**2.11 Effect of rice husk biochar on dry weight of cob sheath, leaf, and stem of maize under drought stress**

A major effect of drought is reduction in photosynthesis, which is associated with reduction in food production and ultimately reduced dry weight of plant parts. Dry weight of cob sheath, leaf, and stem of maize is greatly affected by drought conditions. Application of rice husk biochar increased dry matter of cob sheath, leaf, and stem of maize under drought conditions. Dry weight of cob sheath, leaf, and stem of maize varied significantly with different doses of biochar under drought conditions (**Table 7**).

**2.12 Effect of rice husk biochar on shoot, root, and total dry weight of maize**

In drought stress shoot dry weight of maize reduced, but root dry weight increased, because under drought conditions for searching water, root growth increased, thereby increasing dry weight of root. Application of rice husk biochar reduced the effects of drought. The dry weight of root and shoot varied significantly

Under control condition (80% of FC), 60% of field capacity, and 40% of field capacity, highest dry weights of shoot were 84.1, 83.1, and 75.9 g, respectively, when biochar was applied at 20 t/ha, and lowest dry weights of shoot were 75.4, 68.4, and 63.8 g, respectively, when no biochar was applied. Under control condition (80% of FC), 60% of field capacity, and 40% of field capacity, lowest dry weights of root were 12.4, 15.6, and 16.8 g, respectively, when biochar was applied at 20 t/ha, and highest dry weights of root were 17.5, 26.8, and 27.3 g, respectively, when no biochar was applied. Total dry weight of maize plant was reduced at drought stress conditions, but reduction was not significant. When biochar is applied at different doses under drought conditions, total dry weight increased (**Table 8**). Under control condition (80% of FC), 60% of field capacity, and 40% of field capacity, highest total dry weights were 98.8, 97.0, and 93.9 g, respectively, when biochar was applied at 20 t/ha, and lowest total dry weights were 93.1, 91.1, and 89.3 g, respectively, when no biochar was applied. [45] found that root dry weight increased, while shoot dry weight decreased under drought conditions. [46] marked shoot dry weight increased under drought conditions due to application of

**2.13 Effect of rice husk biochar on number of cob, length of cob, and diameter**

The number of cob was one per plant, and there is no significant difference among numbers of cob per plant under drought stress condition with different

Drought affected growth of maize. Length of cob of maize was reduced under drought conditions. When biochar was applied at different doses, the cob length was increased under drought conditions (**Table 9**). Under control condition highest cob length (17.6 cm) was found when biochar was applied at 20 t/ha, and it was lowest (15.9 cm) when no biochar was applied. Under 60% of field capacity, highest

> **Control 60% of FC**

 75.4a–d 68.4cd 63.8d 17.5a–c 26.8a 27.3a 93.1a 91.1a 89.3a 77.8a–c 71.5b–d 68.2cd 16.7a–c 17.7a–c 24.4ab 95.2a 94.6a 92.6a 81.2ab 79.3a–c 72.9a–d 15.7bc 16.3a–c 21.7a–c 95.6a 95.5a 92.8a 84.1a 83.1ab 75.9a–c 12.4c 15.6bc 16.8a–c 98.8a 97.0a 93.9a

CV (%) 9.3 34.4 8.7

*Effect of rice husk biochar on shoot, root, and total dry weight of maize under drought conditions.*

**Root dry weight (g/plant) Total dry weight**

**40% of FC**

**(g/plant)**

**40% of FC**

**Control 60% of FC**

**of cob of maize under drought stress**

**Shoot dry weight (g/plant)**

> **40% of FC**

**Control 60% of FC**

*Figure having similar letter did not vary significantly.*

with the application of biochar under drought conditions (**Table 8**).

*Amelioration of Drought Tolerance in Maize Using Rice Husk Biochar*

**under drought stress**

*DOI: http://dx.doi.org/10.5772/intechopen.88824*

biochar.

biochar doses (**Table 9**).

**Biochar doses (t/ha)**

**Table 8.**

**69**

#### **Figure 4.**

*Effect of rice husk biochar on proline content of maize under drought conditions. Bar indicates LSD at 5% level of significance.*


#### **Table 7.**

*Effect of rice husk biochar on dry weight of cob sheath, leaf and stem of maize under drought conditions.*

The highest dry weight of stem were 27.28 g, 26.25 g and 22.75 g in control, 60% of field capacity and 40% of field capacity, respectively, when biochar was applied at 20 t/ha, and lowest dry weights of cob sheath were 12.8, 11.7, and 10.3 g, respectively, when no biochar was applied. Under control condition (80% of FC), 60% of field capacity, and 40% of field capacity, highest dry weights of leaf were 42.0, 41.5, and 38.6 g, respectively, when biochar was applied at 20 t/ha, and lowest dry weights of leaf were.

**Table 7**. Effect of rice husk biochar on dry weight of cob sheath, leaf, and stem of maize under drought conditions, 37.2, 35.2, and 34.4 g, respectively, when no biochar was applied. Under control condition (80%of FC), 60% of field capacity, and 40% of field capacity, highest dry weights of stem were 27.2, 26.2, and 22.7 g, respectively, when biochar was applied at 20 t/ha, and lowest dry weights of stem were 24.8, 21.8, and 19.0 g, respectively, when no biochar was applied. [43] found drought stress reduced dry weight of plant parts by affecting photosynthesis. [44] reported that application of biochar increased dry weight of field-grown wheat.
