Utjecaj zrelosti i povezanih uzgojnih postupaka na virdžinijski duhan I. : prinos, cijena i sadržaj nitrata u soku rebra lista kao indikator zrelosti za berbu - Čavlek, Miroslav; Gršić, Kristina (2019)
Istraživanje s ciljem utvrđivanja utjecaja visine zalamanja (17 i 20 listova za berbu), metode berbe (7, 4 i 3 berbe) i zrelosti (nezreli, zreli i prezreli) na prinos, cijenu i sadržaj nitrata u soku rebra u vrijeme berbe, provedeno je 2006. i 2008. godine. Primijenjen je split-split plot dizajn s čeiri ponavljanja. Viši prinosi u vršnom segmentu ostvareni su višim zalamanjem i obratno u dva niža segmenta. Utjecaj metode berbe na prosječne vrijednosti istraživanih svojstava bio je mali. Zrelost listova u vrijeme berbe u 2006. u pet od šest segmenata nije imala utjecaj na prinos. U 2008. najviši prinosi u vršna tri segmenta ostvareni su berbom zrelih listova. Najviše prosječne cijene u drugom i trećem segmentu ostvarene su berbom zrelih, a u višim segmentima prezrelih listova. Različito zreli listovi u vrijeme berbe u nekim segmentima su proizveli različite rezultate ovisno o visini zalamanja i metodi berbe. Sadržaj nitrata u soku rebra lista u vrijeme berbe kada su postignuti podjednaki ili viši prinosi i cijene opadao je odlaganjem berbe i, uz neke izuzetke, od donjih prema gornjim segmentima. Međutim, na osnovi rezultata ovog istraživanja nije bilo moguće odrediti kritične raspone sadržaja nitrata koji bi se mogli koristiti za procjenu zrelosti listova duhana za berbu.
The investigation aiming to determine the effect of topping heights (17 and 20 leaves for harvesting), harvesting methods (7, 4 and 3 harvests) and ripeness (unripe, ripe and overripe) on yield, price and petiole sap nitrate content at harvesting time, was carried out in 2006 and 2008. A split-split plot design with four replications was applied. Higher yields in top segment were achieved with higher topping, and converse in two lower segments. The effect of the harvest method on the average values of the investigated properties was small. Leaf ripeness at harvesting in 2006, in five out of six segments, had no impact on yields. In 2008 the highest yields in the top three segments were achieved by the harvest of ripe leaves. The highest average prices in the second and third segments were realized by harvesting ripe leaves and in the higher segments overripe leaves. Different ripe leaves at harvesting time in some segments produced different results depending on height of topping and method of harvesting. Petiole sap nitrate content at harvest when equal or higher yields and prices were achieved decreased by delaying harvesting and, with some exceptions, from lower to higher segments. However, based on the results of this research it was not possible to determine the critical nitrate content ranges that could be used to estimatia the ripeness of tobacco leaf for harvesting.
Nastavlja se.
Bibliografija: 16 jed.
Sažetak ; Abstract.
Keywords: Virdžinijski duhan -- Zrelost duhana -- Prinosi -- Visina zalamanja -- Nitrati