Rate and duration of seed filling and yield of soybean affected by water and radiation deficits | Pomanjkanje vode in svetlobe vplivata na hitrost in trajanje polnenja semen in pridelek soje

anglais. Seed filling and yield of soybean under water and radiation deficits were investigated during 2011 and 2012. Treatments were irrigations (I1, I2, I3 and I4 for irrigation after 60, 90, 120 and 150 mm evaporation from class A pan, respectively) in main plots and light interceptions (L1: 100 %, L2: 65 % and L3: 25 % sunlight) in sub-plots. Seeds per plant under I1 and I2 decreased, but under I3 and I4 increasedas a result of radiation deficit. Maximum seed weight and seed filling duration of plants under 25 % light interception (L3) were higher than those under full sunlight (L1) and 65 % light interception (L2). In contrast, plants under full sunlight had the highest seed filling rate, particularly under water stress. Seed filling duration under severe light deficit (L3) was about 9 days longer than that under full sunlight (L1), leading to 15.8 % enhancement in maximum seed weight. Decreasing seed yield of soybean under well watering and mild water stress and improving it under moderate and severe water deficit due to low solar radiation are directly related with changes in seed filling duration and consequently in seed weight and number of seeds per plant under these conditions.

slovène. Vpliv pomanjkanja vode in svetlobe na polnenje semen in pridelek soje je bil preučevan v poljskem poskusu v letih 2011 in 2012. Obravnavanja so bila različni režimi namakanja (I1, I2, I3 in I4 kot namakanje po 60, 90, 120 in 150 mm evaporacije iz razreda A) na glavnih poskusnih ploskavah in različni svetlobni režimi (L1: 100 %, L2: 65 % in L3: 25 % delež svetlobe) na podploskvah. Število semen na rastlino se je pri obravnavanjih I1 in I2 zmanjšalo, a se je pri obravnavanjih I3 in I4 povečalo kot posledica pomankanja svetlobe. Največja masa semen in najdaljše trajanje polnenja semen sta bila večja pri rastlinah, ki so rastle pri 25 % osvetlitvi (L3) kot pri rastlinah, ki so rastle na polni (L1) in 65 % (L2) osvetlitvi.V nasprotju s tem, so imele rastline pri polni osvetlitvi največjo hitrost polnenja semen, še posebej ob sušnem stresu. Trajanje polnenja semen je bilo pri večjem pomanjkanju svetlobe (L3) za 9 dni daljše kot pri polni osvetlitvi (L1), kar je vodilo k 15.8 % povečanju maksimalne mase semen. Zmanjšanje pridelka semena soje pri polnem zalivanju ali blagem sušnem stresu in njegovo povečanje pri zmernem in velikem vodnem deficitu je bilo posledica manjše osvetlitve, kar je neposredno povezano s spremembami v trajanju polnenja semen in posledično s spremembami v masi semen in številu semen na rastlino v teh razmerah.