Document Type : Research Paper



This research has been conducted to study the effects of near ambient temperatures occurring in drying process on date pollen viability (PV) and pollen viability declining rate (PVDR) as a factorial experiment with 3 factors namely: temperature in 3 levels (40, 50, and 60 oC), pollen type in 3 levels (Abadan Ghanami, Ahwaz Ghanami, and Shadegan Ghanami), and exposure time (ET) in 7 levels (0, 40, 120, 480, 1140, 4320, and 12960 minutes) in 3 replications. The results showed that the effects of all factors and their interactions except the interaction effects of pollen type and exposure time on pollen viability were significant. Maximum and minimum pollen viability was 84.6% for Abadan Ghanami in 40 oC at ET=0 minute and 0.03% for Shadegan Ghanami in 60 oC at ET=12960 minutes, respectively. On the other hand, the effect of temperature and ET on PVDR was significant and the others were not. Based on data analysis, most of the PV damages occur in the first moments of heat exposure of the pollen grains. Maximum and minimum PVDR were 0.6144 percent per minute in ET period of 0-40 minutes and 0.0003 percent per minute in the ET period of 4320-12960 minutes both for Shadegan Ghanami pollen respectively. In attempt to express this regular pattern, PVDR model as a power function of time variable (Vr=ct-k) with both coefficient and power factors of temperature have been defined.