3 Results

3.1 Electrical conductivity and pH evaluation

The water solution from the soaked seeds showed variation under the imbibition time for electrical conductivity (EC) and pH, Figure 6.1 A-B. The pH range from 7.7 to 5.1 showing difference between the different imbibition time with a reduction of the pH in the time (r = -0.88, p<0.05), Figure 6.1 A. While the EC show a increase in relation to imbibition time (r = 0.80, p<0.05) with value ranges from 0.021 to 0.69 dS m⁻¹, Figure 6.1 B. According the correlation analysis exits a negative correlation between EC and pH (r = -0.74, p<0.05).

3.2 Seed water relation

The initial seed moisture (SMT) was 7.9% and after 24 hours of imbibition was 9.5%, Figure 6.1 C. The SMT show a strong positive correlation with the imbibition time (r = 0.89, p < 0.05). While the seed water content (SWC) show a fast increase reaching up to 25.7% until the first two hour of imbibition; afterwards, the SWC increases continuously to about 59.2% in 24 hours shown an increase around 6.5 times from initial values, Figure 6.1 D; this results is supported for a high correlation between imbibition time with the SWC (r = 0.93, p < 0.05). Also exist a high correlation (r = 0.96, p < 0.05) between SMT and SWC.

3.3 Seed germination analisys

Initial germinability of 85% of the seeds of J. curcas decreases significantly after 2 hours of imbibition. After that, the range of germinability was 68% to 44% from 2 to 24 hour of imbibition (Figure 6.2 A), showing a strong negative correlation with imbibition time (r = -0.72, p < 0.05). The mean germination time from seed without imbibition has a value at 4.8 day in comparison with the other treatments with values around 5.9 to 7.1 day for germination for 2 to 24 hours of imbibition (Figure 6.2 B). Seed germinability presented a negative strong correlation with a mean germination time (r = −0.88, p < 0.05). The germination synchrony didn’t show difference between the imbibition times (Figure 6.2 C); For the experiment, the maximum value for the uncertainty is 4.64 bits and the values ranged from 1.86 to 2.34 bits without difference between treatments and the results didn’t show any trend with the imbibition time. While the germination synchrony show a high correlation (r = −0.92, p < 0.05) with the germination uncertainty.

3.4 Multivariate analisys

The principal component analysis according to the studied variables explain 75.03% of the variance between the first and second dimension. In the first dimension there is a high positive correlation between ELC (r = 0.97, p<0.05), SWC (r = 0.96, p<0.05), SMT (r = 0.91, p<0.05), STW (r = 0.91, p<0.05), IBTH (r = 0.87, p<0.05), MGT (r = 0.82, p<0.05) with a negative correlation with the GRP (r = -0.92, p<0.05) while in the second dimension SFW (r = 0.77, p<0.05), SDW (r = 0.71, p<0.05) present positive correlation in contrast with HPT (r = -0.75, p<0.05) with negative correlation.