Weight Of Root System Research Articles

ОБОСНОВАНИЕ ПРИМЕНЕНИЯ ЭЛЕМЕНТА КАПЕЛЬНОГО ПОЛИВА ДЛЯ ОПТИМИЗАЦИИ ГИДРОТРОФИЧЕСКОГО РЕЖИМА ДЫНИ В УСЛОВИЯХ ЗАЩИЩЕННОГО ГРУНТА

The aim of the study is to investigate the possibilities of using drip irrigation to optimize the hydrotrophic regime of melon in protected ground conditions. The object of the study is the melon crop of the F1 Polidor variety. The study was carried out in 2021–2023 at the enterprise of OJSC Vysokovsky Greenhouse Plant (Kostroma Region) under the adopted technology for growing F1 Polidor melon (control – drip irrigation) and using an additional element of the GTK drip irrigation system (experiment). The experiment was carried out on an area of 200 m2 (the size of the survey site is 25 m2) in accordance with the approved methods. Hydrotrophic capsules were installed when planting seedlings in the ground at the rate of 1 hydrocapsule per 2 plants, while 2 capillaries of the automated irrigation system were mounted in the lid. The frequency and level of water and nutrient solutions supply were programmed in accordance with the requirements of the biology of the crop and were carried out centrally. The experiment was repeated 4 times. Optimization of the water and nutrient supply regime for melons contributed to the development of a powerful root system with a positively changed anatomical and morphological (increase in root system weight by 125.7 g/plant, decrease in the number of root hairs and increase in the size of xylem vessels to 0.32 mm) and functional structure (101 % more working adsorbing surface of roots), increasing the physiological activity of above-ground organs in terms of photosynthetic productivity to 0.99 mgC/dm2/h and reducing water losses by 3.4 %/h/plant, which affected the formation of additional melon production of 8.9 t/ha with high accumulation of sugars (16.4 %) and vitamin C (8.9 mg%). Reducing the costs of additional water consumption will have a positive effect on the cost of production and on the economy of the enterprise as a whole. In greenhouse conditions, a favorable climate will be created for the working personnel, the amount of weeding will be reduced, and the risk of allergic reactions to mold spores will be reduced.

Effects of Fertilization on Growth and Productivity of Three Milk Thistle Populations


 Milk thistle is an important medicinal plant as it contains silymarin which has many pharmaceutical activities. The purpose of this study was to evaluate the influence of a stabilized nitrogen fertilizer alone or combined with a foliar fertilizer, containing phosphorous, potassium, iron, manganese, and zinc, on the plant development and fruit yield of three wild milk thistle populations originated from Greece. The fruits of the populations ‘Palaionterveno’, ‘Mesopotamia’, and ‘Spata’ were sown in plastic pots containing peat. Fertilization treatments were i) control - without application of fertilizer, ii) application of a stabilized nitrogen fertilizer, and iii) use of the stabilized fertilizer followed by applications of foliar fertilizer at three different growth stages. The results revealed that genetic material significantly affected the plant height, rosette diameter, and dry weight of root system. Moreover, the application of the nitrogen fertilizer alone or combined with a foliar fertilizer enhanced plant growth. Regarding the fruit yield, there was an interaction between the two factors.

The influence of highly dispersed humic acids on the growth and decorative qualities of Tagetes patula L.

