Prof. dr. sc. Ružica Lešić (Osijek, 9. siječnja 1928. – Zagreb, 20. prosinca 2022.)

Ožalošćeni smo jer je preminula dr. sc. Ružica Lešić, sveučilišna profesorica Agronomskog fakulteta u Zagrebu. Napustila nas je draga i plemenita osoba koja je odgojila i obrazovala generacije studenata i savjetima pomogla velikom broju uzgajivača povrća

The conditions of tomato growing

Rajčica je jedno od najraširenijih povrća u svijetu. Jede se plod. Cvjetovi rajčice skupljeni su u cvatu u obliku grozda. Pripada skupini termofilnih kultura. Minimalna temperatura klijanja sjemena i nicanja jest 11 do 13 °C, a maksimalna oko 35 °C. Optimalna temperatura rasta jest 20 do 25 °C danju i 13 do 17 °C noću. Rast prestaje pri temperaturi nižoj od 10 °C. Pri temperaturi 0 ºC biljka strada. Potrebna je osvijetljenost najmanje 10.000 lx. Od oplođene plodnice cvijeta do zrelog potpuno obojenog ploda potrebno je 7 do 9 tjedana, ovisno o sorti, položaju cvata na biljci i uvjetima okoliša. Crvena se boja ploda ne razvija ispod 16 ºC. Uzgoj je rajčice na otvorenom moguć samo u bezmraznom razdoblju. Rast i razvoj do prvih zrelih plodova može trajati 90 do 110 dana.Tomato is one of the most widened vegetable crops in the world. Tomato fruits are useful for food. The tomato inflorescence has the form of truss. Tomato belongs to the group of warm season crops. The minimum temperatures for seed germination and plant emergence are between 11 and 13 °C, and the maximum temperatures are around 35 °C. The optimal temperatures of tomato growth are between 20 and 25 °C by day, and between 13 and 17 °C at night. The tomato growth is stopped at temperatures below 10 °C. The tomato plant is damaged by temperature of 0 °C. The tomato growth demands the least 10,000 lx of illuminance. From the ovary fertilization up to the ripe and fully coloured fruit it is necessary 7 till 9 months. That is depended on the variety, the truss position at plant, and the environment conditions. The red colour of fruit does not develop below 16 °C. The tomato growing at the open fields is possible only at frost free period. The period of the tomato growth and development up to the first ripe fruits can be lasted 90 till 110 days

Prof. dr. sc. Ružica Lešić (Osijek, 9. siječnja 1928. – Zagreb, 20. prosinca 2022.)

Ožalošćeni smo jer je preminula dr. sc. Ružica Lešić, sveučilišna profesorica Agronomskog fakulteta u Zagrebu. Napustila nas je draga i plemenita osoba koja je odgojila i obrazovala generacije studenata i savjetima pomogla velikom broju uzgajivača povrća

Comparison of Transpiration Models in Tomato Soilless Culture

A two-year greenhouse study was performed to determine the possibility of estimating the transpiration rate in hydroponically grown tomato on the basis of climate parameters. Transpiration rate, determined by the water balance method on different substrates, was compared to the transpiration rate calculated using the Penman Monteith equation. Regression analysis of the comparison of two different approaches to water consumption determination confirmed that the transpiration rate of greenhouse grown tomato for the studied area can be estimated with high accuracy (R2 > 0.95)

Agronomic traits of tomato at different ammonium nitrate concentrations in the nutrient solution

