Abstract only

Giumri Breeding Station has been engaged in spring barley breeding since 1950. During that period, varieties of spring barley Nutans and Basargechari in 1941, Leninakani 6151 in 1945, Menikum 1 in 1956 and Nutans 115 in 1963 were developed. In 2002, variety Giurnri was released. Thro- ugh a crossing program utilizing complex cross [(Roland x Otis) x (EIginakh x Nutans 115)], large number of segregating populations were generated, which continued unti1 1989. Thereafter, individual plants of the desired type were selected for repro- ducing and testing in breeding nurseries. In 1995 they were included in the station and in 1998 the most advanced lines entered the state variety trials. As a result, spring barley variety Giumri was released in 2002, which exceeded Nutans 115 in yield by 12-15%. Giumri is more resistant to lodging and fungal diseases. Its yield potential under the optimal conditions can reach 6-6.5 ton/ha. To facilitate introduction and utilization of spring barley Giumri, we investigated the effect of seeding and nitrogen application rates on yield and grain quality. During the 2002-2003 seasons, the following seeding rates were studied: 100,150, 200, and 250 kg/ha. The 100-kg/ha seeding rate was studied as a cover crop rate. Seeding rates were studied across the following nitrogen rates: 60,80, and 100 kg, which were combined with p 140 K120. The plot area was 50 m2. The treatments were applied in 4 replications. Before fertilization and sowing, the content of accessible nutrients was determined in the 0-20 and 20-40 cm soil layers. Analysis of the yield data shows that increase of the nitrogen rate up to 60- 100 kg/ha is associated with considerable raise of spring barley yield, which becomes even more prominent at the seeding rate of 150 kg/ha(Table ). Grain yield increase at the seeding rate of 150 kg/ha was estimated in Nutans- 115 and Giumri to be 0.79 ton/ha, and 0.64 ton/ha respectively. Further increase of the seeding rates up to 200-250 kg/ha and nitrogen application rates is not associated with higher grain yield. The data presented in the table below shows that at the seeding rate of 150 kg/ha and at the nitrogen rate of 60- 100 kg/ha variety Giumri produces surplus yield at the level of O.42-0.48 ton/ha, which is by 10-12% higher than that of the check. Since the variety is envisaged for beer brewery purposes, nitrogen rates shall not exceed 60-80 kg/ha a. i., especially if potash and phosphorus fertilizers are not applied to the field. The study results suggest the following: (a) The optimal rates of seeding and nitrogen application for variety Giumri are 150 kg/ha and 100 kg a. i. / ha, respectively. (b) To ensure dense stand and weed control on comparatively poor and weedy soils, the seeding rate should be 200 kg/ha, and the nitrogen rate shall not exceed 60 kg/ha in order to avoid lodging.

English

0409|AGRIS 0401|AL-Wheat Program

Juan Carlos Mendieta

CIMMYT Publications Collection