Table 3.
Mean squares and repeatability values of grain yield and other traits of 36 early maturing maize accessions evaluated under heat stress and combined drought and heat stress during the 2018 and 2019 dry seasons at Kadawa, Nigeria.
| Source | df | GY | AD | SD | ASI | PLHT | EHT | HC | EPP | PASP | EASP | SG | RL | SL | EAROT | TB | LF |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Heat Stress | |||||||||||||||||
| Env | 1 | 57,677,836.7 ** | 604.3 ** | 855.7 ** | 21.8 * | 28713.3 ** | 14600.7 ** | 64.0 ** | 2.8 ** | 42.3 ** | 134.2 ** | 29.3 ** | - | 0 | 0.7 ** | 0 | - |
| Rep (Env) | 2 | 4541,533.3 * | 4.5 | 5.2 | 6.7 | 7009.3 ** | 2634.0 ** | 0.9 | 0.3 * | 4.3 ** | 3 | 9.2 ** | - | 0.0 * | 0.01 | 0 | - |
| Block (Env * Rep) | 20 | 768121.6 | 15.1 * | 13.3 * | 1.3 | 428.9 * | 260.0 * | 0.7 * | 0.1 * | 0.9 * | 2.4 | 1.8 * | - | 0 | 0.0 * | 0 | - |
| Genotype | 35 | 1,836,764.3 ** | 27.7 ** | 31.2 ** | 4.3 * | 951.3 ** | 495.2 ** | 0.7* | 0.1 * | 0.8 * | 4.1 * | 1.0 * | - | 0 | 0.0 * | 0 | - |
| En * Genotype | 35 | 907,223.9 * | 5.6 | 4.9 | 1.8 | 114.6 | 96.8 | 0.5 | 0 | 0.3 | 1.9 | 0.5 | - | 0 | 0 | 0 | - |
| Error | 50 | 444,221 | 6 | 4.3 | 2.5 | 133.6 | 113.6 | 0.4 | 0 | 0.4 | 1.8 | 0.5 | - | 0 | 0 | 0 | - |
| Repeatability | 0.57 | 0.85 | 0.89 | 0.58 | 0.89 | 0.82 | 0.21 | 0.68 | 0.62 | 0.68 | 0.49 | - | 0.17 | - | 0.25 | - | |
| Combined Drought and Heat Stress | |||||||||||||||||
| Env | 1 | 6,582,075.3 ** | 40.1 * | 242.8 ** | 85.6 * | 14336.1 ** | 7764.5 ** | 40.1 ** | 0.2 * | 1.6 | 4.7 * | 0 | 0 | 0 | - | 0.1 ** | 0.1 |
| Rep (Env) | 2 | 1,772,416.6 ** | 72.4 ** | 148.4 ** | 14.3 | 2181.8 ** | 490.6 * | 5.1 * | 0.1 | 2.8 * | 2.4 * | 0.2 | 0 | 0 | - | 0.0 * | 0.4 |
| Block (Env * Rep) | 20 | 271,106.8 * | 12.2 * | 12.5 * | 4.3 | 339.0 ** | 254.7 ** | 1.4 * | 0 | 0.6 | 1 | 1 | 0 | 0 | - | 0 | 0.1 |
| Genotype | 35 | 924,112.7 ** | 29.9 ** | 33.4 ** | 4.7 | 972.4 ** | 795.8 ** | 1.2* | 0.1 ** | 1.0 * | 3.3 ** | 1.5 * | 0 | 0 | - | 0.0 ** | 0.1 |
| Env * Genotype | 35 | 405,956.3 * | 7.0 * | 7.9 | 2.9 | 228.3 ** | 171.8 ** | 0.7 | 0 | 0.5 | 1.3 * | 0.6 | 0 | 0 | - | 0 | 0 |
| Error | 50 | 145,812.4 | 3.7 | 5.7 | 5.6 | 86 | 46.5 | 0.5 | 0 | 0.5 | 0.6 | 0.6 | 0 | 0 | - | 0 | 0 |
| Repeatability | 0.60 | 0.78 | 0.77 | 0.03 | 0.77 | 0.78 | 0.36 | 0.78 | 0.58 | 0.66 | 0.61 | 0.52 | 0.43 | - | 0.68 | 0.29 | |
*, ** Significance at 0.01 and 0.001, respectively; df: degree of freedom; Env: environment/year; Rep: replication; GY: Grain yield; AD: Days to 50% anthesis; SD: Days to 50% silking; ASI: Anthesis-silking interval; PLHT: Plant height; EHT: Ear height; HC: Husk cover; EPP: Ears per plant; PASP: Plant aspect; EASP: EAROT: Ear rot; EASP: Ear aspect; SG: Stay green characteristic; RL: Root lodging; SL: Stalk lodging; TB: Tassel blast; LF: Leaf firing.