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Numerous challenges – from population increase to climate change – threaten the sustainable development of cities and call for a fundamental change of urban development and green-blue resource management. Urban forests are vital in this transition, as they provide various ecosystem services and allow to re-shape and re-think cities. Based on a Europe-wide community effort with diverse experts centered around urban forests and urban greening, we propose five key research fields to generate the knowledge required to unlock fundamental changes in urban development and green-blue resource management: circular bioeconomy, climate resilience, governance, social and human environment, and biodiversity. To support the design of greener, cooler, more inclusive and resilient cities, all these research fields require inter- and transdisciplinary collaboration, engaging stakeholders in transforming urban engagement and functioning. We summarise main inter-, trans- und multi-disciplinary research paths for each field and the cross-cutting knowledge areas that can help to address the challenges many cities face (e.g., modelling and assessment of the urban microclimate). For transforming cities further knowledge is needed on e.g., urban innovation, transition, participation, and more. Finally, we address how the identified research gaps can be implemented (e.g., international coordinated research effort, interdisciplinary networks).

English: Allelopathic plants disrupt germination and growth of agricultural crops which will lead to a lower yield production. However, allelopathy is also important in an environmentally friendly approach to control weeds and reduce chemical herbicide usage. Allelochemicals are secondary metabolites, released into the environment through leaching, volatile emissions, root exudation and the decaying of plant residues. The isolation and identification of allelochemical compounds involved in the plant-plant interactions are of great importance. Amaranthus cruentus is used for both its grain and leaves for consumption. This plant is now being considered at as a new agricultural crop; therefore it is important to understand how this plant will interact within a changing environment and how this will influence other plants. It is known that amaranth plants have the ability to synthesize allelochemicals in order to protect itself from different types of stress. In this study, the leaf litter as well as the polar and non-polar extracts of the leaves of A. cruentus from three different temperature regimes were investigated for their in vitro allelopathic properties towards tomato, pepper, cucumber and lettuce. The chemical compounds induced during each temperature treatment were also compared. Methanol-water and dichloromethane (DCM) crude extracts were prepared from each of the temperature treated amaranth plants using dried ground leaf litter. The identification of compounds present in the different treated plants was done through thin layer chromatography (TLC), high pressure liquid chromatography (HPLC) and gas chromatography coupled to mass spectrometry (GC-MS). TLC indicated the presence of phenolics, terpenes and flavonoids in all A. cruentus extracts. Differences were seen in the number and type of compounds between the temperature treated plant extracts. Methanol-water extracts of the three plant treatments were analysed using HPLC with specific consideration to ph, Afrikaans: Allelopatiese plante ontwrig ontkieming en groei van landbougewasse wat kan lei tot laer opbrengste. Allelopatie is egter ook belangrik in 'n omgewingsvriendelike benadering vir onkruidbeheer en om die gebruik van chemiese onkruiddoders te verminder. Allelochemikalieë is sekondêre metaboliete, wat in die omgewing vrygestel word deur loging, vlugtige vrystellings, wortel afskeiding en die ontbinding van plantmateriaal. Die isolasie en identifisering van allelochemiese verbindings wat betrokke is by plant-plant-interaksies is daarom van groot belang. Beide die graan en blare van Amaranthus cruentus word gebruik. Hierdie plant