Cabbage seedlings morphology and the appearance of harmful organisms in hydroponic cultivation

Proizvodnja kvalitetnih i zdravih presadnica predstavlja jedan od najosjetljivijih dijelova proizvodnje. Tijekom proizvodnje presadnica vrlo je važno spriječiti pojavu i širenje najznačajnijih bolesti i štetnika jer se biljka nalazi u najosjetljivijem periodu života. U istraživanju, presadnice su uzgojene kovencionalno u polistirenskim kontejnerima i hidroponski u plutajućem hidroponu. Usporedbom ovih dviju tehnologija uzgoja dobivene su presadnice različitih morfoloških svojstava uz istovremenu mogućnost praćenja pojave štetnika i bolesti u proizvodnji presadnica. U konvencionalnom uzgoju presadnice su bile kraće, imale manju biomasu, manji broj razvijenih listova manje lisne površine. Presadnice iz hidroponskog uzgoja bile su duže, imale veću biomasu i bolje razvijen korijenov sustav te veći broj listova s većom lisnom površinom. Također, listovi hidroponski uzgojenih presadnica bili su tamnije zelene boje. Iz rezultata se može zaključiti kako su hidroponski uzgojene presadnice zbog svoje razvijenosti bile ranije spremne za sadnju u odnosu na konvencionalne, odnosno moguće je skraćenje proizvodnog ciklusa. Tijekom hidroponske proizvodnje presadnica uočena je pojava kupusnog moljca i kupusnih buhača te u manjem intenzitetu polijeganja presadnica i plamenjače kupusa. Iako su navedeni štetni organizmi temeljem praćenja uspješno suzbijeni primjenom kemijskih mjera zaštite, potrebno je razmotriti i primjenu drgih metoda suzbjanja kao i primjenu sredstava za zaštitu bilja putem hranive otopine.The production of quality and healthy seedlings is one of the most sensitive parts of production. During the seedlings production, it is very important to prevent the appearance and spread of the most significant diseases and pests, because the plant is in the most sensitive period of its life. In the research, seedlings were grown conventionally in polystyrene containers and hydroponically in a floating system. By comparing these two growing technologies, seedlings of different morphological traits were obtained, with the simultaneous possibility of monitoring the appearance of pests and diseases during the seedlings production. In conventional cultivation, the seedlings were shorter, have less biomass, fewer developed leaves and less leaf area. Seedlings from hydroponic cultivation were longer, with higher biomass and a better developed root system, as well as a higher number of leaves with a larger leaf area. Also, the leaves of hydroponically grown seedlings were darker green. From the results, it can be concluded that due to their development, hydroponically grown seedlings were ready for planting earlier than conventional ones, which means that it is possible to shorten the production cycle. During the hydroponic production of seedlings, the appearance of cabbage moth and cabbage leafhoppers was observed, and to a lesser extent, seedling damping off disease and cabbage blight. Although the listed harmful organisms have been successfully controlled by using chemical protection measures based on monitoring, it is necessary to consider the use of other methods of control as well as the use of plant protection agents through nutrient solution