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Mechanism of resistance to Meloidogyne Incognita and Meloidogyne Javanica in Cucumis Africanus and Cucumis myriocarpus seedlingsRamatsitsi, Mukondeleni Ndivhuwo January 2017 (has links)
Thesis (M.Sc. (Horticulture)) -- University of Limpopo, 2017. / Root-knot (Meloidogyne species) nematodes are economically destructive pathogens of over 3000 species, whereas others have resistance to Meloidogyne species. Wild watermelon (Cucumis africanus) and wild cucumber (Cucumis myriocarpus) are highly resistant to Meloidogyne species, particularly M. incognita and M. javanica. The two Cucumis species are used in inter-generic grafting with watermelon (Citrullus lanatus) as nematode resistant rootstocks. Also, the two Cucumis species are used in traditional medicine and in plant-parasitic nematode management as phytonematicides. The form of nematode resistance, which is essential in plant breeding, is not documented for the two Cucumis species. The objective of this study was to determine the form of nematode resistance in the two Cucumis species to M. incognita and M. javanica under greenhouse conditions. Four parallel experiments were each conducted under greenhouse conditions. Uniform six-week old Cucumis seedlings were transplanted into 250 ml polystyrene cups filled with 200 ml growing medium of steam-pasteurised fine sand. A week after transplanting, Cucumis seedlings were each infested by dispensing approximately 100 M. incognita second-stage juveniles (J2) or M. javanica J2 using a 20 ml plastic syringe by placing into 5-cm-deep furrow around the seedling stem and covered with growing medium. Treatments (periodic harvest intervals) were arranged in a randomised complete block design, replicated five times. Five seedlings from each experiment were harvested every second day, for 30 days, with stained roots being assessed for necrotic spot (suberised cells) number, giant cell number, proliferation of rootlet interference number and root gall number. Periodic harvest intervals were highly significant (P ≤ 0.01) on necrotic spot number, proliferation of rootlet interference number and root gall number in C. africanus-M. incognita relations, but were not significant for giant cell number. Treatments contributed 59, 64 and 50% in total treatment variation (TTV) of necrotic spot number, proliferation of rootlet interference number and root gall number, respectively. Harvest period had highly significant effects on necrotic spot number, giant cell number, proliferation of rootlet interference number and root gall number in C. africanus-M. javanica relations. Treatments contributed 55, 71, 63 and 59% in TTV of necrotic spot number, giant cell number, proliferation of rootlet interference number and root gall number, respectively. Periodic harvest intervals were significant (P ≤ 0.05) on giant cell number and highly significant on root gall number in C. myriocarpus-M. incognita relations. However, there were no significant treatment differences on necrotic spot number and proliferation of rootlet interference number. Treatments contributed 57 and 57% in TTV of root gall number and giant cell number, respectively. Harvest period had highly significant effects on giant cell number, proliferation of rootlet interference number and root gall number, but were not significant on necrotic spot number in C. myriocarpus-M. javanica relations. Treatments accounted for 67, 49 and 53% in TTV of giant cell number, proliferation of rootlet interference number and root gall number, respectively. In conclusion, the mechanism of resistance to M. incognita and M. javanica in both C. africanus and C. myriocarpus was post-infectional nematode resistance, which has attributes for introgression into commercial nematode-susceptible Cucumis cultivars. / Agricultural Research Council (ARC),
National Research Foundation of South Africa; and
the ARC-Universities Collaboration Centre for Smallholder Farmers
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Evaluation of yield and protein content ot two cowpea cultivars grown under diferent management practicesSebetha, Erick Tshivetsi January 2009 (has links)
Thesis (M.Sc. (Horticulture)) --University of Limpopo, 2009 / Field experiments were conducted at the University of Limpopo experimental farm,
Syferkuil during 2005/06 and 2006/07 production seasons. This was initiated to examine the effect of leaf removal on cowpea biomass, protein content and grain yield under sole and binary cultures. Treatments consisted of cowpea varieties (Pan 311 and Red caloona),
cropping systems (sole and intercropping) and cowpea-leaf pruning regimes (pruning and
un-pruned). Sweet corn was planted, as a component crop in the intercropped plots while sole sweet corn plot was included as a treatment. All treatment combinations were laid out as Randomize complete block design (RCBD) with four replicates. Supplementary
irrigation was carried out during the plant growth period. Fully expanded leaves were
harvested once on all cowpea plants in the two middle rows from designated plots at
seven weeks after planting for each year. Growth and yield data were collected from
component crops during the course of the trial while the protein content of harvested
leaves and immature pods as well as the different cowpea plant parts at harvest were
determined. Results of the study revealed that leaves of cowpea variety, Pan 311
harvested prior to the reproductive stage had significantly higher protein content than
those of Red caloona. Protein content of immature Pan 311 pods had higher (18.8 to
25.1%) than Red caloona (17.9 to 20.7%) during both planting seasons. The percent
protein content of cowpea stem obtained at harvest for Pan 311 varied between 9.3 and
9.4%, and between 9.9 and 12.3% for Red caloona during both planting seasons. Grain
yield obtained for Pan 311 and Red caloona were 1703.7 kg ha-1 and 1479.8 kg ha-1,
respectively during 2005/06 and 1290.7 kg ha-1 and 511.7 kg ha-1 respectively during
2006/07 planting seasons. Sweet corn intercropped with Red caloona during both
planting seasons had higher average grain yield than when intercropped with Pan 311.
