Effective chemical protection against the raspberry cane midge (Resseliella theobaldi) should be based on the monitoring of the emergence of the pest. Before the application of sex pheromone traps, the results of several international studies carried out to determine the accumulated temperature needed by the larvae to become adults sho
...wed differences in the calculated data. The aim of this paper was to give information on the time of cane midge emergence by using sex pheromone traps and different methods of accumulated temperature calculations. On the basis of three years' results, the use of accumulated soil temperatures turned out to be reliable for the prediction of cane midge flight, and the relative standard deviation was the smallest in the case of 0 °C compared with other values applied as supposed biological zero points. According to our studies, 665 day °C are required for the development of one generation of the raspberry cane midge during the vegetation period. The emergence of the first generation was found at 451 day °C.
The tissue structure of the vegetative organs of strawberry (root, rhizome, stolon, leaf) is discussed in this paper. The authors stated that the root structure described by Muromcev (1969) and Naumann-Seip (1989) develops further from the primary structure. It grows secondarily and the transport tissue becomes continuous having ring shape. In
...the primary cortex of the rhizome periderm like tissue differentiates, but according to the examinations up to now, it does not take over the role of the exodermis. The exodermis is phloboran filled primary cortex tissue with 3-4 cell rows under the rhizodermis. The development of the transport tissue of the petiole is also a new recognition. In the lower third of the petiole the transport tissue consists of 3 collaterally compound vascular bundles. In the middle third there are 5 bundles because of the separation of the central bundle and in the upper third of the petiole 7 bundles can be observed because of the ramification of the outside bundles. Therefore attention must be taken also in the case of other plants at making sections. There might be confusions in the results of the examinations if the number of bundles increases in the petiole. The tissue structure might vary depending on the origin of the tissue segment.
The palisade parenchyma of the leaf blade has two layers and it is wider than the spongy parenchyma. Among the 5-6-angular cells of the upper epidermis do not develop stomata while in the lower epidermis there are a fairly lot of them.