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Lachenalia cv. Ronina, a new flower bulb variety developed by the ARC-Roodeplaat Vegetable and Ornamental Plant Institute, has excellent characteristics as a flowering pot plant, but information on cultivation practices is limited. Temperature is the most important environmental factor regulating the growth cycle of this flower bulb, therefore three temperature regimes, representing a cool, moderate and warm winter climate, were chosen to manipulate floral development. During this study the bulb structure, development and growth were determined during the bulb preparation phase (year 1) and subsequently the morphology of the bulb was evaluated during the pot plant phase (year 2). Regarding the bulb structure and development, cultivar Ronina has a typical rhythmic, sympodial, modular growth. Bulb growth and module formation is affected by temperature. The low (L TR) and moderate (MTR) temperature regime, which represent the cool and moderate winter climate in South Africa were found to be the best temperature regimes for bulb production. The high (HTR) temperature regime caused bulbs to develop faster, but flower abortion occurred. At the end of the bulb preparation phase, daughter bulbs were observed in the axils of the leaf bases in bulbs of all three temperature regime treatments. Additional inflorescences from underdeveloped growth modules were detected in the axils of the inner leaf bases of bulbs of the high temperature regime. The bulbs as well as the roots are the main sinks for the carbohydrates, whereas the inflorescence and especially the leaves are the main source for soluble sugars. Due to the more stable temperature that was applied in the growth cabinets, the flowering date of bulbs in all three treatments flowered two months earlier than plants growing in the open. During this production phase, simultaneous flowering occurred more within bulbs that were subjected to the LTR during the bulb preparation phase. These bulbs also produced broader leaves with more spots on and better quality inflorescences with a longer keeping ability than those of the higher temperature regimes. A correlation was found between the leaf number and the number of inflorescences of plants in the pot plant phase, grown from LTR treated bulbs. The bulb fresh mass/size at the end of the bulb preparation phase cannot be used as a reliable criterion to predict the quality of the pot plant. By examining the bulb structure at the end of the bulb preparation phase, the quality of the pot plant can be predicted. / Thesis (PhD Agric (Horticultural Science))--University of Pretoria, 2007. / Plant Production and Soil Science / unrestricted

Typescript (photocopy). / Digitized by Kansas Correctional Industries

The overall objective of this study was to determine the influence of intermittent water application via overhead irrigation on water and N leaching, substrate water distribution, and plant growth in a pine bark substrate. Intermittent irrigation was defined as the application of a plants' daily water allotment in multiple applications with prescribed intervals between applications. Specifically, experiments were conducted to determine: 1) the influence of water application rate and pre-irrigation substrate moisture content on water application efficiency, 2) the influence of the number of intermittent applications and interval duration between applications on application efficiency, 3) substrate water distribution after intermittent irrigation, 4) efficiency of intermittent irrigation in unamended and sand-amended pine bark, and 5) influence of intermittent irrigation on plant growth. In all experiments, Marigold (<u>Tagetes erecta</u> L. 'Apollo') was grown in unamended or sand-amended pine bark in 3.8-liter containers. After saturation, bark was allowed to dry via evapotranspiration to targeted moisture deficits after which irrigation treatments were applied via a simulated overhead irrigation system. In experiments evaluating intermittent irrigation, water was applied intermittently (multiple applications with intervals between applications) or continuously (single application). After 1 h drainage, collected leachate was measured and analyzed (in two experiments) for electrical conductivity, N0₃-N and NH₄-N and water application efficiency (percentage of applied water that is retained in the substrate) determined. There was an inverse linear relationship between water application rate and efficiency. Leachate N (total) increased linearly as application rate increased. Efficiency increased curvilinearly and leachate N (total and concentration) increased linearly as pre-irrigation substrate moisture content decreased. Efficiency of intermittent irrigation was greater than continuous irrigation over a range of pre-irrigation substrate moisture contents, and in both unamended and sand-amended pine bark. Intermittent efficiency increased linearly as interval duration between applications increased. Efficiency of five 60 ml applications was greater than three 100 ml applications. Gravimetric moisture content of the bottom third of the substrate was greater with intermittent than continuous irrigation. Intermittent efficiency was greater in pine bark than in sand-amended pine bark when the water deficit from container capacity was the same for both substrates. Repeated intermittent irrigations resulted in less water and N leaching compared to continuous irrigation. Intermittent irrigation did not result in substrate nutrient accumulation and had no adverse effect on plant growth. Fresh and dry root weights and shoot and root N concentrations were greater with intermittent irrigation than continuous irrigation. / Ph. D.

