Thèse 3e cycle : Économie rurale : Montpellier I : 1980. / Bibliogr. p. I-IV.

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To evaluate the strip tillage in organic bell pepper (Capsicum annuum L.) production as an integrated system for sustainable vegetable cropping two-years of field trials were conducted in 2011 and 2012. The field trials were conducted to determine the viability of strip tillage in conventional and organic bell pepper production systems by comparing plant growth, water status, and fruit yield to plastic mulch grown plants application under different irrigation regimes. The two-year field data demonstrated that organic pepper with strip tillage application was a viable combination that produced comparable yield to conventional plastic mulch system and utilized water more economically. In 2011 and 2013, strip-tilled rows and plastic mulched rows were used to evaluate the impact of tillage on soil hydraulic conductivity and water internal drainage characteristics. Results indicated that strip-tilled plots had significantly higher in-row penetration resistance compared to the plastic mulch system at depths up to 20 cm, but no differences between the systems were found for layers below 25 cm. In addition, there were no differences in hydraulic conductivity between strip tillage and plastic mulch in both study years over a 30-day period. Also, significant main effects were found for soil layer and time scale on hydraulic conductivity in the first 24 hour of the study in 2013. During field trials in 2011 and 2012, plant tissues were sampled for endophytic bacteria isolation and identification. Differences in endophytic bacteria were obtained among different production combinations. In 2013, endophytic bacteria isolates from 2011 and 2012 trials were re-inoculated to bell pepper grown in greenhouse to assess plant growth. Two Pseudomonas sp. and one Bacillus thioparans strain were screened to evaluate their affects on plant growth under both drought and non-drought conditions. After growth comparisons, the three endophytic strains were used to subsequently study the impacts of endophyte inoculation on regulating plant drought-linked gene expressions in 2014 by conducting real-time PCR. Results demonstrated that plant drought-linked genes, which especially involved plant ethylene biosynthesis, were significantly down-regulated after inoculating the endophytic bacterial strains.

Reduced tillage and living mulches are alternative management strategies that can improve soil quality by minimizing disturbance and building soil organic matter. Weed suppression by these two practices alone is often insufficient to avoid crop yield losses, but their performance in an integrated system is not well understood. This project investigated the production of bell pepper (Capsicum annuum L.) and dry bean (Phaseolus vulgaris L.) in conventional tillage and strip tillage with a living mulch of teff (Eragrostis tef Zucc.) and Korean lespedeza (Kummerowia stipulacea Maxim.). Yields of pepper and bean were generally higher under conventional tillage without living mulch. Weed biomass was not influenced by tillage, and was adequately suppressed by teff in a year when conditions for teff growth were favorable. Mowing appeared to suppress weed growth but not living mulch growth. Soil nitrate and ammonium concentration was generally higher under conventional tillage without living mulch. Delaying living mulch seeding by 15 days after crop establishment generally did not affect weed suppression or crop yield. Soil aggregate stability was not consistently affected by tillage or living mulch. Increased mowing frequency, living mulch planting delay, or distance between the crop row and the living mulch may be necessary to achieve acceptable yields with living mulches.

Der Bericht fasst die Ergebnisse der Beet- und Balkonpflanzensichtungen des LfULG im Zeitraum 2010 bis 2012 zusammen. Für ausgewählte Sorten von Pelargonien, Argyranthemum, Scaevola, Calibrachoa, Verbena und Begonia liegen nun Daten zur Anzucht sowie zu Blühstärke und Wuchsverhalten über die Sommermonate unter sächsischen Bedingungen vor. Weiterhin wurden umfangreiche neue Sortimente von Ipomoea batatas, Portulaca grandiflora und Nemesia Cultivars im Freiland gesichtet. Sortimentszusammenstellungen gelb blühender Bodendecker, kompakt wachsender Mandevilla-Sorten sowie »Kombi-Jungpflanzen« und Mischbepflanzungen wurden im Beet bzw. im Kasten bewertet.

Die Broschüre dokumentiert die Ergebnisse einer Studie zum Wertschöpfungsanteil des Gartenbausektors in Sachsen. Dabei werden die einzelnen Sparten des Gartenbaus als Kernbereich und in weiteren Ebenen die vor- und nachgelagerten sowie stufenübergreifenden Wirtschaftsbereiche betrachtet. Die wirtschaftliche Bedeutung des Gartenbausektors geht weit über den Kernbereich hinaus. So lag die Bruttowertschöpfung bei 580 Mio € und damit 2,5-mal so hoch wie für den Gartenbau allein. Die für den Gartenbausektor ermittelten 26.500 AK-Einheiten entsprachen 1,8 % des gesamten Arbeitsvolumens in Sachsen. Der Umsatz wurde zu 98 % durch den Kern- und nachgelagerten Bereich erwirtschaftet. Damit ist der Beitrag der vor- und stufenübergreifenden Bereiche praktisch zu vernachlässigen.

Commercial production of native tree and shrub species from seed can be unpredictable. Rosa corymbifera 'Laxa' is one such species of commercial importance as a rootstock, and is characteristic of the Rosaceae family. During the investigation, a standard commercial pretreatment was used to determine the unpredictable nature of this species with regard to germination. It was found that germination varied from as low as 2% in one year to a high of 63% in a subsequent year. The average germination was 26% over this period. This presents a very real dilemma to the grower with respect to meeting demand from highly unpredictable species. This dilemma is inherent in native tree production from seed. Germination became high and predictable with the addition of a compost maker, Garotta. During the same five year period the lowest germination achieved was 75% and the highest 99%. The average germination was 89%. Germination was vastly increased in percentage terms as well as becoming reliable from year to year. The benefits to the grower in using this technique are potentially great in terms of time and resources. Not only is this pretreatment highly predictable, it is safe and easy to apply, unlike alternatives such as the use of concentrated sulphuric acid to burn off the seed coat. During the pretreatment of Rosa corymbifera'Laxa' the influence of microorganisms was assessed. Microbes were found within the pretreatment and their presence was established as being required to overcome the dormancy of the seeds. Low microbial numbers and activity were found in the commercial pretreatment, resulting in low germination. High microbial numbers and activity were found in the Garotta pretreatment, resulting in high and predictable germination. Total absence of microbes was found to result in zero germination.

