Chlorophyll levels in l-cm sections of the youngest fully expanded leaves of normal (Y) Festuca pratensis L. declined almost to zero over a period of 6 days after excision. Chlorophyll in a mutant genotype (NY) remained near the initial level for the whole of this period. Abscisic acid promoted pigment loss in Y but had no significant effect on chlorophyll in NY. Kinetin retarded pigment loss i...

Willstätter and Stoll have studied the rate of photosynthesis as a function of chlorophyll content. However, their experiments fail to reveal any regular relationship between these two quantities, probably because, in order to obtain material differing widely in chlorophyll content, they were obliged to use leaves which were not comparable in other respects. The writer describes a method for va...

Barley leaves grown under a natural light/dark regime have a chlorophyll content of 1300 [ig/g fresh weight and a chlorophyll a /b ratio of 2 .5 -3 . When the plants are grown under cycles of 2 min light/118 min dark, the respective values are 50 and 5 — 9. With chloroplasts with low chlo­ rophyll b content variable fluorescence is depressed by about 30% by MgCl2; with those of high chlorophyll...

The present investigation envisages the in vivo measured laser induced chlorophyll florescence spectra of EMS (Ethyl methane sulphonate) treated safflower leaves. Seeds of safflower were treated with 0.5% EMS for three treatment durations (3h, 5h and 7h) to raise the populations. The effect of EMS treatment on chlorophyll content in the leaves was assessed using laser induced chlorophyll fluore...

The aim of this study was to determine the damage caused by adult Mahanarva spectabilis (Distant, 1909) (Hemiptera: Cercopidae) on Brachiaria ruziziensis (Germain & Evard) under field conditions. A total of 0, 4, 8, 12, or 16 M. spectabilis adults per plot were maintained for 6 days. Thereafter, the insects were removed from the plant, and the following parameters were evaluated: chlorophyll co...

Accurate estimation of terrestrial gross primary productivity (GPP) remains a challenge despite its importance in the global carbon cycle. Chlorophyll fluorescence (ChlF) has been recently adopted to understand photosynthesis and its response to the environment, particularly with remote sensing data. However, it remains unclear how ChlF and photosynthesis are linked at different spatial scales ...

-In this study, impacts of vector quantization compression on prediction of leaf chlorophyll content of crops for the application to precision agriculture were evaluated. The compression algorithm tested in this paper is called successive approximation multi-stage vector quantization (SAMVQ). The hyperspectral data used were acquired by CASI over corn fields at L’ Acadie experimental farm (Agri...