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Age-dependent physiological responses of Corchorus olitorius to aqueous extracts of Murraya koenigii and Tithonia rotundifolia
61-66.Views:179Sustainable crop production increasingly utilizes allelopathic plants as sources of bioactive compounds, yet their bimodal inhibitory–stimulatory effects and oxidative mechanisms require further elucidation. This study investigated the concentration-, tissue-, and stage-dependent effects of aqueous shoot extracts from Murraya koenigii and Tithonia rotundifolia on the germination, growth, and oxidative defense of Corchorus olitorius. Seed emergence and elongation of radicles and plumules were monitored in the laboratory using 50% and 100% aqueous extracts, while potted seedlings were treated separately with 100% extracts. Laboratory bioassays demonstrated a dose-dependent response: a 50% M. koenigii extract transiently increased germination by 4%, while higher concentrations of both species inhibited germination by 7–25%. Juvenile growth inhibition was tissue-specific, with 100% M. koenigii primarily suppressing plumule elongation and 100% T. rotundifolia significantly reducing radicle growth. Conversely, pot experiments using 100% extract concentrations of both plants significantly enhanced vegetative growth, physiological traits, and biochemical constituents, including protein and ascorbic acid. These extracts bolstered the antioxidant defense system—increasing superoxide dismutase, catalase, and peroxidase activities—while markedly reducing malondialdehyde levels. These findings provide evidence of allelopathic hormesis, where initial inhibitory effects transition into growth stimulation and oxidative stress mitigation during later developmental stages. The results suggest that M. koenigii and T. rotundifolia shoot extracts serve as effective eco-friendly biostimulants that improve crop performance by modulating antioxidant responses.
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Assessment of different rates of NPK fertilizer on the growth and yield components of two exotic okra (Abelmoschus esculentus L.) western urban of Sierra Leone
55-59.Views:626The experiment was conducted in an Inland Valley Swamp during the dry spell of 2017 laid out in a randomized complete block design (RCBD) three replications at the Kabala Horticultural Crops Research Centre (KHCRC) cropping site, Ogoo Farm of the Sierra Leone Agricultural Research Institute (SLARI), Freetown, Sierra Leone. Raised beds measuring 5m x 1m (6 m2) with a 1m furrow between beds. Inter and intra row spacing of 75 cm by 50 cm with two rows per bed and two seeds per hills were directly sown. The treatments constituted NPK 15:15:15 at the rate of 0, 90, 120 and 150 kg/ha designated as T1, T2, T3 & T4 and Two hybrids of okra were used as experimental materials obtained from Indo-American Hybrid Seed Company, India; Okra-WASA-HyOKR-1 and Okra-WASA-HyOKR-2. Seeds were treated with Thiram Poison for longevity. Result indicates T2 (25.2; 35.1 cm) and T4 (56.9 cm) treatments recorded tallest plant heights followed by T2 (24.0, 34.4 & 50.1 cm), while T1 (18.8, 28.4 & 33.3 cm) had the shortest plant heights at 4, 8 & 10 Week After Planting respectively. Similarly, T4 & T2 (38.9, 65.5 & 44.8 cm) exhibited the largest SG and T1 (21.7, 33.0 & 52.0 cm) the least values at 4, 8 & 10 Week After Planting. While, the widest and narrowest LA at 4, 8 & 10 Week After Planting was observed in T3 (131.3, 135.0 & 158.5 cm2) and T1 (120.8, 121.8 & 128.1 cm2). With respect to yield and yield components, the longest (22.0 cm) and heaviest (112.7 g) fruit were recorded by T3 followed by T2 (19.1 cm & 101.3 g) with T1 having the shortest (11.7 cm) and lightest (52.3 g). The width of pod in T3 (31.2 cm) was greater than the rest of treatments and as usual, T1 indicated the least value (14.6 cm) respectively. The average NP produced plant-1 was shown by T2 & T3 (4.0) with the least of fruit produced by T1 (2.0). Also, 100 seed weight, T3 (106.7 g) weighted the highest followed by T2 (103.3 g), while T1 (60.3 g) accounted for the lowest seed weight. Conclusively, the two materials are adaptable to the climatic conditions of Sierra Leone (Western area). Hence further evaluation required across vegetable growing zones.
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Role of nutrient supply in yield increase and quality improvement of spice pepper
83-86.Views:244Hungarian spice pepper powder is a unique product, a real hungaricum with its flavour and aroma compounds and seasoning effect. Its competitiveness with foreign spice peppers is ensured by its high biological value deriving from the specially Hungarian production and processing technology. Besides the traditional and highly manual labour intensive processing technology, there are some modern industrial technologies as well, where high quality can be guaranteed only by producing excellent base material (raw pepper pods). This is the reason which necessitates the rational development of the elements of the production technology, such as nutrient supply. Our objective was to offer a contribution to this aim by our trials in plant nutrition.
