Effect of Fertilizer Level and Planting Distance on Soil pH, Growth, Fruit Size, Disease Incidence, Yield, and Profit of Two Papaya Varieties

Papaya production in Puerto Rico is low, probably because of diseases and poor management practices. In this study, high yielding varieties were used to compare planting distances and fertilising practices. Plants of varieties PR 6-65 and PR 7-65, planted at 1.8 x 1.8 m were significantly larger than those at 1.2 x 1.2m. The larger size of the plants was reflected in an increase in fruit yield and net profit. PR 6-65 produced a significantly heavier crop and a higher net profit/ha than PR 7-65. PR 6-65 was significantly more susceptible to the Isabela mosaic disease and more tolerant to bunchy top than PR 7-65. Soil pH was significantly lower at the 1.2 x 1.2m planting distance than at the 1.8 x 1.8 m, probably because more fertilizer was used in the closer planting. There were no significant differences between the mean yields of papaya plants receiving monthly applications of .227 and .454 kg of a 15-15-15 fertilizer, suggesting that the smaller amount of fertilizer is enough to produce a heavy crop and obtain a good net profit from papayas grown in Coto clay, an Oxisol.

Download Full-text

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

Advances in Agriculture ◽

10.1155/2018/6042495 ◽

2018 ◽

Vol 2018 ◽

pp. 1-13 ◽

Cited By ~ 1

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.

Download Full-text

Spatial and Temporal Distribution of Iris yellow spot virus and Thrips in Colorado Onion Fields

Plant Health Progress ◽

10.1094/php-2010-0820-01-rs ◽

2010 ◽

Vol 11 (1) ◽

pp. 11 ◽

Cited By ~ 2

Author(s):

Howard F. Schwartz ◽

David H. Gent ◽

Scott M. Fichtner ◽

Rajiv Khosla ◽

Linda A. Mahaffey ◽

...

Keyword(s):

Soil Ph ◽

Management Practices ◽

Disease Incidence ◽

Risk Index ◽

Iris Yellow Spot Virus ◽

Yellow Spot ◽

Onion Thrips ◽

Spot Virus ◽

Negatively Associated ◽

Sodium Percent

Iris yellow spot virus and its onion thrips vector (Thrips tabaci) are yield limiting pests of onion in the western United States. This two-year project investigated the relationship of iris yellow spot to thrips populations, soil properties, and grower management practices in six onion fields during 2005 and 2006 in Colorado. Thrips density (average number of thrips per plant per day) was negatively associated with soil pH (r = -0.61). The incidence of iris yellow spot at harvest was positively associated with organic matter, zinc, potassium, percent sodium, percent hydrogen, copper, iron, and soil pH. Thrips-days had a clear non-linear association with disease incidence at harvest. Onion plant population was positively associated with levels of iron, phosphorus, potassium, and zinc; and negatively associated with calcium, salts, percent potassium, and cation exchange capacity (CEC). Marketable (medium or larger sized bulbs) yield was negatively associated with phosphorus and percent potassium, and positively associated with salts, calcium, and CEC. Results from this project could contribute to the development of a risk index to predict potential risk from Iris yellow spot virus and its onion thrips vector. Accepted for publication 6 July 2010. Published 20 August 2010.

Download Full-text

A cassava mosaic disease epidemiologic factors analysis in the Bas-Congo (DR Congo) zone of savannah. case study: “Secteur de Boko”

International Journal of Biological Research ◽

10.14419/ijbr.v3i1.4069 ◽

2015 ◽

Vol 3 (1) ◽

pp. 56

Author(s):

Bansimba Mukiese J.-Roger

Keyword(s):

Disease Incidence ◽

Mosaic Disease ◽

Cassava Mosaic Disease ◽

Dr Congo ◽

Local Varieties ◽

Epidemiologic Factors ◽

Factors Analysis ◽

Foliar Symptoms ◽

The Mean

This paper aims at evaluating epidemiologic parameters of the African Cassava Viral Mosaic Disease (CMVD) in 25 cassava farmer's fields of «Secteur de Boko» (DR Congo) on the basis of foliar symptoms observation. The results showed that the infection of the local varieties comes mainly from the cuttings whereas that of the improved varieties comes from the flies. The disease incidence varied between 10% and 88.33% with an average of 43.8%. Severity varied between 2.42 and 3.42 with an average of 2.913. The gravity varied between 17.86% and 87.81% while the systemicity varied between 21.42 and 96.66%. The mean number of whiteflies (Bemisia tabaci) by plant (2.068) revealed a preference of the vectors for the improved variety Kindombe which, however, presents a low severity and a less marked gravity. Globally, the CMVD was more severe for the local variety Mpeko with a score of 3.00. A high correlation was found between the gravity and the number of neighbour fields (-0,437*), the density of culture (-0,431*) and also the systemicity of the disease (0,779**). In addition; it appeared that the land topography strongly influences the disease severity (-0,542**).

