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Optimising locally available resources for nutrient management to improve banana productivity in the farming systems in rombo district, kilimanjaro region
No full textA dissertation submitted in partial fulfillment of the requirements for the degree of master of science in soil science and land management of Sokoine University of
Agriculture. Morogoro, Tanzania.Banana is an important staple food in East Africa and an essential cash crop in the national and local economies. In Kagera and Kilimanjaro regions of Tanzania, banana is cultivated by more than 70% of smallholder farmers as a staple food in home gardens ranging from 0.5 to 2 hectares. Decline in banana yield has been reported in banana farming systems as a result of abiotic constraints (nutrient deficiencies and drought stress) and biotic constraints (pests and diseases). Decline in soil fertility and the ensuing nutrient deficiencies are among the major causes of the decline in banana yield. In the banana farming systems, nutrient removal most times exceeds their input, along with years of continuous cultivation results into negative yield trends. Most smallholder farmers are resource-constrained and thus limited in use of inorganic fertiliser due to cost, availability and usage. In this study the aim was to evaluate soil nutrient factors that affect banana production in order to identify localized soil nutrient management practices tailored to the biophysical and socioeconomic conditions of the smallholder farmer improve crop productivity. In evaluating soil fertility status in the banana farming systems, adequate indicators were employed, namely, physico-chemical and nutrient analysis, spatial analysis, crop yield and critical nutrient levels, limiting nutrients and nutrient balances.
A survey approach was employed, involving sample collection in farmers’ banana fields. Using the Probability Sampling Technique, six wards (namely: Aleni, Mamsera, Manda, Mengeni, Mengwe and Shimbi) were selected in a systematic random manner based on banana production areas. Then from the six wards, a total of 100 sites were selected in a stratified random manner and geo-referenced. Allometric measurements, namely: girth at base (Gbase), girth at 1-m height (G1m), number of hands, and number of banana fingers on the bottom row of the second last hand were taken from among three selected mats with a banana plant at fruiting stage per farm site. Analysis considered three banana cultivars, namely, Malindi, Matoke and Mshare that were dominant in the sites and had higher number of observations. Allometric data were used to determine banana bunch weights (Bwt) and above ground biomass (AGB). Results indicated that Matoke had significantly (P≤0.05) higher Gbase, G1m and AGB than Malindi and Mshare, whereas Malindi had significantly (P≤0.05) more number of hands. There was no significant difference (ns) (P≤ 0.05) for number of fingers and Bwt among the cultivars. Soil and plant samples were collected from every site and analysed for physicochemical properties and nutrients concentrations. Boundary line analysis was used to determine plant critical nutrient values. Results indicated critical levels were 2.39, 0.15, 1.5, 0.35 and 0.3% for N, P, K, Ca and Mg, respectively. Results from descriptive statistics, geo-statistics and nutrients maps, coefficient of variation diminished in the order P>Cu>K>Zn>Mn>S.
