Hasil untuk "Plant culture"

Alfonso Morillo De los Santos, Iris Esther Marcano, Juan De la Cruz Araujo-Lara et al.

El uso de bacterias promotoras del crecimiento vegetal (PGPR) representa una alternativa sostenible en la producción agrícola, en especial rubros con exigencias internacionales sobre prácticas sostenibles. El pimiento producido en invernaderos de República Dominicana, representa uno de los cultivos de mayor crecimiento y rentabilidad en las últimas décadas. La investigación tuvo el objetivo de aislar, caracterizar bacterias PGPR y evaluar el potencial efecto bioestimulante en el cultivo de pimiento. Se colectaron muestras de raíces de plantas sanas de pimiento producidos en invernaderos de las provincias Azua, San José de Ocoa y La Vega, República Dominicana. Las bacterias endofíticas fueron aisladas, purificadas e identificadas mediante extracción de ADN, secuenciación del gen 16S rRNA, comparadas en el banco Gene Bank y se realizaron pruebas bioquímicas. Se aislaron 117 bacterias mediante secuenciación molecular de las cuales ocho resultaron ser PGPR. Entre estas se encuentran: Bacillus siamensis, Pseudomonas atacamensis, Rhizobium oryzihabitans, Bacillus haikouensis, Antribacter gilvus, Enterobacter ludwigii, Priestia aryabhattai y Kosakonia pseudosacchari. Estas bacterias crecieron a diferentes rangos de temperaturas, pH y salinidad. Seis fueron positivas a catalasa y una produjo sideróforos. En pruebas en invernadero, con un diseño en bloques al azar, se inocularon plantas de pimiento para evaluar altura, grosor del tallo y biomasa. Las bacterias mostraron diferencias significativas en relación al testigo sin fertilizar ni inocular. Aunque no hubo diferencias significativas con el testigo fertilizado, se observó un efecto positivo, incrementando el desarrollo de las plantas. Los resultados sugieren que especies como Bacillus siamensis tienen potencial como biofertilizantes por su adaptación a las condiciones del medio y por su efecto bioestimulante en las plantas.

J. Son, H. Kim, T. Ahn

Above: Nutrient film technique (NFT) channels are covered with plastic for tomato production in K-State greenhouses. Many people think of hydroponics as growing plants in water, but hydroponic production actually is defined as growing plants without soil. This production system may use a wide variety of organic and inorganic materials. The nutrient solution, rather than the media in which the plants are growing, always supplies most of the plant nutrient requirements. This method of growing has also been referred to as nutrient-solution culture, soilless culture, water culture, gravel culture and nutriculture.

Alice Varaldo, Danielle Borra, Emanuela Vassallo et al.

This study investigates the preferences and the consumption models in the three most relevant F&V EU markets (France, Germany and Italy) in the function of individual attitudes towards local and organic production models. A structured questionnaire was submitted to a sample of 3000 consumers interviewed from December 2021 to January 2022 in the three selected geographical areas. Data were analyzed with the Principal Component Analysis and using the k-means cluster approach. Four main components (European is Better, Organic is Local, Quality is Origin-Related, and Clothes Do Not Make the Product) were defined and used to identify four different consumer clusters (organic and local-sensitive, origin and quality assessment, credence and intrinsic attributes, Global quality evaluation) across the entire sample of consumers. The main findings explain the importance of the origin of the F&V, which, however, is evaluated differently depending on the organic certification, the guarantees made by a brand/logo, and the evaluation of product quality cues. Furthermore, awareness of the logos significantly affects cluster composition and consumption orientation. Finally, the MLR model was applied, highlighting how certain socio-demographic variables, as well as the specific country, explain group membership very well.

Rey David Iturralde-García, Francisco Javier Cinco-Moroyoqui, Oliviert Martínez-Cruz et al.

Fresh-cut fruits have been in great demand by consumers owing to the convenience of buying them in shopping centers as ready-to-eat products, and various advantages, such as the fact that they are healthy and fresh products. However, their shelf lives are brief due to their physiological changes and maturation. Therefore, this review includes information from the physicochemical, microbiological, nutritional, and sensory points of view on the deterioration mechanisms of fresh-cut fruits. In addition, updated information is presented on the different emerging technologies, such as active packaging (edible films, coatings, and modified atmospheres), natural preservatives (antioxidants and antimicrobials), and physical treatments (high hydrostatic pressure, UV-C radiation, and ozone). The benefits and disadvantages of each of these technologies and the ease of their applications are discussed. Having alternatives to preserve fresh-cut fruit is essential both for the consumer and the merchant, since the consumer could then obtain a high-quality product maintaining all its properties without causing any damage, and the merchant would receive economic benefits by having more time to sell the product.