Ryazan Agrotechnological University. P.A. Kostychev, the biocatalytic properties of highly dispersed humic acids (HHA) on various crops are being studied, but the question of the influence of HHA on ornamental crops has not been studied at all. A laboratory experiment on seeds and seedlings of Tagetes patula L. (variety “Makkeny’s Gold”) showed that for the seeds of this crop, the most effective concentration of HHA is 5.0 g/t, which increases germination, the length of the sprout by 2.5 mm (+9.5 %) and root by 3.8 mm (+20.9%), as well as the weight of the sprout by 36.7% and root by 55.9% relative to the control. An experiment on vegetative plants Tagetes patula L. showed that a dose of HHA of 5.0 g/t increases the decorative qualities of this crop, so there was an increase in plant height by 5.1 cm (+21%) and root system weight by 1.3 g ( + 25.5%), the number of leaves per 1 plant increased by 5 pcs (+14.7%), the number of flowers per 1 plant increased by 1.9 pcs (+25%), as well as the flower diameter by 0.9 cm ( +15.3%) relative to control. HHA at a dose of 6.0 g/t most effectively influenced the speed of the vegetation phases, reducing the period from germination to the beginning of flowering by 6 days. Also, when using HHA 6.0 g/t, the maximum seed productivity of Tagetes patula L. was determined, the weight of seeds from 1 plant was 5.3 g, which is higher than the control by 0.8 g (+17.8%).

Germination and Agronomic Traits of Phaseolus vulgaris L. Beans Sprayed with Trichoderma Strains and Attacked by Acanthoscelides obtectus

Acanthoscelides obtectus, one of the world’s most important post-harvest pests, attacks wild and cultivated common beans (Phaseolus vulgaris L.). Four Trichoderma strains, Trichoderma arundinaceum IBT 40,837 (=Ta37), a wild-type strain producer of trichothecene harzianum A (HA); two transformed strains of Ta37, Ta37-17.139 (Δtri17) and Ta37-23.74 (Δtri23); and T. brevicompactum IBT 40,841 (=Tb41), a wild-type strain producer of the trichothecene trichodermin, were evaluated to determine the effect of these compounds on the virulence of A. obtectus and the effect of these strains on the seed’s capacity of germination and on the agronomic traits of the plants grown from these seeds. Treatments of bean seeds with different Trichoderma strains provided varying survival rates in A. obtectus adults, so life survival of insects after Tb41 strain application was reduced to 15 days. Δtri17 and Tb41 strains sprayed on P. vulgaris beans resulted in low weight losses (1.21 and 1.55%, respectively). In spite of the low germination percentage of beans treated with Δtri23 strain (lower than the germination percentages of the rest of the fungal strains applied), this treatment encouraged a greater Wet Weight of Aerial Part of the plants grown from both damaged and undamaged beans. High germination rates of Ta37 and Δtri17 strains (higher than with the rest of treatments), did not turn into a greater Wet Weight Aerial Part and Wet Weight of Root System in the future plants developed. Linear regression between the number of exit holes and the wet weight aerial part on the one hand, and between the number of exit holes and the wet weight root system on the other, showed interaction, so Δtri23 and Tb41 strains behaved differently in comparison to their respective control treatments. The number of exit holes of beans treated with Δtri23 or Tb41 was negatively correlated with both the wet weight aerial part and the wet weight root system in P. vulgaris plants. Δtri23 sprayed on undamaged beans caused the greatest Wet Weight Aerial Part and wet weight root system in plants. Due to the good results obtained by Δtri23 and Tb41 strains in this work, more studies for A. obtectus control, P. vulgaris plant growth and trichothecenes production by these strains should be explored, in order to advance in the knowledge of how these fungi could be used in the field crop, together with the application of management strategies to mitigate risks for farmers and to minimize environmental contamination.

Efeito de bactérias diazotróficas associativas no desenvolvimento produtivo do capim Marandu