Although intercropping decreased the partial land equivalent ratio (LER) value of
individual component crops, the combined LER values of between 1.1 and 2.3 under
intercrop for the different treatment combinations implies that the practice is
advantageous. The results of post harvest soil analyses revealed that topsoil has the pH value of 7.11-7.29 indicating neutral soil while subsoil pH value of 6.27-6.91 indicated
slightly acidic to neutral soil during both planting seasons. Based on the findings of this study, cowpea variety Pan 311 can be recommended as a better vegetable crop than Red caloona since it has higher leaf and immature pod protein content. It also had higher grain yield than Red caloona when intercropped with sweet corn. Sweet corn had high grain
yield when intercropped with Red caloona than when intercropped with Pan 311.
Keywords: Cropping systems, protein content, grain yields, leaf pruning and cowpea.
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The effect of tree windbreaks on the microclimate and crop yields in the Western Cape Region of South AfricaHamlet, Andrew Gordon 12 1900 (has links)
Thesis (MScFor)--University of Stellenbosch, 2000. / ENGLISH ABSTRACT: The windbreak species near Wolseley (WoSl and WoS3) was Casuarina
cunninghamiana. The windbreak species near Saron (SaSl) and Villiersdorp (ViSl) was
Eucalyptus cladocalyx and Pinus radiata respectively. A shelter effect was indicated at
ViSI (from northerly winds in winter/early spring 1999), and WoS3 (from southerly winds
in late spring 1999).
Wind speeds were consistently reduced in the leeward sheltered zone ofViSl and WoS3.
To improve the correlation of the shelter effect, mild contaminating winds (comprising
approximately 28% of the total data recorded at each site) were excluded for the
prediction equations of the shelter effect at each site.
Compared to the more exposed wind speeds at 1.0 H to the windward side, wind speeds
at ViS] were reduced by 32% at 3.0 H. Compared to 11.0 H, wind speeds at ViSl were
reduced by 49 and 46% at 3.0 and 1.0 H respectively. With r2 values above 93%,
accurate linear prediction equations were produced. The early barley damage assessments
indicated that damage was absent or negligible at 11.1 H to the lee, and significantly
highest (X < 0.05) at 13.7 H to the lee and beyond. The crop shelter effect significantly
increased (p < 0.05) barley head number, transformed proportion of total barley head mass
from above-ground mass, potato tuber mass, potato above-ground mass total potato tuber
number, small tuber number, and disproportionate tissue damage to the windward section
of each plant.
For WoS3, the shelter effect became pronounced with severe south-easterly winds. The
average hourly wind speeds at 3.0 H dropped from 0.9 m / s (in the previous and less
windy sampling period) to 0.8 m / s, despite the sharp increase in exposed wind speeds.
Compared to 13.0 H, wind speeds were reduced by 73 and 32% at 3.0 and 7.0 H
respectively. With r2 values above 94%, accurate linear prediction equations were
produced. The crop shelter effect significantly increased (p < 0.05) sub-sample mass of lOO
grains.
At WoS3, strong and sustained wind speeds caused leeward soil temperature increases of
up to 4°C at 3.0 H, compared to 11.0 H. Brief strong winds (characteristic of winds at
ViSl) had little effect on the soil temperature differences. At ViSl, a deviation of soil
moisture content between 3.0 and 11.0 H, following periods of recharge, indicated a
potential soil-moisture conservation effect in the sheltered zone. This did not occur at
WoS3, due partly to a very low soil moisture content that had little scope for variation;
From the crop variations and the microclimate variations at both ViS 1 and WoS3, the
maximum shelter effect extended to approximately 4.0 H, followed by an intermediate
zone of diminishing shelter that extended to approximately 9.0 H.