Arnold W. Schumann, Ariel Singerman, Alan L. Wright et al.

Indraraj Ghasil, Nirmal Kumar Meena, P. Bhatnagar et al.

An experiment was conducted to find out the effects of various postharvest treatments on the biochemical and bioactive compounds of custard apple cv. Balanagar fruits. In the present experiment, three chemicals viz. oxalic acid (OA) (2.5 mM, 5.0 mM, 7.5 mM, and 10 mM; salicylic acid (SA) (0.5 mM, 1.0 mM, 1.5 mM, and 2.0 mM) and Sodium Nitro Prusside (SNP) at 0.5 mM, 1.0 mM, 1.5 mM, and 2.0 mM along with control were applied. Fruits were stored at ambient condition (Temp. 25 ± 2°C and relative humidity (RH) 44 ± 2%). Results indicated that fruits treated with SNP (2.0 mM) had significantly (p≤ 0.05) higher total soluble solids (30.80°B), titratable acidity (TA) (0.33%) and retained higher total sugar content (TS) (25.09%) at the end of the 9th day of storage. At the end of storage, the least reduction in total phenol content (TPC) (492.52 mg gallic acid equivalent (GAE)/100 g (11.62%) was found in SNP (2.0 mM) treated fruits. Likewise, SNP (2.0 mM) significantly (p≤ 0.05) retained higher ascorbic acid (AA) (43.20 mg/100 g), antioxidant activity (AOX) (0.92 µmol Trolox Equivalent (TE)/g), total flavonoids (TF) (71.49 µg CE/100 g) and tannin content (TC) (1.28 mg/g) compared to control during 9 days of storage. Thus, in the present investigation, SNP treatment was most suited to preserve the nutritional quality and bioactive compounds.

Charlotte Lomax, Wen-ju Liu, Liyou Wu et al.

H. Mathews, S. Clendennen, C. Caldwell et al.

Fu Caili, Shi Huan, Quanhong Li

S. O. Trione, G. Almela Pons, H. Morales

Se estudiaron los cambios en la composición diaria de la fracción de nitrógeno soluble en la savia sangrante de Vitis vinifera L. cv. Criolla grande. Los compuestos con un alto contenido de nitrógeno (por ejemplo, asparagina, glutamina, arginina) se habían añadido previamente a la savia mediante inoculación directa en el xilema. Se encontró que la glutamina era el principal compuesto de la fracción de nitrógeno soluble en la savia sangrante recogida durante los primeros tres días. A partir del día siguiente, sin embargo, el ácido glutámico resultó ser el compuesto soluble en nitrógeno dominante de las muestras diarias. La concentración de glutamina y los niveles de nitrógeno soluble total dieron resultados correlacionados. Los patrones de nitrógeno soluble total y los de los aminoácidos en condiciones variables estaban estrechamente correlacionados, con la excepción de la arginina, donde se observaron ligeras diferencias. No se encontró paralelismo cuando se comparó el porcentaje de nitrógeno proporcionado como glutamina, asparagina y arginina con el porcentaje del contenido de nitrógeno correspondiente a estos mismos compuestos en el primer día de muestreo de savia sangrante. Se discute desde un punto de vista metabólico la implicación de los compuestos nitrogenados añadidos, en relación con el retraso observado en el crecimiento de las yemas durante una quincena después del brote.

Robert N. Spengler, Michael Petraglia, Michael Petraglia et al.

Megafaunal extinctions are recurring events that cause evolutionary ripples, as cascades of secondary extinctions and shifting selective pressures reshape ecosystems. Megafaunal browsers and grazers are major ecosystem engineers, they: keep woody vegetation suppressed; are nitrogen cyclers; and serve as seed dispersers. Most angiosperms possess sets of physiological traits that allow for the fixation of mutualisms with megafauna; some of these traits appear to serve as exaptation (preadaptation) features for farming. As an easily recognized example, fleshy fruits are, an exaptation to agriculture, as they evolved to recruit a non-human disperser. We hypothesize that the traits of rapid annual growth, self-compatibility, heavy investment in reproduction, high plasticity (wide reaction norms), and rapid evolvability were part of an adaptive syndrome for megafaunal seed dispersal. We review the evolutionary importance that megafauna had for crop and weed progenitors and discuss possible ramifications of their extinction on: (1) seed dispersal; (2) population dynamics; and (3) habitat loss. Humans replaced some of the ecological services that had been lost as a result of late Quaternary extinctions and drove rapid evolutionary change resulting in domestication.

