scholarly journals Suppression of Phytophthora Blight in Bell Pepper by a No-Till Wheat Cover Crop

1997 ◽  
Vol 87 (3) ◽  
pp. 242-249 ◽  
Author(s):  
Jean B. Ristaino ◽  
Gregory Parra ◽  
C. Lee Campbell
Keyword(s):  
Cover Crop ◽  
Cultural Practices ◽  
Irrigation System ◽  
Disease Incidence ◽  
Cropping System ◽  
Bell Pepper ◽  
Phytophthora Blight ◽  
Plastic Mulch ◽  
Initial Inoculum ◽  
No Till

Four mechanisms of dispersal of propagules of Phytophthora capsici were investigated through modifications in cultural practices and fungicide applications in field plots of bell pepper (Capsicum annuum). Dispersal of soil inoculum was suppressed, and final incidence of disease was 2.5 to 43% when stubble from a fall-sown, no-till, wheat cover crop was present. Final disease incidence was 71 to 72% and pathogen spread occurred within and across rows when all dispersal mechanisms were operative in plots of pepper planted into bare soil. Final disease incidence was 42 to 78% with black plastic mulch when a sporulating pepper fruit placed on the surface served as the source of initial inoculum. The fungicide metalaxyl applied in the irrigation system did not suppress within-row spread of surface inoculum from a sporulating fruit on plastic, but did limit across-row spread; final disease incidence in metalaxyl-treated plots was 11.5 to 14%. Pathogen dispersal mechanisms were modified most dramatically by the no-till cropping system. Thus, simple changes in cultural practices can have dramatic effects on the development of Phytophthora epidemics. Ecologically based disease management strategies have the potential to reduce our reliance on agrichemicals in this and similar pathosystems.

scholarly journals Progress of soybean charcoal rot under tillage and no-tillage systems in Brazil

2003 ◽  
Vol 28 (2) ◽  
pp. 131-135 ◽  
Author(s):  
Álvaro M. R. Almeida ◽  
Lilian Amorim ◽  
Armando Bergamin Filho ◽  
Eleno Torres ◽  
José R. B. Farias ◽  
...  
Keyword(s):  
Cropping Systems ◽  
Disease Incidence ◽  
Cropping System ◽  
Macrophomina Phaseolina ◽  
Conventional System ◽  
Survival Times ◽  
Charcoal Rot ◽  
No Till ◽  
Four Seasons ◽  
Conventional Systems

The increase in incidence of charcoal rot caused by Macrophomina phaseolina on soybeans (Glycine max) was followed four seasons in conventional and no-till cropping systems. In the 1997/98 and 2000/01 seasons, total precipitation between sowing and harvest reached 876.3 and 846.9 mm, respectively. For these seasons, disease incidence did not differ significantly between the no-till and conventional systems. In 1998/99 and 1999/00 precipitation totaled 689.9 and 478.3 mm, respectively. In 1998/99, in the no-till system, the disease incidence was 43.7% and 53.1% in the conventional system. In 1999/00 the final incidence was 68.7% and 81.2% for the no-till and conventional systems, respectively. For these two seasons, precipitation was lower than that required for soybean crops (840 mm), and the averages of disease incidence were significantly higher in the conventional system. The concentration of microsclerotia in soil samples was higher in samples collected in conventional system at 0 - 10 cm depth. However, analysis of microsclerotia in roots showed that in years with adequate rain no difference was detected. In dry years, however, roots from plants developed under the conventional system had significantly more microsclerotia. Because of the wide host range of M. phaseolina and the long survival times of the microsclerotia, crop rotation would probably have little benefit in reducing charcoal rot. Under these study conditions it may be a better alternative to suppress charcoal rot by using the no-till cropping system to conserve soil moisture and reduce disease progress.

scholarly journals Association of Chocolate Spot and Faba Bean Rust Epidemics with Climate Change Resilient Cultural Practices in Bale Highlands, Ethiopia

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Gosaye Eshetu ◽  
Yekedem Bimrew ◽  
Hassen Shifa
Keyword(s):  
Faba Bean ◽  
Weed Management ◽  
Management Practices ◽  
Cultural Practices ◽  
Disease Incidence ◽  
Cropping System ◽  
Previous Crop ◽  
Multiple Variable ◽  
Chocolate Spot ◽  
The Mean