Download Full-text

Effect of Four Training Systems on Growth and Productivity of `Cortland'/M.9 EMLA Apple Trees

HortScience ◽

10.21273/hortsci.33.3.451e ◽

1998 ◽

Vol 33 (3) ◽

pp. 451e-451

Author(s):

J.R. Schupp ◽

S.I. Koller

Keyword(s):

Fruit Size ◽

Vertical Axis ◽

Significant Loss ◽

Training Methods ◽

Cumulative Yield ◽

Or Efficiency ◽

Cross Sectional ◽

Tree Survival ◽

Canopy Volume ◽

Planting Distance

`Cortland'/M.9 EMLA trees were planted in 1991 at 1.8 ×4.2-m spacing. The trees were trained to one of four systems: 1) Vertical Axis; 2) Y trellis; 3) Solen; or 4) Palmette trellis. Tree survival was 86% for Palmette trees and approached 100% for the other three systems. Annual yield and cumulative yield per tree of Vertical Axis and Y trellis was twice that of Solen or Palmette. Tree vigor was sub-optimal relative to planting distance in this study. Trunk cross-sectional area of Vertical Axis trees was larger than that of trees trained to Solen or Palmette, while trees trained to Y trellis were intermediate in trunk growth. Canopy volumes of Vertical Axis and Y trellis trees were similar, and greater than that of Solen or Palmette trees. Fruit size on Solen and Palmette trees was larger than that of Y trellis trees in 1995 and 1996, while fruit size on Vertical Axis trees was intermediate. Cumulative yield per cubic meter of canopy volume was the same for all four systems, suggesting that differences in productivity among systems were attributable to the effects of tree training practices on tree size, not to differences among systems in precocity or efficiency. The low heading cut needed to establish the lowest tier of branches on the Palmette system reduced tree vigor and in some cases, resulted in mortality. The horizontal training of the primary branches of the Solen severely reduced tree vigor. In this study, where tree vigor was sub-optimal due to rootstock selection, the additional restrictions in tree growth resulting from restrictive training methods resulted in a significant loss in productivity.

Download Full-text

Pilonidal sinus disease on the rise: a one-third incidence increase in inpatients in 13 years with substantial regional variation in Germany

International Journal of Colorectal Disease ◽

10.1007/s00384-021-03944-4 ◽

2021 ◽

Author(s):

Christina Oetzmann von Sochaczewski ◽

Jan Gödeke

Keyword(s):

Pilonidal Sinus ◽

Regional Variation ◽

Disease Incidence ◽

Age Groups ◽

Pilonidal Sinus Disease ◽

National Guidelines ◽

Reconstructive Procedures ◽

Sinus Disease ◽

The Mean ◽

Almost All

Abstract Purpose Collective evidence from single-centre studies suggests an increasing incidence of pilonidal sinus disease in the last decades, but population-based data is scarce. Methods We analysed administrative case–based principal diagnoses of pilonidal sinus disease and its surgical therapy between 2005 and 2017 in inpatients. Changes were addressed via linear regression. Results The mean rate of inpatient episodes of pilonidal sinus disease per 100,000 men increased from 43 in 2005 to 56 in 2017. In females, the mean rate of inpatient episodes per 100,000 women rose from 14 in 2005 to 18 in 2017. In the whole population, for every case per 100,000 females, there were 3.1 cases per 100,000 males, but the numbers were highly variable between the age groups. There was considerable regional variation within Germany. Rates of inpatient episodes of pilonidal sinus disease were increasing in almost all age groups and both sexes by almost a third. Surgery was dominated by excision of pilonidal sinus without reconstructive procedures, such as flaps, whose share was around 13% of all procedures, despite recommendations of the national guidelines to prefer flap procedures. Conclusion Rates of inpatient episodes of pilonidal sinus disease in Germany rose across almost all age groups and both sexes with relevant regional variation. The underlying causative factors are unknown. Thus, patient-centred research is necessary to explore them. This should also take cases into account that are solely treated office-based in order to obtain a full-spectrum view of pilonidal sinus disease incidence rates.

