The tomato (Lycopersicon esculentum Mill.), is native to South America. It occupies the second place in worldwide vegetable consumption. Because of this, the evaluation of tomato varieties for the fresh consumption is important. The Mexican production is 1,908,607 tons of fresh product (SAGARPA, 2004). In the state of Colima, production has a mean efficiency of 18.13 t·ha-1 (INEGI, 2000). The following genotypes were evaluated `Peralta', `Montijo', Pavia', `Grande River', and `Yaqui' (control). A randomized experimental block was used, with five treatments and four repetitions. The obtained results indicate that `Yaqui' (control) had the better yield of fresh fruit, with 37.5 t·ha-1, followed by `Peralta' (27.2t·ha-1), and `Montijo' (12.6 t·ha-1), respectively. The height of plant in `Yaqui' was 68.8 cm and 60.26 cm in `Pavia'. In the days to flowering, after showing a homogenous behavior, pronouncing itself up to 27 days after the transplant; whereas the variety `Grande River' was pronounced up to 40 days. With respect to the number of total fruits by plant, a highly significant difference was observed. `Yaqui' produced 91 fruits, with `Pavia' and `Peralta' producing 50 and 37 fruits per plant, respectively. In conclusion, `Yaqui' was the genotype with greater yield and vigor.
Marcelino Bazan Tene, Juan Manuel González Gonzalez, Francisco Radillo Juarez and Pablo Enrique Ramírez Castillo
In the world horticultural production, the tomato (Lycopersicon esculentum Mill.) contributes with the 47% of the destined area. In Mexico, 10% of the area is cultivated under intensive systems, where is used one or more technologies for obtaining higher productivity and quality; however, the environmental conditions are determinant factors to produce red tomato in the dry tropic, influencing the adaptation and persistence in the market. The aim of this research was to evaluate the adaptation and yield performance of tomato hybrids in fresh production under mulching, fertilization and irrigation. The tomato cultivars used were: `Access', `Centurion', `Bishop', `Dean', and `Yaqui' (control). They were distributed under a Completely randomized blocks design with four replications. The experiment was carried out in Villa de Alvarez, Colima, México. `Yaqui' exhibited the highest plant height 98.8 cm, as web as the highest fruit diameter with 4.61 cm; `Bishop' produced the highest number with 154.5 fruits per plant, followed by `Yaqui', and `Centurion', with 91 fresh fruits. In the variable fruit weight, `Yaqui' showed 93.44 g. In total fresh fruit yield per plant, `Yaqui' produced the highest yield with 8.46 kg, followed by `Bishop' with 4.91 kg; and total yield of 117.5, and 68.2 t·ha-1, respectively. Yaqui' was the genotype with best adaptation and agronomic characteristics. We speculate that environment conditions in field are determinant factors in the introduction of new tomato introductions.
Francisco Radillo Juarez, Juan Manuel González Gonzalez, Marcelino Bazan Tene and Luis Fernando Velasco Garcia
In world production of vegetables, the red tomato contributes 47% of the total production and occupies second place in world consumption. The objective of this research was to evaluate 13 genotypes of red tomato with high technology for horticultural production in the greenhouse. This study was realized in “Zamora” greenhouses in Quesería-Montitlán, Colima, Mexico. The evaluated materials were: `Sun', D-0289, D-2465, D-2467, D-2475, D-2503, D-2505, D-2512, D-2515, D-2534, D-2541, D-2552, D-7705, and, as control, the `Roman' variety. The tallest height was that of `Roman' plants, 2.46 m, vs. the height of the first cluster of fruits in D-2575 with 51 cm. With respect to largest number of fruits per cluster and total harvested, D-0289 stood out with four and 18 fruits per plant, respectively. In regard to fruit size, the genotypes D-0289 and D-2534 presented the largest equatorial and polar diameter, with 19.2 and 14.2 cm, respectively. For fruit weight, the genotypes `Sun' and D-0289 presented the largest weight with 160 and 151 g, respectively. We conclude that agronomic management influences production under technical systems. For vegetative and productive desirable characteristics, the genotypes `Roman', D-0289, and D-77055 were the more adaptable for production in the greenhouse.
Denise M. Tieman and Avtar K. Handa
The growth of tomato fruit is the result of cell division early in development followed by cell expansion until the onset of ripening. We have utilized the mRNA differential display technique to clone genes differentially expressed in 10- and 20-day-old tomato fruit, when most fruit cells are undergoing a transition to growth by cell expansion. Of 1753 total bands observed using 30 independent primer sets, 31 differential display bands were obtained only in either 10-or 20-day - old fruit RNAs. Seven differentially expressed bands from 10-day-old fruit RNAs and six from 20-day-old fruit RNAs were cloned and characterized by sequence analysis and mRNA expression patterns in developing fruit, leaf and root tissues. Two clones had sequence similarities to 3-deoxy-D-arabino-heptulosonate-7-phosphate (DAHP) synthase or threonine deaminase genes, while the remaining clones did not correspond to previously characterized genes. Steady state levels of mRNAs corresponding to seven clones were upregulated between 10 and 20 days of fruit development, while two clones were downregulated during growth and ripening. Most clones also hybridize to mRNA species present in leaf and root tissues. Collectively, these results suggest a transition in gene expression between 10- and 20-day-old fruit development.
Douglas C. Sanders, Jennifer D. Cure, Pamela M. Deyton and Randolph G. Gardner
Amount of vascular development (veininess) is an important quality factor for processing wholepack tomatoes. The influences of nutrient and soil moisture stress on the amount of vascular development in `Chico III', `Dorchester', and `Roma' tomato fruit were studied. Fruit subjected to nutrient stress showed the highest amount of veininess. Fruit exposed to moisture stress after initial fruit set did not differ from controls in amount of veininess. Amount of vascularization did not differ among cultivars. A method for quantifying veininess was developed and compared with a traditional subjective rating scale. There was a high correlation (r2 = 0.77) between the subjective rating and quantitative measurement of veininess.