Experiments on the nutrient supply of spice pepper were set up in the 2003 growing season in order to decide whether yields and fruit composition parameters of pepper could be increased by means of increased K fertiliser doses with lower N:K ratios. Several forms of potassium were used, as well as applying microelement top dressings in the single treatments. It was found that the increase of N:K ratio from I:1 to 1:6 did not increase yields, but resulted in higher pigment and dry matter content. Microelement top dressing had a yield increasing effect at each N:K ratio. Higher potassium doses did not accelerate ripening.
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Effects of different rootstocks on the morphologic parameters of watermelon grafts during transplant production
69-73.Views:436Before Hungary joined the EU watermelon production was a key sector of the Hungarian vegetable industry. Its production area shrank by nearly 60 % since 2004, it is only 5000 ha today. Stable and reliable market failed to evolve in the last years and extreme weather events occurred more frequently. An unfavourable growing season can notably affect the production volume of the next season. Information gathered in the last years support the assumption, that suitable stocks can help eliminate the issues caused by extreme weather or short-term crop rotation. Choosing the right grafted or non-grafted transplant is not enough any more, growers also have to select stock. In fruit and vine production choosing the stock, which is the most suitable for the technology is evident and this approach should be widely adapted by watermelon growers as well. In this research we investigated the growth parameters of different watermelon stocks and their effect on the scion during the transplant production. Measurements were carried out on seven different stock-scion combinations of the scion ’Topgun F1’ hybrid. Two of the stocks were interspecific (Cucurbita maxima × Cucurbita moschata) and five stocks were Lagenaria-type (Lagenaria siceraria) stocks. We made and recorded observations of the transplants’ length (cm), diameter of the stock and scion (mm), number of leaves (piece), root length (cm), root mass (g) and shoot mass (g). We concluded that early pricking out of transplants with interspecific stocks is successful due to their hardiness and vigorous growth. The effect of the ’Shintosa camelforce F1’ interspecific stock was outstanding. Furthermore, the results confirmed the practical observation that the root system of interspecific stocks grow vertically more allowing them to take up water and nutrients from lower soil layers in poor sandy soils. From the Lagenaria group the root system of the ’DG-01 F1’ was similar to the interspecific stocks’. It can be grown even in sandy soil, however other Lagenaria-type stocks are more suitable for production in hard soils with nutrient supply because of their compact root system. This study can serve as a basis for further research in the topic that can conduce to site- and technology-specific stock selection.
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Top-dressing of paprika transplants in trays with fertilizers of phosphorus- and nitrogen surplus
47-49.Views:331By our experiments, we wished to answer the question: may top-dressing with nitrogen and phosphorus fertilizers, respectively, improve the quality of transplants grown in trays on a substrate enriched by 2 kg/m3 of retarded fertilizers?
The experiments started in spring and autumn 2002, in a large volume plastic house. The seedlings were grown in trays. Seed was sown directly into KITE trays of 187 cells (28 cm3 volume per cell, 779 seedlings per square meter). The trays were filled by "loose filling" (without packing) with the following soil mixture: 50% Baltic highmoor peat, 50% 'Nitrite lowmoor peat, 1,5 kg/m3 feed chalk, 2 kg/m3 slow acting chemical fertilizer of phosphorus overweight, 2 kg/m3 superphosphate. The test plant was the vegetable paprika variety `Tizenegyes'.
The trials were made in order to clear up if top-dressing done once or twice improves the quality of the seedlings. For this purpose, perfectly soluble fertilizers of phosphorus or nitrogen surplus were used. 3 I fertilizer solution of 0.2% concentration was given per square meter on every single occasion. The control plots received no top-dressing.
The following parameters were registered: stem diameter, plant height, fresh weight of the top, dry matter content of the top, fresh weight of the root system per plant, dry matter content of the roots.
The experimental results with top-dressing have clearly proved the insufficiency of mixing 2 kg/m3 of retarded fertilizer into the substrate, as usual in raising paprika seedlings in trays, because of the long period of transplant raising. According to our experiments the additional nitrogen fertilization influences positively the development of green parts of plants, while the multiple application of fertilizers with higher phosphorus-content helps to develop a strong root system. We suppose, that the more often applied additional fertilizers, maybe the combination of fertilizers with nitrogen and phosphorus amount could give use even better results.
