Farmer Perceptions on Vegetable Diseases and Their Control in Sub-Humid Areas in Zimbabwe

Quail industry has become a promising sector in livestock of Bangladesh in last decade. This study was aimed to find out the incidence of bacterial and viral diseases in Japanese quail (Coturnix coturnix japonica) in Bangladesh. This is the first report about the incidences of diseases in Japanese quail in Bangladesh. The incidences of diseases were investigated by the clinical signs, gross lesions in different organs and histopathological changes of different tissues in bacterial and viral diseases. A total number of 476 birds, either diseased or dead, from 40 quail farms were included in this study. The result showed that the occurrence of viral and bacterial diseases in Japanese quail were 25.21% and 34.45%, respectively where as 15.13% cases were mixed infection. Newcastle disease was found as most prevalent (11.35%) among the viral diseases. On the other hand, colibacillosis was the highest prevalent disease accounting for 15.34% among all bacterial diseases. Moreover, 22.48% cases were other types of infections (mycoplasmosis, coccidiosis, aspergillosis, deficiency disorder and internal parasitic problem) and 2.73% cases were unidentified. The highest numbers of diseases were found in the age group 21 to 30 days (23.53%) whilst the quails aged between 11 to 40 days (59.67) were most vulnerable to various diseases. The highest occurrences of diseases were found in rainy season (39.29%). It can be concluded that Newcastle disease and colibacillosis are the most frequent challenge for the quail farming in Bangladesh. Strict bio-security and proper management system might effectively reduce the incidences of the reported diseases.
 Asian Australas. J. Biosci. Biotechnol. 2016, 1 (3), 410-418

ABSTRACTBacterial tree diseases have been mainly studied in agriculture and horticulture. For forest trees, damage due to bacterial diseases is understudied. Moreover, bacterial tree diseases often appear in the context of so‐called complex diseases, which are dependent on other factors, such as multiple microorganisms, insects or abiotic factors which weaken the host. In recent years, outbreaks of bacterial tree diseases, such as Xylella fastidiosa in the Mediterranean region or acute oak decline (AOD) in the United Kingdom, raised the awareness of bacterial diseases on forest trees. In this review, we aim to summarise the current issues and available knowledge about bacterial diseases of forest trees in Central Europe. Furthermore, we identify potential bacterial pathogens that could gain importance in the future for central European forests. The methods used were a systematic literature search and the analysis of the data collected over the last 10 years on bacterial diseases by the Swiss forest protection service. We conclude that, on one side, complex bacterial diseases could increase in importance, especially considering ongoing climate change. Therefore, the bacterial community of diseased trees (the pathobiome) needs to be studied more in depth to understand the emergence of complex bacterial diseases. On the other side, host ranges of highly pathogenic invasive genera and species, such as Xylella, need to be investigated experimentally for common central European tree species and varieties, to implement proactive risk management strategies against bacterial diseases in forest trees. Finally, urban trees and green spaces should be monitored more closely, as they could serve as starting points for bacterial disease outbreaks in forests, similarly to other emerging diseases and pathogens.

Comparing the perception of farmers to climate change and variability in Bako Tibe, Ethiopia and Abeokuta, Nigeria is important in promoting sustainable agriculture and in understanding the impact of climate change and variability on agriculture in Africa. A total of 153 farmers were interviewed in both study areas using well structure questionnaire. The study describes the socioeconomic characteristics of farmers using descriptive statistics and thereafter the perception of Bako Tibe and Abeokuta farmers to climate change and variability was examined using Likert type scale. The binary logistics regression was later used to ascertain the effect of socioeconomic characteristics on perception of the farmers in both study areas. The farmers in both study areas believed that there have been changes in the amount of rainfall and temperature in the past thirty years. The farmers in Bako agreed that there have been increased temperature and decreased rainfall, contrary to the farmer’s perception in Abeokuta. The binary logistic regression results showed that socioeconomic characteristics of farmers in Bako Tibe, have no effect on the perception of farmers on climate change and variability. However, in Abeokuta, age, land ownership, and distance to market had an effect on the perception on the farmers on climate change and variability. The adaptation strategies to climate change and variability commonly used by Bako Tibe farmers was, improved seed (drought resistance) adaptation method, while most farmers in Abeokuta used soil moisture conservation adaptation method. The study recommends that government and Non-Governmental Organization of both countries should promote more adaptation and mitigation practices to climate change and variability through policy interventions to help curb the impact of climate change and variability to agriculture.