O objetivo deste estudo foi determinar o desenvolvimento do capim Marandu (Urochloa brizantha cv. Marandu) submetido à inoculação com bactérias diazotróficas associadas e cultivadas em Latossolo Vermelho do Cerrado. O experimento foi conduzido em casa de vegetação, com delineamento inteiramente casualizado e cinco tratamentos composto por três estirpes de bactérias associativas fixadoras de nitrogênio, Y2 (Nitrospirillum amazonense), MTH2 (similar à Herbaspirillum spp.), MTB1 (similar à Burkholderia spp.), um inoculante comercial formado pela combinação das estirpes Ab-V5 e Ab-V6 (Azospirillum brasilense), um controle 100 mg dm-3 N-uréia e cinco repetições, foram inoculadas pela inserção de uma alíquota de 3 mL de caldo bacteriano contendo 109 mL-1 de células no solo próximo ao sistema radicular de cada planta. Foram realizados três cortes aos 30, 60 e 90 dias após a semeadura e avaliou-se altura da planta, número de folhas, matéria seca de parte aérea e da raiz do capim Marandu. A altura das plantas (P

Optimization of productivity and quality of cucumber plants in protected ground

The paper studies the effect of growth stimulants on morphometric indicators of cucumber plant growth and development in the phase of intensive vegetation and transition to fruiting. The study was carried out at LLC Agricultural Enterprise “Teplitsy Belogorya” on the parthenocarpic hybrid of cucumber Tristan F1. Within the scientific and production experiment the grown cucumber plants on cotton-mineral cubes with drip watering were additionally vegetatively treated with a humic fertilizer solution and Azosol 36 microfertilizer. Phenological observations were carried out and morphometric parameters were determined: plant height, stem and leaf weight, leaf area, root system weight. Under the influence of treatments, the leaf area and weight of cucumber leaves increased by an average of 20 and 17%, respectively. It was established that vegetative treatment with the studied solutions allows partially controlling physiological processes and organogenesis of the greenhouse cucumber plant. The vegetative organs of the cucumber plant leaf, stem and root were found to exhibit different abilities to accumulate chemical elements within the two experiments. The series of element distribution in the natural substance of the plant vegetative organs are shown (in a decreasing amount, total nitrogen, phosphorus, potassium for a series: leaf – stem – root; calcium, magnesium, zinc, iron, manganese and copper for the series: root – leaf – stem). The use of the studied fertilizers increased the commercial quality of cucumber fruits. Button contained a higher amount of total sugar and vitamin C, were environmentally safe in terms of the content of nitrates and heavy metals (cadmium, lead, arsenic, mercury). The optimization of productivity and quality improvement of cucumber plants using biological humic fertilizer and chelate microfertilizer increased the average yield by 5.5% and the profitability of ecologically safe greenhouse vegetables by 3.3%.

In Vitro Decoated Seed Germination and Seedling Development for Propagation of Wild Mandrake (Mandragora autumnalis Bertol.).

The establishment of an efficient in vitro propagation system for the conservation of the Mediterranean Mandragora autumnalis is highly desirable due to its scarcity, besides its potential medicinal and pharmacological properties. In a separate unpublished study, this species has proved to be resistant to laboratory plant regeneration from vegetative tissue cultures; therefore, an alternative decoated seed (i.e., endosperm enclosed the zygotic embryo) germination approach was conducted in this study. Pre-cold treatment of M. autumnalis seeds, removal of seed coats, and exogenous application of gibberellic acid (GA3) promoted in vitro seed germination and seedling emergence. In two separate experiments, approximately 10–27% of the germinated decoated seeds developed healthy seedlings within two weeks, compared to the non-germinated intact seeds of the potting soil controls. After 72 days, the highest rates of healthy seedlings development (67.4 and 69.4%) achieved in the in vitro decoated seed cultures supplemented with 60 and 100 mg/L GA3, respectively, compared to only 25% seedlings emergence rate of the in vitro cultures devoid of GA3, and 44.2% of the soil controls. The in vitro developed plants were healthy, survived transplantation conditions, and, significantly, grew faster, formed on average more than the double number of true leaves and shoot fresh weight (p ≤ 0.05), 90% more fresh weight of root system (p ≤ 0.05), and ultimately more than the double gross fresh weight (p ≤ 0.05) than that of the in vivo developed plants of the soil controls. Such in vitro seed germination approaches would be favorable due to the higher capacity of uniform seedling establishment year-round under lab-controlled conditions, facilitating proliferation and conservation of rare and threatened species, and providing fresh and axenic plant materials required for downstream studies such as those associated with leaf-derived protoplasts and genetic transformations.

