Agriculture Reference
In-Depth Information
Detailed experimental treatments regarding the water-retaining agent amount and EM-
calcium content were shown in Table 4. EM-calcium with 2.0‰ Ca
2+
concentration was
prepared as 2.2.1.
EM-Ca amount
(ml/time)
Intervals of spraying
(days)
MP3005
(g/plant)
Treatment Ca
2+
concentration
Growth stage
CK
---
---
---
---
---
P1
1‰
2
3
0
Root extending (R)
P2
1‰
2
3
0
Vigorous (V)
P3
1‰
2
3
0
R+V
P4
1‰
2
3
30
R
P5
1‰
2
3
30
V
P6
1‰
2
3
30
R+V
Table 4.
Experimental design
3.1.3. Measurements
3 representative tobacco plants were sampled for each replication. At harvest time, the lower
leaves, middle leaves and upper leaves were collected orderly, killed by 105℃ high tempera‐
ture and toasted to the constant weight (Hou et al., 2012; Maomao Hou, 2013). Weight of dry
tobacco leaves was measured and recorded to calculate the total yield.
IWUE
was calculated by the formula (Aujla et al., 2005; Ünlü et al., 2011):
IWUE
=
Y
I
Where,
IWUE
(kg/m
3
) was the irrigation water use efficiency;
Y
was the tobacco dry yield (kg/
hm
2
); I was the irrigation amount (m
3
/hm
2
).
3.2. Results
3.2.1. Agronomic characters of flue-cured tobacco
Fig. 4 showed the changes of total area of flue-cured tobacco leaves in single plant with days
after transplanted. As shown in the Figure 4, during 45~77 days, flue-cured tobaccos in P4 grew
more satisfactory compared to that in other treatments, and the leaf area of single plant in T4
reached a higher value of 36897.9 cm
2
in 77 days. However, P2 showed a poor performance in
leaf area enhancement, recording as 32110.1 cm
2
only. From the view of leaf area enhancement,
the effects of water-retaining agent treatments were obviously better than those with no water-
retaining agent. Under the same application amount of water-retaining agent, the effects of
EM-calcium spray in root-extending stage were better than those in vigorous stage and root-
extending+vigorous stage. The results were different from the expectation, it was maybe that
the EM-calcium spray blocked the leaf stoma after long-time application. On the whole, P4
was supposed to be the better treatment from a pure view of leaf area increasing.
