Agriculture Reference
In-Depth Information
TABLE 1.6
Shoot Dry Matter Yield (kg ha
−
1
) of Lowland Rice at Different N Rates
Days after Sowing
N Rate
22 (IT)
35 (AT)
71 (IP)
97 (B)
112 (F)
140 (PM)
0
313
815
3065
5650
7694
5278
30
320
860
3709
6913
8953
6764
60
342
1230
3721
8242
11,056
7294
90
374
1044
4164
8695
10,758
7303
120
380
1229
4313
9570
13,378
8215
150
452
1207
4893
10,031
12,745
8624
180
351
1294
5077
11,290
13,682
9060
210
351
1130
5841
10,384
13,490
9423
R
2
0.56*
0.76*
0.97**
0.97**
0.94**
0.96**
Source:
Adapted from Fageria, N. K. and V. C. Baligar. 2001.
Commun. Soil Sci. Plant Anal.
32:1405-
1429. With permission.
Note:
IT, initiation of tillering; AT, active tillering; IP, initiation of panicle; B, booting; F, flowering;
PM, physiological maturity. Values are averages of 3 years field trial.
*,**Significant at the 0.05 and 0.01 probability levels, respectively. Not significant.
Upland rice shoot weight decreased from flowering to physiological maturity (Fageria, 2007).
Dry matter loss from the vegetative tissues during the interval from flowering to maturity was
35%, suggesting active transport of assimilates to the panicles, which resulted in a grain yield of
3811 kg ha
−1
(Fageria, 2007). Fageria et al. (2011a, 2006) reported more or less similar reduction in
the shoot dry weight of upland rice from flowering to physiological maturity.
Increase in shoot weight is important because it is significantly associated with grain yield (Table
1.7; Figure 1.8). Shoot weight is a characteristic of genotypes and is also influenced by environmen-
tal factors. Differences have been observed in grain yield among plants or genotypes having the
same amount of dry matter, because there exists differences in the utilization of photosynthates
among them (Hayashi, 1995). Table 1.8 shows the relationship between N rate and shoot dry weight
TABLE 1.7
Correlation Coefficients (r) between Lowland Rice Grain Yield and
Shoot Dry Matter Production during Different Growth Stages
Parameter
1st Year
2nd Year
3rd Year
Dry matter yield at IT
0.36*
0.37*
0.29
NS
Dry matter yield at AT
0.71**
0.55**
0.42*
Dry matter yield at IP
0.63**
0.51**
0.63**
Dry matter yield at B
0.72**
0.81**
0.61**
Dry matter yield at F
0.81**
0.80**
0.57**
Dry matter yield at PM
0.78**
0.80**
0.53**
Source:
Adapted from Fageria, N. K. and V. C. Baligar. 2001.
Commun. Soil Sci. Plant Anal
.
32:1405-1429. With permission.
Note:
IT, initiation of tillering; AT, active tillering; IP, initiation of panicle; B, booting; F,
flowering; PM, physiological maturity.
*,**Significant at the 0.05 and 0.01 probability levels, respectively. NS, not significant.