Monica Ozores-Hampton and Brain Mardones
Intensive peat mining in Chile and worldwide produces a significant increase in production costs and less market availability. Alternative systems to promote peat mining sustainability are an immediate necessity. A viable alternative for replacing peat in tomato transplant production is to use worm castings or vermicompost. Vermicomposting is a biological process that relies on the action of earthworms (Eisenia sp.) to stabilize waste organic materials. The objective of this study was to evaluate the use of Ecobol-S® worm castings as a replacement for peat in tomato transplant production. Three experiments were designed using a randomized complete-block design containing two factors (planting date and worm casting rate). Tomatoes were seeded in a growth chamber using five growth media made up of the different ratios of worm castings, peat, and rice hulls [0:70:30 (control) 18:52:30; 35:35:30; 52:18:30; and 70:0:30], respectively. It was determined that Ecobol-S® worm castings have an adequate C:N and particle size for tomato transplant production. However, limitations were observed due to its high EC and low C content. During early fall, with high temperature in the growth chamber, it is not recommended to use worm castings in transplant production due to nutrient leaching caused by frequent irrigation. In mid-fall, it is recommended to use a rate of 35% worm castings, while in early winter it is recommended to use a rate of 52% to obtain strong and healthy transplants. Therefore, worm castings can be used as a viable alternative in the tomato transplant industry in Chile and possibly worldwide.
Min Wu and Chieri Kubota
Manipulation of the electrical conductivity (EC) of the hydroponic nutrient solution has been studied as an effective method to enhance flavor and nutritional value of tomato fruit. The objective of this research was to quantitatively understand the accumulation of lycopene, soluble sugars, and the degradation of chlorophyll in fruits as affected by EC and EC application timing relative to fruit ripeness stages. `Durinta' tomato was grown hydroponically inside the greenhouse under two EC (2.3 and 4.5 dS·m-1). The high EC treatment began immediately after anthesis (HEC treatment) or 4 weeks later (DHEC treatment), when fruits had reached maximum size, but still were green. Fruits were harvested weekly beginning 2 weeks after anthesis, until they reached red ripe stage. The chlorophyll concentration in tomato fruits showed no difference between treatments when compared at the same ripeness stages. The lycopene concentration of red ripe tomato fruits in HEC and DHEC treatments was 29% greater than that in low EC control (LEC treatment). However, there was no significant difference in lycopene concentration between HEC and DHEC. Both DHEC and HEC increased total soluble solid concentration (TSS) of red ripe tomato fruits compared with those grown in LEC; while the DHEC showed an increase of fruit TSS of 12%, the HEC had a greater enhancement of TSS of 19%. In addition, the fruit ripeness was accelerated under high EC, regardless of the timing of treatment. High EC treatment at early and mature green fruit developmental stages enhanced both fruit TSS and lycopene concentration; however, the nutrient solution EC effect on lycopene concentration was not dependent on the time of application during fruit development.
Martin P.N. Gent and Vincent Malerba
The soil within a greenhouse was heated by blowing hot air from a forced-air heater through drainage pipes buried beneath raised beds. This warmed the soil from 50F (10C) to 68F (20C) after 1 week of heating in mid-March. Soil in unheated beds did not warm to this temperature until May. The yield of tomato (Lycopersicon esculentum Mill.) planted in heated beds was higher than in unheated beds by 16% over the season in 1992, and by 14% as of early July 1993. The weight fraction of highest-quality fruit also were 11% greater in 1993. This simple method of soil heating involved negligible additional expense
Michael A. Schnelle, B. Dean McCraw and Timothy J. Schmoll
Height control for vegetable transplants has become challenging with the loss of the industry standard growth regulator, daminozide (Alar). One alternative to growth regulators—brushing—was conducted on two cultivars of Lycopersicon esculentum Mill. Five weeks of brushing twice daily resulted in height suppression for both tomato cultivars. Brushing treatments were performed successfully by use of a grower-designed apparatus constructed from readily available materials.
S.M. Lutfor Rahman, Wayne A. Mackay, Eiji Nawata, Tetsuo Sakuratani, A.S.M. Mesbah Uddin and Bruno Quebedeaux
Effects of water stress on superoxide dismutase (SOD) activities, changes in protein content, leaf water potential (Ψl) and growth were studied in drought-sensitive Kyokko (KK) and Ratan (RT), and drought-tolerant TM 0126 (TM) and VF-134-1-2 (VF) cultivars of tomato (Lycopersicon esculentum Mill.) in order to obtain fundamental information for breeding drought tolerant cultivars that may be adapted to water stress in many parts of the world. Growth of drought-tolerant TM and VF was greater than that of drought-sensitive KK and RT under water stress conditions. Leaf water potential (Ψl) decreased by water stress treatments in all the cultivars, but the reduction was much more rapid and pronounced in KK and RT than VF and TM. Ψl of stressed cultivars decreased by 30% to 40% compared to the untreated control cultivars. The initial reduction in the range of 20% to 35% was more rapid in KK and RT than TM and VF. SOD activities were increased by water stress in all cultivars. Increase of SOD activities by water stress was much more rapid and pronounced in TM and VF than in KK and RT. Leaf protein concentration was decreased by the water stress treatments in all cultivars evaluated. In KK and RT, much more rapid reductions in protein concentration were observed than in TM and VF. The regression analysis of Ψl and SOD suggest the possibility to using SOD activities as an additional screening criterion for tomato drought tolerance improvement.