The effects of N dose and stage of ripeness on Fe, Co, Cr, Ni, Se and N concentration and incidence of fungal diseases were measured in winter wheat grain from conventional (CONV) and organic (ORG) systems on neighbouring areas of a 10‐year‐old manure‐based farm. Principal components analysis (PCA) of the data showed that year had the greatest influence on the results, but that cropping system affected N, Ni, Fe and Se content and incidence of diseases. Attack by Dreschlera tritici‐repentis was highest in ORG and attack by Stagonospora nodorum in CONV. Increasing stage of maturity increased incidence of fungal disease and Fe content. Analysis of variance and MANOVA showed that wheat yield was affected by weather (precipitation and temperature), cropping system and N dose. The 10% lower yield in ORG than CONV was explained by a lower amount of plant available N at the same N dose. Nitrogen, Fe, Ni, Se and Co contents in grain were affected by year, while dry matter content was significantly lower in ORG than in CONV. The MANOVA identified correlations between Co and Fe, Ni and Se. Incidence of fungal diseases was foremost affected by weather, stage of ripeness and N dose. Organic cropping increased Fe and Se uptake and decreased S. nodorum attack, but increased attack by D. tritici‐repentis. Copyright © 2006 Society of Chemical Industry

Some researchers have argued that organic agriculture does not yield intended benefits in African smallholder settings because of degraded soils and lack of organic resources. A multidisciplinary case study analysis of selected organic farming gardens in Makoni, Zimbabwe was done to explore farmer resources, perceptions, market access, preferences, and soil fertility status using survey and interview tools and soil analysis. Lack of agricultural water was identified as a major production challenge by 75% of respondents. Unavailable and unreliable transport and low income from sales were identified as the two main challenges (84 % of respondents) in selling organic produce. Roughly 95% of interviewed farmers currently sell their organic produce not marked as organic in the local district. We also reveal that 14-year organic management of soil fertility at MOFA has resulted in increased on average pH (range 0.6 – 2.1 units), and available P (range x6 – x26) compared to adjacent uncultivated areas. Soil organic matter either stayed the same or increased at 5 out of 6 sites and exchangeable Ca, Mg, and K increased by at least 157%, 21%, and 10%, respectively, all compared to uncultivated land. These improvements are likely the reason why 64% of farmers said they had observed yield increases. We conclude that 14 years of organic agriculture has led to the improvement of soil fertility in the initially low-fertility gardens as measured by pH, organic matter, and nutrient content. However, we recommend strengthening the market access to organic produce to sustain organic farming for smallholder farmers in Zimbabwe.

Raw food-containing diets have grown in popularity over the last decades since they correspond with the perception of a healthy lifestyle. However, infections from fruit and vegetables also represent an important food safety issue. Produce-borne out breaks are of concern because of their potentially serious health consequences and the high socioeconomic costs. This review summarizes outbreaks of bacterial disease associated with sprouts, salads, vegetables, fruit, fresh herbs, raw nuts and raw edible seeds registered by proMED-mail during the period between 2011 and mid-2015. The possible pathways of contamination are examined and discussed, with special attention to the role of E. coli and Salmonella as cross-domain pathogens. Various multidisciplinary approaches aimed at reducing the occurrence of pathogenic bacteria in fresh produce are discussed, including the enhancement of surveillance and consumer awareness, improvement of agricultural and trading practices and the development of novel materials and sanitizing methods in the food industry. Thirty-five outbreaks, each associated with a single raw produce were reviewed. Sprouts and lettuce were the most common produce associated with disease. E. coli, especially EHEC O157:H7, and Salmonella spp. were the most common pathogens, causing 42.9 % and 34.3 % of the outbreaks, respectively, while Listeria monocytogenes accounted for 14.3 %. Novel vehicles of disease were noted, including watercress, strawberries and stone fruit.