Download Full-text

Integrated Management of Downy Mildew on Slicing Cucumber With Fungicides and Host Resistance But Not Trellising

Plant Disease ◽

10.1094/pdis-02-19-0323-re ◽

2019 ◽

Vol 103 (10) ◽

pp. 2592-2598

Author(s):

Anthony P. Keinath

Keyword(s):

Downy Mildew ◽

Host Resistance ◽

Management Practices ◽

Integrated Management ◽

Cultivar Resistance ◽

Fall Season ◽

Fungicide Treatment ◽

Progress Curve ◽

Management Techniques ◽

The Mean

The objective of this study was to evaluate fungicide applications, host resistance, and trellising, alone and in combination, as management practices for downy mildew on slicing cucumber. A split-split plot experimental design was used with three and four replications in spring and fall 2017, respectively. The whole-plot treatment was fungicide, four applications of chlorothalonil (Bravo Weather Stik 6SC) alternated with three applications of cyazofamid (Ranman 400SC), or water. Split plots were nontrellised or trellised with four strings supported by stakes. Split-split plots were cultivar Bristol, which is intermediately resistant to downy mildew, or cultivar Speedway, which is susceptible to downy mildew with similar parentage as Bristol. In both seasons, area under the disease progress curve (AUDPC) values were lower with fungicides than water for both cultivars. In the spring, AUDPC for Bristol was lower than for Speedway regardless of fungicide treatment. In the fall, Bristol had a lower AUDPC than Speedway with fungicides, but the AUDPC did not differ between the two cultivars with water. The mean AUDPC for trellised plants (376.2) was lower than for nontrellised plants (434.0; P = 0.007). Fungicide applications increased marketable and total fruit weights in both seasons (P ≤ 0.0002). Marketable weight with fungicides was almost double (93% greater) the marketable weight with water. Marketable weight was 55% greater for Bristol than for Speedway in spring, but yields did not differ between cultivars in fall (season-by-cultivar interaction, P ≤ 0.0003). Because trellising had no effect on marketable yields (P = 0.11), trellising is not recommended for managing downy mildew on slicing cucumber. Of the three management techniques examined, fungicides had the largest effects on disease and yields, followed by cultivar resistance.

Download Full-text

In-Furrow Applications of Metalaxyl and Phosphite for Control of Pink Rot (Phytophthora erythroseptica) of Potato in New Brunswick, Canada

Plant Disease ◽

10.1094/pdis-91-10-1305 ◽

2007 ◽

Vol 91 (10) ◽

pp. 1305-1309 ◽

Cited By ~ 12

Author(s):

Khalil I. Al-Mughrabi ◽

Rick D. Peters ◽

H. W. (Bud) Platt ◽

Gilles Moreau ◽

Appanna Vikram ◽

...

Keyword(s):

New Brunswick ◽

Disease Incidence ◽

Field Trials ◽

Russet Burbank ◽

Viable Option ◽

Potato Plants ◽

Pink Rot ◽

Phytophthora Erythroseptica ◽

Sensitive Isolate ◽

The Mean

The efficacy of metalaxyl-m (Ridomil Gold 480EC) and phosphite (Phostrol) applied at planting in-furrow against pink rot (Phytophthora erythroseptica) of potato (Solanum tuberosum) ‘Shepody’ and ‘Russet Burbank’ was evaluated in field trials conducted in 2005 and 2006 in Florenceville, New Brunswick, Canada. Inoculum made from a metalaxyl-m-sensitive isolate of P. erythroseptica from New Brunswick was applied either in-furrow as a vermiculite slurry at planting or as a zoospore drench in soils adjacent to potato plants in late August. After harvest, the number and weight of tubers showing pink rot symptoms were assessed and expressed as percentages of the total tuber number and total weight of tubers. Metalaxyl-m applied in-furrow was significantly more effective against pink rot than phosphite. The mean percentage of diseased tubers as a percentage of total tuber weight was 1.5% (2005) and 1.2% (2006) for metalaxyl-m-treated plots and 9.6% (2005) and 2.8% (2006) for phosphite-treated plots, a percentage similar to that obtained in inoculated control plots with no fungicide treatment. The mean percentage of diseased tubers expressed as a percentage of the total number of tubers was 1.7% (2005) and 1.3% (2006) for metalaxyl-m-treated plots and 10.1% (2005) and 3.1% (2006) for phosphite-treated plots. Disease incidence was significantly higher using the late-season inoculation technique (respective means in 2005 and 2006 were 9.9 and 3.8% diseased tubers, by weight, and 10.6 and 3.9%, by number) than with the in-furrow inoculation method (respective means in 2005 and 2006 were 3.3 and 0.7% by weight, and 3.7 and 1.3%, by number). The potato cv. Shepody was significantly more susceptible to pink rot (9.9 and 3.3% diseased tubers, by weight, in 2005 and 2006, respectively, and 10.6 and 3.9%, by number) than Russet Burbank (respective means in 2005 and 2006 were 3.4,% and 1.2%, by weight, and 3.7,% and 1.2%, by number). Our findings indicate that metalaxyl applied in-furrow at planting is a viable option for control of pink rot caused by metalaxyl-sensitive strains of P. erythroseptica, whereas phosphite was ineffective.

