Dear Islam, It will be useful to compare weather parameters during various growth stages in two seasons and will be helpful to find out the reasons for yield differences if crop management is same in two seasons.

Balwinder

Weather pattern data in the regions where the experiment was conducted during the (dry and wet) season with respect to growth and yield performance of the rice plant should give information on reasons for differences in crop performance.  Changes in soil pH, moisture level and temperature could also be an influencing factor.

Dear Dr. Islam,

Am I understanding it correctly that you did not have any control with optimum P level? If no additional watering was provided, your results simply means that in the dry season there was not enough water for plant needs, irrespective of available P.

As an alternative, if you have used two levels of P availability during two different seasons and there were differences in response to P deficit, that could be physiologically different story, as wheather conditions affected plant ability to achieve or use P.

Regards,

Gederts

Dear Gederts levinsh,

Thank you so much for your nice answer.

Although there were two seasons, wet and dry, there were no shortage of water in dry season or wet season. Because we tried to maintain same level of water in both season through irrigation. On the other hand, levels of soil available P was similar. However, rice genotype was different but yield potentiality of the genotype used in dry season was more than that of wet seaon. Nevertheless, rice yield was minimum in dry season. 

 Dear Segun Oluwatomiwa Oladele,

Thank you for your nice answer. Soil pH was more or less same in both season. Yes, temperature and moisture levels were different but soil available P was same and normally rice yield is more in dry season than wet season in our field. But we got reverse result. 

Actually yield reduction (difference from yield with optimum P) was sharp in dry season than wet season with same level of soil P. In the wet season rice yield was at per with optimum P but still soil P was much below the critical level of 8 ppm. One thing in my mind that is there need to determine soil P in the field condition (wet soil)? 

Dear Islam

You said that, rice genotype was different. Do you mean that is was not the same genotype that was evaluated trough the two season. If this was the case no need to compare because the difference may be do to genotype. 

However even if it is the same genotype we should keep in mine that genotype yield is the sum of G+G*E (G stands for genotype performance and G*E = geno and environnement interaction). The G*E may change across environment. So we have to meseare the other environment factors as said earlier by others.

Best regards