02088naa a2200169 a 450000100080000000500110000800800410001910000170006024501030007726000090018052016030018965000280179265000160182065300160183670000120185277300540186410724772008-10-17       1983    bl ---       0--  u    #d1 aGHUMAN, B. S  aMulch and irrigation effects on plant-water relations and performance of cassava and sweet potato.  c1983  aMulch and irrigation effects on plant-water relations and performance of cassava cv. TMS 30001 and sweet potato cvs. TIS 2148 and TIS 2295 were investigated at Ibadan, Nigeria. Straw mulch @ 6 t/ha was spread immediately after planting of crops in September 1980. Irrigation equal to pan evaporation was applied during the dry season of 1980/81. Unmulched and/or nonirrigated plants of both crops had lower leaf water potential than mulched and/or irrigated. Averaged over all the treatments and cultivars, cassava had 15.00 h leaf water potential of -3.6 bars as compared to -9.6 bars of sweet potato. The daytime leaf diffusion resistance of cassava was similar (2-5 s cm-1) in unirrigated mulched and irrigated  mulched and unmulched plots. But in unirrigated unmulched plots, the resistance increased to 19 s cm-1 at 15.00 h. Mulching did not affect leaf diffusion resistance (2-8 s cm-1) of both cultivars of sweet potato in irrigated plots. But in nonirrigated plots, leaf resistance increased with time during the day; the increase was lessin in mulched (from 2 to 40 s cm-1 in TIS 2148 and 3 to 13 s cm-1 in TIS 2295) tham in unmulched (from 3 to 54 s cm-1 in TIS 2148 and 2 to 20 s cm-1 in TIS 2295) treatments. At harvest, the yields of cassava and sweet potato were not singnificantly affected by mulching. However, cassava yield was significantly greater in irrigated (24.7 t/ha) than in nonirrigated plots (18.2 t/ha). Similarly, irrigated sweet potato (at 8.5 t/ha of TIS 2148 and 8.7 t/ha of TIS 2295) outyielded the nonirrigated (at 5 t/ha of TIS 2148 and 2.8 t/ha of TIS 2295) one.  aAdubação de Cobertura  aIrrigação  aBatata-doce1 aLAL, R.  tField Crops Researchgv. 7, n. 1, p. 13-29, 1983.