Effect
Amalgerol treated Mandarin showed a mean increase of 10% in plant vigour following the first biostimulant treatment and maximum increases in vigour of 15% following the second and third treatment, no difference in shoot length, no difference in plant height except at the end of May, a significant bigger canopy diameter (east-west orientation) from the beginning of April, no difference in canopy diater (north-south orientation) (only at the end of March), no differences in trunk diameter compared to untreated control plants. Biostimulant treated plants showed increased soil respiration, increased leaf net photosynthesis, increased stomatal conductance, no difference in midday stem water potential, increased microbiological activity and increased water use efficiency, following three applications, compared to untreated control plants. Biostimulant application had no effect on soil respiration under periods of drought stress or recovery, no effect on leaf net photosynthesis under periods of stress or recovery, increased stomatal conductance in 1/3 measurements under stress and in 2/3 measurements under recovery , increased midday stem water potential in 2/3 measurements under stress and 1/3 measurement under recovery and no effect on water use efficiency under periods of stress of recovery, compared to untreated control plants.
