A balanced nutrient supply is essential for the healthy growth of plants in hydroponic systems. However, the commonly used electrical conductivity (EC)-based nutrient control for plant cultivation can provide amounts of nutrients that are excessive or inadequate for proper plant growth. In this study, we investigated the kinetics of major and minor nutrient uptake in a nutrient solution during the growth of tomato (Solanum lycopersicum var. cerasiforme Alef.) in a closed hydroponic system. The concentrations of major and minor ions in the nutrient solution were determined by various analytical methods including inductively coupled plasma-optical emission spectroscopy (ICP-OES), ion chromatography (IC), ion specific electrodes, and/or colorimetric methods. The concentrations of the individual nutrient ions were compared with changes in the EC. The EC of the nutrient solution varied according to the different growth stages of tomato plants. Variation in the concentrations of NO3-, SO42-, Mg2+, Ca2+, and K+ was similar to the EC variation. However, in the cases of PO43-, Na+, Cl-, dissolved Fe and Mn, Cu2+, and Zn2+, variation did not correspond with that of EC. These ions were generally depleted (to 0 mg L-1) during tomato growth, suggesting that these specific ions should be monitored individually and their supply increased. Nutrient uptake rates of major ions increased gradually at different growth stages until harvest (from 15 mg L-1 d-1). Saturation indices determined by MINEQL+ simulation and a mineral precipitation experiment demonstrated the potential for amorphous calcium phosphate precipitation, which may facilitate the abiotic adsorptive removal of dissolved Fe, dissolved Mn, Cu2+, and Zn2+.

Characterizing nutrient uptake kinetics for efficient crop production during Solanum lycopersicum var. cerasiforme Alef. growth in a closed indoor hydroponic system.

Yield quality and irrigation with saline water under environmental limitations: the case of processing tomatoes in California

The tomato cultivars Edkawi and UC 82B (Lycopersicon esculentum Mill.) were grown hydroponically in a solution (electrical conductivity (EC) 2.4 dS·m -1 ) containing 150 mM Na (EC 11.4 dS·m -1 ), 37 mM of K (EC 14.1 dS·m -1 ), or 75 mM of K (EC 19.7 dS·m -1 ). The leaf Na content of 'Edkawi' and 'UC 82B' reached values of 1717 and 2022 mmol·kg -1 dry weight at EC 19.7 dS·m -1 , respectively. The high levels of K in the hydroponic solution reduced the Na concentration in the roots, petioles, and stems, but not in the leaves. Potassium concentrations in the petioles of 'Edkawi' and 'UC 82 B' reached values of 2655 and 2966 mmol·kg -1 dry weight, respectively. At these elevated ECs, the Ca concentrations in the leaves of 'Edkawi' and 'UC 82B' were 30% and 40% lower than in the control, respectively. The elevated rates of K improved the fruit : flower ratio of 'UC 82B', but the high salinity of the solution reduced yields significantly. Plant fresh weight and root dry weight of 'UC 82B' were most affected by high EC levels. The elevated levels of K used in this study did not increase yield, but K ions can adjust to Na uptake. in the soil reduce K content and increase Na content in the tissues (Graifenberg et al., 1995, 1996). Schachtman and Schroeder (1994) and Rubio et al. (1995) assumed that a common mechanism of absorption for K and Na ions in higher plants could exist and was regulated by the concentration of the two ions present in the substrate. Therefore, elevated levels of K could modulate the absorption and the transport of Na and limit the damages attributed to it. The purpose of this experiment was to determine the effects of high amounts of K in the hydro- ponic solution on the uptake and accumulation of Na in tomatoes.

https://journals.ashs.org/downloadpdf/journals/hortsci/35/7/article-p1220.pdf

Potassium affects sodium content in tomato plants grown in hydroponic cultivation under saline-sodic stress

A pot experiment was set in a completely randomized design with factorial arrangement using tomato (Lycopersicon esculentum cv “Tatto”) to examine the effect of cyclic irrigation with good and saline waters and mineral fertilization on yield and mineral constituents. The experiment consisted of two irrigation practices (W1 and W2) and two levels of phosphorus (P1 and P2) equivalent to 350 and 470 kg superphosphate/ha, respectively, added at the beginning of the experiment. The nitrogen (N) levels were 0, 800, and 1600 kg urea/ha, respectively, split into six doses. A basal dose of potassium (K) was added at the rate of 350 kg K2SO4/ha. One healthy seedling of tomato was transplanted three weeks after germination to each pot (0.07 m2) filled with soil classified as Torrifluvents. The treatments were replicated thrice and the pots were put in an open area at the Rumais Research Station facility. The quantity of irrigation water applied was approximated according to the data available at Rumais stat...

