Introduction. A study was done to compare Gruesa, a local dwarf Cavendish selection, with two other cultivars of the Cavendish subgroup in the open air or under greenhouse conditions in two localities of the Canary Islands. Materials and methods. The trials were set up with the cultivars Zelig, Grande Naine and Gruesa in four plots on the northern slope: one outdoors and three under three different greenhouse covers (one with polyethylene lamina and the other two with different types of mesh), and in one outdoor plot on the southern slope of the island of Tenerife. Morphological, phenological and production characteristics were studied over three productive cycles. Results. Significant differences were found in both plant height (Grande Naine > Zelig > Gruesa) and pseudostem thickness (Gruesa > Grande Naine = Zelig). Each cultivar showed a stable [height:thickness] ratio, remaining the same in all trial conditions. Gruesa cycle length was longer than those of the other two cultivars, emitting more leaves until bunch emergency. Gruesa produced the most hands per bunch and the most fingers per hand. In all cultivars, finger length was directly related to pseudostem height. All three cultivars produced well, with fruits very similar in organoleptic traits. A reduction in cycle length and a slight increase in productivity were observed in the northern plot under the polyethylene cover compared with the plots under other covers and outdoors. Conclusion. Gruesa appears more recommendable than Zelig and Grande Naine for open-air plantations in windy localities.

Reform of the European Union's Common Agricultural Policy (CAP), especially through Regulation 2078/92, provided a dual role for farmers as food producers and stewards of the environment and the countryside. Implementation of integrated pest management (IPM) in greenhouse enterprises in Greece is a part of this effort. In this study, the effectiveness of the adoption and implementation of IPM practices in greenhouse vegetable cultivation in Central Macedonia (Greece) was assessed. Eighty-six farmers enrolled in an IPM programme and 28 conventional greenhouse farmers were selected and interviewed in 1997, using a questionnaire designed to assess their behaviour in the greenhouse and examine their attitudes towards the environment. Wide adoption of IPM was found still to face many hindrances, mainly due to the lack of appropriate technical and advisory support by the agricultural local services, and farmers' low level of knowledge of IPM. Comparisons between IPM and conventional farmers revealed that: (1) the two groups' behaviour did not differ significantly in greenhouse production practices, but (2) IPM farmers were more aware of the new environmental dimension of the CAP, and (3) they expressed more concern about the negative effects of modern agriculture on nature, than conventional farmers.

The number of species of insect pests, estimated to be maximally 10,000 worldwide, forms only a small part of the millions of species of plant-eating insects. Chemical pest control is becoming increasingly difficult and objectionable in terms of environmental contamination so that other methods of pest control need to be developed. One of the best alternatives is biological control. Natural and inoculative biological control has already proven successful against a variety of pests over large areas. One is inclined to forget, however, how successful a biological control program has been as soon as the pest problem has been solved. Other types of biological control involving the regular introduction or augmentation of natural enemies are better known, although these have been applied on a much smaller scale; a survey of the present-day application of these latter types of biological control is presented here. Phases in the implementation of biological control are illustrated and needed future developments in research are discussed. The main limitation on the development of biological control is not the research, since natural enemies are easier found and with a much lower investment than new chemical pesticides, but rather the attitudes held by growers and disinterest on the part of industry, policy-makers, and politicians. The first priority for those concerned with the development and application of safer pest control should, therefore, be to change the perceptions that these other groups have of biological control.