A field experiment studied the effect of salicylic acid and calcium chloride (CaCl2) on tomato growth and yield. The experiment used a randomized block design with five salicylic acid sprays (0-200 ppm) and five CaCl2 sprays (0-2%). Results showed that 150 ppm and 200 ppm salicylic acid significantly increased plant height, leaves per plant, and fruit yield. Similarly, 1.5% and 2% CaCl2 sprays also increased these parameters. The highest values were recorded at 200 ppm salicylic acid and 2% CaCl2. The study suggests that salicylic acid and CaCl2 have a positive effect on tomato growth and fruit development, and can be used as a foliar spray to enhance growth, yield, and quality. However, both these treatments significantly increased growth characters at different stage (plant height, number of leaves per plant and DMA/plant, yields attributes (number of fruits per plant, diameter of fruit, average fruit weight, fruit yield per plant and yield during both the year as well as pooled analysis.

Tomato (Solanum lycopersicum L.), a member of the Solanaceae family, is a widely cultivated vegetable renowned for its exceptional nutritional value. Rich in proteins, minerals, calcium, and vitamins (particularly vitamin A and C), tomato is considered a protective food. Phenolic compounds produced by plant roots play a crucial role in plant growth and development. Salicylic acid (SA) has been shown to regulate plant growth, development, and responses to environmental stresses (Yalpani et al., 1994; Senaratna et al., 2000). Low concentrations of SA have been found to enhance photosynthesis, growth, and various physiological and biochemical characteristics in plants (Fariduddin et al., 2003). However, high concentrations of SA can induce stress in plants. Pre-treatment with exogenous SA has been reported to increase tomato resistance to cold injury and reduce decay incidence in low-temperature storage (Ding et al., 2002). As an endogenous plant growth regulator, SA has a wide range of metabolic and physiological responses that impact plant growth and development (Hayat et al., 2010). Calcium is essential for plant growth, playing a critical role in cell division, elongation, and membrane permeability. Adequate calcium levels are necessary for normal plant membrane function, and calcium pectate formation strengthens cell walls and middle lamellae, improving fruit quality (Carpita and McCann 2000). Calcium also enhances tomato quality by increasing firmness, reducing physiological disorders, delaying ripening, and prolonging shelf life (Sharma et al., 1996). Plant hormones regulate Ca transportation and distribution within plants, with auxins promoting Ca transport in tomato fruit (Banuelos et al., 1988). The present investigation aimed to study the effect of salicylic acid and CaCl2 on growth, yield attributes, and yield of tomato variety "INDAM- 14301" in the arid environment of western Rajasthan.

A field experiment was conducted during the winter (rabi) seasons of 2020-21 Bikaner, Rajasthan, to study the effect of salicylic acid and CaCl2 on growth and yield of tomato.  The experiment was laid out in randomized block design (factorial), comprising combinations of 5 salicylic acid spray and 5 calcium chloride (CaCl2). The soil of experimental site was loamy sand, neutral in reaction, low in available N, medium in available P and medium in available K status. Crop sown on 22 October, 2020-21 and harvested 14 April, 2021. The total rainfall was 255 mm during 2020-21. The maximum and minimum temperature during crop-growing season ranged between 18.3oC to 39.5oC and 2.3oC to 23.8oC and during rabi 2020. The treatments comprising combinations of comprising combinations of 5 salicylic acid spray (Fresh Water spray as control, 50 ppm SA spray, 100 ppm SA spray, 150 ppm SA spray, 200 ppm SA spray) and 5 calcium chloride (Fresh Water Spray as control, CaCl2  Spray 0.5%, CaCl2  Spray 1%, CaCl2  Spray 1.5%, CaCl2  Spray 2%). These 25 treatment combinations were replicated thrice. Tomato variety ‘INDAM- 14301’ was used as a test crop. The seeds were sown in furrow opened at the depth of about 4–5cm using seed rate of 350 g/ha, with inter-row spacing of 0.5m.