Trichoderma spp. and its effects on seeds physiological quality and seedlings development of African mahogany

Trichoderma is a beneficial fungus that can be used in both the control of phytopathogens and in promoting germination and plant growth. Thus, this study aimed to evaluate the effect of five Trichoderma isolates (T09, T12, T52, Tc and Tce) in seven different application modes on seeds and seedlings of the Khaya ivorensis A. Chev. (African mahogany). Fungi applications were tested by microbiolization of the seeds, in the pre-planting substrate, by monthly applications in the seedlings and in four combinations of these three treatments. Under laboratory conditions, the germination, germination speed index (GSI), and radicle and hypocotyl lengths were evaluated in seeds, treated and untreated, with Trichoderma. In the nursery, it was evaluated the height, root collar diameter, number of leaflets, root length, and the dry weight of root system and aerial part in seedlings with different forms of Trichoderma application. Trichoderma isolates did not influence germination percentage, GSI and radicle length. The fungus application methods in the K. ivorensis seedlings increased the height and leaflets number of the plants by at least one of the Trichoderma isolates tested in this study.

Agroecosystem Management Practices on some Cucumber Plant Parameters using Integrated Fertilization under Green House

This study was conducted in Tainal watershed, Bazian City, west of Sulaimaniyah, north of Iraq (35º57’31’’N, 45º 17’98’’E), the soil fertility was analyzed before the application of kinds of soil biofertilizer like dry yeast Saccharomyces cerevisiae with two concentrations (5g-L, 10 g-L) of dry yeast. Biofertilizers, organic matter like humic acid and chemical fertilizer for more comparison and water as a control. Results using dry yeast (10 g-L) have significant differences in (P?0.05) on the vegetable parameters, plant height, leaf area, yield, the number of harvest day and the weight of root system. Also the humic acid and biofertilizers have a significant effect (P?0.05). The yeast (10 g/L) have significant differences on (P?0.05) on yield (1.3 ton/ha) comparing with control of 48.73 kg/5 m2, and the total leaf area of 1.5 m2 comparing with the control 1.16 m2. The experiment was performed as factorial with randomized completely block design (R.C.B.D) on Cucumber plant type of (SAIF F1) with three replicates; each unit from the 18 unite (plot) contained 18 cucumber plant. The data were analyzed by using XLSTAT program statistically analyst.

Phytotoxicity of chromium and nickel in early stage of ontogenetic development of corn

