بررسي اثرات دور آبياري و كود نيتروژن بر شاخص هاي فيزيولوژيكي رشد و عملكرد ذرت علوفه اي (هيبريد S.c704) در شرايط آب و هوايي استان مازندران

Surveying the effects of irrigation interval and nitrogen fertilizer on physiological index of Growth and yield of silage corn (hybrid S.c704) in climatic conditions of Mazandaran provience

In this research to survey the effects of irrigation interval and nitrogen fertilizer on physiological indexes of growth and function of silage corn (hybrid S.c. 704), we did an examination as split plots in randomized complete block design with 3 replications in agricultural research station- Biokola (Neca) in 2009 culturing year. Irrigation interval were in four levels of irrigations 75, 100, 125 and 150mm evaporation from class A evaporation pan as main factor and three levels of nitrogen values 0, 96 and 184 kg/ha (in order 0, 200 and 400kg urea/ha) as sub ordinate factor. Results showed that irrigation interval in characteristics like grain yield, biologic yield and stalk yield (5%) and nitrogen values in characters like grain yield, biologic yield and stalk yield, harvest index, hundred grain weight, ear length, number of row in row of ear, number of grains in each row and grain number per row of ear (1%) and ear thick (5%) became significant and also interaction between irrigation interval and nitrogen values and biologic yield and stalk yield had significant effect (1%). Grain yield consumption 184 kg nitrogen in hectar than to not consuming 19.8% had significant in crease. The maximum harvesting index obtained for treatment without consuming nitrogen and increasing nitrogen consumption until 184 kg/ha, harvesting index decreased because of intensity of increasing stalk yield than to grain so that stalk yield than to control in creased about 45.3%. The relatively growth rate under nitrogen values for irrigation interval 75, 125 and 150mm evaporation from class A evaporation pan was almost equal and just under irrigation interval 100mm evaporation from evaporation class A evaporation pan, the relatively growth rate consuming 96 and 184 kg/ha nitrogen increased in all growth stages. In leaf area index and special leaf weight in treatments of irrigation interval consuming 184 kg nitrogen in hectar specially in final stages of growth period was maximum. Net assimilation rate in conditions without consuming nitrogen for all irrigation interval in final of growth period comparison to consumption 96 and 184 kg nitrogen in hectar became negative. The most changes processes of bush height observed from stage 8 leaves to then consuming 184 kg nitrogen in hectar and bush height in tassel appearance with irrigation interval 125mm evaporation from evaporation class A pan obtained.