Pest management challenges for smallholder vegetable farmers in Zimbabwe

Toward a General Theory for How Climate Change Will Affect Infectious Disease

Kisii County’s agricultural systems largely depends on rain-fed conditions which are affected by the weather instabilities that cause climate variability. This has led to fluctuations in diverse crop production and in particular tea yields. The study aimed to assess the perceptions of tea farmers on the effect of temperature and rainfall variation on tea production in Kisii County. The study adopted a correlational research design. The sample size was 400 farmers but only 352 farmers returned duly signed questionnaires. The study targeted small scale tea farmers, Kisii Meteorological Department, and three Kenya Tea Development Agency factories of Kisii County. The study used questionnaires to collect primary data from small scale tea farmers and document analysis was used to collect secondary data. Interview schedules were used to collect data from the field service coordinators who were key informants. Primary data collected from small scale tea farmers included their perception on the effect of temperature and rainfall variability on tea production. Purposive and random sampling were used to choose tea factories and farmers respectively. The findings of the study reveals that the perception of the farmers concerning the effects of temperature is that scanty rainfall reduces tea yields, heavy rainfall causes erosion of top soil and washes away available fertilizer thus affecting tea production, and that frostbites reduce tea yields and production significantly since hailstones destroy the tea leaves and reduces tea yields drastically.

From the mid-1980s through the early 1990s, outbreaks of bacterial kidney disease (BKD) caused by Renibacterium salmoninarum continued in Chinook salmon Oncorhynchus tshawytscha in Idaho Department of Fish and Game (IDFG) hatcheries despite the use of three control methods: (1) injection of returning adult fish with erythromycin to reduce prespawning BKD mortality and limit vertical transmission of R. salmoninarum, (2) topical disinfection of green eggs with iodophor, and (3) prophylactic treatments of juvenile fish with erythromycin-medicated feed. In addition, programs to manage BKD through measurement of R. salmoninarum antigen levels in kidney tissues from spawning female Chinook salmon by an enzyme-linked immunosorbent assay (ELISA) were tested over 13–15 brood years at three IDFG hatcheries. The ELISA results were used for either (1) segregated rearing of progeny from females with high ELISA optical density (OD) values (usually ≥0.25), which are indicative of high R. salmoninarum antigen levels, or (2) culling of eggs from females with high ELISA OD values. The ELISA-based culling program had the most profound positive effects on the study populations. Mortality of juvenile fish during rearing was significantly lower at each hatchery for brood years derived from culling compared with brood years for which culling was not practiced. The prevalence of R. salmoninarum in juvenile fish, as evidenced by detection of the bacterium in kidney smears by the direct fluorescent antibody test, also decreased significantly at each hatchery. In addition, the proportions of returning adult females with kidney ELISA OD values of 0.25 or more decreased 56–85% for fish reared in brood years during which culling was practiced, whereas the proportions of ELISA-negative adults increased 55–58%. This management strategy may allow IDFG Chinook salmon hatcheries to reduce or eliminate prophylactic erythromycin-medicated feed treatments. We recommend using ELISA-based management of BKD in Chinook salmon hatcheries where it is a concern.

Tilapia culture is an important source of income and nutrition to many rural families. Since 2000, the production of tilapia increased and reached domestic and global markets. Major farmed species is Nile tilapia (Oreochromis niloticus), in earthen ponds and cage cultures. Intensification contributed to global tilapia disease outbreaks, with bacterial infections causing mortalities and morbidities, threatening sustainable production. At tilapia farms, high nutrient concentrations, water temperature and fish densities enhance bacterial growth including virulent bacterial clones and potential zoonotic bacteria. Global warming favours this. This review respectively provides a comprehensive overview of the most common and emerging bacterial pathogens, diseases, clinical presentations and diagnostics of tilapia, including bacteria and diseases with zoonotic potential. First, common bacterial disease outbreaks, including streptococcosis, motileAeromonassepticaemia, francisellosis, columnaris disease and vibriosis are described. Then, information on emerging bacterial infections of concern for tilapia, like edwardsiellosis throughEdwardsiella ictaluriandE.tarda, as well asAeromonas schubertiiis provided. Reports of infectious bacterial tilapia disease outbreaks from other bacteria, includingLactococcus garvieae,Aerococcus viridans,Pseudomonasspp.,Mycobacterium marinumandChlamydiaspp., and others are reviewed. Furthermore, bacteria with zoonotic potential, likeStreptococcus agalactiaeST283,S.iniae,Aeromonassp.,E.tarda,Vibrio vulnificuspathovar (pv)piscisandM.marinumare included in the review, to provide the most current overview of the disease risks affecting production and post‐harvest stages. Additionally, the status and risks of antimicrobial resistance in bacteria from tilapia and other cultured fish through imprudent use of antibiotics, and its future at a global level are provided.