Studies were conducted to evaluate the effect of pre-irrigation media moisture deficit, irrigation application rate, and intermittent irrigation on irrigation efficiency [(amount applied - amount leached) amount applied' 100] of spray stake-irrigated, container-grown plants. In the first experiment, pine bark-filled containers were irrigated to replace moisture deficits of 600, 1200, or 1800 ml. Deficits were returned in single, continuous applications at application rates of 148, 220, and 270 ml/min. Application rate did not affect irrigation efficiency. Efficiency decreased with increased medium moisture deficit. In the second experiment, containers, at 600 ml media moisture deficits, were irrigated with 400 or 600 ml (65% and 100% water replacement, respectively). Irrigation volumes were returned in a single, continuous application or in 100ml applications with 30 min intervals between irrigations (intermittent). Irrigation efficiency was greater with intermittent irrigation, 95 % and 84 % for 400 and 600 ml replacement, respectively, than with continuous irrigation, 84% and 67% for 400 and 600 ml replacement, respectively. When applied intermittently, most water loss from containers occurred after 400 ml were applied. In the third experiment, containers were irrigated with 600 ml (100% water replacement) in 50, 100, or 150 ml applications with 20, 40, or 60 min intelVals between applications. A control was included in which 600 ml was applied in a single, continuous application. Irrigation efficiency increased with decreasing application volume and increasing length of interval between applications. The greatest efficiency (86%) was produced with an irrigation regimen of 50 ml applications with at least 40 min between applications. The control treatment (continuous) produced an irrigation efficiency of 62%. When applied intermittently, most water loss from containers occurred after a total of 300 ml were applied. / Master of Science

Home gardening has historically been a subsistence or supplemental form of food procurement worldwide and promoted as a food security project in times of economic hardship. Qualitative research was used to investigate container gardening's potential to provide the impetus for further agricultural activities within low-income, low-food-access, rural Appalachian Virginia, thereby impacting community food security, food choices of individuals, and the local food system. Ethnography and phenomenology methodologies were used through the lens of community-engaged research, and the lived experiences of participants were recognized as valid representations of food insecurity. Semi-structured interviews with fourteen participating households revealed program involvement was deeply connected to previous food production experiences and fueled by existing interest in home gardening. Containers were valued as providing alternative modes to continue a meaningful practice, specifically mitigating challenges of limited mobility for the elderly. As rural areas are experiencing an outmigration of young people and struggling social services, container gardening could be utilized as a low-cost culturally appropriate mental- and nutritional-health service for the rural elderly. Similar initiatives should begin with appreciative inquiry into existing perceptions, values, assets, and potentials within a target community. Through preliminary investigation, needs and barriers can be acknowledged and community-identified solutions can be implemented through culturally sensitive program development. With the existing impetus for home gardening in the region, program expansion could potentially impact food security and the local food system. Overall, this case study serves to further endorse a public effort to support home food production in rural areas of the United States. / Master of Science

