A steady and progressive increase in rapeseed yield was observed with each increment in applied nitrogen rates up to 213 kg/ha in both seasons. As for nitrogen application times, the analyzed data showed that adding a split dose (either 1/2 or 1/3) before the third irrigation was a common part between high yielding treatments in 1985/86 season. Nitrogen rates X application times interaction affected rapeseed yield significantly during the first winter season. The highest seed yield of 2.5 t/ha was obtained by adding 213 kg N/ha in two split doses at sowing and just before the third irrigation. The second yield value of 2.47 t/ha was produced under the same N rate when applied in two split doses before second and third irrigation. However, in the second season (1986/87), rapeseed plants did not exhibit significant responses to nitrogen rates X application times interaction. Chemical analyses showed that rapeseed oil content and its fatty acids (Palmetic, Stearic, Oleic, Linoleic, Linolenic, Arachidic and Erucic) percentages were not significantly affected by either nitrogen rates or application times in both seasons. A very low content of Erucic acid (0.1–0.9 %) in all tested sample was noticed.

Two field experiments were carried out at the Agric. Exp. Sta. Fac. Agric., Cairo Univ., Giza, during 2009 and 2010 seasons to study the response of three hybrids of maize, Zea mays L. (S.C. 10, S.C. 122 and T.W.C. 321) to four plant densities (4.76 plants/m 2 , 5.56 plants/m 2 , 6.67plants/m 2 and 8.33 plants/m 2) on yield and yield components. Results showed that, significant differences between maize hybrids in plant height, number of ears/plant, barren %, LAI, number of kernels /row, grain weight/ear and grain yield/plant in both seasons. Number of rows per ear, number of ears/plant, number of kernels per row, weight of grains/ear, seed index, shilling percentage and grain yield/plant decreased significantly and gradually by increasing plant densities from 4.76 plants/m 2 to 8.33 plants/m 2. Plant height, barren %, LAI and grain yield per hectare significantly increased by increasing plant densities from 4.76 plants/m 2 to 8.33 plants/m 2. The highest grain yield/ha (9.96 and 10.32 ton/ha) were obtained by planting 8.33 plants/m 2 in 2009 and 2010 seasons. The lowest 7.88 and 8.28 tons/ha were recorded by planting 4.76 plants/m 2 in 2009 and 2010 seasons, while planting 6.67 plants/m 2 and 5.56 plants/m 2 were intermediate in grain yield/ha. Increasing plant density from 4.76 plants/m 2 to 8.33 plants/m 2 increased grain yield/ha by 25.70 and 24.98 % in 2009 and 2010, respectively, while this increase was 11.09 and 8.05 % for plant density of 6.67 plants/m 2 in 2009 and 2010 seasons. The effect of the interaction between hybrids differences and plant density treatments on yield and yield components are not significant in most studied characters except number of ears/plant, LAI and grain yield/plant.

Two field experiments were conducted during 1984/1985 and 1985/1986 seasons to study the effect of Alachlor, Metolachlor, Pendimethalin, Diphenamid, CGA 10832 and Oxadiazon as pre-emergence herbicides and EPTC as presowing herbicide at two doses as well as hand-hoeing treatment on weed spread and rapeseed yield under Egyptian conditions. All the tested herbicides except "Oxadiazon" gave satisfactorily good annual grass weed control up to harvest time. While, Oxadiazon and Diphenamid at both doses controlled adequately the growth of annual broad-leaved weeds. The highest rapeseed yield was achieved under the application of Metolachlor at 2.4 and 3.6, Pendimethalin at 1.8, Diphenamid at 1.8, CGA 10832 at 2.4 and Oxadiazon at 1.2 kg a.i./ha. While, Pendimethalin at 2.4, Diphenamid at 2.4, CGA 10832 at 3.6, Oxadiazon at 1.8 and EPTC at 5.5 kg a.i./ha exhibited an obvious phytotoxic effect on rapeseed plants.

The combination of urea or ammonium sulphate (A\so4) with farmyard manure (FYM) as well as using anyone of them alone as a source of nitrogen for rice cultivation was studied at Rice Research and Training Center (RRTC), Sakha, Kafr EL-Sheikh Governorate, Egypt during 2005 and 2006 seasons. The results revealed that, grain and straw yields and yield components significantly increased with the application of nitrogen sources in comparison to unfertilized check. There were no significant differences between urea and ammonium sulphate on the above mentioned characters. The ability of FYM alone to provide nitrogen is insufficient because of its lower N-content and higher C\N ratio. Generally, the combination of urea or ammonium sulphate with FYM in 75:25 ratio and full dose of mineral fertilizer either urea or ammonium sulphate gave the same effect of yield and yield components of rice. Under this study we can recommended that application of urea or ammonium sulphate or its combination with FYM in ratio 75:25 gave the best grain yield of rice.

Two field experiments were carried out during 2013/2014 and 2014/2015 winter seasons at Agric. Res. Stat., Fac. Agric., Cairo Univ. Giza, Egypt to study the effect of two seeding rates i.e.50 and 65 kg seed/ faddan (4200 m 2) and seven treatments of N, P and K fertilizers with or without Cerealin inoculation on wheat growth, grain yield and its components. These seven treatments were T1 (0-0-0 NPK), T 2 (50-30-24 NPK), T 3 (65-37.5-36 NPK), T 4 (80-45-48 NPK), T 5 (T 2 + Cerealin), T 6 (T 3 + Cerealin), and T 7 (T 4 + Cerealin). A split plot design in randomized complete blocks arrangement with three replications was used. Seeding rates were randomly assigned for the main plots while, fertilizer treatments were randomly arranged for the sub plots. The obtained results showed that seeding rates had no significant effect on all yield attributes except, number of shoots m-2 , number of grains spikes-1 in 2013/2014 season, number of shoots m-2 , number of spikes m-2 , straw yield /faddan and harvest index in 2013/2014 season. Mineral NPK fertilizers with bio-fertilizer (Cerealin) had significant effect on yield and its components except, spike length in both seasons. Grain, straw and biological yields and its attributes i.e. plant height, number of shoots m-2 , number of spikes m-2 , number of grains spike-1 , grains weight spike-1 , 1000-grain weight were significantly increased by adding bio-fertilizer compared to none adding in both seasons, respectively. Adding 75% of recommended dose of NPK mineral fertilizer combined with Cerealin inoculation resulted in significant increment in plant height, number of shoots m-2 , number of spikes m-2 , number of grains spike-1 , grains weight spike-1 , 1000-grain weight, grain, straw and biological yields as well as harvest index compared with other combination treatments. The interaction between seeding rate and fertilizer treatments was significant for all characters under study in both seasons. The highest grain yield (4.31 and 4.07 ton / faddan) in both seasons, respectively was recorded by sowing 65 kg seed faddan-1 with adding 65 kg N + 37.5 kg P 2 O 5 + 36 kg K 2 O + Cerealin inoculation compared with other tested treatments.