Severe outbreaks of bacterial stem rot disease occurred on dieffenbachia plants (Dieffenbachia amoena cv. Tropic Snow) during the autumn and spring seasons of 2002 and 2003 in two commercial glasshouses (3.5 ha) near Adana and Mersin in the Eastern Mediterranean Region of Turkey. Characteristic symptoms of the disease were wilting of the lower leaves, darkening and water soaking of the leaves and stem at or below the soil level, and browning in the vessel and pith of the diseased plants. Eventually, the stem and leaves completely rotted, and the plants collapsed. Nearly 30 and 40% (2002 and 2003, respectively) of the 20,000 potted plants in the glasshouses were destroyed because of the disease. Cuttings often developed a typical soft rot during propagation. Disease incidence was estimated at approximately 50% on propagating material during 2003. Isolations were made from rotted stems, leaves, and discolored vessels of the dieffenbachia plants on King's medium B. Bacteria consistently isolated from the diseased tissues formed white-to-cream colonies on the medium. Bacteria from purified colonies were gram, oxidase, and arginine dyhidrolase negative, catalase positive, and facultative anaerobic. Ten representative strains all fermented glucose and reduced nitrates to nitrites. The strains caused soft rot of potato slices within 24 h at 25°C. All strains were resistant to erythromycin in an antibiotic disk (15 μg) assay. Negative results were obtained from utilization of α-methyl glycoside, reducing substance from sucrose, and indole production from tryptophane and phosphathase activity. Positive results were obtained from pectate, aesculin, and gelatine liquefaction for all strains. Acid was produced from glucose, sucrose, mannitol, mannose, lactose, raffinose, melibiose, trehalose, and L(+)-arabinose but not Darabinose, sorbitol, inulin, and maltose. Pathogenicity was confirmed by needle-stab inoculation at the stem on three plants each of dieffenbachia and tomato plants (5-week-old cv. H-2274). Sterile distilled water was used as a negative control. All plants were covered with polyethylene bags for 48 h at 25°C. Within 72 h after inoculation, water-soaking and soft-rot symptoms were observed on dieffenbachia and tomato plants. All of the bacterial strains isolated in the present study were identified as Erwinia carotovora subsp. carotovora (Jones) based on fatty acid methyl ester analysis with similarity indices ranging from 80 to 94%. Furthermore, Biolog GN (Department of Plant Protection, Faculty of Agriculture, Ataturk University, Erzurum, Turkey) profiles identified them as the same pathovar with similarity values of 67 to 72%. All of the test results were similar to those of reference strain GSPB 435 (Gottinger Sammlung phytopathogener Bakterien, Georg-August University, Gottingen, Germany) of E. carotovora subsp. carotovora used in this study. To our knowledge, this is the first report of the occurrence and outbreak of a bacterial rot disease on dieffenbachia grown in the Eastern Mediterranean Region of Turkey. Contaminated cuttings may be the primary source of inoculum within and between glasshouses.

Managing storage pests of maize: Farmers' knowledge, perceptions and practices in western Kenya

Both weather fluctuation and farming system influence the epidemiology of crop diseases. However, short-term experiments are difficult to mechanistically extrapolate into long-term ecological responses. Using a mechanistic model with Bayesian inference, long-term data spanning 10 years were used to construct relationships among weather fluctuation (temperature, relative humidity, wind, and rainfall), farming system (conventional and low-external-input farming), and crop disease in experimental rice fields in Taiwan. Conventional and low-external-input farming had similar influences on the disease incidence of rice blast. Temperature had a positive influence on the disease incidence only under high relative humidity. Rainfall positively affected the disease incidence until an optimum level of rainfall. Low-external-input farming, with a lower application of fertilizers and other sustainable nutrient management, achieved similar effects on the disease incidence to those achieved by conventional farming. This suggests that weather fluctuation may override the effect of the farming systems on fungal disease incidence in rice fields.

Effect of hand-hoe based conservation agriculture on soil fertility and maize yield in selected smallholder areas in Zimbabwe