DOI: 10.7904/2068–4738–IV(7)–95

 Kaberi DUTTA, Md. Raihan ALI, S M mahbubur RAHMAN and Md. Shamim AKHTER

Abstract.Epicotyls, hypocotyls & shoot tip were collected as explants from aseptically grown seedling for callus induction. MS media supplemented with different concentrations of 2,4–D (1.0, 2.0, 3.0, 4.0and 5.0mg.L^-1) along with NAA (0.2 mg.L^-1 or 0.5 mg.L^-1) or IAA (0.5 mg.L^-1) were used for efficient callus induction. Whitish, soft and watery calli were observed on the media supplemented with 0.5 mg.L^-1NAA + 2,4–D (1.0-5.0 mg L^-1) and 0.5 mg.L^-1 IAA + 2,4–D (1.0–5.0 mg.L^-1). The highest (100%) callusing response was obtained in MS + 2.0 mg.L^-1 2,4–D + 0.5 mg.^-1 NAA after three weeks of culture. Then subculture was done after four weeks for further growth onto same medium. Callus weight was recorded to find out the increasing potentiality of callus at different concentration of auxins.

Key words:  germination, Callus induction, sterilization, regeneration

DOI: 10.7904/2068–4738–IV(7)–86

 Lyubomir Iliev IVANOV, Nataliya Hristova PETROVSKA

Abstract. Maize is a thermophylic and hydrophilic crop. In the region of IASS “Obraztsov Chiflik”–Rousse temperature conditions are favorable for its cultivation, and precipitation and its distribution during vegetation proved to be a limiting factor. The objective of the study was the contrasting influence of the agro–climatic conditions on the mass of 1000 seeds, hectoliter mass and germination of RL 61/31 and H–108 lines to be determined in relation to their seed production and as donors of valuable genes in breeding. The experiment was conducted at the Experimental field of IASS “Obraztsov Chiflik”–Rousse during the period 2006–2008. It was designed after the Block method, in four replications. The results obtained showed that mass of 1000 seeds, hectoliter mass and germination in both lines were the lowest in the year with significant drought. Germination in both lines was strongly influenced by the agro–climatic conditions.

Keywords: maize, parental components, stress, tolerance

DOI: 10.7904/2068–4738–IV(7)–74

Anna ILIEVA, Viliana VASILEVA

Abstract: Effect of liquid organic humate fertilizer Humustim on chemical composition of aboveground biomass, root biomass and grain of spring forage pea was studied at the Institute of Forage Crops, Pleven, Bulgaria (2002–2004). Presowing treatment of seeds and treatments during vegetation were applied. The treatment with Humustim increased content of crude protein, macro elements and water–soluble carbohydrates in the aboveground biomass of plants. The highest content of crude protein (13.69%) and water–soluble carbohydrates (8.40%) was found for presowing treatment with Humustim at the dose of 1.2 L/t seeds + one treatment during vegetation. Applying of Humustim decreased crude protein content in roots from 5.0% to 17.8%. Treatment with Humustim had no effect on crude protein content in grain and increased water–soluble content (from 3.3% to 10.0%) and Са (from 11.1% to 77.8%). Better growth and development of spring forage pea were observed after treatment with Humustim–plant height and root length increased.

Keywords: spring pea, Humustim, crude protein, macro elements, water soluble carbohydrates

DOI: 10.7904/2068–4738–IV(7)–64

Vladimir LINGORSKI

Abstract.During the 2011–2012 period in the Research Institute of Mountain Stockbreeding and Agriculture (RIMSA) in Troyan (Bulgaria) the effect of sowing timeon somebio–productive indicators (green mass and dry matter yields, weed infestation) ofthe forage from annual winter cereal and legume mixture of winter barley and winter pea was performed. As variants the following sowing periods carried out during 10 days were studied: 1. 20^th–30^th September (Standard); 2. 1^st–10^th October; 3. 11^th–20^th October; 4. 21^st–30^th October. It was established that the most optimal time for sowing of mixed crop grown under foothill conditions of the Central Balkan Mountains (Troyan region) is the period from 1^st to 20^th October. The received forage amounted to 2.38 t.ha^–1 green mass and 0.59 t.ha^–1 dry mass, which exceeded the standard sowing period (20^th–30^th September) with 25.26% and 59.46%, respectively.Irrespective of the autumn sowing period, weed infestation of the crop of winter cereal–legume mixture was comparatively low, ranging from 0.74 to 4.88%.

Key words: winter crop,cereal and legume mixture, sowing time, forage productivity, weed infestation, foothill region, Central Balkan Mountains.

DOI: 10.7904/2068–4738–IV(7)–54

Vladimir LINGORSKI

Abstract.During the 2011–2012 periods in the Research Institute of Mountain Stockbreeding and Agriculture (RIMSA) in Troyan (Bulgaria) the effect of sowing timeon somebio–productive indicators (green mass and dry matter yields, weed infestation) ofthe forage from annual early–spring cereal–legume mixture from oats and field pea was performed. As variants the following periods of sowing were studied: 1. 10^th–20^th March (Standard); 2. 21^st–30^th March; 3. 1^st–10^th April; 4. 11^th–20^th April. It was established that the optimum time for sowing of annual early spring pea and spring oats mixed crop was the period from 10^th to 20^th March. Then was received most plant production (1.84 t.ha^–1 green mass and 0.41 t.ha^–1 dry matter), which exceeded the other sowing periods from 7.07% (21^st–30^th March) to 27.72% (11^th–20^th April) and from 1.6 to 8.13%, respectively. In the different sowing times the weed infestation of crops varied and was a highest in early spring sowing (10^th–20^th March)–from 8.40 to 9.26%.

Key words: early–spring crop,cereal and legume mixture, sowing time, forage productivity, weed infestation, foothill region, Central Balkan Mountains.