A survey was carried out to identify agronomic management practices and production constraints. Survey data were used to categorise farmers into wealth classes based on resources owned (Resource-rich L3, medium L2 and poor L1 households) as well as classes based on cattle ownership. Soil samples were collected from each farm at a depth of 30 cm and nutrient concentrations analysed. The aim was to determine most-limiting yield nutrients in the farms using nutritional index (NI). Bunch weight was compared to optimum attainable bunch weight of 28 kg and 69 low-yield farms were obtained. The major nutrient deficiencies were K>Mn>P=Zn>Cu in 40, 35, 34 and 32% of low-yield areas, respectively. L3 owned more land area under banana than L2 and L1 households by 8% (ns). Yet L3 had significantly (P≤0.05) higher banana Bwt. Survey data along with data from nutrient analysis were used for estimating partial nutrient balances in home gardens across household classes. Large nutrient input observed was by farmyard manure application and removal by crops harvested and their residues. Higher negative N and K balances were obtained in home gardens of less resource households and those with few (≤ 2) cattle, while positive P balances were obtained for home gardens across all household classes indicating less P-removal,. Positive NPK balances were obtained for households with more (>2) dairy cattle, but these were just a few representation of households. Hence, indicating the need to employ an integrated nutrient management approach using other nutrient sources, other than farmyard manure, in order to increase nutrients input and thereby increase and sustain banana yield. Dr. Godfrey Tauly
Leptospirosis in sugarcane plantation and fishing communities in Kagera northwestern Tanzania
No full textResearch Article 2019Background
Leptospirosis is a bacterial zoonotic disease of worldwide importance, though relatively
neglected in many African countries including sub Saharan Africa that is among areas with
high burden of this disease. The disease is often mistaken for other febrile illnesses such as
dengue, malaria, rickettsioses and enteric fever. Leptospirosis is an occupational disease
likely to affect people working in environments prone to infestation with rodents which are
the primary reservoir hosts of this disease. Some of the populations at risk include: sugar-
cane plantation workers, wetland farmers, fishermen and abattoir workers. In this study we
investigated the prevalence of antibodies against Leptospira among sugarcane plantation
and factory workers, fishing communities as well as among rodents and shrews in domestic
and peridomestic environments within the study areas.
Methods
The study was conducted in Kagera region, northwestern Tanzania and it involved sugar-
cane plantation workers (cutters and weeders), sugar factory workers and the fishing com-
munity at Kagera Sugar Company in Missenyi district and Musira island in Lake Victoria,
Kagera, respectively. Blood was collected from consenting human adults, and from rodents
and shrews (insectivores) captured live using Sherman traps. Serological detection of lepto-
spiral antibodies in blood serum was carried out by the microscopic agglutination test (MAT).
Results
A total of 455 participants were recruited from the sugarcane plantation (n = 401) and fishing
community (n = 54) while 31 rodents and shrews were captured. The overall prevalence of
antibodies against Leptospira in human was 15.8%. Sugarcane cutters had higher seroprev-
alence than other sugar factory workers. Prevalent antibodies against Leptospira serovars
in humans were against serovars Lora (6.8%), Sokoine (5.3%), Pomona (2.4%), Hebdoma-
dis (1.1%) and Kenya (0.2%). Detected leptospiral serovars in reservoir hosts were Sokoine (12.5%) and Grippotyphosa (4.2%). Serovar Sokoine was detected both in humans and
small mammals.
Conclusion
Leptospirosis is a public health threat affecting populations at risk, such as sugarcane plan-
tation workers and fishing communities. Public awareness targeting risk occupational
groups is much needed for mitigation of leptospirosis in the study areas and other vulnerable
populations in Tanzania and elsewhere
Soil characterization and effects of n, p and k on the growth, yield and root quality of cassava (manihot esculenta crantz) in the lake zone of Tanzania
No full textMASTERS DISSERTATIO
Epidemiology of hepatitis E virus infection in pregnant women in sekondi-Takoradi Metropolis, Ghana
No full textA thesis, Degree of Doctor of PhilosophyInfections caused by hepatitis E virus (HEV) constitute a global public health burden.