The data on phytotoxicity of the combined action of chromium and nickel ions on maize hybrids Premiya 190 MV and Euro 401 SV in laboratory vegetation experiments have been analyzed. Plants were grown during 6 days in vegetation vessels at the temperature of 26–27°C on standard Hogland-Snyder’s nutrient medium, with the illumination of 15,000 lux for 16 hours per day and the aeration of nutrient medium. Then chromium and nickel compounds were added into the growth vessels. The effect of the combined action of aqueous solutions of chromium (III) and nickel (II) sulfates was studied in the following variants of the experiment: control (distilled water); 1MPC Ni2++1MPC Cr3+; 10MPC Ni2++ 1MPC Cr3+; 1MPC Ni2++10MPC Cr3+; 10MPC Ni2++10MPC Cr3+ (MPC – maximum permissible concentration). In the experiments, it was assumed that MPC of Cr is 6 mg/l and MPC of Ni is 4 mg/l. Then, after 24 and 72 hours of applying of chromium and nickel solutions, the length of the main root and the height of the aerial part and their weight were measured, and the root index value was calculated. Analysis of the data showed that the inhibitory effect of chromium and nickel ions on the growth of plant of hybrid Premiya 190 MV was 1.4 times less than that for plants of Euro 401 SV hybrid. At 72 hours of plant growth with a minimum concentration of chromium on the background of maximum nickel, the growth inhibition of main root of plants of hybrid Premiya 190 MV was 27%, while at the maximum concentration of chromium on the background of the minimum nickel content – 19.4%. For hybrid Euro 401 SV more effective inhibition of root growth was found: in the variant with the maximum nickel on the background of minimum chromium – by 54.6%, and at the maximum chromium content – by 40%. At the same time, it was found that chromium and nickel ions in minimal concentrations stimulated the main root growth by 16–17 % in Premiya 190 MV, whereas in Euro 401 SV – suppressed by 33%. In general, the similar effects were observed for the production of weight of root system. Most significantly, this effect was revealed in the Euro 401 SV hybrid. Reducing the weight of wet and dry mass of this hybrid plants at the maximum nickel content was 50 and 28%, whereas at the maximum concentration of chromium it was 40 and 20% respectively. The obtained results indicate both the greater negative effect of chromium ions on maize plants and the lower metal tolerance of Euro 401 SV hybrid seedlings compared to the Premiya 190 MV at joint influence of chromium and nickel. The results allow to state that in maize plants at the early stages of their ontogenetic development, there is a greater up to 15% negative effect of nickel ions than chromium on the root and aerial part growth, formation of wet and dry weight. Combined action of chromium and nickel ions shows a greater phytotoxic effect on the root system development than on the aerial parts of plants. This effect is, most likely, due to the functioning of the anatomical, physiological and biochemical barrier mechanisms in the root-leaf system with respect to the excessive translocation of metal ions that cause inhibiting effects.

EFFECT OF SOWING DATE AND TREATMENT WITH ASCORBIC ACID ON GROWTH AND YIELD OF FLAX (Linum usitatissimum L.

The present study was conducted during the growing season 2015/2016 and 2016/2017 in medicinal and aromatic plants field of the College of Agriculture/ Basrah University, to study the effect of sowing date 1/11, 1/12 and spraying with Ascorbic acid 400mg. L-1 or without (spraying with distil water) after 30 and 60 day from planting and their interaction on growth and seed, oil yield of flax plant (Linum usitatissimum L.). The results showed Cultivated plants on 1/11 had a significant increases in plant height, number of main vegetative branches.plant-1, leaves number. plant-1, length and weight of root system, Seed yield. plant-1, seed yield. unit area-1, oil percentage, oil yield. plant-1, oil yield. hectare-1 for both seasons, seed yield. hectare-1 in second season only. Spraying with Ascorbic acid 400 mg. L-1 give significant increases in, leaves number. plant-1, length of root system for both seasons, plant height, weight of root system, weight of 1000 seed, oil percentage in second season only. oil yield. plant-1 in first season only. The interaction between first sowing date and spraying with Ascorbic acid gave highest in leaves number. plant-1, highest percentage of the dry matter of the vegetative total, length and weight of root system, seed and oil yield. plant-1, seed yield. unit area-1, oil percentage and seed and oil yield. hectare-1

EFFECT OF FOLIAR APPLICATION SALICYLIC ACID ON CITRUS ROOTSTOCKS TOLERANCE TO SOIL SALINITY

This experiment was carried out at the private nursery located at Baquba city/ Diyala governorate during 2015 agricultural season on three years old Citrus rootstocks seedlings to study the effect foliar application of salicylic acid on seedlings tolerance to soil salinity. The experiment included 24 treatment represented three factors: soil salinity levels (1.14,4.62 and 5.30 dSm-1) , two levels of salicylic acid (0 and 250 mg.l -1) and four citrus rootstocks (Sour orange, Cleopatra mandarin, Volkamariana lemon and Troyercitrange ),and their interactions with three replications . The results showed that: increasing soil salinity reduced most studied growth parameters (number and length of branches, number of leaves and fresh weight of the vegetative and root system). Salicylic acid application caused an increment in number of leaves, fresh and dry weight of root system. Citrus rootstocks Troyercitrange was superior on other rootstocks by giving highest values branches length, whereas Cleopatra mandarin rootstock was superior in the number of leaves.

