Meloidogyne incognita root-knot nematode is one of the main causes of tomato root damage and consequently crop production losses. Thus, in in vitro conditions, the number of nematodes hatched eggs ...(%) at 4 and 6 days and nematode mortality (J2 stage) at 8, 18, and 24 h, were evaluated in Petri dishes containing the candidate rhizobacteria Enterobacter asburiae (BA4-19 and PM3-14), Acinetobacter calcoaceticus (BM2-12), Klebsiella variicola (BO3-4) and Serratia marcescens (PM3-8). The well-known Pseudomonas protegens (CHA0) and P. veronii (R4) were used as controls. In greenhouse conditions, plant height, root weight, and symptoms, as well as gall and nematode numbers, were determined in tomato plants infected by M. incognita and treated with the seven rhizobacteria. In addition, all variables were correlated using Pearson's analysis. In general, a significant correlation was observed among the variables of both experiments, showing the antagonistic capacity of the strains against nematode. It seems, that PM3-8 and PM3-14 strains reduce hatching, and cause mortality of nematodes J2 if compared with CHA0 and R4 strains. Likewise, tomato treated with BM2-12 strain shows a higher height and root weight, as well as a smaller number of galls and nematodes in their roots. This study provides evidence that PM3-8 and PM3-14 strains reduce the M. incognita egg hatching, and that the BM2-12 strain can be a plant growth-promoter potential of tomato plants.
Objetivou-se avaliar a produção e a qualidade de tomates cereja fertirrigados com água residuária da piscicultura com e sem adição de probióticos. O experimento foi conduzido em vasos, sob condições ...de ambiente protegido por sombrite 50%. O delineamento experimental foi o inteiramente casualizado com quatro tratamentos e quatro repetições, sendo a unidade experimental constituída por trinta e duas plantas. Foram testados quatro lâminas de água: água; água residuária da piscicultura sem o uso de probiótico; água com probiótico e água residuária da piscicultura com probiótico. A adição de probiótico foi realizada a cada 48 h, sendo 0,5 g de probiótico contendo no mínimo 5x109 bilhões de unidades formadoras de colônia por grama viável para cada 8 L de água, cada planta recebia 1 L de água manualmente no período da manhã. O solo utilizado no experimento para preenchimento dos vasos é classificado como um NEOSSOLO QUARTZARÊNICO, distrófico textura arenosa fase caatinga litorânea, misturado com composto orgânico. Os resultados mostraram que não houve diferença entre os tratamentos para produção, número de frutos, peso de frutos e pH, o tratamento de água com probiótico foi o que apresentou menor acidez e melhor relação SST/ATT. O reuso da água da piscicultura com e sem adição do probiótico para fertirrigação da cultura do tomate cereja não interferiu na produção dos frutos.
Bioslurries, obtained by anaerobic digestion of fresh organic matter, are emerging as a cheaper and low-impact alternative for synthetic products in agriculture. The aim of this study was to evaluate ...bioslurry obtained from biogas digestion (Biog), bioslurry for plant nutrition by FAO (Bfao), and lactic fermentation (Blac) as biostimulant in tomato and lettuce plants. Based on a toxicity test, a 10% dilution was finally applied to the plants. In lettuce, Bfao and Blac significantly increased aerial biomass (2.17 ±0.54 and 2.33 ±1.13 g respectively), regarding water control (1.16 ±0.60 g), while root biomass was only increased by Bfao (1.60 ±0.44 g) compared to control (0.66 ±0.34 g). All digestates increased chlorophyll content index (CCI), while yield (Fv/Fm) and performance index (Plabs) did not show differences with water control. In tomato, only aerial biomass was significantly increased by Bfao. All digestates significantly increased CCI, while Fv/Fm was only significantly higher in Bfao and Blac, related to water control. PIabs showed no differences. In both plant species, commercial fertilizer showed significantly higher values for all parameters. In conclusion, all digestates stimulated plant growth, Bfao showed the highest effect on tomatoes and lettuce biomass followed by Blac and Biog, being a cheaper, safer and lower-impact alternative for traditional products for crop growing.