Worldwide, over 20 million new cases of asymptomatic infections, 3.4 million illnesses
and 70 000 deaths due to HEV occur each year. Infections with HEV are the leading cause
of oro-fæcally acquired viral hepatitis and outbreaks have occurred in more than 61
countries. In developing countries particularly in Asia and Africa HEV outbreaks cause
10-30% case fatality rates in pregnant women and the infection is more common and fatal
during the third trimester of pregnancy. Several reports in Ghana have pointed to the
country being HEV endemic and sporadic maternal deaths and abortions due to HEV
infections. However, there is not a surveillance system for HEV infections and the Ghana
Ministry of Health (MOH) expressed concerns over knowledge gaps about the infection
and particularly among the most HEV-vulnerable pregnant population.This is important
because in the absence of vaccine to control HEV infection individual actions by the
affected pregnant women to lower the effect of risk factors becomes necessary. There is
also the policy implication of this study. In the absence of vaccines to control HEV
infections the strategy of education becomes an important tool to lower the effects of the
risk factors. The objectives of this thesis therefore were to determine seroprevalence of
subclinical infections of HEV in the third trimester of pregnancy, risk factors and the
delivery outcomes due to infections with HEV in the Sekondi-Takoradi Metropolis,
Ghana. Asymptomatic and apparently healthy pregnant women in third trimester, of 18
years and above were purposively selected in a cross-sectional study. The third trimester
was selected because this is the period reported to be associated with most HEV-related
vulnerabilities of abortions, faetal and maternal mortalities. To reduce confounding effects
on estimates pregnant women with hepatitis B, C and active liver disease profiles
examined earlier as part of antenatal care in routine checks and found not to be free of
these infections were excluded from the study. Because reports have associated human
immunodeficiency virus (HIV) with increased infections of HEV infections those with
HIV have also been excluded. Blood samples were collected and analyzed for HEV
infection. Socio-demographic and household data were collected. Household proximity to
wetlands and domestic pig farms were estimated and farmed swine from two districts
from where the sampled pregnant women originated were also tested for HEV infection.
Data on diagnoses and mode of delivery of the pregnant women were collected from
books on their discharge and also from the Regional Hospital Database. Bivariate and
multivariate logistic regression (LR) analysis was done in SPSS version 20 and by
Microsoft Excel, respectively. R code version 4.1 was used to check model assumptions
and geographical dependence in the dataset. Anti-HEV IgM was 22.5% (81/360) 95%
CI:18.2-26.8: and the anti-HEV IgG 11.0% (11/100) 95% CI: 5.6-18.8. In bivariate LR
analysis statistically significant associations were found between recent HEV infections
and age-groups, level of education, access to household flash water toilet systems. Three
out of 12 (25%) domestic pig farms were infected with HEV. Proximity to 20% (5/20)
farms were significantly associated with recent infections with HEV. Infection with HEV
was significantly associated with complications at delivery (P = 0.029: OR 1.24 95% CI
1.021-1.496). Surprisingly, among 22 diagnoses recorded in ward discharge log books,
normal pregnancy (NP) was the only significant outcome (P = 0.000: OR 0.349 95% CI
0.232-0.525), an indication of recent infections with HEV protective of normal deliverys.
Seroprevalence of active infection with HEV in the third trimester of pregnancy is 22.5%
in Sekondi Takoradi Metropolis of Ghana. The absence of water closet toilets and
proximity to domestic pig farms are risk factors for HEV infection, whilst proximity to
wetlands is not indicative of an infection risk to HEV. Active infection with HEV is not
indicative of having an adverse outcomes on deliveries at delivery. Metropolitan,
municipal and local government authorities should increase support for water closet toilet
facilities in households. Improved swine farm effluent management systems should also
be encouraged. Health authorities should encourage public awareness creation about HEV
infection in pregnancy. Even though the outcomes during delivery of recent HEV
infections appear to be protective of normal pregnancy, clinical realities may be different.
Therefore, research institutions should consider swine HEV as a One Health challenge to
reduce the potential of swine-HEV risks for the development of liver cancers in pregnant
women. The current study provided insights for dealing with geospatial analysis and
provided additional analytic approach in dealing with geospatial data. The seroprevalence
data on recent HEV infections adds to existing data on HEV during pregnancy and the
first study of HEV in swine in Ghana. In the absence of vaccine against HEV infections
education against HEV during pregnancy by the Ministry of Health and related
institutions will improve disease prevention and control
Occurrence of fungal infections in Rufiji tilapia and hybrids of female Nile tilapia and male Rufiji tilapia at different salinities
No full textA DissertationFungal diseases are prevalent in fish and have the potential of limiting productivity in
aquaculture. This study aimed to isolate and determine fungal infections in hatchery with
female Rufiji tilapia and their hybrids of male Rufiji tilapia and female Nile tilapia. An
experimental study design was conducted to determine the occurrence of fungal infections
and to characterize the isolates of Aspergillus flavus and Aspergillus niger. Fish samples
were randomly collected from the hatchery at the Institute of Marine Sciences Mariculture
centre in Pangani. In the sampled fish the gills, gastrointestinal tract and skin were
collected. The morphological and physiological tests were employed to isolate and
identify fungi using SDA. The lactophenol detached crystal cotton blue was used for
characterization of fungi. The Rufiji tilapia stocked at different salinities were infected by
