽  
Sowing Time ◽  
Maize Yields ◽  
Total Seed

SUMMARYThe effect of variations in the relative sowing time and density of component crops in a maize/cowpea intercrop were examined in two experiments. In the first experiment, maize and cowpea were sown together, and either 10 or 21 days before or after each other. Maize yield was reduced when sown at the same time or after cowpea; intercrop cowpea yields were less than sole cowpea yields at all sowings. In the second experiment, maize densities of 35, 50 and 70 × 103plants ha−1were combined with cowpea densities of 70, 100 and 140 × 103plants ha−1. Increasing the density of either crop in the mixture resulted in increases in total yield. Maize reduced cowpea yields more than the effect of cowpea on maize yields. In terms of LER and total seed protein yield, there was no advantage of either staggered sowings over simultaneous sowing or of the various intercrop density combinations, except between the lowest and the highest densities of either maize or cowpea. The LERs appeared to follow the trends in cowpea yields and total seed protein yields the trends in maize yields.

International Mycotoxin Check Sample Program: Part I. Report on Laboratory Performance for Determination of Aflatoxins B1, B2, G1, and G2 in Raw Peanut Meal, Deoiled Peanut Meal, and Yellow Corn Meal

1982 ◽  
Vol 65 (4) ◽  
pp. 855-863
Author(s):  
Marlin D Friesen ◽  
Liliane Garren
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
High Performance ◽  
Peanut Meal ◽  
Check Sample ◽  
Corn Meal ◽  
Sufficient Data ◽  
Statistical Comparison ◽  
Yellow Corn

Abstract Three aflatoxin-contaminated samples (raw peanut meal, deoiled peanut meal, and yellow corn meal) were analyzed by 121 laboratories in 31 countries. Sufficient data were obtained to permit a statistical comparison of the performance of laboratories using the BF, CB, and EEC methods and those using high performance liquid chromatography (HPLC) for quantitation. No significant differences were found between means for laboratories using these 4 methods for the analysis of raw peanut meal or yellow corn meal. However, for deoiled peanut meal, means were significantly different for laboratories using the BF method compared with the CB or EEC methods for B1 and B2, and for laboratories using the CB method compared with HPLC methods for G2.

scholarly journals Unravelling the variability and causes of smallholder maize yield gaps in Ethiopia

Food Security ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 83-103 ◽  
Author(s):  
Banchayehu Tessema Assefa ◽  
Jordan Chamberlin ◽  
Pytrik Reidsma ◽  
João Vasco Silva ◽  
Martin K. van Ittersum
Keyword(s):  
Stochastic Frontier Analysis ◽  
National Level ◽  
Total Yield ◽  
Maize Yield ◽  
Sub Saharan Africa ◽  
Yield Gap ◽  
Potential Yield ◽  
Frontier Analysis ◽  
Yield Gaps ◽  
Maize Yields

AbstractEthiopia has achieved the second highest maize yield in sub-Saharan Africa. Yet, farmers’ maize yields are still much lower than on-farm and on-station trial yields, and only ca. 20% of the estimated water-limited potential yield. This article provides a comprehensive national level analysis of the drivers of maize yields in Ethiopia, by decomposing yield gaps into efficiency, resource and technology components, and accounting for a broad set of detailed input and crop management choices. Stochastic frontier analysis was combined with concepts of production ecology to estimate and explain technically efficient yields, the efficiency yield gap and the resource yield gap. The technology yield gap was estimated based on water-limited potential yields from the Global Yield Gap Atlas. The relative magnitudes of the efficiency, resource and technology yield gaps differed across farming systems; they ranged from 15% (1.6 t/ha) to 21% (1.9 t/ha), 12% (1.3 t/ha) to 25% (2.3 t/ha) and 54% (4.8 t/ha) to 73% (7.8 t/ha), respectively. Factors that reduce the efficiency yield gap include: income from non-farm sources, value of productive assets, education and plot distance from home. The resource yield gap can be explained by sub-optimal input use, from a yield perspective. The technology yield gap comprised the largest share of the total yield gap, partly due to limited use of fertilizer and improved seeds. We conclude that targeted but integrated policy design and implementation is required to narrow the overall maize yield gap and improve food security.

Sign in / Sign up

Export Citation Format

Share Document