Field survey was conducted in south eastern Ethiopia to determine the disease intensity of chocolate spot and rust and to investigate the association of disease intensity (incidence and severity) with environmental factors and crop cultural practices. A total of 280 faba bean fields were surveyed in eight districts, and type of cropping system, weed management practices, crop growth stage, previous crop in the field, and sowing date were recorded. The associations of disease intensity with independent variables were evaluated using logistic regression model. Mean disease incidence of chocolate spot varied from 70.9 to 93.2% in most fields while percentage severity index (PSI) ranged from 10.5 to 47.1%. In a reduced multiple variable model, chocolate PSI ≤ 30% showed high probability of association with mixed cropping system, good weed management practices, late planting, and when faba bean was rotated with vegetables and cereals. The mean disease incidence of faba bean rust was varied from 23.6 to 78.2%, while the mean PSI of rust was varied from 4.8 to 37.9%. In Gasera, Dinsho, and Agarfa districts, poor weed management practices, fields planted in the month of July, and when previous crop was legume had a high probability of association to (>20) rust PSI in a multiple variable reduced model. In contrast, soil types, fertilizer applied, and fungicides sprayed were not associated with disease intensity. The present study has identified cropping system, planting date, previous crop, district, and weed management practices as important variables that influence faba bean chocolate spot and rust epidemics in diversified fields. Therefore, proper weeding management practices, late planting, crop rotation habit, and other related farm practices should be carried out to reduce chocolate spot and rust impact until resistant faba bean genotypes are developed and distributed to the area.

scholarly journals Evaluation of the Agronomic Performance of Organic Processing Tomato as Affected by Different Cover Crop Residues Management

Agronomy ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 504 ◽  
Author(s):  
Abou Chehade ◽  
Antichi ◽  
Martelloni ◽  
Frasconi ◽  
Sbrana ◽  
...  
Keyword(s):  
Plant Growth ◽  
Cover Crop ◽  
Nitrogen Availability ◽  
Crop Residues ◽  
N Uptake ◽  
Total Yield ◽  
Soluble Solids ◽  
Plastic Mulch ◽  
Processing Tomato ◽  
No Till

No-till practices reduce soil erosion, conserve soil organic carbon, and enhance soil fertility. Yet, many factors could limit their adoption in organic farming. The present study investigated the effects of tillage and cover cropping on weed biomass, plant growth, yield, and fruit quality of an organic processing tomato (Solanum lycopersicon L. var. Elba F1) over two seasons (2015–2017). We compared systems where processing tomato was transplanted on i) tilled soil following or not a winter cover crop (Trifolium squarrosum L.) and with/without a biodegradable plastic mulch; and ii) no-till where clover was used, after rolling and flaming, as dead mulch. Tomato in no-till suffered from high weed competition and low soil nitrogen availability leading to lower plant growth, N uptake, and yield components with respect to tilled systems. The total yield in no-till declined to 6.8 and 18.3 t ha−1 in 2016 and 2017, respectively, with at least a 65% decrease compared to tilled clover-based systems. No evidence of growth-limiting soil compaction was noticed but a slightly higher soil resistance was in the no-till topsoil. Tillage and cover crop residues did not significantly change tomato quality (pH, total soluble solids, firmness). The incorporation of clover as green manure was generally more advantageous over no-till. This was partly due to the low performance of the cover crop where improvement may limit the obstacles (i.e., N supply and weed infestation) and enable the implementation of no-till in organic vegetable systems.

scholarly journals Insensitivity to Ridomil Gold (Mefenoxam) Found Among Field Isolates of Phytophthora capsici Causing Phytophthora Blight on Bell Pepper in North Carolina and New Jersey

Plant Disease ◽  
1998 ◽  
Vol 82 (6) ◽  
pp. 711-711 ◽  
Author(s):  
Greg Parra ◽  
Jean Ristaino
Keyword(s):  
North Carolina ◽  
New Jersey ◽  
Cultural Practices ◽  
Phytophthora Capsici ◽  
Significant Proportion ◽  
Bell Pepper ◽  
Economic Losses ◽  
Mating Types ◽  
Phytophthora Blight ◽  
Field Isolates