For ViSl, WoS3 and SaSl, a shading effect significantly reduced yields (p<0.05) at
1.0 H from the respective northern windbreak, compared to yields at 2.0 H. At ViS 1 and
WoS3, soil probes did not indicate a depletion of soil moisture resulting from the
respective windbreaks. Soil moisture competition was indicated on the northern side of
the WoSl windbreak with drier conditions; where soil moisture levels at 1.0 and 3.0 H
diverged from a negligible level to a 22% lower level (p > 0.05) at 1.0 H, compared to
3.0H. / AFRIKAANSE OPSOMMING: Die boomsoorte wat as windbreke gedien het was Casuarina cunninghamiana naby
Wolseley (WoS 1 en WoS3), en Eucalyptus cladocalyx en Pinus radiata by Saron
(SaS 1) en Villiersdorp (ViS 1) respektiewelik. Beskutting is aangetoon by ViS 1 (teen
noordelike winde in winter/vroee lente 1999) en WoS3 (teen suidelike winde in laat
lente 1999).
Windspoed is konsekwent aan die lykant sones van ViS 1 en WoS3 verminder. Ten
dien einde die korrelasie van die beskuttings effek te verbeter, is matige
kontaminerende winde (ongeveer 28% van die totale waargenome data by elke plek)
buite berekening gelaat vir die voorspellingsvergelykings van die beskuttingseffek.
In vergelyking met die meer blootgestelde windspoede by 1.0 H aan die windkant, is
windspoede by ViSl met 32% verminder by 3.0 H. In vergelyking met 11.0 H is
windspoede by ViSl met 49 en 46% by 3.0 en 1.0 H respektiewelik verminder. Met
r2 waardes hoer as 93%, is akkurate lineere voorspellingsvergelykings verkry. Die
vroee gars skade opnames het aangetoon dat geen of minimale skade by 11.1 H aan
die lykant aangerig is, en beduidend die hoogste (x< 0.05) by 13.7 Hen verder aan die
lykant was. Die gewas beskuttins effek het beduidende toenames (p< 0.05) in garsare,
getransformeerde verhouding van totale gars-are massa van bo-grondse massa,
aartappelknol massa, aartappel bo-grondse massa, totale aantal aartappeiknolle, en
oneweredige weefsel beskadiging aan die windkant van elke plant tot gevolg gehad.
Vir WoS3 het die beskuttingseffek beduidend geword met baie sterk suidoostelike
winde. Die gemiddelde uurlike windsnelhede by 3.0 H het van 0.9/ (in die vorige en
minder winderige toetstydperk) tot 0.8 m/" verminder, ten spyte van die skerp
toename in blootgestelde windsnelhede. In vergelyking met 13.0 H is windsnelhede
met 73 en 32% by 3.0 en 7.0 H respektiewelik verrninder. Met r2 waardes hoer as
94% 15 akkurate lineere voorspellingsvergelykings verkry. Die gewas
beskuttingseffek het sub-monster massa van 100 graankorrels beduidend (p< 0.05)
verbeter.
By WoS3 het sterk en volgehoue windsnelhede grondtemperature aan die lykant met
tot 4°C by 3.0 H verhoog in vergelyking met 11.0 H. Kortstondige sterk winde
(tipiese winde by ViS1) het weinig uitwerking op grondtemperatuursverskille gehad.
By ViS1 het 'n afwyking van grondwaterinhoud tussen 3.0 en 11.0 H na tydperke van
aanvulling, 'n potensiele grondwaterbewaringseffek in die beskutte gebied getoon.
Soortgelyke tendense het nie by WoS3 voorgekom nie, gedeeltelik as gevolg van 'n
baie lae grondwater inhoud wat nie veel kon varieer nie.
Van die variasies wat in gewasse en mikroklimaat voorgekom het, by beide ViSl en
WoS3, kan afgelei word dat maksimum beskutting tot by ongeveer 4.0 H verleen is,
gevolg deur 'n intermediere sone van verminderende beskutting tot ongeveer 9.0 H.
Vir ViS1, WoS3 en SaSl het 'n skadu-effek gewasopbrengs beduidend (p< 0.05) by
1.0 H verminder in vergelyking met opbrengste by 2.0 H. By ViS 1 en WoS3 het
grondwater strooiingspeilers nie 'n uitputting van grondwater as gevolg van die
windbreke getoon nie. Kompetisie vir grondwater is getoon aan die noordelike kant
van die WoS1 windbreek met droer toestande.
Grondwatervlakke by 3.0 H het minimaal maar by 1.0 H met 22% beduidend
(p> 0.05) teenoor 3.0 H gedaal.