A. niger and A. flavus at 72.4 % and 17.1% (n = 61) respectively. The prevalence of A.
niger and A. flavus in water of tilapia and hybrids was 37.4 % and 10.6% respectively.
Rufiji tilapia and hybrids were infected by A. niger and A. flavus at 37.9 % and 6.5 % (n =
62) respectively. For PCR based analysis, fragments of bp400 and 895 were detected for
A.flavus and bp290 for A.niger. Despite the percentage variations for fungal isolates in
some of the fish, overall, there was a significant (P0.05) reduction of prevalence of
fungal infections with increasing salinities. In the hybrids, an increase in salinity did not
influence the prevalence of Aspergillus species (P0.05). Increase in salinity has no
influence on the growth of A. flavus in fish organs of Rufiji tilapia. Conventional methods
are time-consuming and less sensitive; PCR methods provide more specification and high
sensitivity of the target organism. Different salinities of 15, 25 and 35 are potential for
mariculture since they cannot support the existence of A. niger unlike A. flavus, which
showed significant difference in fish organs
Distribution, population structure and carbon storage of bamboo species in Tanzania
No full textProceedings of the conclusive workshop of the INFORES project, Morogoro, 25th-26th September, 2019. Pp 60-71.Sustainable management of forest resources requires information regarding quantities and quality
of the resources. Despite this fact, the existing information for bamboo forest resources in Tanzania
regarding abundance, distribution along altitudinal ranges, density, basal areas and carbon stocks
is inadequate, site specific and fragmented. Based on 696 plots out of 30 773 plots surveyed by the
National Forest Resources Assessment and Monitoring (NAFORMA), the present study assessed the
distribution, abundance and carbon storage of bamboo species in Tanzania in R software. Results
indicates that, 11 bamboo species from five genera and two tribes were recorded in Tanzania. They are
dominated by Arundinaria alpina and Oxytenanthera abyssinica that constitutes 55.9% of the total
bamboo population and are distributed in only 11 administrative regions of the country. They occur
at altitude of 76 m.a.s.l to 2592 m.a.s.l, whereby about 85.2% of bamboo population are distributed
below 1500 m.a.s.l. Moreover, bamboo occurs more abundantly in woodland (66%) and least in
open land (0.1%). Similarly, most of the bamboo is in the production forests (44.7%) followed by
Agriculture land (19.5%) while wetlands have the least (0.4%). Results further indicates that bamboo
species have a mean stocking, basal area and carbon stocks of 2460 culms/ha, 2.391 m 2 /ha and 1.566
tC/ha respectively. Since most of the carbon is stored by Arundinaria alpina and Oxytenanthera
abyssinica that contributes 58.2% of the total carbon stored by bamboo species in the country, efforts
should be strengthened to manage these species. Likewise, for mitigating climate change bamboo
species should be planted in altitude below 1500 m a.s.l. Due to lack of bamboo allometric biomass
models in Tanzania, the models used in this study was borrowed from Kenya and Ethiopia, indicating
the need to develop such models for Tanzanian bamboo
Consumer behavior and consumption practices towards less documented wild leafy vegetables among rural households in Dodoma Region, Tanzania
No full textInternational Journal of Environment, Agriculture and Biotechnology (IJEAB) Vol -4, Issue-4, Jul-Aug- 2019Inadequate dietary diversity is a key challenge in many countries in sub-Saharan Africa.