Phytophthora blight caused by the pathogen Phytophthora capsici has caused economic losses in bell pepper and cucurbit fields in the U.S., and the prevalence of the disease has increased in recent years. The pathogen can be dispersed in soil, with surface water, and via splash dispersal from the soil to foliage. Management of the disease relies on modifications in cultural practices, crop rotation, and judicious use of fungicides. Disease occurred in fields that were sprayed with multiple applications of Ridomil Gold (mefenoxam) according to labeled recommendations in 1997. Mefenoxam is the active enantiomer contained in the racemic fungicide metalaxyl. Mefenoxam was widely used on bell pepper for the first time in 1997, but disease was widespread. Insensitivity to mefenoxam and metalaxyl has not been reported previously in field isolates of P. capsici. However, selection for metalaxyl insensitive isolates in the laboratory after mutagenesis has been reported. Insensitivity to metalaxyl has been reported among other Oomycete pathogens including Phytophthora infestans, Pseudoperonospora cubensis, Peronospora tabacina, Bremia lactucae, and Pythium spp. Infected plants were collected from 12 fields in North Carolina by the authors and one additional field in New Jersey (courtesy of Steve Johnston). Infected plants (10 to 30 per field) were surface disinfested in 10% bleach and plated on selective media to isolate P. capsici. Colonies of the pathogen were transferred to V8 juice agar or maintained on cornmeal agar slants. Mefenoxam-amended V8 juice agar was prepared at levels of 0, 5, and 100 ppm. Screening for sensitivity was conducted by placing agar plugs containing the pathogen onto two replicate plates of mefenoxam-amended media at each concentration. Isolates were categorized as sensitive if growth was less than 40% of the unamended control at 5 ppm. Intermediate isolates exhibited growth greater than 40% of the unamended control at 5 ppm but less than 40% of the unamended control at 100 ppm mefenoxam. Insensitive isolates exhibited growth greater than 40% of the unamended control at 100 ppm mefenoxam. Concentrations of the fungicide used to screen for insensitivity were within the range applied in the field. Thus far, 161 isolates have been screened for sensitivity. Of these, 54 isolates were classified as sensitive, 15 as intermediate, and 92 or 57% of the isolates were insensitive. Three quarters of the fields sampled contained insensitive isolates and insensitivity ranged from 11 to 80% within fields. Both A1 and A2 mating types were recovered from some fields and insensitive isolates occurred among both mating types. Isolates that were insensitive to mefenoxam were also insensitive to metalaxyl. A significant proportion of the isolates obtained from infected plants in fields where Ridomil Gold has been used recently were insensitive. The ability of insensitive isolates to cause disease on fungicide-treated plants will be studied in further experiments. Isolates collected between 1988 and 1994 were screened and all isolates were sensitive to metalaxyl (Ridomil 2E). A dramatic shift in populations of P. capsici to insensitivity to the new metalaxyl substitute mefenoxam has occurred in bell pepper fields in a 3-year period.

scholarly journals Cover Crop as Living Mulch: Effects on Energy Flows in Mediterranean Organic Cropping Systems

Agronomy ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 667
Author(s):  
Francesco Montemurro ◽  
Alessandro Persiani ◽  
Mariangela Diacono
Keyword(s):  
Energy Balance ◽  
Total Energy ◽  
Cover Crop ◽  
Crop Yields ◽  
Cropping Systems ◽  
Cropping System ◽  
Energy Output ◽  
Living Mulch ◽  
No Till ◽  
Energy Inputs

Sustainability of agricultural practices is one of the most important issues in organic agriculture and its assessment is crucial. To this aim, evaluating the balance between the energy inputs and outputs in crop rotations could be a valuable tool. Therefore, we compared different management strategies in a four-year organic cropping system, by estimating the energy balance of crop production. Two different living mulches with no-till (B1) and green manure (B2) were compared with a cropping system without cover crop (B3), performing both energy analysis and energy balance. Energy parameters were also evaluated. The energy input of fertilizers and water was more than 55% of the total energy required by the cropping systems, suggesting that these agronomic practices should be tailored by farmers to decrease total energy inputs. The potential energy output was significantly higher in the B1 than the B2 and B3 cropping systems (20% and 54%, respectively). Results indicated that B1 and B2 could enhance the energy outputs without negatively affecting the energy consumption, since these cropping systems also showed higher energy efficiency. The introduction of the cover crop as living mulch combined with no-till could be a powerful tool to enhance systems sustainability, without compromising the crop yields.

scholarly journals Cover crop root contributions to soil carbon in a no-till corn bioenergy cropping system

