Table I.

Grain and dry matter yield, harvest index, kernel no. per ear, and predawn leaf water potential (ψ_w) in maize in treatments ranging from well-watered to severe drought stress

Treatment	Grain Yield	Dry Matter Yield	Harvest Index	Kernel No. per Ear	Predawn ψw
	g m−2				MPa
[tc]	723  a	1415  b	0.51  a	299  a	−0.10 a
[t1]	844  a	1509  b	0.56  a	295  a	−0.11 ab
[t2]	953  a	1865  a	0.51  a	177  ab	−0.14 b
[t3]	426  b	899  c	0.48  a	191  ab	−0.23 c
[t4]	218  b	815  c	0.27  b	101  b	−0.39 d

Yield characters were measured at kernel maturity, and pressure chamber values of ψ_w of the last fully developed leaf obtained on the last day of the drought period. The depletion of available soil water content characterizing the five treatments is shown in Figure 1. Statistically significant differences between treatments were assessed by F-tests using the analysis of variance procedure PROC GLM (SAS Institute, 1988). Provided that the F-test was significant at the 5% level or less, comparison of means was performed with the Gabriel-algorithm of PROC GLM, and results are shown by letters after the values. Mean values that are significantly different at α ≤ 5% have no letters in common. No. of observations for each treatment (n = 3–4).