Highlights
Digestates are valuable by-products, with different characteristics and effects on plant biomass, suggesting complex interactions.
All digestates stimulated tomatoes and lettuce growth.
The digestate designed by FAO showed the highest effect on plant biomass, constituting an adequate alternative for a cheaper, safer and low-impact strategy for crop growth.
At its most basic, grafting is the replacement of one root system with another containing more desirable traits. Grafting of tomato ( Solanum lycopersicum ) onto disease-resistant rootstocks is an ...increasingly popular alternative for managing economically damaging soilborne diseases. Although certain rootstocks have demonstrated ancillary benefits in the form of improved tolerance to edaphic abiotic stress, the mechanisms behind the enhanced stress tolerance are not well understood. Specific traits within root system morphology (RSM), in both field crops and vegetables, can improve growth in conditions under abiotic stress. A greenhouse study was conducted to compare the RSM of 17 commercially available tomato rootstocks and one commercial field cultivar (Florida-47). Plants were grown in containers filled with a mixture of clay-based soil conditioner and pool filter sand (2:1 v/v) and harvested at 2, 3, or 4 weeks after emergence. At harvest, roots were cleaned, scanned, and analyzed with an image analysis system. Data collected included total root length (TRL), average root diameter, specific root length (SRL), and relative diameter class. The main effect of cultivar was significant ( P ≤ 0.05) for all response variables and the main effect of harvest date was only significant ( P ≤ 0.01) for TRL. ‘RST-106’ rootstock had the longest TRL, whereas ‘Beaufort’ had the shortest. ‘BHN-1088’ had the thickest average root diameter, which was 32% thicker than the thinnest, observed in ‘Beaufort’. SRL in ‘Beaufort’ was 60% larger than ‘BHN-1088’. This study demonstrated that gross differences exist in RSM of tomato rootstocks and that, when grown in a solid porous medium, these differences can be determined using an image analysis system.
Obtaining high quality vegetable seedlings in seedlings allows producers to reduce the lossof seed, reduce the time to reach the optimum transplant height, minimize the loss of plants in soil or ...substrate and better adapt to the environment where the final transplant is performed. Producing seedlings in the best substrate and nutrition conditions increases the success of any crop. In most cases, imported substrates are used to produce seedlings in Mexico. For this reason, it is convenient to investigate alternatives of locally available substrates. The objective was to compare four substrates intwo concentrations of the Steiner nutrient solution and a rooting agent in tomato seedlings (Lycopersicum esculentumMill.) in the greenhouse. A factorial experiment with 16 repetitions was established in a completely randomized design. The variables were: days to emergence and appearance of the first true leaves, seedling height, stem thickness, number of leaves, fresh and dry weight of biomass and root. The results showed that the substrates that provided the best seedling quality characteristics werepeat moss and tezontle, although there were no significant differences between 50% and 100%, tothe nutrient solution, the concentration at 100% showed plants with higher quality and the rooting did not show a positive effect on the quality of the seedlings.Based on the above, the tezontle is recommended as a substrate to produce tomato seedlings because it is low cost, with a 100% Steiner nutrient solution, without applying a rooting agent.
La obtención de plántulas de hortalizas de alta calidad en almácigo permite a los productores disminuir la pérdida de semilla, reducir el tiempo hasta alcanzar la altura óptima de trasplantarse, minimizar la pérdida de plantas en suelo o sustrato y adaptarse mejor al medio donde se realice el trasplante final. Producir plántulas en las mejores condiciones de sustrato y nutrición, aumenta el éxito de cualquier cultivo. En la mayoría de los casos, para producir plántula en México, se hace uso de sustratos importados por esta razón, es conveniente investigar alternativas de sustratos disponibles localmente. El objetivo fue comparar cuatro sustratos en dos concentraciones de la solución nutritiva Steiner y un enraizador en plántulas de jitomate (Lycopersicum esculentum Mill.) en invernadero. Se estableció un experimento factorial con 16 repeticiones en un diseño completamente al azar. Las variables fueron: días a emergencia y aparición de las primeras hojas verdaderas, altura de plántula, grosor del tallo, número de hojas, peso fresco y seco de biomasa y raíz. Los resultados mostraron que los sustratos que propiciaron las mejores características de calidad de plántula fueron: peat moss y tezontle, aunque no se presentaron diferencias significativas entre 50% y 100%, a la solución nutritiva, la concentración al 100% mostró plantas con mayor calidad y el enraizador no presentó efecto positivo sobre la calidad de las plántulas. Con base en lo anterior, se recomienda el tezontle como sustrato para producir plántulas de jitomate por ser bajo costo, con una solución nutritiva Steiner del 100%, sin aplicar enraizador.
