Calcium and potassium-enhanced growth and yield of tomato under sodium chloride stress
The effects of salinization of nutrient solutions with NaCl, Ca(NO3)2 and KNO3 on selected root, leaf and yield parameters of five tomato cultivars were investigated under greenhouse condition. Results of the study showed that addition of 50 mM NaCl to nutrient solution significantly reduced root volume and fresh weight, calcium and potassium concentrations, leaf number and fresh weight, as well as fruit yield. Addition of calcium and potassium, either alone or in combination with each other, to saline nutrient solution increased root volume, fresh weight and calcium concentration, leaf fresh weight and fruit yield per plant. Moreover, root potassium concentration and leaf fresh weight increased when 20 mM Ca(NO3)2 was added to saline nutrient solution but not with 2 mM KNO3. Leaf number, on the other hand, increased with K but not with Ca application to the saline nutrient solution. Of the five cultivars screened, ‘Pearson’ showed the best performance followed by ‘Montecarlo’, ‘UC 82L’, ‘Pakmore’ and ‘Strain B’ in decreasing order. 
Pre-sowing magnetic treatments of tomato seeds increase the growth and yield of plants
The effects of pre-sowing magnetic treatments on growth and yield of tomato (cv Campbell-28) were investigated under field conditions. Tomato seeds were exposed to full-wave rectified sinusoidal non-uniform magnetic fields (MFs) induced by an electromagnet at 100 mT (rms) for 10 min and at 170 mT (rms) for 3 min. Non-treated seeds were considered as controls. Plants were grown in experimental plots (30.2 m2) and were cultivated according to standard agricultural practices. During the vegetative and generative growth stages, samples were collected at regular intervals for growth rate analyses, and the resistance of plants to geminivirus and early blight was evaluated. At physiological maturity, the plants were harvested from each plot and the yield and yield parameters were determined. In the vegetative stage, the treatments led to a significant increase in leaf area, leaf dry weight, and specific leaf area (SLA) per plant. Also, the leaf, stem, and root relative growth rates of plants derived from magnetically treated seeds were greater than those shown by the control plants. In the generative stage, leaf area per plant and relative growth rates of fruits from plants from magnetically exposed seeds were greater than those of the control plant fruits. At fruit maturity stage, all magnetic treatments increased significantly (P < .05) the mean fruit weight, the fruit yield per plant, the fruit yield per area, and the equatorial diameter of fruits in comparison with the controls. At the end of the experiment, total dry matter was significantly higher for plants from magnetically treated seeds than that of the controls. A significant delay in the appearance of first symptoms of geminivirus and early blight and a reduced infection rate of early blight were observed in the plants from exposed seeds to MFs. Pre-sowing magnetic treatments would enhance the growth and yield of tomato crop. 
The effect of fly ash on plant growth and yield of tomato
A gradual increase in fly ash concentrations in the normal field soil (0, 10, 20 … 100% volume/volume) increased the porosity, water holding capacity, pH, conductivity, C.E.C., sulphate, carbonate, bicarbonate, chloride, P, K, Ca, Mg, Mn, Cu, Zn and B. Fly ash additions to soil caused significant reductions in nitrogen content, it being almost nil in 90 and 100%. Tomato plants grown in the ash-soil mixture showed luxuriant growth with bigger and greener leaves. Plant growth, yield, (flowering, fruiting, fruit weight/plant, mean fruit weight), carotenoids and chlorophylls were mostly enhanced in the treatments with 40–80% fly ash, being optimal at 50 or 60%. From 60 or 70% onwards, the measured parameters tended to reduce. At 100% fly ash, yield (weight of fruits/plant) was considerably reduced. The boron content of tomato leaves displayed a gradual increase with fly ash addition from 20% onwards, while response of foliar nitrogen was just the opposite. The most economic level of fly ash incorporation was 40%, which improved the yield and market value of tomato fruits (mean weight) by 81 and 30%, respectively. 
Response of Tomato (Solanum lycopersicum L.) to Salicylic Acid and Calcium
Aims: The current piece study was conducted to find out the role of exogenous foliar application of salicylic acid (SA) and calcium (Ca2+) on growth, reproductive behavior and yield of tomato.
Study Design: The single factor experiment was laid out in Randomized Complete Block Design (RCBD) with three replications.