Download Full-text

Long-term annual fertilization with nitrogen and potassium affect yield and mineral composition of 'Fuji' apple

Scientia Agricola ◽

10.1590/s0103-90162009000300013 ◽

2009 ◽

Vol 66 (3) ◽

pp. 377-385 ◽

Cited By ~ 20

Author(s):

Gilberto Nava ◽

Antonio Roque Dechen

Keyword(s):

Mineral Composition ◽

Fruit Size ◽

N Fertilization ◽

K Fertilizer ◽

Fuji Apple ◽

The Mean ◽

K Concentration ◽

Fertilizer Rates ◽

K Fertilization

Nitrogen (N) and potassium (K) are closely related to orchard productivity, since they are usually found in higher concentrations than others macronutrients in apple (Malus × domestica Borkh) fruits. This research was carried out to assess the effect of eight years of soil additions of N and K on yield, fruit size and mineral composition of 'Fuji'/Marubakaido apple in São Joaquim, State of Santa Catarina, Southern Brazil. A factorial design was used with N and K annual fertilizer rates (0, 50, 100, 200 kg ha-1 of N and K2O) replicated in three orchards from 1998 to 2006. Yield was estimated by multiplying the total number of fruit per tree by the mean weight of 100 randomly sampled fruit. Fifteen days prior to harvest, 24 fruit pulps were analyzed for N, K, Ca and Mg contents. Increases in yields were noticed in five and four years, due to the N and K fertilizer additions, respectively. Fruit size was more affected by K than by N fertilization. Fruit mineral composition was affected by both N and K fertilization. N concentration and N:Ca ratios were enlarged by N fertilization. K concentration and K:Ca ratios were also enlarged by K fertilization. Ca fruit concentration was reduced by N fertilization and often by K. Ca-related fruit disorders were not observed even after 180 days storage. However, N and K fertilization affected Ca nutrition. Thus, when fertilizing with N and K, it is imperative to use combined practices in order to offset the detrimental effect that these nutrients may cause on Ca concentration in the fruit.

Download Full-text

Cacao agroforestry systems do not increase pest and disease incidence compared with monocultures under good cultural management practices

Crop Protection ◽

10.1016/j.cropro.2019.105047 ◽

2020 ◽

Vol 130 ◽

pp. 105047 ◽

Cited By ~ 5

Author(s):

Laura Armengot ◽

Leone Ferrari ◽

Joachim Milz ◽

Fortunato Velásquez ◽

Pierre Hohmann ◽

...

Keyword(s):

Management Practices ◽

Disease Incidence ◽

Agroforestry Systems ◽

Cultural Management

Download Full-text

PRE- and POST-STORM LiDAR SURVEYS FOR ASSESSMENT OF IMPACT ON COASTAL EROSION

ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences ◽

10.5194/isprs-archives-xlii-3-w8-261-2019 ◽

2019 ◽

Vol XLII-3/W8 ◽

pp. 261-266

Author(s):

A.-L. Montreuil ◽

M. Chen ◽

A. Esquerré ◽

R. Houthuys ◽

R. Moelans ◽

...

Keyword(s):

Management Practices ◽

Morphological Changes ◽

Storm Surges ◽

High Water ◽

Water Levels ◽

Airborne Lidar ◽

Coastline Change ◽

The Mean ◽

The Impact

Abstract. Sustainable management of the coastal resources requires a better understanding of the processes that drive coastline change. The coastline is a highly dynamic sea-terrestrial interface. It is affected by forcing factors such as water levels, waves, winds, and the highest and most severe changes occur during storm surges. Extreme storms are drivers responsible for rapid and sometimes dramatic changes of the coastline. The consequences of the impacts from these events entail a broad range of social, economic and natural resource considerations from threats to humans, infrastructure and habitats. This study investigates the impact of a severe storm on coastline response on a sandy multi-barred beach at the Belgian coast. Airborne LiDAR surveys acquired pre- and post-storm covering an area larger than 1 km2 were analyzed and reproducible monitoring solutions adapted to assess beach morphological changes were applied. Results indicated that the coast retreated by a maximum of 14.7 m where the embryo dunes in front of the fixed dunes were vanished and the foredune undercut. Storm surge and wave attacks were probably the most energetic there. However, the response of the coastline proxies associated with the mean high water line (MHW) and dunetoe (DuneT) was spatially variable. Based on the extracted beach features, good correlations (r>0.73) were found between coastline, berm and inner intertidal bar morphology, while it was weak with the most seaward bars covered in the surveys. This highlights the role of the upper features on the beach to protect the coastline from storm erosion by reducing wave energy. The findings are of critical importance in improving our knowledge and forecasting of coastline response to storms, and also in its translation into management practices.

Download Full-text