The interaction between different level of water stress and potassium on growth of Wheat plant (Triticum aestivum L.)at booting stage.

This study was carried out using plastic pots in the Department of Biology- College of Education for Pure Sciences / University of Karbala during the growing season (2013 - 2014), in order to study the Effect of the overlap between different levels of water stress and potassium added in vegetative growth indicators to plant wheat, which included (plant height , Leaf area, number of branches, number of leaves, Dry weight of root system, Dry weight of shoot) at booting stage. Factional experiment within a completely randomized design (C.R.D.) with three replications was applied . The experiment included three concentrations of potassium (0, 150 and 200) kg K.ha-1 , and three levels of stress irrigation water by adding water amount (100%, 75%, 50%) of the value of the field capacity. The experiment included 27 pot (experiment unit).The result has been analyzed and means were compared using L.S.D at 0.05 probability level. The water level 100% of the value of the field capacity gave the highest values ​​of the studied traits(Plant height, number of leaves, number of branches, leaf area, Root dry weight system, Shoot dry weight). The results also showed that the added concentration of potassium (200) kg K. ha-1 gave higher values for the above-mentioned traits.Meanwhile showed bilateral interactions between the levels of water stress and potassium added showed a various effect on the studied traits.

Modification of the tree root electrical capacitance method under laboratory conditions.

For many years, scientists have been searching for nondestructive methods for the measurement of plant root system parameters. The measurement of electrical capacitance (EC) across the root has been proposed as one such nondestructive method. This article presents a study on the determination of relationships between EC measurement and the shape and size of the electrodes immersed in medium that are used for measurement. Measurement of EC and the parameters characterizing root systems of 1-year-old seedlings of the common beech Fagus sylvatica L. was conducted under laboratory conditions. The measurements of EC were performed between seedling root systems and two different electrodes in the form of a cylinder or a rectangular plate. Statistically significant correlations were found between the capacitance and root system parameters in both the variants; however, the correlations were higher in the case of the flat rectangular plate. Correlation coefficient (r) between EC and total root length was 0.688 for cylindrical electrode and 0.802 for rectangular plate, for total root area 0.641 and 0.818, and for dry weight of root system 0.502 and 0.747. The best-fitted linear regression relationships between the EC and the measured parameters were characterized by low determination coefficients in variants with cylindrical electrodes, and higher with flat rectangular plate electrodes. The results indicated that a two-dielectric media concept is a better model than Dalton's model when attempting to interpret the behavior of root and soil capacitance. The different electrodes probably allow root capacitance measurements to be interpreted from different aspects. However, this hypothesis requires further verification.

Aboveground to root biomass ratios in pea and vetch after treatment with organic fertilizer

ABS TRACT: Some growth parameters of pea (cv. Pleven 4) and vetch (cv. Obrazets 666) after treatment with organic fertilizer were studied in a field trial carried out at the Institute of Forage Crops, Pleven, Bulgaria. Humustim as organic fertilizer was applied through presowing treatment of seeds, treatment during vegetation and combination between both, at different doses. Ratios of aboveground weight to root system weight, aboveground height to root system length, as well as specific root length were determined. It was found that the growth variables of plants were positively influenced by organic fertilizer. The aboveground weight to root system weight ratios of pea ranged from 4.80 to 6.29 and was higher than vetch. Aboveground height to root system length ratio in pea ranged from 6.95 to 7.93, and in vetch from 5.30 to 7.39. The use of organic fertilizer at the dose of 1.2 L/t and treatment during vegetation resulted in better performance of root system and specific root length was 78.6 for pea and 84.3 for vetch.