Cherry tomato (Lycopersicon esculentum Mill) fruits are susceptible to contamination by Aspergillus flavus, which may cause the development of fruit rot and significant postharvest losses. Currently ...there are significant drawbacks for the use of synthetic fungicides to control pathogenic fungi in tomato fruits, and it has increased the interest in exploring new alternatives to control the occurrence of fungal infections in these fruits. This study evaluated the efficacy of chitosan (CHI) from Mucor circinelloides in combination with carvacrol (CAR) in inhibiting A. flavus in laboratory media and as a coating on cherry tomato fruits (25°C, 12 days and 12°C, 24 days). During a period of storage, the effect of coatings composed of CHI and CAR on autochthonous microflora, as well as on some quality characteristics of the fruits such as weight loss, color, firmness, soluble solids, and titratable acidity was evaluated. CHI and CAR displayed MIC valuesof 7.5 mg/mL and 10 μL/mL, respectively, against A. flavus. The combined application of CHI (7.5 or 3.75 mg/mL) and CAR (5 or 2.5 μL/mL) strongly inhibited the mycelial growth and spore germination of A. flavus. The coating composed of CHI (3.75 mg/mL) and CAR (2.5 or 1.25 μL/mL) inhibited the growth of A. flavus in artificially contaminated fruits, as well as the native fungal microflora of the fruits stored at room or low temperature. The application of the tested coatings preserved the quality of cherry tomato fruits as measured by some physicochemical attributes. From this, composite coatings containing CHI and CAR offer a promising alternative to control postharvest infection caused by A. flavus or native fungal microflora in fresh cherry tomato fruits without negatively affecting their quality over storage.
Background: Diversified food crop production systems with high‐value vegetable crops are increasingly replacing conventional rice–wheat rotations across Nepal. These newly emerging systems are likely ...to enhance the demand for the micro‐nutrients boron (B) and zinc (Zn), which are already widely deficient throughout in Nepal. However, B and Zn fertilizers often are either unavailable in rural areas, not available in a timely manner, or when available not affordable by smallholder farmers.
Aims: To overcome multiple constraints concerning the need and efficient use of B and Zn amendments in a technical feasible way with a high financial efficiency for farmers and without compromising the environment, the current study assessed whether soil stock provisioning, e.g., B and Zn fertilizer applications to dry season crops, may provide sufficient residual effects for the succeeding non‐fertilized wet season crop.
Methods: A pot experiment was conducted in a sheltered greenhouse using two contrasting but representative soil types (Acrisol and Fluvisol) collected from rice‐ and from maize‐based production systems in Nepal. Boron and Zn amounts were supplied individually or in combination to wheat, cauliflower, and tomato grown in the dry season of 2018, whilst measuring biomass accumulation, B and Zn concentrations in plant tissues of all crops which allowed calculating B and Zn uptake in the unfertilized follow‐up crop of maize.
Results: Soil‐applied B and Zn fertilizers, sole and combined, slightly enhanced biomass of the succeeding non‐fertilized maize only, but significantly increased total B and Zn plant uptake, with significant differences between soil types. Furthermore, while maize shoot B concentrations were consistently increased above the critical levels in both soils, but especially in the Fluvisol after wheat and cauliflower pre‐crops, Zn uptake of maize was more enhanced in the Acrisol.