Place and Duration of Study: At the experimental farm of Sher-e-Bangla Agricultural University, Dhaka, during the winter season of November 2013 to April 2014.
Methodology: BARI Tomato-15 was used as planting material. Six different treatments viz., A0=0 mM of SA and 0 mM Ca2+, A1=0.25 mM SA and 0 mM Ca2+, A2=0 mM SA and 5 mM Ca2+, A3 =0.25 SA and 5 Ca2+, A4 =0 of SA and 10 Ca2+ and A5 = 0.25 SA and 10 mM Ca2+ were applied in the morning at 15, 30, and 45 days after transplanting (DAT). Data of plant height, branch plant-1, cluster plant-1, flowers plant-1, fruits plant-1, fruit length (cm), fruit diameter (cm) and yield were recorded and analyzed for logical interpretation.
Results: The morphological and yield contributing characters as well as yield of tomato were positively influenced with single and combined application salicylic acid (SA) and calcium (Ca2+). Significant increase of plant height and number of leaves plant-1 at 20, 40 and 60 DAT was observed with the application of A3 treatment. Application of A3 treatment also showed significant influence on production of cluster plant-1 (20.44), flowers plant-1 (168.1), and fruits plant-1 (99.42) as well as fruit yield (72.57 t ha-1). However application of A4 treatment failed to improve the morphological and yield contributing characters as well as yield of tomato over the A0 treatment (control).
Conclusion: Results suggest that combined application of SA and Ca2+ successfully increase the tomato fruit yield by altering the morphological and reproductive characters. 
Comparative Effect of Pig Manure and NPK Fertilizer on Agronomic Performance of Tomato (Lycopersicon esculentum Mill)
Field experiments were performed to investigate the effectiveness of pig manure (PG) used alone and combined with NPK fertilizer on nutrients composition, growth and yield of tomato (Lycopersicon esculentum Mill.). Treatments were replicated three times in a randomized complete block design and applied to tomato seedlings grown on beds at Oba-Ile and Iju in the rainforest zone of Southwest Nigeria Six treatments compared were: (a) the control, (b) 25t/ha pig manure, (c) 250kg/ha NPK (15:15:15) fertilizer, (d) 187kg/ha NPK + 6t/ha PG (75:25), (e) 125kg/ha NPK + 12t/ha PG (50:50) and (f) 62kg/ha NPK + 18t/ha PG (25:75) Soil and plant nutrients composition, growth parameters and fruit weight were determined. The test soils were sandy loam, low in organic matter and marginal in Nitrogen. Pig manure, NPK, used alone or combined at reduced rates significantly increased soil N, P, K, Ca, Mg, number of leaves, plant height, stem girth and fruit weight significantly. The 187kg.ha NPK + 6t/ha PG gave highest soil N, leaf N and fruit weight. Combinations of NPK and PG gave relatively high soil N, Ca and Mg and adequate concentrations of leaf N, P, K, Ca and Mg. Mean fruit weight per plant given by the control and 187kg/ha NPK + 6t/ha were 91 and 1016 gm respectively. 
 Lopez, M.V. and Satti, S.M.E., 1996. Calcium and potassium-enhanced growth and yield of tomato under sodium chloride stress. Plant science, 114(1), pp.19-27.
 De Souza, A., Garcí, D., Sueiro, L., Gilart, F., Porras, E. and Licea, L., 2006. Pre‐sowing magnetic treatments of tomato seeds increase the growth and yield of plants. Bioelectromagnetics: Journal of the Bioelectromagnetics Society, The Society for Physical Regulation in Biology and Medicine, The European Bioelectromagnetics Association, 27(4), pp.247-257.
 Khan, M.R. and Wajid, M., 1996. The effect of fly ash on plant growth and yield of tomato. Environmental Pollution, 92(2), pp.105-111.
 Afsana, N., Islam, M.M., Hossain, M.E., Nizam, R., Monalesa, N., Hussain, M.A. and Parvin, S., 2017. Response of tomato (Solanum lycopersicum L.) to salicylic acid and calcium. Journal of Applied Life Sciences International, pp.1-7.
 Awosika, O.E., Awodun, M.A. and Ojeniyi, S.O., 2014. Comparative effect of pig manure and NPK fertilizer on agronomic performance of tomato (Lycopersicon esculentum mill). Journal of Experimental Agriculture International, pp.1330-1338.