Thesis (M. A. Agriculture (Plant Protection)) -- University of Limpopo, 2019 / The influence of cultural practices can be modified by environmental conditions such as container-type or positioning. The objective of the study was to determine whether container-type and positioning would have an influence on the growth of tomato plants and suppression of Meloidogyne javanica exposed to biomuti (Trial 1) and Afrikelp (Trial 2). Different container-types were filled with approximately 10.4 L growing mixture comprising steam-pasteurised sandy loam soil and Hygromix-T at 3:1 (v/v) ratio. The containers were established in microplots at 0.6 m × 0.6 m spacing, with treatments being brown pot-below; brown pot-above, black pot-below, black pot-above, plastic bag-above and plastic bag-below. Tomato (Solanum lycopersicum L.) cv. 'Floradade' seedlings were each transplanted and irrigated with 500 ml chlorine-free tapwater every other day. Seven days after transplanting, each plant was inoculated with 2000 eggs and second-stage juveniles (J2) of M. javanica. Biomuti and Afrikelp, obtained from the Agricultural Research Council (ARC) Vegetable, Ornamentals and Plants (VOP), were applied in separate trials weekly at 2.5%. At 56 days after inoculation, plant growth including selected nutrient elements and nematode variables were measured. Data were subjected to analysis of variance, with separation of means achieved using Fisher’s Least Significant Difference test at the probability level of 5%. In the biomuti trial, container-type and positioning had a significant effect on plant height, fruit number, dry root mass, dry shoot mass and fruit mass, contributing 82, 48, 44, 85 and 89% in total treatment variation (TTV) of the respective variables. Relative to brown pot-below; black pot above, plastic bag-above and brown pot-above reduced plant variables, whereas treatment effects were not significant on nematode variables. In the Afrikelp trial, trends where similar to those in biomuti, treatments had highly significant effects on xvi plant height, dry root mass, dry shoot mass and gall rating, contributing 91, 88, 66 and 60% in TTV of the respective variables. Relative to brown pot-below; black pot above, plastic bag-above and brown pot-above reduced the plant variables, but had no significant effects on nematode variables. Generally, plastic bags and polyethylene pots below-ground improved most plant growth variables when compared to those in containers positioned above-ground.

Peat extraction for horticultural production poses a threat to wetland ecosystems. The rapid growth rate of the horticulture industry has prompted an ongoing search for sustainable alternative growth media components to replace peat. The alternative components need to provide properties (physical and chemical) similar to or better than peat and provide conditions that will enhance ideal growth and yield of potted plants. Potted Dendranthema x grandiflorum is one of the most important pot plants cultivated worldwide in the floriculture industry. There is a global research effort to replace peat with a sustainable alternative growth media for potted plants; however, so far, no study has been conducted in South Africa that used similar treatments on potted Dendranthema x grandiflorum. The aim of this study was to determine a suitable alternative growth media to replace peat as a growth media for cultivation of potted D. x grandiflorum. A greenhouse experiment was conducted at the University of South Africa’s Horticulture centre in Florida, Johannesburg for 89 days. Eight growth media (100 % peat (T1) (control), 100 % bagasse (T2), 50:50 % v/v