The performance of free-space optical (FSO) communications that using an optical amplifier (OA) in the scheme of an amplify-received (AR)-relaying has a major drawback in the detection of input signal quality under the effects of turbulence. As an OA is based on a fiber-detection (FD) method to receive and delivers a signal at the amplification process stage, there is an opportunity to implement an optical spatial filter (OSF) to improve the quality of an input signal. In this paper, as the continuation of previous work on the direct-detection, the OSF is applied on the AR-relaying. The novelty proposed in this work is the improvement of FD method where the OSF is designed as the integration of cone reflector, pinhole and multi-mode fiber with an OA. The OSF produces an optical signal, the input of the OA, which minimizes the effects of turbulence, background noise and signal fluctuation. Thus, OA in AR-relaying produces signal output with high power and rise up below threshold level. Additionally, an OSF with a lower pinhole diameter produces the best quality of the signal spectral to be delivered into an EDFA. Through this implementation, the performance of optical relaying on FSO can be significantly improved.

It was confirmed that in the north of Poland winged specimens of Myzus persicae (Sulz.) start to migrate in spring approximately over three weeks later than in the central and sou them regions. It was observed that during the 1981-1990 and 1991-2000 decades, M. persicae started its flights approximately over two weeks earlier than during the 1971-1980 decade. With this respect one may conclude that the changes are permanent. There were also changes in quantity. In some places the M. persicae share in the entire aphid fauna on potato crops was observed to have decreased as the time passed, which, as it seems, may be associated with a decrease in potato crops area in Poland. Such a correlation can also be confirmed by the fact that in the area where M. persicae share increased, the potato crops area also increased extensively.

Bacterial speck of tomato caused by Pseudomonas syringae pv. tomato appeared to be recently the most important disease on tomato in Poland. The genetic relationships among four Polish strains of race 0 P. syringae pv. tomato of different origin, isolated from tomato plants, were examined by RAPD and PCR-RFLP techniques. Amplification of bacterial DNA using 33 primers with RAPD technique showed, that similarity of strains expressed by the Nei-Li coefficient was very high (above 0.8). Next, the restriction analysis of amplified region ITS with the use of 5 endonucleases revealed, that profiles obtained from electrophoretic separation of DNA fragments were also very similar. On the basis of those analyses it was concluded that all strains tested constituted a closely related group. However, they showed various level of virulence as was demonstrated on the inoculated leaves of tomato plants growing in the greenhouse.