word nou oorweeg as 'n nuwe landbougewas, daarom is dit belangrik om te verstaan hoe hierdie plant binne 'n veranderende omgewing sal reageer en hoe dit ander plante kan beïnvloed. Amarantus plante is daarvoor bekend dat hulle die vermoë het om allelochemikalieë te sintetiseer vir beskerming teen verskillende tipes stres situasies. In hierdie studie was A. cruentus onder drie verskillende temperatuur toestande gekweek en die in vitro allelopatiese eienskappe van die droë blaarmateriaal (residu), asook polêre en nie-polêre ekstrakte daarvan, teenoor tamatie, peper, komkommer en blaarslaai getoets. Die chemiese verbindings wat gedurende die verskillende temperatuur toestande gesintetiseer is, was ook vergelyk. Metanol-water en dichlorometaan (DCM) ekstrakte was berei uit die residu van die verskillende temperatuurstres behandelde amarantus plante. Identifisering van die verbindings in die verskillende plante is gedoen deur middel van dunlaagchromatografie, hoë druk vloeistofchromatografie en gaschromatografie gekoppel aan massaspektrometrie. Dunlaagchromatografie het die teenwoordigheid van fenole, terpene en flavonoïede in alle A. cruentus ekstrakte aangedui. Verskille in die aantal verbindings tussen die verskillende temperatuur- behandelde ekstrakte is opgemerk. Hoë druk vloeistofchromatografie, met spesifieke verwysing na fenoliese v, Faculty of Natural and Agricultural Sciences

English: Rainfall in semi-arid areas fluctuates constantly and it is difficult for farmers to increase crop productivity. The rainfall is insufficient, erratic and unreliable, which is associated with poor water availability due to increased water losses such as high evaporation from the soil (Es) due to rising temperatures, runoff (R) and deep drainage (D). These unproductive losses (Es, R & D) contribute to inefficient rainfall, which increases food insecurity and poverty. Crops produced in semi-arid areas under rainfed agriculture by smallholder farmers are usually produced using conventional tillage (CON). This system uses a moldboard plough, which turns and exposes the soil and therefore increases Es and R while organic matter is decreasing. In many semi-arid areas, research was conducted to improve crop production. One of these researches was conducted in South Africa at the Thaba Nchu villages where the Agricultural Research Council (ARC-ISCW) introduced an In-field rainwater harvesting technique (IRWH) to increase efficiency and use of limited water. This system was used to reduce unproductive water losses especially Es and R, to optimize rainwater productivity (RWP). This study was conducted to investigate the ability of different rainwater harvesting and conservation (RWH&C) techniques to produce higher yield in using and storing water efficiently under rainfed conditions of Glen/Oakleaf ecotope. To test the hypothesis, a field experiment was conducted in a semi-arid area under rainfed conditions at the Glen/Oakleaf ecotope in Bloemfontein. The area is characterized by an average long-term (LT) rainfall in the growing period of 262 mm and an evaporation demand of 758 mm. Treatments used were In-field rainwater harvesting with a 2.0 m runoff strip (IRWH-2.0m), In-field rainwater harvesting with a 2.4 m runoff strip (IRWH-2.4m), Mechanised basins (MB), Minimal tillage (MIN), Darling plough (DAL) and Conventional tillage (CON). The experiment was conducted in, Afrikaans: Reenval wissel in semi ariede gebiede, wat dit moeilik maak vir boere om gewas produksie te verbeter. Die reenval is min, onvoorspelbaar en wisselvallig. Dit veroorsaak min water beskikbaarheid vir die volgende redes, verdamping (Es), verhoogde temperature, afloop (R) en diep dreinering (D). Hierdie onproduktiewe verliese (Es, R & D)dra by tot swak reenval, wat voedsel onveiligheid bevorder en sodoende armmoede tot gevolg het. Gewasse wat geproduseer word in semi ariede gebiede onder reenwater toestande, word gewoonlik op die Konvensionele Bewerkings Metode (CON) geproduseer. Hierdie sisteem gebruik gewoonlik ‘n ploegskaar, wat die grond omdop en blootstel aan die son, dit bevorder Es en R terwyl organiese materiaal