Alternate Use of Good and Saline Irrigation Water (1:1) on the Performance of Tomato Cultivar

The present investigation entitled “Diallel analysis for fruit yield and nutritional quality in tomato (Lycopersicon esculentum Mill.)” was undertaken to examine the magnitude of various heterosis estimates, inbreeding depression, combining ability and gene effects of eight diverse parents, their 28 F1s and 28 F2s for fruit yield and nutritional quality characters. The experimental crossing work was done at Vegetable Research Station, Junagadh during September 2004 to February 2005. The F2 seed production was done at the Horticultural Instructional Farm, J.A.U., Junagadh during June to September 2005. The fruit and nutritional quality study was conducted at Biochemical Laboratory, Department of Agricultural Process Engineering, College of Agricultural Engineering and Technology, J. A. U., Junagadh and for yield and related character at Agricultural Experimentation Station, J. A. U., Junagadh during October 2005 to March 2006. The analysis of variance revealed highly significant differences among parents, 28 F1s and 28 F2s for almost all traits in the present study, indicating considerable amount of genetic variability present in the population studied. The cross GT 1 x H 24 exhibited higher heterobeltiosis as well as standard heterosis along with considerable inbreeding depression followed by Pusa Ruby x H 24 and Pusa Ruby x Arka Vikas crosses indicating that these crosses could be suitable for exploitation of hybrid vigour on commercial scale. The cross, Pusa Ruby x Arka Vikas had stable performance in both generations. The crosses Pusa Ruby x Ec 398704, GT 1 x Ec 398704, Ec 163599 x Ec 177371, GT 1 x Ec 163599, GT 1 x Pusa Ruby, Ec 163599 x Ec 398704 and Ec 490190 x Arka Vikas exhibited comparatively high heterosis with low inbreeding depression hence, can be exploited for development of high yielding stable lines and or isolation of desirable segregants. The estimates of analysis of variance due to general and specific combining ability indicated that both additive as well as non additive gene effects played an important role in the expression of almost all characters under present study. However, predictivity ratio showed that non additive gene action was predominant in the expression of number of primary branches plant-1, fruit yield plant-1, polar fruit diameter in both generations. The characters locules fruit-1 and ascorbic acid in F1 generation was found to be inherited by additive genetic variance and in F2 generation by non additive genetic variance. The advantage of existence of dominance observed for days to 50 per cent flowering, pericarp thickness, protein, vitamin C, β carotene and potassium content could be exploited through heterosis breeding. The analysis regarding general combining ability revealed that parents GT 1, H 24 and Pusa Ruby were good general combiners for maximum number of characters under present study. Whereas, parents Ec 490190, Ec 163599 and Ec 177371 were good general combiners for fruit and nutritional quality characters. A close relationship existed between per se performance of crosses and sca effects, suggesting that it can be taken as criteria for effective heterosis. The sca effects manifested by GT 1 x H 24, Pusa Ruby x Arka Vikas, GT 1 x Ec 490190, Arka Vikas x Ec 163599, and H 24 x Arka Vikas crosses were considered important in self pollinated crop like tomato for heterosis breeding in future improvement programme. A population with preponderance of additive gene action would support the improvement of a character through selection in segregating generations. While the presence and magnitude of various components of non additive gene effect can be justified with heterosis breeding.

DIALLEL ANALYSIS FOR FRUIT YIELD AND NUTRITIONAL QUALITY IN TOMATO (Lycopersicon esculentum Mill.)

A sand culture experiment was conducted to study the effect of saline water on the growth and fruit quality of processing tomato (Lycopersicon esculentum Mill) Seedlings of five tomato cultivars were transplanted in quartz‐sand pots in a greenhouse at the Agricultural Experiment Station of Sultan Qaboos University There were four saline nutrient solutions and a control consisting of half‐strength Hoagland solution Salinity treatments were: 50 raM NaCl + 3 mM K2SO4 (EC 675), 50 mM NaCl + 15 mM orthophosphoric acid (EC = 718), 50 mM NaCl + 15 mM orthophosphoric acid + 3 mM R2SO4 (EC 729), and 50 mM NaCL (EC = 56) Treatments were applied daily commencing two weeks after transplanting Data were collected on growth, and fruit yield and quality Partitioning of mineral elements was determined in the vegetative tissue The results obtained clearly show that concentrations of total soluble solids were increased in fruits treated with saline nutrients Dry matter content of fruits exposed to sa

R. A. Al‐Yhyai

Papers

Fruit quality and partitioning of mineral elements in processing tomato in response to saline nutrients