Growth and development of barley from planting to harvesting

Ječam (Hordeum vulgare L.) je jednogodišnja biljka iz porodice Poaceae (trava), roda Triticum. Jedna je od najstarijih i najvažnijih krušarica na svijetu. Ima žiličast korijenov sustav i člankovitu, šuplju stabljiku, visine do 1,5 metar. Stabljika ječma naziva se vlat. List je građen od plojke i rukavca između kojih su smještene uške i dobro razvijen jezičak. Najgornji list naziva se zastavica i ima najveći utjecaj na prinos. Cvat se naziva klas. Na svakom nodiju klasnog vretena može razviti po jedan, dva ili tri klasića. Ovisno o tome imamo dvoredni (pivarski), višeredni (stočni) i prijelazni ječam. Plod ječma je zrno ili pšeno koje je sraslo s pljevicama. Može se uzgajati kao ozimi ili jari, a tijekom životnog ciklusa ječam prolazi 8 faza rasta i razvoja (klijanje, nicanje, busanje, vlatanje, klasanje, cvatnju, formiranje i nalijevanje zrna i zriobu), 12 etapa organogeneze i 5 stadija razvoja (jarovizacija, svjetlosni stadij, spektrostadij, stadij intenzivne svjetlosti i stadij naglašene mineralne ishrane). Trajanje određenih faza značajno ovisi o čimbenicima vanjske sredine, prvenstveno o vremenskim prilikama u pojedinoj godini, pa sukladno tome varira i prinos zrna ječma. Kultura je dugog dana, vrlo rana, napušta tlo 8 do 10 dana ranije od pšenice. Skromnih je zahtijeva prema temperaturi, nakon kaljenja mlade biljke mogu izdržati i do –12 °C, a u fazi nalijevanja zrna lakše podnosi visoke temperature (od 38 °C do 40 °C). Dobro podnosi sušu jer ekonomično troši vodu i ima mali transpiracijski koeficijent (300 do 350). Zbog slabo razvijenog korijenovog sustava potrebno ga je uzgajati na plodnijem tlu. Ječam je potrebno uzgajati u plodoredu. Najbolji predusjevi za ječam su jednogodišnje zrnate mahunarke. Gnojidbu je potrebno obavljati sukladno namjeni ječma i na osnovu kemijske analize, a gnojiva dodavati u različitim vremenskim periodima kako bi hranjiva bila dostupna biljci u svim fazama razvoja, u osnovnoj obradi, pripremi tla za sjetvu, u startu i prihrani. Osnovna obrada tla za ječam obavlja se na dubini 20 cm do 25 cm. Optimalni rok za sjetvu ozimog ječma je od 1. listopada do 15. listopada, a jarog kraj veljače i početak ožujka. Žetva ječma obavlja se žitnim kombajnom, najvećim dijelom krajem lipnja i početkom srpnja. U Hrvatskoj se godišnje zasije više od 50 000 ha ječma s prosječnim prinosom preko 3 t/ha. U Njemačkoj prosječan prinos ječma je iznad 5 t/ha, u Belgiji čak i preko 7 t/ha.Barley (Hordeum vulgare L.) is a one year plant from the family Poaceae (grass), genus Triticum. It is one of the oldest and most important grains in the world. It has a haired root system and a branch like, hollow stem which grows to a height of 1,5 m. The barley stem is called a collar and consists of the leaf blade, leaf sheath wrapping around the stem, auricles and ligule. The topmost blade is called the flag leaf and it has the most influence on the plant yield. The floral structure is made up of two or three spikelets and depending on the amount of spiklets barley is divided into two-row and six-row barley. The product of barley is kernal. The growth cycle of barley is as follows: germination, seedling establishment and leaf production, tiltering, stem elongation, pollination and kernal development and maturity, which includes 12 stages of organogenesis and 5 stages of development (vernalization, light stage, spectro stage, stage of intense light and stage pronounced mineral nutrition). Many different factors affect the growth and duration of each part of the cycle with the main influence having weather conditions which directly affect the quality and amount of yield. Barley begins its growth a full 8 to 10 days before wheat, with it begin more adaptive to temperature changes. It is possible for barley, in the seedling establishment phase, to survive temperatures for the plant are between 38 °C and 40 °C. As far as water consumption is concerned, it has a transpiration koeficient of 300 to 350 allowing it to handle drought easily. The main drawback is that the root system is weak and so the plant must be grown in fertile ground to maximise output. For maximum output barley should be grown in crop rotation, with the previous years harvest being one year legumes. Additional fertilization should be done in accordance with the chemical analysis of the ground and at times when this is optimal for the plant. Those times may be: during different phases of development, primary processing of the plant, or preparation for harvesting. Primary ground preparation for barley is done at a debth of 20 cm to 25 cm. The optimal planting times for barley are from October 1. to October 15., or the end of February and begining of March, while harvesting is done with wheat combines during June and July. Croatia plants more that 50 000 ha of barley with an average yield of 3 t/ha. Germany has a barley yield of 5 t/ha while Belgium has an average of over 7 t/ha