in die grond verminder word. Navorsing is in baie semi ariede gebiede gedoen om te bepaal of water retensie en gewas produksie kan verbeter. Een van die gebiede is in Suid Afrika, by die Thaba Nchu nedersettings, waar die Landbounavorsings Raad (ARC-ISCW) ‘n Binneveld Reenwater Oes Tegniek (IRWH) gevestig het. Dit het die doeltreffendheid en gebruik van reenwater baie verbeter. Die sisteem word gebruik om watervermorsing as gevolg van Ese n R baie te beperk, en dit veroorsaak dat die beskikbare water geoptimaliseer word. Hierdie studie is gedoen om vas te stel of verskillende grond bewerkings tegnieke en verskillende reenwater oes metodes (RWH&C) ‘n verskil sal maak aan gewas produksie om sodoende armmoede te beveg. Om hierdie hipotese te toets, is gebruik gemaak van ‘n semi ariede gebied wat bestuur word onder reenval toestande, die Glen/Oakleaf ekotoop net buite Bleomfontein. Hierdie gebied word gekenmerk deur ‘n gemiddelde langtermyn (LT) reenval in die groeiseisoen (262 mm) en ‘n verdampings anvraag van 758 mm. Die behandelings wat toegepas is, is Binneveld reenwater opvangs met ‘n 2 m afloop strook (IRWH-2m), Binneveld reenwater opvangs met ‘n 2.4 m afloop strook (IRWH-2.4m), Gemeganiseerde dammetjies (MB), Minimum bewerking (MIN), Daling, Agricultural Research Council (ARC-ISCW)

English: Several environmental factors constantly play a role in crop failures. Of these high temperature and limited water supply are major factors that limit plant productivity and threatens food security. Hence, a search for alternative crops with good tolerance characteristics towards abiotic stress is an ongoing process. Amaranth has been established as an annual vegetable and grain crop and is seen as a prospective alternative crop. Seed germination and seedling development are presumed to be the most critical stages in the life cycle of many seed propagated crops. This served as a rationale for the underlying study on two amaranth species in terms of seed germination, as well as the morphological and physiological response of seedlings to different temperature (25, 30, 35, 40˚C) and water potential (0, -250, -500, -750, -1000, -1250 kPa) regimes. For A. cruentus the optimum temperature was between 25 and 30oC and between 30 and 35oC for A. hybridus in terms of seed germination and early seedling growth. A. hybridus showed a greater level of adaptation to the higher temperature regimes as well as when simultaneously exposed to a rather stringent water potential of -1250 kPa by maintaining root growth better than A. cruentus. Moreover, the imposed temperature/drought stress condition had no significant effect on either of the physiological parameters tested in the former species. These included sugar and total water soluble protein levels as well as photosynthesis and respiratory capacity. Together with the ability of stressed seedlings to maintain growth, the latter strongly suggests that the metabolic events were scarcely affected in A. hybridus, supporting the postulate that it showed a higher degree of tolerance towards abiotic stress conditions. Alternatively, more than half of these events were found to be upgraded in A. cruentus seedlings and interpreted as an attempt by this species to counteract the stress effects, but not successfully, as measured by, Afrikaans: Verskeie omgewingsfaktore speel ‘n rol in oesverliese. Van hierdie is hoë temperatuur en beperkte watervoorsiening die hoofoorsake wat plantproduktiiteit beperk en voedselsekuriteit bedreig. Gevolglik is ‘n soeke na alternatiewe gewasse met uitstekende weerstandseienskappe t.o.v. abiotiese stremming ‘n aanhoudende proses. Amaranthus is reeds as ‘n eenjarige groente- en graangewas gevestig en word beskou as ‘n potensiële alternatiewe gewas. Saadkieming en vroeë saailingontwikkeling is van die mees kritieke ontwikkelingsfases in die lewensiklus van baie saad gepropageerde gewasse. Laasgenoemde het die rasionaal verskaf vir die onderhawige studie op twee Amaranthus species in terme van saadkieming sowel as die morfologiese en fisiologiese respons van saailinge op verskillende temperatuur (25, 30, 35, 40˚C) en