GCB Bioenergy ◽  
2017 ◽  
Vol 9 (7) ◽  
pp. 1252-1263 ◽  
Author(s):  
Emily E. Austin ◽  
Kyle Wickings ◽  
Marshall D. McDaniel ◽  
G. Philip Robertson ◽  
A. Stuart Grandy
Keyword(s):  
Soil Carbon ◽  
Cover Crop ◽  
Cropping System ◽  
No Till ◽  
Crop Root

scholarly journals Interaction between Fusarium head blight and crown rot disease incidence and cultural practices on wheat in the south of Iraq, Basra province

2019 ◽  
Vol 43 (1) ◽  
Author(s):  
Mohammed Hussein Minati ◽  
Mohaned Khalaf Mohammed-Ameen
Keyword(s):  
Cultural Practices ◽  
Disease Incidence ◽  
Agricultural Practices ◽  
Cropping System ◽  
Crown Rot ◽  
Wheat Crop ◽  
Continuous Cropping ◽  
The South ◽  
Head Blight ◽  
South Of Iraq

Abstract Background This study was conducted to estimate Fusarium head blight (FHB) and crown rot (FCR) disease incidence on wheat and their interaction with cultural methods (cultivar types, planting time, seed rate, crop rotation, and fertilizer practices) that are used in wheat cropping system in the south of Iraq, Basra province. Results The results showed that the mean average of FHB and FCR was 27.2% and 31%, respectively. This displays that very nearly one-third of wheat crop planted in those 14 fields were infected by both diseases but not very severely, except in two fields (D and HM), which were devastating, 54% and 71% and 41% and 52% for FHB and FCR, respectively. The highest level of incidence for both diseases was associated with the earlier and latest planting dates 28 Oct. and 10 Dec., while the lowest was with 1, 10, and 23 Nov. A 200 and 120 kg/ha were the highest and lowest seed rates used in this study. The selected wheat fields differed in their pre-crop rotations (legume, corn, sorghum, okra, and continuous cropping system of wheat) in a previous year. The amount of added fertilizers (urea, DAP, and NPK) to the studied fields was in a high variation. The seven wheat cultivars examined in this study showed different levels of susceptibility to both diseases. Conclusion The results verified that most of the agricultural practices examined in this study were associated with positive correlation for FHB and FCR in the occurrence of disease incidence. Except the cultivar type and fertilizer application had unclear relationship with the incidence of both diseases.

scholarly journals First Report of Phytophthora capsici Infection on Bell Peppers (Capsicum annuum L.) from Punjab, Pakistan

2018 ◽  
Vol 7 (1) ◽  
pp. 51-51
Author(s):  
Sajjad Hyder ◽  
Muhammad Inam-ul-Haq ◽  
Raees Ahmed ◽  
Amjad S. Gondal ◽  
Nida Fatima ◽  
...  
Keyword(s):  
Capsicum Annuum ◽  
Irrigation System ◽  
Phytophthora Capsici ◽  
Bell Pepper ◽  
Fluorescent Light ◽  
Phytophthora Blight ◽  
Seedling Mortality ◽  
Canal Irrigation ◽  
First Report ◽  
Capsicum Annuum L

Bell pepper (Capsicum annuum L.) is one of the extensively cultivated vegetable crop in Punjab, Pakistan. During two years of field surveys, February-November 2016-17, damping off and blight symptoms were observed. Average seedling mortality was recorded as 18.7% while yield loss due to blight was estimated 32 to 41% at mature stages. Maximum blight infection was recorded from the areas frequently flooded with canal irrigation system. At early stages, lesions were noticed on stem portions at soil line level while at crop maturity stages blight symptoms were noted. Leaves were blanched and wilted while fruits were covered with white mold. Masses of sporangia were evident on and inside the infected fruits under humid conditions. A total of twelve isolates were recovered from infected root, stem and fruit portions on rye agar media (Caten and Jinks, 1968) incubated at 25oC under fluorescent light. Papillated sporangia were averaged 42 ± 2.6 X 27 ± 1.7 μm in size (range 27 - 52 × 23 - 36 μm). Oospores were produced on 20% V8 agar and were spherical 22 ± 1.4 μm in diameter (range 14 to 27 μm) while average pedicels length was recorded as 58 ± 12.5 μm (range 13 to 120 μm). These observations were similar to those described for P. capsici (Cocoa, 1988). DNA was extracted using Cetyl Trimethylammonium Bromide (CTAB) method and the internal transcribed spacer regions (ITS1 and ITS2) were amplified by polymerase chain reaction (White et al., 1990). The amplicons were purified and sequenced in both directions (GenBank Accession No. MF322868 and MF322869). BLAST analysis revealed these isolates showed 99% identity with ITS sequences of Phytophthora capsici (KM369964 and KU518782). Pathogenicity assay was performed on healthy bell pepper seedlings with five repeats. Soil was flooded with 20ml sporangial suspension (1 x 103 sporangia/ml) in pots containing seedlings while 5ml suspension was sprayed until run off on mature plants (Hyder et al., 2018). A set of uninoculated seedlings was used as control. Pots were kept in dew chamber for 10-20 days at 25±2 oC. Seedling mortality was observed five days after inoculation while at later stage plants develop brown-to-black stem lesions with white mycelial growth on leaves. These symptoms were identical to the P. capsici infections in field. Consistent re-isolations of P. capsici confirm its association with the disease. To our knowledge, this is the first report of Phytophthora blight on bell pepper from Pakistan

