Tomato

The present investigation was carried out at Vegetable Research Centre, G. B. Pant University of Agriculture and Technology, Pantnagar, Uttarakhand during the 2013 and 2014 to evaluate the effectiveness of thiamethoxam, used as seed treatment against the sucking insects of tomato. The seed treatment with thiamethoxam protected tomato seedlings from aphids and thrips at the early season from the onset of seed planting. There was a fast initial effect against the pests then gradually decreased to reach a moderate effect. Data revealed that Thiamethoxam 70% WS @ 4.2 g a.i./kg of seed showed the significant pest reduction followed by Thiamethoxam 70% WS @ 3.85 g a.i./kg of seed. Highest yield was recorded by Thiamethoxam 70% WS @ 4.2 g a.i./kg of seed (28.25 t/ha) closely followed by Thiamethoxam 70% WS @ 3.85 g a.i./kg of seed (25.00 t/ha) as compared to untreated check (20.91t/ha). Percent increase in yield over control was highest (35.10%) in Thiamethoxam 70% WS @ 4.2 g a.i./kg of seed followed by Thiamethoxam 70% WS @ 3.85 g a.i./kg of seed (19.56%). The percent reductions of predators by Thiamethoxam, used as seed treatment, in both the seasons ranged from 1.65-2.58% which was very minimum. Hence, it was concluded that the seed treatment of tomato with Thiamethoxam 70% WS @ 4.20 g a.i/kg of seed reduced the early season insect-pests (aphid and thrips) and had very less effect of natural enemies population as compared to control and also increased the fruit yield significantly than other treatments.

The enhanced laboratory and field emergence characteristics of osmo- and halo-primed tomato seeds (cv. Pusa Ruby) were related to changes in hydration–dehydration kinetics, modified sorption properties and nuclear magnetic resonance (NMR) relaxation behaviour of humidified and imbibed seeds. Water sorption isotherms were constructed for primed and unprimed seeds by equilibrating to different water activities (aw) at 25°C. Analysis of the isotherms by the D'Arcy–Watt equation revealed that priming reduced the number of strong binding sites and the associated water content, and increased significantly the number of weak binding sites and the associated water content. This redistribution of water, which increased the availability of seed water, may be the reason for the higher speed of germination of primed seeds. The changes in transverse relaxation time (T2) of seed water and its components, measured in vivo using nuclear magnetic resonance spectroscopy, showed interesting differ...

Each year begomoviruses cause millions of dollars in damage to tomato crops in Central America. Attempts to create a resistant plant with a suitable fruit through breeding programs have been unsuccessful. This study hoped to develop a molecular marker for the gene that controls resistance to begomoviruses. A successful molecular marker would enable breeders to quickly determine a tomato's susceptibility or resistance to begomoviruses and greatly aid in the creation of a commercially viable resistant hybrid. We hypothesized that a molecular marker for begomovirus resistance could be found within either the resistance gene hotspots on chromosomes one or seven, or the resistance gene homologue hotspots on chromosomes two, four, or eleven. To accomplish our goal we used a PCR-based tagging method to identify differences in sequences between resistant and susceptible tomato breeding lines. The results of the study indicate that the begomovirus resistance gene is not located at any o...

Tomato juice samples were ozonated with control variables of ozone concentration (1.6–7.8 %w/w) and treatment time (0–10 min). Effects of ozone processing variables on quality parameters of pH, oBrix, titratable acidity (TA), cloud value, non-enzymatic browning, colour values (L*, a*, and b*) and ascorbic acid (AA) content were determined. No significant changes (P > 0.05) in pH, oBrix, TA, cloud value and Non enzymatic browning (NEB) (P ≤ 0.05) were found with ozonation. L*, a* and b* colour values were significantly affected by ozone concentration and treatment time. A significant reduction of AA (96 %) was observed at an ozone concentration of 7.8%w/w and a treatment time of 10 min. Results presented in this study indicate that visual colour and nutritional quality is significantly affected during ozone processing. Thus, the effects of ozonation on the nutritional properties of tomato juice should be considered by processors prior to its adoption as a preservation technique.

Curly top disease is caused by a complex of curtoviruses (family Geminiviridae), and it continues to plague tomato production in California. To better understand the etiology of curly top of tomatoes in California, polymerase chain reaction (PCR)-based methods were developed and used to characterize the curtoviruses involved, and to monitor for these viruses in the beet leafhopper vector, Circulifer tenellus. From 2002 to 2008, 86 processing and fresh market tomato fields in the Central Valley of California were surveyed for the incidence of curly top symptoms. Representative samples with curly top symptoms were collected from the surveyed fields, as well as from another 24 fields. The incidence of curly top symptoms in most fields ranged from trace (<1%) to low (1 to 5%); however, in 2002, 2003, and 2008, some fields had medium (5 to 20%) or high (>20%) incidences. PCR with general and species-specific primers was used to establish that the predominant species associated with...