water potensiaal (0, -250, -500, -750, -1000, -1250 kPa) reeks. Vir A. cruentus was die optimum temperatuur tussen 25 en 30oC en tussen 30 en 35oC vir A. hybridus in terme van beide saadkieming en vroeë saailinggroei. A. hybridus het egter ‘n hoër mate van aanpassing by die boonste gedeelte van die temperatuurreeks asook tydens die gesamentlike blootstelling aan ‘n taamlik streng waterpotensiaal van - 1250 kPa getoon deur wortelgroei beter te onderhou as A. cruentus. Meer nog het die temperatuur/droogte stremming wat opgelê is geen betekenisvolle effek op enige van die fisiologiese parameters wat getoets is in eersgenoemde spesies getoon nie. Hierdie parameters het suiker en totale wateroplosbare proteïen inhoud asook fotosintese en respirasiepotensiaal ingesluit. Tesame met die vermoë van gestremde saailinge om groei te onderhou, onder hierdie omstandighede, ondersteun laasgenoemde die postulaat dat metaboliese aktiwiteite skaars in A. hybridus beïnvloed is en dat hierdie spesies inherent oor ‘n hoër mate van weerstand teen abiotiese stremmingsfaktore beskik. Alternatiewelik is meer as die helfte van die fisiologiese prosesse deur die stremming in A. c, Directorate of Training in the Ministry of Agriculture, Water and Forestry of the Republic of Namibia

English: Regardless of past research, great uncertainty still exists amongst the research community, fertilizer agents and farmers alike with regard to the benefits of foliar inorganic fertilizer application for crop production. This supplied a rationale for investigating foliar nutrition as an agricultural practice, with the main aim of increasing maize kernel yield, under standard farm management practices. Fertilizer salts used in this study included potassium nitrate (KNO3), mono potassium phosphate (MKP) and mono ammonium phosphate (MAP). Three objectives were set in order to obtain information about i) the optimal application growth stage (2004/05 season), ii) the optimum concentration rate (2005/06 season) and iii) the contribution of either the P or K moiety (or both) contained in foliar applied salts towards growth, physiological and yield responses measured in maize (2006/07 season). During the 2004/05 season a 4% solution of MKP and a 3% solution of KNO3 were applied at growth stages V3 and V8. MKP applied at V8 was the best treatment as it increased plant height significantly (11%) as well as plant fresh and dry mass markedly, compared to the control, when measured at the end of the vegetative growth period at V19. The higher yield (+23%) obtained with MKP applied at V8 during season one, compared to treatment at V3, corresponded with an increase in grain filling of the second ear (+16%), total ear mass (+20%), kernel mass (+20%) and number of kernels (+16%) as well as higher total sugar and starch that accumulated in kernels. During the 2005/06 season, vegetative growth and yield parameters showed no significant differences between the single and double rates for both salts applied at V8. However, MKP applied at both the single and double rates contributed to marked yield increases of 12% and 14% respectively. Although neither KNO3 nor MKP significantly influenced chlorophyll content or photosynthesis efficacy (chlorophyll a fluorescence), higher sugar, Afrikaans: Ten spyte van vorige navorsing bestaan daar nog groot onsekerheid tussen navorsers, bemestingsagente en boere ten opsigte van die potensiële voordele, al dan nie, wat blaartoegediende bemestingstowwe vir gewasproduksie inhou. Dit het ‘n rasionaal verskaf vir onderhawige ondersoek na blaarbemesting as ‘n landboupraktyk met die hoofdoel om die opbrengs van mielies onder standaard plaasbestuurspraktyke te verhoog. Bemestingsoute wat in die studie gebruik is het kaliumnitraat (KNO3), mono kaliumfosfaat (MKP) en mono ammonium fosfaat (MAP) tegnies ingesluit. Drie doelwitte is geformuleer ten einde inligting te bekom betreffende i) die optimum toedieningstyd (2004/05 seisoen), ii) die optimum konsentrasie (2005/06 seisoen) en iii) die moontlike bydra van P of K of albei om ‘n groei-, fisiologiese- en/of opbrengsrespons by mielies te ontlok (2006/07 