Susceptibility of peanut yield to water stress at three growth stages

الملخص EN

There are controversial opinions in literature concerning the stage or stages of development in peanut most susceptible to drought.

In view of this, some studies were carried out in an attempt to evaluate this issue.

Accordingly, the effects of water stress imposed at different growth stages were studied.

Four treatments were applied, [control, stressed at the beginning of flowering (35 days after sowing, DAS), stressed at the beginning of pegging (55 DAS) and stressed at the beginning of pod-setting (75 DAS)].

The control plants were watered every other day while the stressed plants were subjected to successive drying cycles by watering them every 21 days until harvest (140 DAS), during which photosynthesis rates, stomata conductance and transpiration rates were measured.

As expected, all the measured parameters were higher in control plants whereas in stressed plants the effects differed according to the time of duration of water stress i.e.

they followed the pattern: pod-setting < flowering < pegging.

The plants that were stressed at pegging stage showed the lowest values of yield and yield components compared to the control (P = 0.001, Table 3), while the plants that were stressed at pod-setting stage were able to obtain higher values of yields and its components (no significant difference compared to the control).

These results indicate that pegging stage is the most sensitive stage to drought.