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Evaluation of biological control option for Bagrada bug (Bagrada hilaris (Burmeister)) in Kenya
43-47.Views:347Brassica production is important for economic development of Kenya. Bagrada bug, a significant pest of brassicas, affects their yields and quality, currently posing a threat to both local and commercial vegetable production in Kenya. Biological control of bagrada bug using natural enemies is a cheaper and environmentally friendly method. The study aimed to identify native egg parasitoid species in Kenya. A field prospection survey of the bagrada bug egg parasitoid was done by a series of bagrada bug egg exposure in different parts of the country. Freshly laid bagrada bug eggs in cards were exposed for possible parasitism in the field for three days. The eggs were later carried to the laboratory at NSRC to await hatching. Two egg parasitoid species Trissolcus basalis (Hymenoptera, Scelionidae) and Gryon sp. were identified during the study after a period of bagrada bug egg exposure in Machakos and Kisumu. Two cards with parasitized bagrada bug eggs were recovered from Machakos from which one card yielded four parasitoids of one species Trissolcus basalis and the other yielded two parasitoids Trissolcus basalis and Gryon sp. One card with two parasitized eggs by Trissolcus basalis was recovered from Kisumu, however, there were no parasitoids identified in Nanyuki, Naivasha and Kitengela where bagrada bug is also prevalent. Results showed parasitoid presence in fields with high bug populations compared to areas with few or no Bagrada bug infestations. Conducting trials in both laboratory and field settings is recommended to obtain clear data on the effectiveness of the identified egg parasitoid in managing the bagrada bug population.
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Dr. Ottó Orsós, the forgotten Hungarian pioneer in plant tissue culture
9-13.Views:475The knowledge of tissue culture deserves attention in respect of understanding the development of universal biology. This study intends to contribute to the past of the plant tissue culture by such data of the history of science which have been unprocessed so far. It seems that the life-work of the Hungarian biologist, Dr. Ottó Orsós is a missing and essential link between those early plant hormone researchers and the representatives of the pioneers of tissue culture schools who have contributed substantially to the development of the modern in vitro plant morphogenesis and plant cell biology. Orsós cultured kohlrabi tuber cubes on White culture medium in a sterile manner. This way, he could efficiently direct the in vitro morphogenesis of the kohlrabi, the regeneration of its shoot and root, and the formation and steps to subculture of pure callus tissues in 1938. He supported the correctness of its statements by means of detailed anatomical examinations. Orsós successfully rooted and aclimatized complete regenerated plants. We may as well call the above system — in remembrance of the creators of the original concept — "Haberlandt-Orsós model". Between the publishing of his main paper in 1938 and 2003, a period of 65 years has lapsed. On the occasion of this anniversary, we bow before this forgotten pioneer.
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Perspectives and tasks in horticultural production
11-22.Views:1248The work summarizes the prospective conceptions of all the five horticultural branches. These branches (vegetable, fruit, grape and wine, herb and ornamental plant production) with the production of propagating material together amount to round 30-35% of the total value of the entire plant production. The performance of horticultural branches declined significantly because of privatisation and lack of capital. The accession to the EU urges the development of modernization and competitiveness, therefore the state subsidies are indispensable.
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The effect of soil coverage on the soil quality
77-80.Views:317In this study we carried out experiments with soil samples originated from the Haschberg variety elderberry orchard and wild-growing plants from Szigetcsép Experimental Farm.
During the examinations we wanted to know how the black polyethene foliar soil coverage influences the quality of soil and the distribution of different nitrogen forms.
We studied the individual covered (foliar soil coverage for every plant), the full covered (foliar soil coverage was laid in the rows) and the uncovered threatments.
During the experiments we pointed out that the foliar coverage influences the condition of the soil unfavourably. Because of the coverage there is less air flow in soils, the lack of oxygen leads to degradating of soil life and results humus materials of poor quality.
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Efficacy of N-phenylphtalamic acid in some Solanaceae species
89-91.Views:272: N-phenylphthalamic acid — Cl4H1 1 NO3 (Nevirol 60 WP) was successfully used for enhancing yield in some important vegetable crops namely, tomato (Lycopersicon esculentum), chilli (Capsicum annuum) and brinjal (Solanum melongena) of Solanaceae. Aqueous sprays with 0.2% and 3.0% significantly enhanced fruit production in chilli and tomato respectively. On the other hand, various treatments in brinjal failed to enhance yield significantly. The increase in yield in both tomato and chilli is largely due to increase in the number of flowers and fruit-set percentage.