seisoen). Tydens die 2004/05 seisoen is ‘n 4% MKP en ‘n 3% KNO3 oplossing apart toegedien op groeistadia V3 en V8. MKP, op V8 toegedien, was die beste behandeling in die sin dat dit planthoogte betekenisvol (11%) sowel as plant vars- en droë massa merkbaar verhoog het teen die einde van die groeiseisoen op stadium V19, in vergelyking met die onbehandelde kontrole. Verder het die hoër opbrengs (+23%) wat met die MKP behandeling op V8 tydens die eerste seisoen bekom is ooreengestem met ‘n verhoging in graanvulling van die tweede kop (+16%), totale kopmassa (+20%), pitmassa (+20%) en aantal pitte per kop (+16%) asook hoër suiker- en stysel akkumulasie in graan in vergelyking met behandeling op die V3 groeistadium. In die 2005/06 seisoen is geen verskille ten opsigte van vegetatiewe groei en opbrengs tussen die enkel en dubbel konsentrasie bespuitings van beide soute wat op V8 toegedien is waargeneem nie. Maar, MKP teen beide konsentrasies toegedien het bygedra tot merkbare opbrengsverhogings van 12% en 14% respektiewelik. Alhoewel nie KNO3 of MKP die chlorofilinhoud of fotosintese kapasiteit (chlorofil a fluoressensie)

This study was undertaken to determine the effect of different concentrations of phosphate, ammonium, nitrate, and sulphate as well as that of shading and moisture stress on oil yield and quality of hydroponically grown rose geranium. Five separate trials were conducted during the 2009 and 2010 growing seasons. Different concentrations of phosphate, ammonium, nitrate and sulphate were used in the first four trials, while the last study focused on the effects of shading and moisture stress on rose geranium. The phosphate, nitrate, ammonium and sulphate trials were conducted in a greenhouse at the west campus of the University of the Free State in Bloemfontein, South Africa. Plants were grown for four months using a randomized complete block experimental design. The concentrations of phosphorus evaluated were 0.10, 0.80, 1.50 and 2.20 meq L-1. Ammonium concentrations were 0.00, 0.50, 1.00 and 1.50, nitrate concentrations were 8, 10, 12 and 14 and sulphate concentrations were 0.36, 1.90, 3.44 and 4.98 meq L-1. Foliar drymass and oil yields increased as P concentrations were increased to 2.20 meq L-1. Both, the guaia-6,9-diene content and the citronellol:geraniol (C:G) ratio were better at the high level of phosphate indicating that the best quality oil, as required by the perfume industry is obtained with relatively high phosphate concentrations. Plant growth as measured by the number of branches and biomass production, peaked at 10 to 12 meq L-1 nitrate concentrations. The highest chlorophyll content in the foliage was found at the nitrate concentrations of 10 and 12 meq L-1, where the best oil yield was also produced. At this nitrate level the citronellol:geraniol (C:G) ratio was slightly higher than the upper limit required for good oil quality but the geraniol and citronellylformate contents were within range for top quality oil. Height, biomass, oil yield and chlorophyll content of the leaves were not affected by ammonium, but the concentrations of plant tissue su, National Research Foundation (NRF), Central University of Technology

Field trials were conducted on the West Campus facility of the Department of Soil, Crop and Climate Sciences of the University of the Free State in Bloemfontein during 2009 and 2010. The first trial during 2009 investigated the response of onion (Allium cepa L.) cultivars to sowing date. Cultivars namely; Charlize, Jaquar, Python and South Wester were used in 2009. Onions were sown on 31 April, 7 May and 21 May during 2009. The second trial was conducted during 2010, where cultivar Ceres Gold was used to replace South Wester as the latter was no-longer available in the market and sowing was done on 11 May, 25 May and 8 June. In both seasons, experiments were laid out as a randomized complete block design with each treatment combination replicated three times. During 2009, plant population of 41 plants m·2 was used, while in 2010 plant population of 61 plants m·2 was used. Plots of 1.8 m2 were used with each plot having