Diversifying diets with African indigenous vegetables is a sustainable way to supp ly a variety of nutrients to
household members due to their richness in vitamins and minerals. Understanding the preferences and
consumption practices of different varieties of wild vegetables is important information for agricultural
promoters and is scarcely explored in Tanzania. This study aimed to gain an understanding of consumer
behavior and consumption practices of wild vegetables in semi -arid areas in Tanzania in order to inform food
policy and agricultural promoters. The study was conducted in two villages; Ilolo and Idifu from the semi-arid
Dodoma region in Tanzania. Focus group discussions were conducted with forty women from both villages
because women are more involved in cultivation, gathering and preparation of vegetables. Information collected
in the focus group discussions included; perceptions, preferences, beliefs and taboos associated with
consumption of wild vegetables. Participants reported that wild vegetables are seasonally available with most
time of the year being scarce. The majority of the women reported consuming the wild ve getables due to good
taste, abundance of nutrients, availability/affordability (they are mostly free), and because the other sources of
relish are usually scarce. The most common wild vegetables that were consumed in the past 24 hours preceding
the focus group discussions in the two villages included Ipomoea pandurate which is locally known as
chiwandagulu and Corchorus trilocularis commonly known as ilende. For most vegetables, leaves and stems
were common parts consumed. The women in both villages ranked Corchorus trilocularisas the most preferred
wild vegetable. Women also reported some medicinal values attached to some of the wild vegetables such as
Bidens Pilosa leaves which are claimed to increase blood. Generally, wild vegetables have the capability to
escalate their significance to household income generation if farmers are given the chance to market them. Also
domestication and promotion of these vegetables may help to enhance food and nutrition security
Status of geoinformatics education and training in Sub-Saharan Africa: initiatives taken and challenges
No full textThis paper presents an update on some of the activities that have taken place since aWorld Bank report; “Guidelines for Education and Training in Environmental Information Systems in Sub-Saharan Africa: Some Key Issues” was published and provides details on the current situation. It shows how organizations such as the African Association on Remote Sensing of Environment, International Society of Photogrammetry and Remote Sensing, European Association of Remote Sensing Companies, Group on Earth Observation, and several others have helped to increase manpower resources in the region and strengthened institutional capacity in the field of geoinformatics, through capacity building, technology transfer, international cooperation and the provision of
internal African resources. After reviewing what has happened in the field of geoinformatics education and training, we focused on current initiatives taken and challenges in five Sub-Saharan countries: Ethiopia, Nigeria, South Africa, Tanzania, and Zimbabwe. We reviewed GIS education and training in the private sector, government, information communications technology in higher education institutions, GIS application
areas and challenges facing GIS education and training. Findings show that; change should involve education stakeholders in all levels of education and curriculum quality, regional and international cooperation through exchange programs, should be a priority for Sub-Saharan Africa countries
Micronutrients composition of selected sun-dried and cooked indigenous leafy vegetables in Dodoma, Tanzania.
No full textA Dissertation 2019Indigenous leafy vegetables are important in human diet as they supply a number of
important nutrients for human health. A cross-sectional study was carried out at
Chamwino District (Mzula and Chinoje villages), Dodoma to assess the effect of
drying and cooking on nutrients composition of selected indigenous leafy vegetables.
