The Influence of Flower Structures on the Seeds Productivity of the Carrot Breeding Lines The aim of the study was to examine the morphological diversity of flowers of male-sterile (CMS) and male-fertile breeding lines of carrot and its influence on seed setting. In examined male-sterile carrot population stamens are transformed into petal-like structures of different shapes. It was observed that in some anther-like structures sporogenic tissue degenerates. It is supposed that decrease of seeds productivity of carrot breeding lines could be caused by morphological abnormalities of mother and father-parental flowers. Degeneration of pollen, the absence of endothecium, which is responsible for opening the anthers and growth of pollen tubes on the external area of the pistil, decreasing the number of functional pollen influence negatively fertilization. Moreover, other specific traits of male-sterile mother plants, as reduction of nectaries size, pistils deformation, ovule and embryo degeneration also inhibit process of seed setting. The lowest amount of seeds produced plants with multiple stigma pistils and nectaries deformations. Male-sterile plants with white flower petals, big nectaries, exposed, doubled pistils and big ovaries produced more seeds than the other mother plants.
Some Quality Characteristics Including Isothiocyanates Content of Horseradish Cream as Affected by Storage Period During two-year experiments the effects of long-term storage at three temperature levels (2°C, 8°C and 18°C) on content of some nutritive components, including pungent compounds - isothiocyanates (ITC), in processed horseradish (cream) were studied. The significant changes of content of reducing sugars, total isothiocyanates and color indexes in horseradish cream after its storage were noted. The higher temperature of storage the higher content of reducing sugar in horseradish cream was observed. Content of allyl isothiocyanate (AITC) and especially phenylethyl isothiocyanate (PEITC) in fresh horseradish cream was lower in comparison to non-processed horseradish roots. Contents of both isothiocyanates decreased significantly during storage period. The highest decline of isothiocyanates level was observed during first four months of storage. The highest temperature of storage studied (18°C) caused faster decline of both isothiocyanates concentration in horseradish cream. To maintain the human health-promoting compounds in processed horseradish, as well as to keep sensory attributes (color), it is suggested to store horseradish cream in cold condition.
The Influence of pH of Nutrient Solution On Yield and Nutritional Status of Tomato Plants Grown in Soilless Culture System The aim of the studies conducted in the years 2004-2006 was determination the influence of nutrient solution of different pH on the yield and nutritional status of tomato plants grown in soilless culture in organic and inert medium. Tomato plants were grown on slabs made of shredded rye straw and on slabs of peat and rockwool. The plants were fertilized with standard nutrient solution of different pH: 4.5, 5.0, 5.5, 6.0, 6.5. Nutrient solution pH and the kind of applied growing substrates were exerted significantly influence on the height of total and marketable yield of tomato cv. Blitz F1. Early yield was not depended on pH of nutrient solution and the kind of using substrates. The highest total and marketable yield was observed in tomato grown in rockwool slabs. For all the growing media, the highest yield of tomatoes was obtained after feeding the plants with the nutrient solution of pH 5.5. The kind of growing substrates and pH of nutrient solution were significantly differenced the nutritional status of tomato plants. Despite of considerable differentiation of means concentration of mineral nutrient in tomato leaves, the plant growth and development were proper. Concentration of mineral nutrients was comprised at the optimum range of nutritional status of tomato plants. The pH of nutrient solution at the range of 4.5-6.0 was not exerted significantly influence on nutritional status of tomato plants with nitrogen, potassium and magnesium. With the increase of the pH nutrient solution the average phosphorus, iron and manganese content was decreased. The higher concentration of nitrogen, calcium and magnesium was occurred in tomato plants cultivated in organic substrates than in rockwool. The phosphorus and manganese content was higher in the leaves of tomato plants grown in rockwool compared to those in the organic media. Tomato plants grown in the straw substrate contained lower concentrations of potassium and iron and more calcium in comparison to peat.