five rows. Each row had fifteen plants during 2009 and twenty two plants during 2010. Before planting, soil sampling and analysis were made, thereafter, fertilizers were applied as per soil analysis results. A third field trial was conducted in 2010 to evaluate the three sowing dates (11 May, 25 May and 8 June) with a combination of five plant populations (95, 83, 74, 67 and 61 plants rn") using one onion cultivar ('Jaquar'). The experiment was laid out as a randomized complete bock design, with three replications having 1.8 m2 plots. In each plot there were five rows. A bulb storage trial was also conducted under room (±25°C) and cold room temperatures (±5°C). This was done for all field trial in both seasons. In a trial investigating response of cultivars to sowing date, better plant height, number of leaves, bulb fresh mass, and yield were observed when sowing was done from the end of April to the end of May. Sowing date significantly influenced bulb and neck diameters only during 2009. Bulbs were becoming more firm as sowing date was delayed, and, Government of Botswana

The influence of temperature on yield and quality of carrots were examined using two pot trials that were conducted in the glasshouse and growth chambers at the Department of Soil, Crop and Climate Sciences, on the Bloemfontein campus of the University of the Free State in 2009 and 2009/10. In the first trial the influence of four temperatures (10, 18, 26 and 32°C) on the growth, yield and quality of two pre-pack carrot cv’s. Nectar and Star 3002 were studied. Carrot seed were sown in 0.34 m x 0.34 m x 0.35 m pots, filled with topsoil of the sandy loam Bainsvlei form. Pots were kept in the glasshouse at 20°C (±1°C) for four weeks to allow the seedlings to establish and reach the first true leaf stage whereupon they were moved to the controlled environment chambers at different temperatures for 20 weeks. Growth parameters such as leaf number, plant height and leaf growth were significantly influenced by temperature and all these parameters performed the best at 10°C at the end of the growth season irrespective of cultivar. Root fresh and dry mass did not differ significantly between the two cultivars but the affect of temperature was significant. The highest root fresh mass for both cultivars was also obtained at 10°C, with “Star 3002” with the highest mass (39.12 g) followed by “Nectar” (34.26 g). Both cultivars exhibited the highest root dry mass at the lower temperature treatment (10°C) with “Star 3002” having a higher root dry mass (4.15 g) than “Nectar” (3.87 g). External quality parameters such as root length and diameter differed significantly between the temperature treatments and only the length of carrot roots did not differ significantly between the cultivars. Both “Nectar” and “Star 3002” exhibited the longest roots at 10°C and the shortest roots at 18°C. Root diameter for both cultivars was significantly greater at 10°C than at 18°C. The only defects observed were green shoulder and misshapen roots. Although not significant, the percentage green shoulder, ICART/SADC

English: A number of the commercially available maize cultivars were screened in order to establish their tolerance to acetochlor. These cultivars demonstrated significant differences in their tolerance, with some cultivars being tolerant and others sensitive to the herbicide. The cultivar PAN6Q521R was the most tolerant and DKC 73-76R was the most sensitive, while most other cultivars were intermediate in their sensitivity. This indicates that maize tolerance to acetochlor is genetically controlled. The influence of planting depth on maize tolerance to acetochlor was investigated using these two cultivars. Both cultivars were found to be more sensitive as the planting depth increased to 45 mm. However, seedlings of DKC 73-76R exhibited more phytotoxicity than PANQ6521R at all planting depths. The effect of seed size on acetochlor tolerance could not be determined with any clarity. Cultivar sensitivity to the herbicide as well as seed shape appeared to also play a role. In DKC 73-76R it appeared as though large flat seeds