The rural poor of Hazaribag suffer from vitamin A and iron deficiencies from meals containing rice (200-400g) and limited (25-50g) slow-cooked vegetables with potatoes. This causes undernourishment in 50% of children and 40% of women. The two main causes are lack of access to nutritious foods, and lack of knowledge about nutrition. Through extension, 24 women were taught and quantitatively assessed about growing avocado and drumstick trees, and proper nutrition. Participants were monitored for four months using persistent observation to qualitatively evaluate the adoption process of four behaviors (eating and feeding avocados to children; increasing consumption of drumstick leaves/pods; caring for grafted avocado trees, and planting avocado seeds) and their consequences. From the assessment of knowledge gained and retained, results indicate a statistically significant difference among all test scores, T1 and T2 (p = .001, t = -5.58), T1 and T3 (p = .001, t = -6.98), T2 and T3 (p = .038, t = -2.20), and T4 perceptions of knowledge before/after training (p = .001, t = -16.32). Qualitative studies show the women did adopt a majority of the behaviors, with 100% eating or feeding avocados to children; 60% eating more drumstick leaves/pods; 90% caring for avocado trees and 50% planting seeds. A number of consequences were associated with the adoption of the behaviors. Many of the women reported perceptions of improved health and expressed that children were falling sick less often due to the avocados and drumstick leaves/pods. The MUAC test showed that children who ate avocados weekly had increases in their mid-upper-arm circumference. And, people outside the study became interested in avocados because the participants shared their new knowledge. Most extension programs result in knowledge gains, but this study showed that with continued engagement and interaction, the participants were able to retain and gain additional knowledge about agriculture and proper nutrition. From the data collected, it is clear that the women learned and adopted the behaviors to improve their nutrition resulting in positive changes. Ultimately, there is a connection between extension, knowledge gains, and behavior adoption. This could be a powerful tool to address malnutrition in Hazaribag.

Auf Versuchsflächen des Friedhofes in Pirna (Sachsen) wurden unter alten und jungen Birken verschiedene Stauden und Gräser getestet. Untersucht wurde, wie sich die Konkurrenz um Wasser, Nährstoffe und der Einfluss von Schatten und Laubfall der Gehölze auf das Anwuchsverhalten, die Entwicklung, den Pflege- und Materialaufwand der getesteten Pflanzen auswirkt. Besonders geeignet als Unterpflanzen sind im Ergebnis der fünfjährigen Versuche die Gänsekresse (Arabis), das Stachelnüsschen (Acaena) und der Schlangenbart (Ophiopogon). Der Bericht enthält Informationen zum Anwuchsverhalten der Arten in den ersten zwei Jahren und ihrer weiteren Entwicklung. Empfehlenswert sind eine optimale Pflanzvorbereitung mit mindestens 10 cm Bodenaustausch, die Pflanzdichte von 18 Pfl./m² und vier Pflegedurchgänge im Jahr. Ein Ereigniskalender zeigt die Monate der Blüten- und Fruchtschmuckbildung und der Laubfärbung der Versuchspflanzen.

Eucalyptus species, particularly stringybarks, which produce hard, durable wood are potentially useful in New Zealand, but most species are site sensitive. Twelve species (E. agglomerata, E. baxteri, E. botryoides, E. cladocalyx, E. globoidea, E. microcorys, E. muelleriana, E. nitens, E. obliqua, E. pilularis, E. regnans and E. saligna) were compared on four hill country microsites; upper and lower slope on sunny and shady aspects. Assessments included survival, foliar macro-nutrients, diameter at breast height (DBH), height, stem form, basic wood density and health to age 5 years. Site monitoring included solar radiation, temperature, rainfall and exposure. Foliar nutrients were strongly influenced by species and moderately influenced by microsite. Inter-nutrient and nutrient-growth correlations were identified and discussed. Subgeneric differences in nutrient profile were analysed with the aid of principal components analysis. Solar radiation and temperature were seasonal on both aspects but higher on the sunny face than the shady. Aspect differences were moderate, being greatest in the winter and least in the summer. A strongly seasonal growth pattern resulted, maximum DBH and height increments occurring in the spring and summer respectively. Growth was least in the winter. Seasonal and aspect effects on growth were related to solar radiation. Height and DBH (5 years) were significantly higher on the sunny face than the shady in all species. Slope position did not influence height but DBH on the lower slope was less than on the upper. Aspect had little influence on basic wood density and form. Species differed in growth, form and basic density. E. nitens was the most productive species but basic density was low. Conversely, density was highest in E. cladocalyx, among the least productive species. The stringybarks were intermediate in growth, form and density. The relationships between growth, form, density and environmental factors were explored with canonical correlation. Two species (E. botryoides and E. saligna) were adversely affected by possum browsing and infection by a leaf gall wasp (Ophelimus eucalypti). Discussion of the results includes consideration of the merits of assessments of relatively young trees as well as implications for tree growers.