Effect of the Colour of Light on Cucumber (Cucumis Sativus L.) Seedlings Seedlings of a greenhouse variety of cucumber, Marinda F1, were produced in a growth chamber under fluorescent lamps emitting ‘daylight’ and blue light, each at quantum irradiance of 50, 55 or 60 μmol·m-2·s-1. The seedlings were assessed in terms of growth dynamics, the more important morphological features and the concentration of selected pigments in fresh leaf weight. It was found that plants growing under blue lamps were taller, had longer internodes, a thicker stem and a higher dry matter content in fresh shoot weight. The number of leaves was not dependent on either the colour of light or the level of quantum irradiance. However, plant height, internode length and stem thickness, and dry matter content in fresh shoot weight increased as the irradiance level increased from 50 to 60 μmol·m-2·s-1. At the highest level of quantum irradiance, the concentrations of chlorophyll and carotenoids were greater in the leaves of plants grown in ‘daylight’. The concentration of anthocyanins did not depend on the colour of light or the level of quantum irradiance.
The Effect of Living Mulches on Yield and Quality of Tomato Fruits In the experiment conducted in 2004-2006 there was evaluated the effects of living mulches in tomato (Lycopersicon esculentum Mill.) cultivation. As the living mulches there were used white clover (Trifolium repens L.), serradella (Ornithopus sativus Brot.), perennial ryegrass (Lolium perenne L.), and pot marigold (Calendula officinalis L.). All these species were sown in the field in early and late April, at the time of tomato planting (20 May) or three weeks thereafter. In some treatments growth rate of living mulches was restricted by mowing or gliphosate application. Tomato plants cv. Delfine F1 were trained to one stem and tied to stakes. Harvest of fruits was conducted in one week intervals since the end of July till the end of September. In samples of fruits harvested at the end of August there were evaluated the contents of dry matter, vitamin C, total and reducing sugars. Data of the study showed that serradella and perennial ryegrass were less competitive for tomato than white clover and marigold, due to lower production of biomass at the end of growing period. In the average they reduced the yield of fruits by 21.6%. Irrespective of the plant species used as living mulch, the delay of undersowing to the date of tomato planting or three weeks thereafter as well as restriction of their growth by mowing were the efficient methods for increasing tomato fruit yield. Chemical analysis of tomato fruits did not show any significant influence of compared living mulch species or date of undersowing on contents of dry matter, vitamin C, total and reducing sugars.
Our objective was to identify the effects of Gibberellic acid (GA(3)), Prohexadione-Calcium (Prohex-Ca). Cycocel and Ethephon applied as foliar sprays, on pre- and post-harvest physiology and quality characteristics of melon (Cucumis melo L.). GA(3) promoted melon growth, while a significant inhibition with Cycocel and Ethephon was observed. The chlorophyll a+b concentration as well as the chlorophyll fluorescence characteristics were negatively affected by Prohex-Ca, Cycocel and Ethephon application. The maximum quantum yield of PSII (Fv/Fm) was declined showing an impairment of the primary photochemical efficiency of the photosynthetic apparatus during the time course of the experiment. The significant decrease of Fv/Fo is an indicator of structural damage, which occur in the thylakoids and affects the photosynthetic electron transport. With GA(3) application, fructose, glucose and soluble solids remained unchanged. whereas ascorbic acid content increased significantly. With the retardants a significant decrease in sugars, soluble solids and ascorbic acid content and ail increase in respiration rate and in titratable acidity of fruits, was induced. Less Soluble solids accumulation in melon from plants treated with growth retardants Could be a consequence of delayed maturity a fact that it can be proved by the lower Maturity index.
Fusarium basal rot of onion, caused by Fusarium oxysporum f.sp. cepae, is a steadily increasing problem in The Netherlands. Financial losses for Dutch farmers confronted with Fusarium basal rot is substantial, due to yield reduction and high storage costs. This paper describes the development and life cycle of Fusarium basal rot in onions and summarizes the results of research done in The Netherlands regarding the different methods for disease control (with emphasis on the use of tolerant cultivars).