bagasse:peat (T3), 75:25 % v/v bagasse:peat (T4), 25:75 % v/v bagasse:peat (T5), composted bagasse (T6), Coir (T7), and pine bark (T8)) as treatments and one hybrid (Mount® Runca) of D. x grandiflorum were arranged in a randomized complete block design with four replicates. In this study, nutrient uptake, chlorophyll content, growth, and yield parameters were measured for potted D. x grandiflorum grown in all eight growth media. The results show that treatments had different chemical and physical properties compared to peat. The pH of 100 % bagasse and coir were within the ideal range recommended for growth media. The EC results indicated that after the experiment, other treatments were within the defined range except for composted bagasse due to high concentration of soluble salts. The BD of control and composted bagasse were similar and may have resulted in the low root response. The concentration of total N was high in the shoots of plants cultivated in 100 % peat with a subsequent increased fresh and dry shoots weight. The highest significant chlorophyll content was present in plants cultivated in composted bagasse, which contained high total N and, Fe and Zn concentrations in shoots. Taken together, the results showed that composted bagasse was the best alternative to replace peat for cultivation of potted D. x grandiflorum. / Turfonttrekking vir tuinboukundige produksie hou ʼn bedreiging vir moerasland-ekostelsels in. Die vinnige groeitempo van die tuinboubedryf het gelei tot ʼn voortdurende soektog na volhoubare groeimediakomponente om turf te vervang. Die alternatiewe komponente moet (fisiese en chemiese) eienskappe kan bied wat soortgelyk aan, of beter as dié van turf is, en moet toestande gee wat die ideale groei en opbrengs van potplante verbeter. Potplant- Dendranthema x grandiflorum is een van die belangrikste potplante wêreldwyd wat in die blomboerderybedryf aangeplant word. Daar word wêreldwyd navorsing gedoen om turf met ʼn volhoubare groeimedium vir potplante te vervang; sover is daar egter nog nie in Suid-Afrika ʼn studie gedoen wat soortgelyke behandelings vir potplante- Dendranthema x grandiflorum gebruik nie. Die doel van hierdie studie was om ʼn gepaste alternatiewe groeimedium te bepaal om turf as ʼn groeimedium te vervang vir die aanplanting van D. x grandiflorum-potplante. ʼn Kweekhuis-eksperiment is by die Universiteit van Suid-Afrika se Tuinbousentrum in Florida, Johannesburg uitgevoer vir 89 dae. Agt groeimedia (100% turf (T1) (beheer), 100% bagasse (T2), 50:50% v/v bagasse:turf (T3), 75:25% v/v bagasse:turf (T4), 25:75 % v/v bagasse:turf (T5), bagasse wat tot kompos verwerk is (T6), klapperhaar (T7), en dennebas (T8)) as behandelings en een hibried (Mount® Runca) van D. x grandiflorum is in ʼn verewekansigde, volledige blokontwerp met vier repliserings gerangskik. In hierdie studie is voedingstofopname-, chlorofilinhoud-, groei- en opbrengs-parameters gemeet vir potgroei van D. x grandiflorum in al agt groeimedia. Die resultate toon dat die behandelings verskillende chemiese en fisiese eienskappe in vergelyking met turf het. Die pH van 100% bagasse en klapperhaar val binne die ideale reikwydte wat vir groeimedia aanbeveel word. Volgens die EG (elektriese geleiding)-resultate was ander behandelings binne die gedefinieerde reikwydte – behalwe vir bagasse wat tot kompos verwerk is – vanweë die hoë konsentrasie oplosbare soute. Die BD van beheer en bagasse wat tot kompos verwerk is, was soortgelyk en kon die lae wortelrespons veroorsaak het. Die konsentrasie totale N was hoog in die lote van plante wat in 100% turf aangeplant is, met ʼn gevolglike verhoging in die gewig van vars en droë lote. Die hoogste beduidende chlorofilinhoud was teenwoordig in plante wat gekweek is in bagasse