New types of tomato puree products were developed by blanching matured tomatoes (Lycopersicon esculentum) for 1 min, 2 min and 3 min individually with or without addition of the mixture of turmeric and lime during the blanching time. Soluble solid content and pH of the puree products were in the range of 11 - 12.6 � Brix and 4.32 -

Two cherry tomato plant cultivars (Lycopersicon esculentum Miller, cultivars ‘Koko’ and ‘Pepe’) were supplied with high (395 ppm), medium (266 ppm) and low (199 ppm) concentrations of nitrogen to determine the influence of nitrogen fertilization on development, cultivar preference and honeydew production by greenhouse whiteflies, Trialeurodes vaporariorum (Westwood) (Hemiptera: Aleyrodidae). The nitrogen, protein, and chlorophyll contents of tomato leaves were higher in the

We developed an efficient procedure for transformation and regeneration of L. esculentum cv. Moneymaker from cotyledon explants. The effect of two parameters on the transformation frequency was investigated in detail. The use of feeder layers during cocultivation proved to be critical. In addition, it was found that Agrobacterium strains harbouring a L,L-succinamopine type helper plasmid yielded significantly higher transformation frequencies than those with octopine or nopaline type helper plasmids. The optimized protocol was used to obtain transformation frequencies averaging 9%. Of the plants produced approximately 80% proved to be diploid, of which 67% contained the transgene(s) on a single locus.

Commercial horticulture in many regions of the world depends upon Sphagnum peat as a potting-media substrate, but extracting peat has serious environmental consequences. Composts may be able to serve as effective substitutes for peat and offer potential environmental advantages. The suitability of compost as potting media depends upon the raw materials as well as processing methods used. This study includes two related experiments—one with beet (Beta vulgaris L.) and the other with tomato (Solanum lycopersicum L.)—aimed at assessing the potential viability of farm-produced, food-residuals compost as a replacement for peat-based potting media in the production of organic vegetable transplants. The experiments were conducted in 2021 on the Berea College Farm in Kentucky, USA, a USDA certified organic farm. The results indicated that potting media composed of 75% to 100% compost performed as well as fertilized, peat-based growing media for plant growth. Further, although weeds were pre...

Inositol-(1,4,5)-trisphosphate (InsP3) is a second messenger in plants that increases in response to many stimuli. The metabolic consequences of this signalling pathway are not known. We reduced the basal level of InsP3 in tomato (Solanum lycopersicum cv. Micro-Tom) by expressing the human type I inositol polyphosphate 5-phosphatase (InsP 5-ptase) gene. Transgenic lines producing InsP 5-ptase protein had between 15% and 30% of the basal InsP3 level of control plants. This increased hydrolysis of InsP3 caused dramatic increases in drought tolerance, vegetative biomass and lycopene and hexose concentrations in the fruits. Transcript profiling of root, leaf and fruit tissues identified a small group of genes, including a cell-wall invertase inhibitor gene, that were differentially regulated in all tissues of the InsP 5-ptase expressing plants. Significant differences were found in the amounts of carbohydrates and organic phosphate in these plants. Plants with increased hydrolysis of InsP3 in the cytosol also showed increased net CO2-fixation and sucrose export into sink tissue and storage of hexoses in the source leaves. The increase in biomass was dependent on the supply of inorganic phosphate in the nutrient medium. Uptake and storage of phosphate was increased in the transgene expressing lines. This suggests that in tomato, increased flux through the inositol phosphate pathway uncoupled phosphate sensing from phosphate metabolism. Altering the second messenger, InsP3, revealed multiple coordinated changes in development and metabolism in tomato that have potential for crop improvement.

The apparent diffusivity of NaOH (D) through the skin of processing tomatoes was estimated for various concentrations and temperatures as it relates to chemical peeling. For concentrations of 2M NaOH or greater, D was independent of concentration, which allows the Fick's law of diffusion to be used for simulation of the events during chemical peeling. The temperature dependence of D was of the Arrhenius type (for temperatures greater than 50°C) with an estimated activation energy Ea = 71.2 KJ/mol.

In this article we strive to develop some basic “economics” of traceability in order to demonstrate that beyond its major use as a food safety tool, mandatory traceability strongly aects the organization of food system, as well as its structures and strategies. In some cases organizational eects can even overwhelm the safety assurance eects. The general eect of treaceability on the organization of the food systems is to drive even more national brands towards procurement policies based on the outsourcing. Traceability can heavily aect the nature of relationships along the food supply chain, replacing contractual relationships strongly relied on trust, with highly engineered technological links based on formal short-period contracts.

The changes induced in the levels of proline, tyramine and polyamines in response to salt (NaCl) shock treatments were studied using tomato (Lycopersicon esculentum Mill.) leaf discs incubated in saline media supplemented with various concentrations of CaCl2 and KCl. When the leaf discs were subjected to high salinity (100–300 mM NaCl), they accumulated significant amounts of proline (Pro), tyramine, 1,3-diaminopropane (Dap), cadaverine (Cad) and agmatine (Agm) while their free polyamine (PA) content decreased. Under salinized conditions (250 mM NaCl), increase of Pro content in leaf tissues and CaCl2 concentration in the external medium were positively correlated. This correlation was even stronger doubling KCl concentration. Cad and Dap were also accumulated, while tyramine was not significantly modified. In contrast, the amount of free Agm, putrescine (Put), spermidine (Spd) and spermine (Spm) decreased to very low levels. Under non salinized conditions the amount of Put and Spd also decreased in response to the increase of CaCl2 concentration in the external medium and this effect was reinforced in presence of highest concentrations of KCl. While analyzing the changes in the internal ionic status of the leaf explants in response to the salt treatment, it became clear that the internal Na+ and Ca2+ levels exert a positive effect on Pro, tyramine, Agm and Dap levels and a negative one on the levels of Put and Spd. The physiological interest of these responses is discussed.