Leaf photosynthesis and tuber crop productivity in topinambour plants

High-precision IR gasometry and pulse-amplitude modulated fluorometry were used under field conditions to study photosynthetic CO2 exchange, transpiration (H2O release), and the light stage of photosynthesis in intact fully expanded leaves of 15 varieties of topinambour (Helianthus tuberosus L.). At the end of the growth period, fresh weights of the root system and tubers were determined. Water delivery from the roots to shoots was found to be the limiting factor for photosynthetic gas exchange. The results also showed the proportional relationship (R2 = 0.88) between the weight of root system and tuber crop productivity. It is concluded that the root system plays the primary role in variety-specific features of water supply to leaves in topinambour plants: the root system was the rate-limiting factor of photosynthesis and accounted eventually for different productivities of tuber crops. Based on the results obtained, the fresh root weight indicative of root system development is recommended as a useful trait in breeding for plants with a high yield of topinambour tubers.

Efeito de extratos aquosos de espécies de Asteraceae sobre Meloidogyne incognita

Estudou-se, in vitro e in vivo a atividade nematicida dos extratos aquosos de vedélia (Sphagneticola trilobata), erva-de-touro (Tridax procumbens), cravo-de-defunto (Tagetes patula), girassol mexicano (Tithonia diversifolia), botão de ouro (Unxia suffruticosa) e zínia (Zinnia peruviana), sobre Meloidogyne incognita. Os extratos foram preparados na proporção de 1,0g do material seco e triturado para 10mL de água destilada e armazenados por 24h, sendo seguidamente utilizados nos experimentos. Nos testes in vitro, foram depositados 4,0mL do extrato bruto e 2,0mL de uma suspensão aquosa contendo 200 ovos do nematóide em placas de Petri de 5cm de diâmetro e, quinze dias após, procedeu-se a contagem do número de juvenis eclodidos e dos ovos remanescentes para o cálculo das porcentagens de eclosão. Nos testes in vivo, os extratos foram aplicados, separadamente, via pulverização foliar, tratamento de raiz e vertido no solo, semanalmente durante 60 dias. Como testemunha utilizou-se apenas água nos dois experimentos. No ensaio in vitro observou-se que todos os extratos foram eficientes na redução da eclosão de juvenis de M. incognita quando comparados à testemunha, as porcentagens de redução foram 89,96%, 91,13%, 92,48%, 92,72%, 93,2% e 97,48% para erva-de-touro, cravo-de-defunto, girassol mexicano, vedélia, botão de ouro e zínia, respectivamente, e no ensaio in vivo, que os tratamentos não exerceram nenhum efeito sobre o peso do sistema radicular dos tomateiros, no entanto, observou-se que os resultados diferiram entre as espécies utilizadas e a forma de aplicação do extrato na avaliação do peso fresco da parte aérea das plantas. Quanto ao fator de reprodução, observou-se que nenhum dos extratos apresentou diferença estatística em relação à testemunha, no entanto, quando se compara as diferentes formas de aplicação dos mesmos, observa-se que houve diferença estatística quando os extratos de erva de touro e girassol mexicano foram aplicados via pulverização foliar e no tratamento de raiz, contudo, não houve diferença quando estes extratos foram aplicados em forma de rega no solo.

Influência da contaminação do solo por cobre no crescimento e qualidade de mudas de açoita-cavalo (<i>Luehea divaricata</i> Mart. & Zucc.) e aroeira-vermelha (<i>Schinus therebinthifolius</i> Raddi)