scholarly journals Amelioration of Blossom-end Rot of Bell Pepper by Rowcovers and Supplemental Calcium

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 530B-530
Author(s):  
George H. Clough ◽  
Shara E. Alexander
Keyword(s):  
Irrigation System ◽  
Total Yield ◽  
Bell Pepper ◽  
Plastic Mulch ◽  
Marketable Yield ◽  
Yield And Quality ◽  
Supplemental Calcium ◽  
Blossom End Rot ◽  
Black Plastic ◽  
Calcium Fertilization

A 2-year study was conducted in eastern Oregon to evaluate the effects of hooped spunbonded polypropylene rowcovers and calcium fertilization on yield and quality of drip-irrigated bell pepper grown on black plastic mulch. The experiment was a complete factorial with four replications of two varieties, covered and uncovered plots, and three levels of supplemental calcium fertilization at 0, 34 and 68 kg·ha–1 applied through the drip irrigation system as Ca(NO3)2. Marketable yields increased with rowcover, both at the first harvest and over the season. Blossom-end rot and sunscald were reduced substantially by rowcovers; the effect was greatest during the earlier harvests. First harvest and season total yield of fancy grade peppers increased linearly as rate of supplemental calcium increased, as did total marketable yield at the first harvest. There was a trend to decreasing yield of fruit with blossom-end rot as calcium rate increased, and the percent fruit with blossom-end rot at the first harvest decreased linearly with increasing rate of calcium fertilization. Yield of fruit affected by sunscald decreased linearly as supplemental calcium rate increased at the first harvest; overall, yield of sunscald fruit was reduced by application of calcium at either rate.

scholarly journals Spunbonded Rowcover and Calcium Fertilization Improve Quality and Yield in Bell Pepper

HortScience ◽  
1998 ◽  
Vol 33 (7) ◽  
pp. 1150-1152 ◽  
Author(s):  
Shara E. Alexander ◽  
George H. Clough
Keyword(s):  
Irrigation System ◽  
Total Yield ◽  
Bell Pepper ◽  
Plastic Mulch ◽  
Marketable Yield ◽  
Yield And Quality ◽  
Blossom End Rot ◽  
Black Plastic ◽  
Calcium Fertilization

A 2-year study was conducted in eastern Oregon to evaluate the effects of hooped spunbonded polypropylene rowcovers and Ca fertilization on yield and quality of drip-irrigated bell pepper (Capsicum annuum L. Grossum group) grown on black plastic mulch. The experiment was a complete factorial with four replications of two cultivars, covered and uncovered plots, and three levels of supplemental Ca fertilization at 0, 34, and 68 kg·ha-1 applied through the drip irrigation system as Ca(NO3)2. Rowcovers increased marketable yields both at the first harvest and over the season. Blossom-end rot and sunscald were reduced substantially by rowcovers; the effect was greatest during the earlier harvests. First-harvest and season total yield of fancy grade peppers increased linearly as rate of supplemental Ca increased, as did total marketable yield at the first harvest. Both yield of fruit with blossom-end rot and the percentage of fruit with blossom-end rot at the first harvest decreased as Ca rate increased. Yield of fruit affected by sunscald decreased linearly as supplemental Ca rate increased at the first harvest; overall, yield of sunscalded fruit was reduced by application of Ca at either rate.

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