The productivity of tef-sunfl ower intercropping, with or without fertilizer, was assessed by fi eld trials in northeast Ethiopia. Mixed planting of 10-50% of sunfl ower with tef had yield advantages of 20-39% and 58-77% at two different sites. The crop proportions giving the greatest yield benefi t varied between the sites. The greatest net income benefi ts were US$515 ha −1 and US$69 ha −1 at the two sites. ConclusionMixed cropping of tef and sunfl ower increased yields and land productivity, and improved the monetary return, and can thus be recommended. However, the optimum level seems to depend on the variety and location: in this study, mixed cropping of sunfl ower with tef at 50% gave signifi cantly better returns at Sirinka, but at Kobo there were no signifi cant differences in net income from the fi ve mixed-cropping treatments.

A pot experiment was conducted at Sirinka Agricultural Research Center, Ethiopia in 1999 to evaluate the level of resistance of local and improved sorghum varieties to Striga hermonthica (Del.) Benth. The results indicate that the three exotic varieties, which were bred for striga resistance (P-9401, P-9403 and SRN-39), and two local varieties (AyefereAsfachew and Wotere) supported significantly lower numbers of emerged striga compared to the susceptible checks. Striga dry biomass weight and shoot height were also significantly lower for these varieties. Plant height, dry shoot weight and dry root weight were also least affected by striga infestation in these varieties. Most of the local sorghum varieties, which were praised for their resistance, had disappointing infestation levels.

) with three replications. Results revealed that yield and yield components of food barley were significantly affected by P fertilizer application. Phosphorous fertilizer application at different rates increased grain yield of food barley by 23 to 46% compared to the control. Available soil test P concentrations analyzed three weeks after planting were affected significantly by P fertilizer application rate. Relative yield and Bray-2 soil test phosphorous value correlation indicated that soil test phosphorous values greater than 13 mg kg -1 was found to be sufficient for food barley production. The average phosphorous requirement factor (P f ) calculated from soil test phosphorous values of all treatments for study area was 10.2. Most sites tested had Bray 2 P values <10 mg kg −1 . In the absence of a soil test, a recommendation of 40 kg P ha -1 , resulting in the best response overall, could be made for the first year of application. It was also recommend that to prevent a potential loss of barley yield, a maintenance application of at least 5 to 10 kg P ha −1 be applied every year, irrespective of the calculated recommended rate, in order to replace P exported from the field in the form of grain and straw yield. Further field trials are required to determine interactions between P response and the effects of climate, soil properties, and other management practices.