A contaminação do solo por cobre tem se tornado comum em áreas de mineração e de viticultura no Rio Grande do Sul. O trabalho objetivou avaliar o efeito de doses de cobre sobre o crescimento e qualidade de mudas de açoita-cavalo e aroeira-vermelha. O delineamento foi inteiramente casualizado num fatorial (2 x 5), sendo as duas espécies florestais e cinco doses de cobre: 0, 64, 128, 192 e 256 mg kg-1 de solo, com cinco repetições. Avaliaram-se altura da planta, diâmetro do colo, peso da matéria seca radicular e da parte aérea, comprimento e área superficial específica radicular, e os índices de qualidade de mudas: relação entre altura da parte aérea e diâmetro do coleto; altura da parte aérea e peso da matéria seca da parte aérea e o Índice de Qualidade de Dickson. Os resultados revelaram que as doses testadas de cobre não alteraram a qualidade de mudas de aroeira-vermelha, enquanto que o açoita-cavalo apresentou melhor qualidade com aplicação de 64 mg kg-1 de Cu. O cobre afeta primeiramente o sistema radicular das mudas de açoita-cavalo e aroeira-vermelha. A aroeira-vermelha é mais tolerante a elevadas doses de cobre do que o açoita-cavalo.

Enraizamento de estacas herbáceas dos porta-enxertos de videira ‘Campinas’ (IAC 766) e ‘Jales’ (IAC) 572 em diferentes substratos

O presente trabalho teve por objetivo avaliar o enraizamento de estacas herbáceas de dois porta-enxertos de videiras (‘Campinas’ - IAC 766 e ‘Jales’ - IAC 572) em três tipos de substratos (casca de arroz carbonizada, vermiculita de grânulos finos e vermiculita de grânulos médios). Para tanto, estacas retiradas de plantas matrizes livres de vírus foram preparadas a partir das porções medianas de ramos tenros e verdes. O enraizamento foi realizado em caixas plásticas perfuradas contendo os substratos em câmara de nebulização. O delineamento experimental empregado foi o inteiramento casualizado com 6 tratamentos e 5 repetições, sendo cada parcela composta por 10 estacas. Após quatro semanas da estaquia, o efeito dos fatores (porta-enxertos e substratos) foi avaliado, e se pode concluir que: a) a porcentagem média de enraizamento dos porta-enxertos nos diferentes substratos é alta (90%); b) a casca de arroz carbonizada propicia os melhores resultados de enraizamento para os porta-enxertos estudados; e c) o ‘Campinas’ é superior em relação ao ‘Jales’ quanto ao número de raízes emitidas por estaca e à matéria do seu sistema radicular.

Effect of Grafting on Growth, Yield, and Verticillium Wilt of Eggplant

Eggplant (Solanum melongena L.) seedlings (`Tsakoniki') were grafted by hand on the Verticillium dahliae Kleb. resistant wild species Solanum torvum Sw. (GST) and Solanum sisymbriifolium Lam. (GSS). Grafted and nongrafted eggplants were transplanted to a fumigated soil with methyl bromide and to infested soil with microsclerotia of V. dahliae. Grafted plants were more vigorous, as measured by plant height, main stem diameter, and root system weight, than the nongrafted `Tsakoniki'. This resulted in an increased early production (GST, 45.5%; GSS, 18.4%) and late production (GST, 69.3%; GSS, 59.2%) as compared to the noninfected controls. The mean yield reduction (over years) in early production caused by the disease, as compared to the controls grown in fumigated soil, was 29.4%, 36.6%, and 77.9% for eggplant grafted on S. torvum, S. sisymbriifolium, and nongrafted plants, respectively. This yield reduction in total production was 6.9%, 20.5%, and 56.8%, respectively. The disease incidence in ungrafted plants was 96% and 100% during early and late harvest periods. In contrast, the disease incidence in grafted plants was significantly lower, averaging 28.1% (GST) and 52.6% (GSS) in early production, and 37.6% and 79.3%, respectively, in late production. Solanum torvum was found more resistant than S. sisymbriifolium, because grafted infected plants developed mild symptoms, as indicated by significantly lower leaf symptom index (average value 1.2 and 2.22) and disease index (average value 1.55 and 3.38), respectively. In conclusion, grafting of eggplant on either wild species had positive effects on growth, production, and verticillium wilt control.