wat tot kompos verwerk is, en wat hoë totale konsentrasies van N, Fe en Zn in die lote bevat het. Alles in ag genome het die resultate getoon dat bagasse wat tot kompos verwerk is, die beste alternatief is om turf te vervang in die kweking van D. x grandiflorum in potte. / Go ntsha borubu mo kumong ya mokgwa wa temo go na le matshosetsi mo matshelong a diphologolo le ditlhare tsa lefatshe le le kolobileng. Kelo ya kgodiso e e bonako ya intaseteri ya matshelo a diphologolo le ditlhare e susumetsa patlo e e tswelelang ya dikarolo tsa mekgwa ya kgodiso ya thefosano e e tswelelang ya go emela go ntsha borubu. Dikarolo tse dingwe di tlhoka go neela dipharologantsho (sebopego le khemikale) tse di tshwanang le kgotsa botoka mo go ntsheng borubu le go neela mabaka a a ka tsholetsang kgodiso e e ikaeletsweng, mme ya ntsha dijalo tse di ka fa dipitseng. Dendranthema x grandiflorum e e ka fa dipitseng ke thefosano nngwe ya dijalo tsa ka fa dipitseng tse di botlhokwa thata tse di jadilweng mo lefatsheng ka bophara mo intasetering ya mokgwa wa temo ya dithunya. Go na le boiteko jwa patlisiso ya bogotlhe ya go emela go ntsha borubu ka mokgwa wa kgodiso wa thefosano o mongwe o o tswelelang wa dijalo tsa ka fa dipitseng; le gale, go le kalo, ga go na thuto e e setseng e dirilwe mo Aforikaborwa e e dirisang ditshwaro tse di tshwanang mo go Dendranthema x grandiflorum e e mo dipitseng. Maikaelelo a thuto eno e ne e le go tlhomamisa mekgwa ya grandiflorum e e mo dipitseng. Maikaelelo a thuto eno e ne e le go tlhomamisa mekgwa ya kgodiso ya thefosano e mengwe e e tshwanelang go emela go ntsha borubu jaaka mekgwa ya kgodiso ya go jala D. x grandiflorum ka mo dipitseng. Tekelelo ya ntlo e tala e ne ya dirwa kwa lefelong la Mokgwa wa matshelo a diphologolo le ditlhare ya Yunibesiti ya Aforikaborwa kwa Florida, Johannesburg mo matsatsing a le 89. Mekgwa ya kgodiso e merobedi (100 % ya go ntsha borubu (T1) (taolo), 100 % bagasse (T2), 50:50 % v/v bagasse: go ntsha borubu (T3), 75:25 % v/v bagasse: go ntsha borubu (T4), 25:75 % v/v bagasse: go ntsha borubu (T5), bagasse e e bodisitsweng (T6), Coir (T7), le kutu ya phaene (T8)) jaaka ditshwaro le lotswakwa lo lo longwe (Mount® Runca) ya D. x grandiflorum di ne di beilwe ka moakanyetso wa boloko e e feletseng ka kakaretso ka ditshwano di le nne. Mo thutong eno, go tsaya kotlo, diteng tsa setalafatsi, kgodiso le diparametara tse di ntshitsweng di ne tsa lekanyediwa mo go D. x grandiflorum e e mo dipitseng e e jadilweng mo mekgweng ya dikgodiso tse di robedi tse tsotlhe. Dipheto di bontsha gore ditshwaro di na le dikarolo tsa dikhemikale le dibopego tse di farologaneng fa di tshwantshanngwa le go ntsha borubu. Bagasse ya pH ya 100 % le coir di ne di le magareng ga paka ya botlhokwa ya kgodiso e e atlenegisitsweng mo mekgweng ya kgodiso. Dipheto tsa EC di bontsha gore morago ga tekelelo, ditshwaro tse dingwe di ne di le magareng ga paka e e tlhalositsweng kwa ntle ga bagasse e e bodisitsweng kwa kokoanong e e kwa godimo ya matswai a a tlhaolositsweng. BD ya taolo le bagasse e e bodisitsweng, mme go ka bo go dirile gore go nne le tsibogelo ya medi e e kwa tlase. Kokoano ya N yotlhe e ne e le kwa godimo mo matlhogeding a dijalo tse di jadilweng ka go ntsha borubu jwa 100 % ka koketso e e latelang ya bokete jwa matlhogedi a mantshwa le a a omileng. Diteng tsa setalafatsi se se botlhokwa se se kwa godimodimo di ne di le teng mo dijalong tse di jadilweng ka bagasse e e bodisitsweng, e e nang le kokoano ya bogotlhe jo bo kwa godimo jwa N, Fe le Zn mo matlhogeding. Di tserwe mmogo, dipheto di bontsha gore bagasse e e bodileng jaaka sengwe se se gaisang go emela go ntsha borubu mo jalong ya D. x grandiflorum ka mo dipitseng. / School of Environmental Sciences / M. Sc. (Ornamental Horticulture)