Effect of interaction between thermal radiation and seasonal variation on some physical properties of selected cassava cultivars(esculentacrantz) in the niger delta nigeria.

Abstract

The effect of interaction between thermal radiation and seasonal variation on some physical properties of selected cassava cultivars in the Niger Delta Nigeria was studied. The study was carried out around Emuoha Local government Area of River State for a period of twelve (12) months from July to June. Three exotic cassava cultivars (coded TMS-30572; NR-8082 and NR-84292) were planted and monitored at various distances from thermal radiation source (flare site): 0-150m; 150-300m; 300-450m; 450-600m and 1000-2000m. The results showed that there were significant effects of thermal radiation on leaf area (0.561**) at 0- 600m (448.91±5.37d w/m 2 ,) but the effect was not significant (0.132) at 1000-2000m ( 428.83±0.79ew/m 2 ).Similar trends were observed with other physical parameters except for plant height and number of leaves. Results of seasonal variation showed favourable values for physical parameters at early dry and late wet seasons for all three cassava cultivars. However, NR-8082 and TMS-30572 show high degree of resistance to heat and other environmental stress while NR 84292 exhibited less resistance to radiation effect. The effect of season was significant (P<0.001). For NR-84292, early wet 117.9 ± 6.71 cm 2, late wet 192.59 ± 14.17 cm 2 , the values for early dry and late dry were 183.54 ± 10.00 cm 2 and 121.17 ± 5.05 cm 2 respectively. TMS-30572 showed high response to seasonal variations. Early dry 219.63 ± 6.93 cm 2 and late dry 153.73 ± 3.33 cm 2 .The disease index was severe (DI=3.1 ± 0.2) at late dry season with NR-8082 and less with NR-84292 and TMS-30572 (DI=0.7 ± 0.2) at late wet season the effect was significant (P<0.001).Further work that could allay the fears of the rural communities as well as guarantee cassava tolerance potential has been suggested.