produced plants more tolerant to acetochlor than smaller flat seeds. The effect of soil type on acetochlor phytotoxicity on a tolerant (PANQ6521R) and sensitive (DKC 73-76R) maize cultivar was examined in two trials, one using an average application rate on all soils, and the second utilizing the recommended application rates for each soil. Acetochlor activity was found to be lowest on the clay loam soil (38% Clay) and highest on the sandy soil (8% Clay) in the first case, with severe phytotoxicity occurring on the latter soil. In the second trial bioactivity was similar on all soils, although greater on the sand. This indicated that the recommended application rate on sandy soils might need adjustment. The influence of temperature on maize tolerance to acetochlor was investigated at suboptimal (15/8oC), optimal (25/18oC) and supra-optimal (35/28oC) temperature regimes (day/night temperature respectively). Seedling growth of both cultivars was inhi, Afrikaans: ‘n Aantal mielie cultivars wat in die handel beskikbaar is, is getoets vir hulle sensitiwiteit teenoor asetochlor. Betekenisvolle verskille m.b.t. sensitiwiteit van hierdie cultivars is gevind, met sommige cultivars wat verdraagsaam was teenoor die onkruiddoder, terwul ander sensitief was. Die cultivar PAN6Q521R het die hoogste verdraagsaamheid getoon, terwyl DKC 73-76R die sensitiefste was. Die meeste ander cultivars was intermediêr in hulle verdraagsaamheid. Hierdie gee ‘n aanduiding dat die verdraagsaamheid van mielies teenoor asetochlor geneties beheer word. Die invloed van plantdiepte op die sensitiwiteit van mielies teenoor asetochor is ondersoek met beide cultivars. Dit is gevind dat beide cultivars meer sensitief geraak het na mate die plantdiepte na 45 mm toegeneem het. Saailinge van DKC 73-76R het grootter fitotoksisiteit getoon as die van PAN6Q521R by alle plantdieptes. Die invloed van saadgrootte op asetochlor verdraagsaamheid kon nie met sekerheid bepaal word nie. Cultivar sensitiwiteit teenoor die onkruiddoder asook saadvorm het skynbaar ‘n rol hier gespeel. Dit blyk dat groot plat sade saailinge geproduseer het wat meer verdraagsaam teenoor asetochlor was as die van klein plat sade in DKC 73-76R. Die invloed van grondtipe op asetochlor fitotoksisiteit op ‘n verdraagsame (PAN6Q521R) en sensitiewe (DKC 73-76R) cultivar is in twee proewe getoets. Die eerste proef het ‘n gemiddelde toedienings hoeveelheid van die onkruiddoder op alle gronde gebruik, terwyl die tweede proef die aanbevole toedieningshoeveelheid vir elke grond gebruik het. Asetochlor aktiwiteit was die laagste op die klei-leem grond (38% klei) en die hoogste op die sand grond (8% klei) in die eerste proef, en ernstige fitotoksisiteit het op die sandgrond voorgekom. Bioaktiwiteit was soortgelyk op alle gronde in die tweede proef, alhoewel dit strawwer was op die sandgrond. Hierdie het ‘n aanduiding gegee dat die aanbevole toedieningspeil op die sanderige grond moontlik aangepas beh, ICART-SADC/EU

English: Cotton (Gossypium hirsutum) is a globally important fibre crop. The cottonseed has a high oil and protein content and is used for human and animal consumption. Innumerable commodities are made from cotton. Annual cultivar evaluations are essential to compare the yield and quality obtained in different production areas, to obtain experimental data to recommend the most suitable cultivar for a production area. The objective of this study was to evaluate the performance of different cotton cultivars under irrigation in South Africa. The cultivars planted from the 2003/2004 season up to the 2005/2006 season were NuOPAL, DeltaOPAL, DeltaOpal RR, LS9219 and SZ9314. The localities were Loskop (Mpumalanga Province), Makhathini (KwaZulu- Natal), Rustenburg (North-West Province), Vaalharts and Upington (Northern Cape) and Weipe (Limpopo Province). The Additive Main Effects and Multiplicative Interaction (AMMI) statistical model was used to describe the effect of cultivar x environment interaction on the yield of cotton planted under irrigated conditions. It is recommended that cotton producers should plant NuOPAL, since it was selected by the