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Tomato stem trichomes and dispersal success of Phytoseiulus persimilis relative to its preyTetranychus urticae

Tomato varieties used at present for commercial production in Dutch glasshouses have a high density of glandular trichomes on the stem, but a very low density on the leaves. The two-spotted spider mite, Tetranychus urticae Koch, and the predatory mite, Phytoseiulus persimilis Athias-Henriot, usually disperse from leaf to leaf via the stem, thereby incurring high risks of entrapment (and death) in the exudate of the glandular trichomes. These risks have been quantified on the tomato cv. 'Turbo' and an accession of Lycopersicon peruvianum almost free of glandular trichomes. The possible consequences for biological control are discussed and new perspectives for predator release strategies and for plant breeding are considered. © 1987 Elsevier Science Publishers B.V.

Personalization for specific users

Creating adaptive systems becomes increasingly attractive in the context of specific groups of users, such as agricultural users. This group of users seems to differ with respect to information processing, knowledge management and learning styles. In this work we aim to offer directions toward increasing decision support systems usability, by tailoring toward user learning styles. The results show that decision support systems need to be redesigned toward providing agricultural users with a more efficient time management and study environment, and facilitating group interaction.

The phosphate balance: current developments and future outlook

Phosphate is essential for agricultural production and therefore plays a key role in the global production of food and biofuels. There are no agricultural alternatives for phosphate, and a substantial fraction of our annual phosphate consumption is dispersed into the environment where it is largely lost to agriculture. Phosphate is an irreplaceable, and to a considerable extent non-renewable, resource that is being exploited at an ever increasing rate. The ongoing depletion of phosphate resources combined with recently increased phosphate prices urge us to reconsider our phosphate consumption patterns. In addition to economic and geo-political reasons, further reducing phosphate consumption would moreover be beneficial to the quality of our environment. Even if we increase the reserve base, for which there are plenty of opportunities, it is clear that the phosphate industry will sooner or later have to make a switch from a reserve-based industry to a recycling industry

A knowledge approach to sustainable agriculture

Bat boxes as a tool for biological insect pest control on cocoa plantations in Ghana

Ghanaian farmers suffer from a decline in cocoa production partly due to damages and diseases from insect pests. To increase predation by bats on insects on the cocoa plantations we installed two different types of bat boxes on 15 plantations around the village of Buoyem. Bat activity, bat species composition (numbers of insectivorous and frugivorous bats) and insect abundance were measured before and after bat box installation. Insectivorous bats were present on all ofthe sampled plantations, namelyleaf-nosed bats (Hipposideros sp.), slit-faced bats (Nycteridae sp.), horseshoe bats (Rhinolophus sp.) and vesper bats (Vespertilionidae sp.). Furthermore, no correlation between insect abundance and bat activity could be detected. The bat boxes were not occupied yet during the research period since rainy season started in the second half of the measurements and bat activity decreases with increasing precipitation which is supported by our Un dings. Additionally, the available time period between in stallation and measuring of the effects of the boxes was very short when compared to similar researches. Bats alsohave different preferences per species for size and shape of bat boxes and the number of naturally available roosting sites also influences bat box occupancy. Our results suggest that bats are abundant above cocoa plantations in Buoyem and therefore bat boxes have the potential to be ahelpful tool in insect pest control.

Biomimicry

There is more to be learned from nature as a whole. In practice ‘nature’ is often used in teaching, training, consultancy and organisational development as a metaphor, as a source of inspiration or as an example for all kinds of processes, including leadership, cooperation, relationships and the development of organisations and society. Mainly ecological, and much less frequently biological, processes are generally involved here. The question has gradually arisen whether we can learn more from nature in the social environment than what we ‘see’ on the surface - which is often translated in metaphors. Seen more holistically, this is about the systemic side, the complexity, the context and the coherence. For example, can we demonstrate that applying fundamental ecological principles, such as cycles (learning, self-organising, selfregulating and self-sufficient capacity), succession, diversity and resilience, social and cooperative behaviour, interconnectedness and interdependency within an organisation leads to a sustainable organisation? Mauro Gallo is conducting research into the significance of technical innovation in and for the agricultural and food sector, and into the question whether biomimicry can in fact be backed up in such a way that it contributes to the social sciences domain. At the same time there is a clear teaching issue: Is it logical from the perspective of our green DNA to include biomimicry thinking in our teaching? Is it possible to learn to apply biomimicry, and can biomimicry be applied in teaching/learning? (How) can we apply biomimicry in green VMBO and MBO, pass it on to the teachers of the future in teacher training courses and include it in making current lecturers more professional? Is it conceivable that it could become an integral component of the curricula in green HBO?