Conclusions: The residual effects of B and/or Zn applied to preceding dry season crops benefitted the subsequent wet season maize, especially after the pre‐crops wheat and cauliflower in the Fluvisol for B, and after wheat and tomato in the Acrisol for Zn. They may suffice to attain reasonable yields of wet season crops in the emerging vegetable‐based cropping systems of Nepal, even if fertilizers are not consistently available. The magnitude of the residual effects of pre‐applied Zn largely depended on the soil type, while those of B were mainly determined by the pre‐crop.
•Treatments with copper-free formulations provided acceptable disease control.•Protective treatments had no effect on the content of lycopene in tomato fruits.•Vitamin C, α-tocopherol, phytoene, ...lutein and β-carotene were cultivar related.•Higher levels were usually found in copper-sprayed integrated and organic fruits.
The present study investigates the effect of exclusion of copper preparations from spray programs for disease control in integrated and organic tomato production systems on disease incidence, yield and fruit vitamin C, α-tocopherol and carotenoids content for Monroe, Optima and Paki cultivars. Open field trials were conducted in a randomized block system with four repetitions over two years. Treatment for plant disease control comprised four spraying programs, two within each production system. Yields were significantly affected by cultivar, pest management system and their interaction. Copper-free integrated and organic spraying programs were almost as effective in disease control as standard treatments which included copper preparations. The spraying program significantly affected the contents of vitamin C, α-tocopherol, phytoene, and β-carotene in fruits; however, the effect was cultivar related. The lycopene contents appeared to be unaffected by the spraying program or growing system.
•Effect of nectar and host-feeding (HF) on T. absoluta and N. artynes is studied.•Floral nectar enhanced lifetime fecundity in T. absoluta and N. artynes longevity.•Only HF increased fecundity in N. ...artynes.•Flowers had different effects on lifetable parameters of both pest and parasitoid.
Several parasitoids require both host and non-host resources, such as nectar, for maintenance, survival and egg maturation. However, the impact of sugar feeding has primarily been studied in parasitoid species that do not engage in host-feeding, and the importance of non-host resources for host-feeding parasitoids has so far received little attention. The Palaearctic parasitoid Necremnus artynes has been shown to attack the exotic invasive Tuta absoluta in the field, but its parasitism is generally low. Understanding the use of host and non-host resources by this parasitoid could reveal whether there is potential for enhancing the biocontrol of T. absoluta through provision of targeted food supplements. Cage experiments were conducted to investigate the influence of selected non-host resources on the longevity and fecundity of both the pest and its parasitoid. The parasitoid was also provided with the opportunity to feed on larvae of the pest. Sweet Alyssum, Lobularia maritima, had the most pronounced effect on the fecundity and longevity of T. absoluta, while buckwheat Fagopyrum esculentum had the strongest effect on parasitoid longevity. Fecundity of T. absoluta was shown to be a function of the age of the adults and food sources provided. Sugar resources did not influence the egg load of N. artynes, whilst host-feeding was relatively ineffective at enhancing parasitoid longevity. Host-feeding had a strong positive effect on egg load. The impact of non-host resources on host-parasitoid interactions and the potential for using selective food resources in conservation biological control of the exotic pest T. absoluta are explored.
Food contamination can be a serious concern for public health because it can be related to the severe spreading of pathogens. This is a main issue, especially in the case of fresh fruits and ...vegetables; indeed, they have often been associated with gastrointestinal outbreak events, due to contamination with pathogenic bacteria. However, little is known about the physiological adaptation and bacterial response to stresses encountered in the host plant. Thus, this work aimed to investigate the adaptation of a commensal
strain while growing in tomato pericarp. Pre-adapted and non-adapted cells were compared and used to contaminate tomatoes, demonstrating that pre-adaptation boosted cell proliferation. DNA extracted from pre-adapted and non-adapted cells was sequenced, and their methylation profiles were compared. Hence, genes involved in cell adhesion and resistance against toxic compounds were identified as genes involved in adaptation, and their expression was compared in these two experimental conditions. Finally, pre-adapted and non-adapted
were tested for their ability to resist the presence of toxic compounds, demonstrating that adaptation exerted a protective effect. In conclusion, this work provides new information about the physiological adaptation of bacteria colonizing the tomato fruit pericarp.
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