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Effect of genotype and phosphorus fertilizer rates on water use and yield of chickpeaMadzivhandila, Thendo 09 December 2013 (has links)
MSCAGR / Department of Plant Production
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Climate change and agricultural production in Limpopo Province : impacts and adaptation optionsMaponya, Phokele Isaac 12 1900 (has links)
The primary aim of my research was to identify the impacts and adaptation options of
climate variability and change on agricultural production in Limpopo province. The
following objectives were identified: To understand the impacts of climate variability and
change on agricultural production in Limpopo province , To assess the impacts of climate
variability and change on agricultural production in Limpopo province and To identify
adaptation measures that reduces the impacts of climate variability and change on
agricultural production in Limpopo province. A representative sample of 300 farmers aged
16- 65+ years (46 percent males and 54 percent females) participated in the study. The
study involved Sekhukhune and Capricorn districts, with 56 percent farmers in Capricorn
and 44 percent in Sekhukhune district. The following 11 local municipalities were visited:
Elias Motsoaledi, Makhuduthamaga, Fetakgomo, Ephraim Mogale, Tubatse, Lepelle
Nkumpi, Blouberg, Aganang, Polokwane, and Molemole.
The Limpopo province is one of the poorest provinces in the country, characterized by
high unemployment rate, poverty and lack of access to a range of resources that frustrate
majority of people ability to secure their livelihoods. In this study the province's
economic, biological and physical environment were highlighted. The study further covers
the province, s farming enterprises, systems, categories, infrastructure as well as other
constraints that maybe facing the emerging farmer in the province.
It is assumed that the majority of farmers in both the Capricorn and Sekhukhune districts
are using different coping and adaptation strategies in order to increase their crop yields.
Literature studies show that climate variability and change adaptation strategies vary from
area to area due to agro ecological zones and the harshness of the effects of climate
variability and change. It has also been noted that climate change is fast pushing the
poorest and most marginalized communities beyond their capacity to respond. This study
draws on lessons learned, experiences, and other existing research on climate change
impacts and adaptation across the globe. It sets out what is needed to enable people living
in poverty to adapt to climate change, and a range of interventions that are available across
climate - sensitive sectors.
The study has provided a literature review of the impact of climate change on the
agricultural sector. In fact, it has documented some of the likely impacts of climate change
based on International, continental, regional, national and provincial agricultural sector.
The study highlighted the impact of climate change also on various climate - sensitive
sectors including understanding water resources, forestry, natural ecosystem human health,
infrastructure and coastal zones. This research also confirmed that being a full time farmer,
gender, information on climate change, information received through extension services
and adaptation to climate change are some of the important determinants of agricultural
production, food scarcity and unemployment. A worrying situation is reviewed globally in
this study and it can be concluded that climate variability and change is affecting every
sector in society and it needs urgent attention. Statistics was used to determine climate
variability and change impact on agricultural production. Results indicate that farmers are
aware that Limpopo province is getting warmer and drier with increased frequency of
droughts, changes in the timing of rains, observed trends oftemperature and precipitation.
The study also presented perceived adaptation strategies used by farmers in Limpopo
province. Some of their perceived adaptation strategies included: (a) Soil management
strategies, (b) Water management strategies and (c) Others like use of subsidies and use of
insurance. Other important adaptation options being used by farmers were also discussed
in this study including different adaptation measures against colds, heat, frost, abnormal
wind, hail, lack of extension support, nematodes, insecticides, worms, temperature and
rainfall. The results of this study are potentially valuable to the agricultural sector
considering the threats that climate change poses across climate sensitive sectors. / Environmental Sciences / D. Phil. (Environmental Management)
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The impact of climate change on agricultural crop production in the Vhembe District Municipality, Limpopo Province South AfricaMusetha, Mboniseni Aubrey 09 1900 (has links)
The aim of this research was to identify the impacts and adaptation options of climate variability and change on agricultural crop production in Vhembe District Municipality. The study will contribute to the expansion of existing literature on climate change impacts on agricultural sector. The following two main objectives were formulated for the purpose of this study:
To determine the level of awareness of small-scale maize farmers about climate change impacts and threats in Vhembe District Municipality (VDM),
