RESPONSES OF TEF [Eragrostis tef (Zucc.) Trotter] VARIETIES TO BLENDED NPSB FERTILIER RATES AT GELAN, CENTRAL ETHIOPIA

Abstract

Tef is the major crop grown in Ethiopia and the study area. However, its productivity is low mainly due to limited use of improved varieties and low soil fertility as result of intensive soil erosion and long history of cultivation. Therefore ,a field experiment was carried out on a farmer’s field at Gelan Akaki district during the 2018 main cropping season (from July to November 2018) to assess the response of tef varieties to blended NPSB fertilizer rates and to identify the economically feasible rates of blended NPSB fertilizers for the tef varieties. The treatments consisted of factorial combinations of three varieties of tef (Qunch, Kora and Dagim) and five levels of blended NPSB (0, 50, 100, 150 and 200 kg ha-1 ) fertilizer rates. The experiment was laid out in randomized complete block design in a factorial arrangement with three replications. All the plots were supplemented with 46 kg N ha-1 in the form of urea. Analysis of the results revealed that days of panicle emergence (DPE), days to physiological maturity (DPM), plant height (PH) and grain yield (GY) were highly significantly (p<0.01) affected by main effects of varieties and NPSB rates. On the other hand, panicle length (PL), harvest index (HI) and thousand kernels weight (TKW) were highly significant (p<0.01)affected only by the main effect of varieties while numbers of total tillers (TT) and productive tillers (PT) were highly significantly (p<0.01) affected only by NPSB fertilizer rates. The longest DPE (57.20 days) and DPM (94 days) were recorded for variety Dagim while the highest GY (3936 kg ha-1 ), PL (44.29 cm), HI (29.63%) and TKW (0.2413 g) were recorded for variety Quncho. Similarly Kora the highest PH (114.0 cm), TT (956.1 m-2 ) and PT (911.7 m-2 ) were obtained at 200 kg NPSB ha-1 whereas the highest GY (3985 kg ha-1 ) was obtained at 150 kg NPSB ha-1 . The interaction of varieties and NPSB rate was significant (p<0.01) on aboveground dry biomass (ABY), straw yield (SY) and lodging index (LI). The highest ABY (15926 kg ha-1 ) and SY (11537 kg ha-1 ) were obtained from combination of variety Quncho with 200 kg NPSB ha-1 . The result of economic analysis showed that application of 200 kg NPSB ha-1 for variety Quncho gave the highest economic benefit of 79531.67 Birr ha-1 with the marginal rate of return of 790%. Therefore, variety Quncho at 200 kg NPSB ha-1 supplemented with 46 kg N ha-1 can be tentatively recommended for production of tef in the study area