AMMI model as the best performer in respect of seed cotton yield and fibre yield (kg ha-1) in fifteen out of eighteen environments., Afrikaans: Katoen is bekend as een van die mees veelsydige landbouprodukte in die wêreld. In Suid-Afrika word katoenaanplantings negatief beinvloed deur relatiewe lae pryse, hoë insetkoste, wisselkoerse, goedkoop invoere van katoenvesel en internasionale subsidies. Cultivar keuse is die belangrikste besluit wat gemaak word om optimum opbrengste te verseker. Anders as onkruid- of insekdoder keuses wat deur die seisoen aangepas of verander kan word, word cultivar keuse slegs een maal per seisoen gedoen en die besluit wat geneem word, bepaal die verbouiingsbestuur vir die hele seisoen. Ten einde aanbevelings aan produsente te verskaf aangaande die aanpasbaarheid en stabiliteit van verskillende cultivars, is vyf cultivars geplant op ses lokaliteite gedurende die periode 2003 tot 2006. Saadkatoenopbrengs, veselpersentasie, veselopbrengs en veselkwaliteite is bepaal en cultivars is geëvalueer vir prestasie en opbrengs stabiliteit in die agt veskillende katoen produserende areas. Die cultivars wat geplant is onder besproeiingstoestande, is NuOPAL, DeltaOPAL, DeltaOpal RR, LS9219 en SZ9314. Die lokaliteite was Loskop, (Mpumalanga Provinsie), Makhathini (KwaZulu-Natal Provinsie), Rustenburg (Noord-Wes Provinsie) Vaalharts en Upington (Noord-Kaap Provinsie) en Weipe (Limpopo Provinsie). Die gekombineerde variansie volgens die “Additive Mean Effective And Multiplicative Interaction (AMMI)” model is uitgevoer met die GENSTAT program en is gebruik om die effek van cultivar x omgewing interaksie te bepaal op die parameters gemeet. Om grafies die cultivar x omgewings interaksie en aanpasbaarheid van cultivars ten opsigte van omgewings te beskryf, is die AMMI model 2 XY-grafiek gebruik waar ‘n IPCA-waarde (Die “Principle Component Interaction Analysis”) geplot is teen die gemiddelde opbrengs. Die IPCA waardes van cultivars in die AMMI analise gee ‘n aanduiding van die cultivar se stabiliteit oor verskillende omgewings. Alhoewel die cultivar, LS9219, NuOPAL oortref het wat veselleng, Agricultural Research Council (ARC)

PURPOSE: A multi-centre study to assess the value of combined surgical resection and radiotherapy for the treatment of desmoid tumours. PATIENTS AND METHODS: One hundred and ten patients from several European countries qualified for this study. Pathology slides of all patients were reviewed by an independent pathologist. Sixty-eight patients received post-operative radiotherapy and 42 surgery only. Median follow-up was 6 years (1 to 44). The progression-free survival time (PFS) and prognostic factors were analysed. RESULTS: The combined treatment with radiotherapy showed a significantly longer progression-free survival than surgical resection alone (p smaller than 0.001). Extremities could be preserved in all patients treated with combined surgery and radiotherapy for tumours located in the limb, whereas amputation was necessary for 23% of patients treated with surgery alone. A comparison of PFS for tumour locations proved the abdominal wall to be a positive prognostic factor and a localization in the extremities to be a negative prognostic factor. Additional irradiation, a fraction size larger than or equal to 2 Gy and a total dose larger than 50 Gy to the tumour were found to be positive prognostic factors with a significantly lower risk for a recurrence in the univariate analysis. This analysis revealed radiotherapy at recurrence as a significantly worse prognostic factor compared with adjuvant radiotherapy. The addition of radiotherapy to the treatment concept was a positive prognostic factor in the multivariate analysis. CONCLUSION: Postoperative radiotherapy significantly improved the PFS compared to surgery alone. Therefore it should always be considered after a non-radical tumour resection and should be given preferably in an adjuvant setting. It is effective in limb preservation and for preserving the function of joints in situations where surgery alone would result in deficits, which is especially important in young patients.