Mohammad H. Dawood, Mohammad H. Dawood, John C. Snyder

Allelochemicals that are present in trichome secretions of wild tomato species play a major role in mediating interactions with arthropods, often conferring a high level of resistance via antibiosis and antixenosis. Many accessions of the wild tomato relative, Solanum habrochaites (S.h), possess high levels of resistance to arthropods. The monocyclic sesquiterpene hydrocarbon, 7-epi-zingiberene, is a major defensive component found in trichome secretions of certain accessions of S.h. We have used LA2329, an S.h. accession, as a donor in a breeding program designed to introgress zingiberene into cultivated tomato. However, the composition of trichome secretions in our population of LA2329 is segregating, with some individuals producing mainly 7-epi-zingiberene in their secretions while others producing two additional, unidentified compounds in their trichome secretions. To investigate if these other compounds may also contribute to arthropod resistance, trichome secretions were collected from plants of S.h LA2329 grown under greenhouse conditions and then major compounds were isolated by silica gel column chromatography and tested for their ability to repel two spotted-spider mite (TSSM), Tetranychus urticae. Isolation and identification of allelochemicals were aided by use of gas chromatography/mass spectroscopy. The results revealed the presence of three predominate chromatographic peaks: 7-epi-zingiberene, 9-hydroxy zingiberene, and 9-hydroxy,10,11-epoxy-zingiberene. Results of testing isolated compounds for repellency to TSSM using bridge bioassays revealed that the repellent activities of 9-hydroxy zingiberene and 9-hydroxy,10,11-epoxy-zingiberene were each significantly higher than that for 7-epi-zingiberene. These results support the idea that the degree of repellency may differ among plant allelochemicals and also emphasize the potential value of introgressing the presence of 9-hydroxy zingiberene and 9-hydroxy,10,11-epoxy-zingiberene into cultivated tomato to enhance its arthropod resistance.

Walenty Poczta

W roku ubiegłym minęło 30 lat od początku polskiej transformacji i 15 lat od wstąpienia Polski do Unii Europejskiej. Obydwa procesy, tj. transformacja i integracja europejska, są z sobą ściśle powiązane, warunkiem polskiego członkostwa w Unii Europejskiej było bowiem wcześniejsze zaawansowanie transformacji ustrojowej. Procesem transformacji w sposób istotny objęte zostało m.in. rolnictwo. Jedną z cech gospodarek krajów postsocjalistycznych było ich „przeagraryzowanie”, które przejawiało się w nadmiernym udziale tego sektora w angażowaniu zasobów pracy i wytwarzaniu PKB. Transformacja w Polsce, podobnie jak w innych krajach, spowodowała radykalne zmiany struktury gospodarki narodowej i pozostawała w ścisłych zależnościach przyczynowo-skutkowych z procesami alokacji zasobów produkcyjnych i zmianami ekonomicznych warunków gospodarowania (wynikającymi głównie z relacji cenowych kształtowanych przez rynek oraz swobody wymiany gospodarczej z zagranicą). W pierwszych latach transformacji nastąpiła też prywatyzacja sektora państwowego w rolnictwie oraz rozpoczęły się przemiany strukturalne w rolnictwie indywidulnym. Przystąpienie Polski do UE przyspieszyło procesy zainicjowane w pierwszych latach transformacji ustrojowej, jednocześnie radykalnie wzrosły wsparcie i osłona tych przemian ze środków publicznych (z budżetu UE). Po akcesji nadal uwalniano z rolnictwa nieefektywne zasoby pracy, jednak proces ten zachodził wolno i nie we wszystkich latach. Objęcie polskiego rolnictwa przez WPR UE stworzyło warunki do wzrostu produkcji, a przede wszystkim dochodów rolniczych. Na możliwości podażowe istotnie wpłynęły transfery środków z budżetu UE. Rosnące nakłady inwestycyjne, będące wynikiem objęcia rolnictwa środkami II filaru WPR, pozwoliły zahamować procesy dekapitalizacji majątku trwałego w rolnictwie i umożliwiły modernizację rozwojowych gospodarstw rolnych. Na stronę popytową wpłynęło uczestnictwo w Jednolitym Rynku Europejskim, a szczególnie dynamiczny wzrost eksportu rolno-żywnościowego. Procesy te spowodowały wzrost wartości i wolumenu produkcji rolnej, a szczególnie dochodów rolnictwa, w znacznej mierze dzięki dotacjom otrzymywanym przez polskie rolnictwo z tytułu udziału w WPR.

Barnaby E. Walker, Tarciso C. C. Leão, Steven P. Bachman et al.

