A standardized impregnated filter-paper bioassay technique was specially developed for screening insecticides against adults of the whitefly Bemisia tabaci Genn. (Homoptera, Aleyrodidae). It was found that the most suitable exposure period, after which mortality counts should be made, was 11·7 ± 2·1 h. Two different techniques for applying the insecticide solutions to the filter paper disks were tested and verified.

Two bean genotypes differed in rate of root extension and elongation when grown under different soil water stresses in transparent tubes placed at an angle of 25°. Root intensity (the root length visible cm−2 of the viewing surface) gave a quick indication of the distribution of the total root length when screening cultivars for drought resistance.

The structural and transport properties of thin FePc films of various thickness deposited onto glass substrates have been studied at several temperatures. The structural studies show that the films belong to monoclinic system of β-phase. This structure is confirmed by infrared absorption analysis. The dark electrical resistivity was found to decrease with increasing the film thickness. Graphical representation of $\log \rho$ as a function of reciprocal temperature yields two distinct linear parts indicating in turn the existence of two activation energies $\Delta E_1$ and $\Delta E_2$ . Measurement of the thermoelectric power showed that FePc thin films behave as p-type semiconductor over the temperature range $300{-}450$  K. Analysis of thermoelectric power connected with the resistivity results reveals some essential parameters such as: hole mobility $\mu_{\rm h} \approx 2 \times 10^{-6}$  m2 V-1 s-1, hole concentration $p \approx 5\times 10^{18}$  m-3 and the ratio $c = \mu_{\rm e}/\mu_{\rm h} \approx 0.25$ . Capacitance-voltage data confirm that the Au/FePc interface does not form a Schottky barrier and measurements of the dependence of capacitance on film thickness indicate that the relative permittivity of the films is approximately 3.7. Room temperature current density-voltage characteristics showed ohmic conduction in the lower voltage range and space-charge-limited – conductivity (SCLC) in the relatively high voltage. The SCLC controlled by an exponential distribution of traps above the valence band edge. The temperature dependence of current density in accordance with the theory for the exponential trap distributions yielded some essential parameters such as: the hole mobility, the relative permittivity, the trap concentration, the characteristic temperature and the trap density.