All seed germination related indexes were analyzed at different rates of CaC2 by subordinate function formulae.
Particles of 2-4 mm diameter of CaC2 were mixed thoroughly with molten wax, paraffin or paint mechanically in a drum shape container and then mixed with plaster of Paris by gentle manual rubbing to avoid stickiness of particles.
Encapsulation was done by filling gelatin capsules with the measured amount of powdered CaC2. Different rates of each coated CaC2 (0, 100, 200 and 300 mg kg-1) were placed 6 cm deep in soil in the center of pots after the seedlings were allowed to establish themselves.
Ethylene released from germinating seeds was increased with increasing rates of CaC2 except the treatment where the highest level of CaC2 (40 mg plate-1) was applied which significantly reduced the ethylene release (Fig.
Responses of Seed Germination and Morphological Characteristics of Cucumber to Exogenous Application of CaC2 Maximum germination rates (94.8% and 93.3%) were recorded in the treatments receiving 20 and 30 mg CaC2 plate-1, respectively.
The inhibition of apical growth may have been due to ethylene released from CaC2 which inhibits elongation and promotes radial expansion because of its more impact on cell enlargement instead of division of cells (Kieber et al., 1993) and plant polar auxin transport (Arora et al., 1982).
Similar reduction in plant height by application of CaC2 has been reported in various vegetable crops (Kashif et al., 2008; Siddiq et al., 2009, 2012; Ahmed et al., 2014).
Earliness in fruit maturity from CaC2 treated plants was might be due to acceleration of physiological maturity by ethylene hormone accompanied with loss of chlorophyll and breakdown of carbohydrate, protein and RNA with increasing activity of chlorophylase, protease, ribonuclease etc.
Statistical comparison among mean values reveals that CaC2 affected the photosynthetic activity of tomato cultivars, but the extent of effect was not similar.
Plant height: Reduction in plant height was noted by the application of CaC2 as compared to control where only fertilizer was applied (Table 3).
Number of days required for flowering: A reduction in time to initiate flowering in tomato cultivars was noted where CaC2 was applied compared to control plants.
Root dry weight: It is evident from the data that all rates of CaC2 and cultivars were statistically different from one another regarding effect on dry weight of root.