Diurnal patterns of leaf water potential (ΨW), canopy net photosynthetic rate (PN), evapotranspiration rate (E), canopy temperature (Tc), and water use efficiency (WUE) of clusterbean [Cyamopsis tetragonoloba (L.) Taub., cv. Desi] were studied at six phenological stages of plant development under field conditions at CCS Haryana Agricultural University, Hisar. The highest PN, E, and WUE were observed at pod initiation stage (61 DAS). Daily maxima of PN were usually between 11:00 to 14:00 h while those of E and WUE between 12:30 and 16:00 h. PN was mainly dependent on photosynthetically active radiation and E on air temperature (Ta) but the relationships varied at different growth stages. WUE declined with the increase in Ta. At mid-day, ΨW was highest during pod initiation. and A. Kumar ... [et al.].
Diurnal patterns of canopy net photosynthetic rates (jPií), evapotranspiration (£) and
water use efBciency (WŤJE = P^^E) of field grown irrigated wheat (Triticum
aestivum L. cv. WH 147) were studied fi'om tillering to maturity at Haryana
Agricultural University Farm, Hisar, India. Hie maximum photosynthetic rates
(^N, max) increased fi'om tillering to anthesis and declined at a rapid rate thereaňer till
maturity. Relatively high £'mav but low WUE„ax were recorded at tillering, milk ripe
and dough stages of growth. Diumally foUowed die course of photosynthetícaUy
active radiation (PAR) fiom tillering to wateiy ripeness but it declined at high PAR at
latter reproductive stages of growth. E was curvilinearly related to air temperature.
There was a lag of about 2 h between ^N, „lax (12.00 h) and E„,ax (14.00 h) during
the day. WUE was high fi-om 07.30 to 10.00 h, depressed during midday and a
slightly increased fi^om 15.00 to 16.00 h.Diurnal patterns of canopy net photosynthetic rates (jPií), evapotranspiration (£) and water use efBciency (WŤJE = P^^E) of field grown irrigated wheat (Triticum aestivum L. cv. WH 147) were studied fi'om tillering to maturity at Haryana Agricultural University Farm, Hisar, India. Hie maximum photosynthetic rates (^N, max) increased fi'om tillering to anthesis and declined at a rapid rate thereaňer till maturity. Relatively high £'mav but low WUE„ax were recorded at tillering, milk ripe and dough stages of growth. Diumally foUowed die course of photosynthetícaUy active radiation (PAR) fiom tillering to wateiy ripeness but it declined at high PAR at latter reproductive stages of growth. E was curvilinearly related to air temperature. There was a lag of about 2 h between ^N, „lax (12.00 h) and E„,ax (14.00 h) during the day. WUE was high fi-om 07.30 to 10.00 h, depressed during midday and a slightly increased fi^om 15.00 to 16.00 h.
We investigated the lead (Pb) effect on chlorophyll (Chl) fluorescence and photosynthetic electron transport system in Talinum triangulare (Jacq.) Willd. Plants were exposed to different concentrations of Pb(NO3)2 (i.e. 0, 0.25, 0.5, 0.75, 1.0, and 1.25 mM) for seven days in hydroponic experiments. Pb-treated leaves exhibited a relative decrease in Chl fluorescence induction curve, which resulted in the decrease of maximal fluorescence yield, maximal quantum yield, and effective quantum yield of PSII, while nonphotochemical quenching, quantum yield of regulated and nonregulated energy dissipation of PSII significantly increased during Pb stress. Furthermore, Pb concentrations also caused a decrease in maximal P700 change, photochemical quantum yield, nonphotochemical quantum yield, and ETR of PSI. We suggested that the changes in these parameters were a manifestation of Pb interference in the electron transport chain in both PSII and PSI. The sensitivity of PSII was greater than that of PSI in T. triangulare leaves., A. Kumar, M. N. V. Prasad., and Obsahuje bibliografii