Radiation use efficiency by tomato transplants grown under extended photoperiod
Laen...
Kuupäev
2020
Kättesaadav alates
Autorid
Rakutko, S.
Avotiņš, A.
Berzina, K.
Rakutko, E.
Alsina, I.
Ajakirja pealkiri
Ajakirja ISSN
Köite pealkiri
Kirjastaja
Abstrakt
The study focused on the effect of an extended photoperiod on the radiation use
efficiency (RUE) by the tomato transplants (Solanum lycopersicum L.) in the pre–reproductive
period. In two consecutive series of experiments, the photoperiod was 16 and 22 hours. The
photon irradiance at the plant tops was maintained at low, medium and high levels: 100, 170 and
240 μmol m–2
s
–1
, respectively. The plants were grown under two lighting systems with different
light quality. The difference was7% higher blue flux share in Spectrum II. The use of an extended
photoperiod, especially in combination with high irradiance level, resulted in the plant leaf
chlorosis. When varying the radiation dose components, the deviation from the reciprocity law
was recorded. By the analysis results, the chlorophyll degradation was a response to the extended
photoperiod rather than the radiation dose. Without additional blue flux, under a regular
photoperiod, RUE reduced by 8% at the high irradiance level. Under extended photoperiod, the
shift from the low to high irradiance level reduced RUE by 20–37%, with bigger reduction values
being observed at higher irradiance levels. Seven percent addition of blue flux made it possible
to increase RUE by 5–8% at the same and lower irradiance levels and under the regular
photoperiod. With the extended photoperiod under these conditions, RUE decreased by 8–21%.
The study results verify a great influence of an extended photoperiod on RUE, while the degree
of influence depends on other parameters of light environment – light quality and irradiance level.
Kirjeldus
Märksõnad
photoperiod, irradiance, light quality, doze, biometry, radiation use efficiency, chlorophyll, chlorosis, articles