The results (Table 1 & 2) indicated that spray of 150 ppm salicylic acid had significant effect on growth characters at different stage (plant height, number of leaves per plant and DMA/plant), yields attributes (number of fruits per plant, diameter of fruit, average fruit weight, fruit yield per plant) and yield which was at par with spray of 200 ppm salicylic acid. However, both these treatments significantly increased growth characters at different stage (plant height, number of leaves per plant and DMA/plant, yields attributes (number of fruits per plant, diameter of fruit, average fruit weight, fruit yield per plant and yield during both the year as well as pooled analysis. Spray of 150 ppm salicylic acid significantly increased plant height at last picking, number of leaves per plant at last picking and DMA/plant, number of fruits per plant, diameter of fruit, average fruit weight, fruit yield per plant and yield during experimental years and pooled analysis. The corresponding increases in plant height at last picking, number of leaves per plant at last picking and DMA/plant, number of fruits per plant, diameter of fruit, average fruit weight, fruit yield per plant and yield with the Spray of 200 ppm salicylic acid was respectively.

The results (Table 1 & 2) indicated that spray of CaCl2 1.5 % had significant effect on growth characters at different stage (plant height, number of leaves per plant and DMA/plant), yields attributes (number of fruits per plant, diameter of fruit, average fruit weight, fruit yield per plant) and yield which was at par with CaCl2 2.0 %. However, both these treatments significantly increased growth characters at different stage (plant height, number of leaves per plant and DMA/plant), yields attributes (number of fruits per plant, diameter of fruit, average fruit weight, fruit yield per plant) and yield. Spray of CaCl2 1.5 % significantly increased plant height at last picking, number of leaves per plant at last picking and DMA/plant, number of fruits per plant, diameter of fruit, average fruit weight, fruit yield per plant and yield during both the years of study and pooled analysis.The corresponding increases in plant height at last picking, number of leaves per plant at last picking and DMA/plant, number of fruits per plant, diameter of fruit, average fruit weight, fruit yield per plant and yield with the CaCl2 2.0 % was higher. Foliar spraying with salicylic acid (SA) had positive effect on vegetative growth of tomato at the concentrations of 150 and 200 ppm compared with the untreated control. The highest mean values of plant height, number of leaves per plant and DMA/plant, number of fruits per plant, diameter of fruit, average fruit weight, fruit yield per plant and yield were recorded when salicylic acid was sprayed at the concentration of 200 ppm. However, no significant differences were detected between 150 and 200 ppm in terms of plant height, number of leaves per plant and DMA/plant, number of fruits per plant, diameter of fruit, average fruit weight, fruit yield per plant and yield during both the year as well as pooled analysis. The positive effect of salicylic acid on tomato plant growth might be attributed to increased water use, endogenous phytohormones and carboxylation efficiencies in association with high photosynthetic rate in plants. Javaheri, et al. (2014); Ilyas et al. (2014) also reported that both SA and Ca2+ independently increased the plant height of tomato. Application of SA and Ca2+ produced higher number of tomato leaves. This result was supported by many authors like Kazemi (2013) and Salem (2013). Previously many authors reported that SA and Ca2+ played an important role in the fruit development and setting in many crops. Current result suggest that SA and Ca2+ has positive functions on fruit diameter (cm) as supported by the findings of Javaheri et al. (2014); Martin et al. (2003); Rab and Haq (2012). Significant increase in fruit length with exogenous application of SA and Ca2+ was reported by Javaheri et al. (2014); Abbasi et al. (2013) ; Salem (2013). The exogenous combined application of SA and Ca2+ had a great regulatory influence on umber of fruits plant-1 and increased the fruit yield as suggested by Javaheri et al. (2014); Plasencia et al. (2011); Ilyas et al. (2014) ; Kazemi (2013). Lolaei (2012); Shehana et al. (2001) also reported that application of SA and Ca2+ increased the yield of tomato.

Table 1:  Effect of salicylic acid and CaCl2 on plant height, No. of leaves at different stages and DMA/ plant (g) of tomato (Pooled data).

Table  2:  Effect of salicylic acid and CaCl2 on specific gravity, fruit yield per plant and yield ton per hectare of tomato (Pooled data).

It is concluded that spray of salicylic acid @ 150 ppm and CaCl2 @ 1.5 %  enhance the growth, yield and quality of tomato. Based on results emanated from the present investigation it is concluded that spray of salicylic acid @ 150 ppm recorded significantly higher fruit yield (49.11 t/ha) and spray of CaCl2 @ 1.5 % gave maximum fruit yield (48.82 t/ha).