Lakshmy Gopinath, Matthew Barton, Justin Quetone Moss

The availability of freshwater is a growing concern throughout the world as it is an increasingly valuable and limited resource. Alternative water resources such as recycled water low in quality and high in salinity are now frequently used to irrigate turfgrass. However, irrigating with highly saline water can affect the growth, performance, appearance, and quality of turfgrass. Bermudagrass (Cynodon sp.) is the most commonly used turfgrass throughout the southern United States. In this study, the spectral reflectance and visual response of ‘Riviera’ common bermudagrass (Cynodon dactylon) were evaluated by consecutively irrigating with 12 salinity concentrations (4–48 dS·m−1) in increments of 4 dS·m−1 via manual overhead irrigation for 30 days. The experiment was replicated in time in a controlled environment with four replications for each salinity treatment and control. ‘Riviera’ maintained a leaf firing (LF) value above 5 (rated on a scale from 1 to 9) when irrigated with 28 dS·m−1 for 30 days. Also, the LF value did not fall below 2 when irrigated with a salinity concentration of 48 dS·m−1 for 30 days, suggesting high salinity tolerance of ‘Riviera’. However, in this study, the normalized difference vegetation index (NDVI) had a lower ability to detect the increase in salinity stress due to the limited area measured by the NDVI measuring device used. An increase in sodium ion concentration was observed in the shoot with increasing salinity concentrations. The NDVI was highly correlated (r = 0.93) to LF, indicating the usefulness of NDVI as a tool to measure the magnitude of salinity stress. The multiple linear regression analysis revealed that the data showed a linear response to salinity stress with LF (r2 = 0.86) and NDVI (r2 = 0.76) decreasing linearly as the salinity concentration and days of treatment increased. This study provides an accurate depiction of the spectral and visual responses of ‘Riviera’ when exposed to multiple salinity concentrations with narrow increments.

P. Maliga, Agnes Sz.-Breznovits, L. Marton

Ricardo José Stein, Guilherme Leitão Duarte, Lívia Scheunemann et al.

Iron (Fe) is an essential element to plants, but can be harmful if accumulated to toxic concentrations. Fe toxicity can be a major nutritional disorder in rice (Oryza sativa) when cultivated under waterlogged conditions, as a result of excessive Fe solubilization of in the soil. However, little is known about the basis of Fe toxicity and tolerance at both physiological and molecular level. To identify mechanisms and potential candidate genes for Fe tolerance in rice, we comparatively analyzed the effects of excess Fe on two cultivars with distinct tolerance to Fe toxicity, EPAGRI 108 (tolerant) and BR-IRGA 409 (susceptible). After excess Fe treatment, BR-IRGA 409 plants showed reduced biomass and photosynthetic parameters, compared to EPAGRI 108. EPAGRI 108 plants accumulated lower amounts of Fe in both shoots and roots compared to BR-IRGA 409. We conducted transcriptomic analyses of roots from susceptible and tolerant plants under control and excess Fe conditions. We found 423 up-regulated and 92 down-regulated genes in the susceptible cultivar, and 42 up-regulated and 305 down-regulated genes in the tolerant one. We observed striking differences in root gene expression profiles following exposure to excess Fe: the two cultivars showed no genes regulated in the same way (up or down in both), and 264 genes were oppositely regulated in both cultivars. Plants from the susceptible cultivar showed down-regulation of known Fe uptake-related genes, indicating that plants are actively decreasing Fe acquisition. On the other hand, plants from the tolerant cultivar showed up-regulation of genes involved in root cell wall biosynthesis and lignification. We confirmed that the tolerant cultivar has increased lignification in the outer layers of the cortex and in the vascular bundle compared to the susceptible cultivar, suggesting that the capacity to avoid excessive Fe uptake could rely in root cell wall remodeling. Moreover, we showed that increased lignin concentrations in roots might be linked to Fe tolerance in other rice cultivars, suggesting that a similar mechanism might operate in multiple genotypes. Our results indicate that changes in root cell wall and Fe permeability might be related to Fe toxicity tolerance in rice natural variation.

Frederick M. Fishel

In 1992, the US Environmental Protection Agency issued a comprehensive regulation called the Worker Protection Standard for Agricultural Pesticides (WPS). The EPA has made several changes to the WPS since it was fully implemented in 1995. This 5-page document will address the WPS protections commercial pesticide handler employers must provide to their handlers. Written by Frederick M. Fishel and published by the UF/IFAS Agronomy Department, January 2018. http://edis.ifas.ufl.edu/pi275 Accessibility Summary: In accordance with Title II regulations this content meets all points of exemption as Archived web content and/or Preexisting conventional electronic documents.

P. S. Carlson, H. Smith, R. D. Dearing

D. Lawlor