A total of 120 randomly selected participants were interviewed using pretested
structured questionnaires with the main focus on vegetable production, processing and
storage practices. For laboratory analysis, three commonly consumed varieties of
indigenous leafy vegetables namely ''Amaranthus'' (Amaranthus hybridus), ''Jute
mallow'' (Corchorus olitorius L.) and ''Spider flower'' (Cleome gynadra L.) were
selected from each village and divided into three groups; uncooked (fresh) to serve as
control samples, the dried-cooked samples and fresh-cooked samples. The samples
were analysed for β-carotene by using Ultra Violet Visible Spectrophotometer;
Vitamin C by titration method and minerals (iron, calcium and zinc) by Atomic flame
emission Spectrophotometer. The results showed that the concentration of β-carotene
in indigenous leafy vegetables ranges from 328 - 179 μg/ g, vitamin C (89 - 23 mg/100
g), iron (46 - 27 g/100 g), calcium (62 - 31 g/100 g) and zinc (45 - 13 g/100 g). Sun-
drying and cooking had significant (p<0.05) impact in reduction of micronutrients in
the selected vegetables. The β-carotene was reduced by 64 % in sun - dried and by 90% in
dried cooked vegetables; Vitamin C was reduced by 33% in sun - dried and by 64 % in dried
cooked; Iron was reduced by 34% in sun - dried and by 57 % in cooked dried, calcium by 21%
in sun - dried and by 65 % in cooked dried. The highest percentage retention of β-carotene
was seen in Corchorus olitorius L. (36%), Vitamin C in Amaranthus hybridus L.
(67%), Zinc in Amaranthus hybridus L. (92%), Calcium in Cleome gynadra L. (79%)
and Iron in Amaranthus hybridus L. (65%). The results from the present study
Effects of pre-harvest hexanal application on yield and quality of major fruits in Eastern Zone of Tanzania
No full textA ThesisOrange (Citrus sinensis L.), mango (Mangifera indica L.) and tomato (Lycopersion
esculentum Mill.) are among the important horticultural crops in Tanzania. Fruit
production in Tanzania is constrained by several pre-harvest factors which cause
production of inferior quality. The major pre-harvest causes of low fruit production and
quality are pests, diseases, weather conditions, especially drought stress, and improper
agronomic practices. Hexanal formulation is relatively a new technology that has been
reported to reduce pre-harvest and postharvest losses of fruits and vegetables in temperate
and subtropical climates. However, there is limited information on the effect of pre-
harvest field application of hexanal on marketable yield and quality of selected fruit
varieties grown in Tanzania. Similarly, the effects of field hexanal application on pre-
harvest yield losses of selected fruits are also not well known. Therefore, the objectives of
this study were to: (i) determine the key fruit attributes used by buyers in selecting fruits;
(ii) determine the effects of pre-harvest hexanal application on market fruit attributes, and
(iii) determine the effects of field application of hexanal on pre-harvest fruit losses of
selected major crops in Tanzania.
To achieve objective 1, a study was conducted at Muheza district in Tanga region and
Mkuranga district in Coast region to identify key orange and mango fruit attributes
preferred by buyers. A total of 179 participants were engaged to evaluate the fruit
attributes that influence marketing, longevity and endurance of Orange and Mango. Of the
total participants, 50.3% assessed orange fruit attributes and 49.7% assessed similar
attributes for mangoes. Data were collected by interviewing consumers, farmers and
traders of oranges and mango using open and close ended questionnaires. Results revealed
that buyers strongly associate fruit colour, freshness, firmness, spots free and medium size with marketability of mango and orange fruits. Moreover, buyers strongly correlate fruit
freshness, colour, spots free and firmness with shelf life of mango and orange fruits
whereas buyers further associate spots free, freshness and firmness fruit attributes with
endurance of mango and orange fruits. It is recommended that sellers of orange and mango
fruits should apply technologies which can improve fruit freshness, firmness and colour,
and reduce pest incidences.
To achieve objective 2, an experiment was laid out in a Completely Randomized Design in
a 4 x 4 factorial arrangement using well established and maintained farmers‟ of orange,
mango and tomato orchards. The factors A was hexanal concentrations (0.01, 0.02, 0.04%
and control - untreated fruits) and factor B was time of hexanal application prior to fruit
harvest (7, 21, 42 and 60 days to harvest) for orange varieties (Early Valencia, Jaffa and
Late Valencia) and mango varieties (Apple, Palmer and Keitt). For tomato (Mwanga, Rio
Grande and Tanya) cultivars, the factor A was hexanal concentrations (0.01, 0.02, 0.04%
and control - untreated fruits) and factor B was time of hexanal application prior to fruit
harvest (7, 14, 21 and 28 days to harvest). Each fruit species was treated as an individual
factor to achieve this objective.