To compare the level of production scales between the farmers who are aware and the farmers who are not aware of climate change impacts and its threats. The study area was the Vhembe District Municipality; a representative sample of 150 farmers (aged 18 – 65+ years, 46 percent males and 54 percent females) participated in the study. Vhembe District Municipality is one of poorest municipalities in Limpopo due to lack of infrastructure development, and as a result of that, there is an increase of socio-economic problems such as food prices increase, unemployment, scarcity of food, and lack of local markets. The study further covers the municipality’s farming enterprises, systems, categories, infrastructure as well as other constraints that may be facing the emerging farmer in the District. The study highlighted the lack of climate change information, reduction of livestock production and crop yields of the farmers in the Vhembe District. The literature studies show climate variability and change adaptation strategies such as planting different varieties, crop diversification, different planting dates and shortening of growing periods. This study draws on lessons learned, experiences, and other existing research on climate change impact and adaptation across the globe. It was concluded during the research that change in climate was already perceived by farmers in the Vhembe District and the study also presented perceived adaptation strategies used by farmers in the Vhembe District. The study concludes that there is lack of local market, and low level of farmers’ awareness about the impact of climate change on the crop production in the Vhembe district. This low level of awareness translates into a low level of crop production which results in increased socio-economic problems, low income, increased unemployment, increased crops diseases and reduced crop yields. / Environmental Sciences / M. Sc. (Environmental Management)
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Climate change and agricultural production in Limpopo Province : impacts and adaptation optionsMaponya, Phokele Isaac 12 1900 (has links)
The primary aim of my research was to identify the impacts and adaptation options of
climate variability and change on agricultural production in Limpopo province. The
following objectives were identified: To understand the impacts of climate variability and
change on agricultural production in Limpopo province , To assess the impacts of climate
variability and change on agricultural production in Limpopo province and To identify
adaptation measures that reduces the impacts of climate variability and change on
agricultural production in Limpopo province. A representative sample of 300 farmers aged
16- 65+ years (46 percent males and 54 percent females) participated in the study. The
study involved Sekhukhune and Capricorn districts, with 56 percent farmers in Capricorn
and 44 percent in Sekhukhune district. The following 11 local municipalities were visited:
Elias Motsoaledi, Makhuduthamaga, Fetakgomo, Ephraim Mogale, Tubatse, Lepelle
Nkumpi, Blouberg, Aganang, Polokwane, and Molemole.
The Limpopo province is one of the poorest provinces in the country, characterized by
high unemployment rate, poverty and lack of access to a range of resources that frustrate
majority of people ability to secure their livelihoods. In this study the province's
economic, biological and physical environment were highlighted. The study further covers
the province, s farming enterprises, systems, categories, infrastructure as well as other
constraints that maybe facing the emerging farmer in the province.
It is assumed that the majority of farmers in both the Capricorn and Sekhukhune districts
are using different coping and adaptation strategies in order to increase their crop yields.
Literature studies show that climate variability and change adaptation strategies vary from
area to area due to agro ecological zones and the harshness of the effects of climate
variability and change. It has also been noted that climate change is fast pushing the
poorest and most marginalized communities beyond their capacity to respond. This study
draws on lessons learned, experiences, and other existing research on climate change
impacts and adaptation across the globe. It sets out what is needed to enable people living
in poverty to adapt to climate change, and a range of interventions that are available across
climate - sensitive sectors.
The study has provided a literature review of the impact of climate change on the
agricultural sector. In fact, it has documented some of the likely impacts of climate change
based on International, continental, regional, national and provincial agricultural sector.
The study highlighted the impact of climate change also on various climate - sensitive
sectors including understanding water resources, forestry, natural ecosystem human health,
infrastructure and coastal zones. This research also confirmed that being a full time farmer,
gender, information on climate change, information received through extension services
and adaptation to climate change are some of the important determinants of agricultural
production, food scarcity and unemployment. A worrying situation is reviewed globally in
this study and it can be concluded that climate variability and change is affecting every
sector in society and it needs urgent attention. Statistics was used to determine climate
variability and change impact on agricultural production. Results indicate that farmers are
aware that Limpopo province is getting warmer and drier with increased frequency of
droughts, changes in the timing of rains, observed trends oftemperature and precipitation.
The study also presented perceived adaptation strategies used by farmers in Limpopo
province. Some of their perceived adaptation strategies included: (a) Soil management
strategies, (b) Water management strategies and (c) Others like use of subsidies and use of
insurance. Other important adaptation options being used by farmers were also discussed
in this study including different adaptation measures against colds, heat, frost, abnormal
wind, hail, lack of extension support, nematodes, insecticides, worms, temperature and
rainfall. The results of this study are potentially valuable to the agricultural sector
considering the threats that climate change poses across climate sensitive sectors. / Environmental Sciences / D. Phil. (Environmental Management)
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Adaptation strategies for climate change-induced household food and nutrition insecurity in smallholder maize farming within Thulamela Local Municipality, South AfricaMahlawule, Khanyisa Dorris 18 September 2017 (has links)
MRDV / Institute for Rural Development / See the attached abstract below
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