During a five-year period several greenhouse experiments were carried out in which the feasibility of different cultural practices, including method of growing, fertilization, watering, mulching etc., was evaluated to reduce the bromide residues in tomato fruits after soil fumigation with methyl bromide. Growing tomato by ring culture, the method still very common in Poland, provided a well marked decrease of inorganic bromide content in the fruits, ranging from 13 to 51 %, on average 27 %. Fertilization of nonleached soil with KCl reduced the bromide residues in tomato fruits by 15-50 % comparing to KNO3 or K2SO4 fertilization. Application of KCl on leached soil had less pronounced effect on reduction of bromide residues (6-28 %) Amendment of the soil after fumigation with peat or fine brown coal had no clear impact on bromide concentration in tomato fruits. High level of NPK fertilization mentained both pre-and postplanting, resulted in a significant increase of bromide uptake by tomato plants compared with high preplanting and low postplanting fertilization or reverse fertilization program. In general, high soil salinity enhanced the extent of bromide uptake. Drip irrigation significantly reduced bromide residues only at low soil salinity. A screening of 15 tomato cultivars revealed profound varietal differentiation in bromide accumulation. Tested cultivars, grown under the same conditions, differed even sixfold in their bromide concentrations. In most cases the propensity of various cultivars to accumulate bromide ion was inconsistent from year to year.

Biologia plantarum, an international journal for experimental botany founded in 1959 by Professor Bohumil Němec. Covers all branches of experimental botany ranging from molecular biology and biotechnology to whole-plant and stand functioning.

The effect of methyl jasmonate (JA-Me), applied to mature green tomato fruits cv. Modena, on the content of some fatty acids in ripe fruits was studied. Methyl jasmonate greatly increased content of linolenic acid and in the lesser degree decreased the amount of linoleic acid. The ratio of linolenic acid to linoleic acid content increased 4.5 - 7.7 times in methyl jasmonate treated samples in comparison to untreated-controls. JA-Me did not affect the contents of lauric, myristic, palmitic, stearic, palmitoleic and oleic acids.

The effect of methyl jasmonate on ethylene production and ethylene-forming enzyme activity in fruits on the non-ripening nor and rin tomato mutants was investigated. Fruits of nor and rin mutants produced a low level of ethylene but ethylene-forming enzyme activity was high in the nor mutant and low in the rin mutant. Methyl jasmonate evidently stimulated ethylene production and EFE activity in fruits of both tomato mutants, more efficiently in the nor than in the rin tomato mutant.

The effect of methyl jasmonate (JA-Me) on fatty acid and sterol concentrations in the first internode of tulip stem during JA-Me induction of gum production (gummosis) was investigated. JA-Me greatly increased the concentrations of free and bound oleic and linoleic acids, and did not affect the concentrations of free and bound palmitic, stearic and linolenic acids. Methyl jasmonate approximately doubled the concentration of stigmasterol and did not influence the concentrations of campesterol and β-sitosterol. The changes in fatty acid and sterol concentrations induced by methyl jasmonate in tulip stem may be caused by increased senescence and possibly may be associated with induction of gum formation.

Aminooxyacetic acid (AOA), an inhibitor of ACC biosynthesis, applied together with methyl jasmonate (JA-Me) to mature green and light-green tomatoes cv. Venture greatly inhibited ethylene production stimulated by JA-Me, when analyzed in ripe and overripe stages. AOA applied alone did not affect ethylene production in the same conditions of treatment and analysis. It is suggested that after JA-Me treatment of tomatoes the turnover rate of ACC is higher (JA-Me stimulates EFE activity) in comparison to control tissues, and, consequently, AOA inhibited ethylene production stimulated by methyl jasmonate.

It was found previously that methyl jasmonate inhibits lycopene accumulation and stimulates ethylene formation in different stages of ripening tomatoes. Present studies show that methyl jasmonate stimulates ethylene production and chlorophyll disappearance but does not induce polygalacturonase activity in mature green tomatoes. Methyl jasmonate stimulates ethylene production in ripening tomatoes but inhibits development of polygalacturonase activity.

The effect of methyl jasmonate (JA-Me) applied in concentration 1.0 % in lanolin paste to detached tomato fruits at the mature green, advanced mature green and light red stages on the ethylene production and l-aminocyclopropane-l-carboxylic acid (ACC) content was investigated at different times after treatment. JA-Me stimulated ethylene production in all stages of ripening, but the level of ACC increased or decreased in comparison with control depending on the stage of ripening. Higher level of ACC in JA-Me treated tissue was found in mature green stage and fully ripened tomatoes-treated at advanced green stage; lower one in light red stage — treated at advanced green stage and fully ripened stage - treated at light red stage.

Methyl jasmonate (JA-Me) at concentration of 0.5 % and 1.0 % in lanolin paste applied to the surface of postclimacteric apples cultivars McIntosh, Spartan, and Cortland inhibited ethylene production in slices of cortex with a skin cut to a depth of about 2 mm. The level of 1-aminocyclopropane-l-carboxylic acid (ACC) was decreased in tissues of apples treated with methyl jasmonate. Methyl jasmonate stimulated ethylene production in preclimacteric apples cv. McIntosh.

Methyl jasmonate at a concentration of 0.5% in lanolin paste was applied to detached mature green and red ripe tomatoes cv. Tempo. One to 10 days after treatment, slices were cut at a depth of about 2 mm for ethylene determination. It was found that methyl jasmonate strongly stimulated ethylene production both in green and red fruits, production was about 1.6 to 7.9 times higher than in control tissue.

The influence of cycloate (active component of Ro-Neet 6E) on the biological value and residues in spinach was studied. During the growing season of spinach, cycloate residues decreased rapidly until by harvest time levels 0.0005--0.0008 mg/kg. had been reached. None of the studied herbicides had negative influence on the chemical composition of spinach.

The residues of heptenophos and triazophos (active components of Hostaquick and Hostathion) were determined in several vegetable crops during the growing period. Heptenophos residues decreased below the limit of detection (0.001 mg/kg) in most of the crops one week after the treatment. However, the decline of triazophos in vegetables below the limit of detection (0.002 mg/kg) depended on the method of crop treatment.