Orange: Results show that application of hexanal at 0.01% improved fruit marketable
yields by increasing fruit firmness and marketable yield of Early Valencia, Jaffa and Late
Valencia varieties. The orange marketable yield increased by 19.28, 26.21 and 30.74%
over the controls for Early Valencia, Jaffa and Late Valencia, respectively. Similarly, fruit
firmness increased by 9.07, 9.64 and 10.12 N/mm 2 over the control for Early Valencia,
Jaffa and Late Valencia, respectively.
Mango: Results indicated that application of hexanal concentration 0.01% increased
mango marketable yield by 24.54, 19.64 and 20.40% over the controls for Apple, Palmer
and Keitt varieties, respectively. Likewise, fruit firmness increased by 11.19, 9.97 and
10.05 N/mm 2 over the control for Apple, Palmer and Keitt varieties, respectively. Tomato: Results show that hexanal application 0.01% increased tomato marketable yield
by 23.38 and 23.10% over the controls for Mwanga and Rio Grande cultivars,
respectively. Similarly, hexanal application at 0.01% increased fruit firmness by 5.03, 5.77
and 5.19 N/mm 2 over the control for Mwanga, Rio Grande and Tanya tomato cultivars,
respectively.
To achieve objective 3, an experiment was laid out as in objective 2 above.
Orange: Results show that application of hexanal at 0.01% reduced number of dropped
fruits by 22.62, 37.73 and 46.31% over the untreated fruits (control) for Early Valencia,
Jaffa and Late Valencia orange varieties, respectively. Similarly, application of hexanal at
0.01% reduced non-marketable yield by 21.39, 26.10 and 30.74% over the control for
Early Valencia, Jaffa and Late Valencia orange varieties, respectively. Likewise,
application of hexanal at 0.01% decreased incidences of pest damage by 21.59, 22.50 and
24.86% over the control for Early Valencia, Jaffa and Late Valencia, respectively.
Mango: Results further show that application of hexanal at 0.01% reduced number of
dropped fruits by 25.94, 20.77 and 22.58% over the control for Apple, Palmer and Keitt
mango varieties, respectively. Moreover, application of hexanal at 0.01% reduced non-
marketable yield by 24.82, 19.59 and 21.40% over the controls for Apple, Palmer and
Keitt mango varieties, respectively. The application of hexanal at 0.01% also reduced
incidences of pest damage on fruits by 27.93, 17.05 and 19.58% over the control for
Apple, Palmer and Keitt mango varieties, respectively.
Tomato: Results show that application of hexanal 0.01% reduced non-marketable yield by
23.24, 23.27 and 28.39% over the control for Mwanga, Rio Grande and Tanya tomato
cultivars, respectively. Similarly, the application of hexanal at 0.01% also decreased
incidence of pest defects by 22.53, 22.00 and 23.02% over the control for Mwanga, Rio
Grande and Tanya tomato cultivars, respectively. General conclusion and recommendation: According to farmers, traders and consumers
the main fruit attributes which influence purchase preference of mango and orange are
freshness, colour, spots free and firmness. Pre-harvest application of hexanal at 0.01%
improves fruit attributes namely firmness and freedom of fruit skin from pest damage of
orange, mango and tomato treated varieties. The application of hexanal at 0.01% further
increases marketable yield of oranges, mango and tomato treated varieties by reducing
dropped fruits, number of non-marketable yield and incidences of pest damage. It is
recommended that farmers should apply hexanal at 0.01% from 42 to 7 days before fruit
harvest in order to improve fruit attributes to enhance marketing, and increase marketable
yield of orange (Early Valencia, Jaffa and Late Valencia), mango (Apple, Palmer and
Keitt) and tomato (Mwanga, Rio Grande and Tanya)