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Basismateriaal van vegetatiewaarnemingen in de Sahel, met name gedurende de tweede helft van de jaren 70 van de 20ste eeuw. Het materiaal is goed gepresenteerd in een aantal boeken. Het basismateriaal is echter van belang wanneer men, in het kader van het bestuderen van de mogelijke effecten van klimaatsverandering op vegetatiedynamiek, theorieën wil verifiëren dan wel helpen opstellen door nieuw vegetatieonderzoek.

The tomato crop growth model described in part I of this study has been parameterized on the basis of the results of experiments conducted in greenhouses in the northern Negev of Israel. Iterative procedures were applied to derive the parameters for the functional responses of various processes to temperature, radiation intensity and carbon dioxide concentration. The model was subsequently validated on the basis of the results of completely independent experiments. It is shown that the model accounts for the major phenomena observed under greenhouse conditions, and may be used, therefore, with confidence to examine the effects of environmental conditions and management practices on tomato fruit yield. It may also form the basis of decision support systems, aiming at recommendations for crop management. To improve its performance and range of applicability, further development of the model is necessary, including more morphological detail, as well as effects of other environmental factors.

Zuiveringsinstallaties voor huishoudelijk afvalwater emitteren mogelijk verontreinigingen naar de atmosfeer. Er zijn vermoedens dat deze verontreinigingen schade aan vegetaties kunnen veroorzaken. In dit rapport wordt deze kans op schade besproken. Directe aanleiding voor deze evaluatie is een aantal bezwaren, die gemaakt zijn tegen de bouw van een waterzuiveringsinstallatie in de directe omgeving van een plantenkwekerij. Als specialiteit heeft deze kwekerij het kweken van varens. Aan dit specifieke geval wordt aandacht besteed.

The tomato crop growth model described in part I of this study has been parameterized on the basis of the results of experiments conducted in greenhouses in the northern Negev of Israel. Iterative procedures were applied to derive the parameters for the functional responses of various processes to temperature, radiation intensity and carbon dioxide concentration. The model was subsequently validated on the basis of the results of completely independent experiments. It is shown that the model accounts for the major phenomena observed under greenhouse conditions, and may be used, therefore, with confidence to examine the effects of environmental conditions and management practices on tomato fruit yield. It may also form the basis of decision support systems, aiming at recommendations for crop management. To improve its performance and range of applicability, further development of the model is necessary, including more morphological detail, as well as effects of other environmental factors.

Zuiveringsinstallaties voor huishoudelijk afvalwater emitteren mogelijk verontreinigingen naar de atmosfeer. Er zijn vermoedens dat deze verontreinigingen schade aan vegetaties kunnen veroorzaken. In dit rapport wordt deze kans op schade besproken. Directe aanleiding voor deze evaluatie is een aantal bezwaren, die gemaakt zijn tegen de bouw van een waterzuiveringsinstallatie in de directe omgeving van een plantenkwekerij. Als specialiteit heeft deze kwekerij het kweken van varens. Aan dit specifieke geval wordt aandacht besteed.

In this chapter, the authors develop the concept of the endophyte as a unique candidate for genetic engineering for the purpose of conferring resistance. Endophytes should be viewed as an important genome for crop protection. Genetic engineering of well-chosen endophytes offers several advantages over other means of imparting insect and disease resistance to crops: the freedom of interspecific gene movement expands possibilities beyond that of traditional breeding. Scientists at Crop Genetics International (CGI) have chosen the bacterium Clavibacter xyli subsp. cynodontis (Cxc) for commercial development to produce and deliver biopesticides in planta. Since Cxc is the only endophyte being engineered for commercial development, it will serve as the chapter's primary example of potential benefits of the endophyte approach to crop improvement. CGI is continuing product development research to identify appropriate market opportunities for endophyte-based crop protection products.

Crop production is of paramount importance to every person in every country. It is essential for life. Increased crop production will be necessary to provide food, feed, and fiber to the growing world population, which is projected to reach 8 billion by the year 2015. Research priorities define which research projects will be addressed and assign a relative emphasis to each. The choice of projects and the amount of resources devoted to each directly affect the progress which can be made in maintaining and improving crop production. Careful determination of research priorities is necessary to obtain funding from local or national governments, bilateral agreements, international bodies, and donor agencies. Each of these entities has its own mandate and, thus, priorities that determine which research projects will be funded and the regional allocation of support. Priorities are set on an international and regional basis.