Cilj istraživanja bio je utvrditi agronomska svojstva dva kultivara rajčice u hidroponskom uzgoju na kamenoj vuni, pri standardnoj i 50 % povećanoj koncentraciji amonijevog nitrata u hranjivoj otopini. Tijekom plodonošenja brani su plodovi s 8 grozdova prikraćenih na 5 plodova. Utvrđeni su masa i prinos tržnih plodova po grozdu i ukupno, broj tržnih i netržnih plodova po m2 te udio netržnih plodova sa simptomima vršne truleži. Po m2 ubrano je od 99,2 do 112,0 tržnih plodova, a udio netržnih plodova je iznosio od 5,42 do 8,38 %. U interakciji sa standardnom otopinom oba kultivara su na svim grozdovima razvila krupnije plodove. Tijekom plodonošenja razvili su plodove podjednake krupnoće (od 205 do 207 g). Najkrupnije plodove, mase 220 g razvio je kultivar Buran uz primjenu standardne hranjive otopine. Kultivar Buran je ostvario 7,24 % viši ukupni tržni prinos od kultivara Belle (21,40 kg/m2) dok je primjenom standardne hranjive otopine ostvaren 13,79 % viši prinos u odnosu na otopinu s povećanom koncentracijom NH4NO3 (20,74 kg/m2). Najviši ukupni tržni prinos ostvario je kultivar Buran uz primjenu standardne hranjive otopine (24,55 kg/m2), a najniži kultivar Belle uz primjenu hranjive otopine s povećanom koncentracijom amonijevog nitrata (20,13 kg/m2). Zbog razvijenih krupnijih plodova i višeg ostvarenog prinosa te manjeg udjela netržnih plodova prilikom primjene standardne otopine za krupnoplodne kultivare se ne preporučuje povećanje koncentracije amonijevog nitrata u hranjivoj otopini.The aim of this research was to determine the agronomic traits of two tomato cultivars grown in soilless culture on rockwool, fertigated with the standard and 50 % increased ammonium nitrate concentration in the nutrient solution. During the harvest period, fruits from 8 clusters shortened to 5 fruits were harvested. Fruit weight and marketable yield per cluster and in total, the number of marketable and unmarketable fruits per m2 and share of unmarketable fruits with blossom-end rot symptoms were determined. Between 99.2 and 112.0 marketable fruits was harvested per m2, while the share of unmarketable fruits varied from 5.42 to 8.38 %. Both cultivars developed larger fruits in all clusters when they were fertigated with the standard nutrient solution. During the harvest period they developed fruits which weighed between 205 to 207 g, respectively. Cv. ‘Buran’ fertigated with the standard nutrient solution has developed the highest fruit weight (220 g). The same cultivar has achieved a 7.24 % higher marketable yield than cultivar Belle (21.40 kg/m2). Fertigation with the standard nutrient solution resulted in 13.79% higher yield compared to the solution with higher NH4NO3 concentration (20.74 kg/m2). The highest total marketable yield (24.55 kg/m2) was achieved by cv ‘Buran’ fertigated with the standard nutrient solution, while the lowest (20.13 kg/m2) was achieved by cv. ‘Belle’ fertigated with nutrient solution that contained higher concentration of ammonium nitrate. Because of the higher fruit weight and marketable yield, and also the lower unmarketable fruits share was achieved with the standard nutrient solution, increasing the ammonium nitrate concentration for beefsteak cultivars is not recommended

Agronomic traits of tomato at different ammonium nitrate concentrations in the nutrient solution

Cilj istraživanja bio je utvrditi agronomska svojstva dva kultivara rajčice u hidroponskom uzgoju na kamenoj vuni, pri standardnoj i 50 % povećanoj koncentraciji amonijevog nitrata u hranjivoj otopini. Tijekom plodonošenja brani su plodovi s 8 grozdova prikraćenih na 5 plodova. Utvrđeni su masa i prinos tržnih plodova po grozdu i ukupno, broj tržnih i netržnih plodova po m2 te udio netržnih plodova sa simptomima vršne truleži. Po m2 ubrano je od 99,2 do 112,0 tržnih plodova, a udio netržnih plodova je iznosio od 5,42 do 8,38 %. U interakciji sa standardnom otopinom oba kultivara su na svim grozdovima razvila krupnije plodove. Tijekom plodonošenja razvili su plodove podjednake krupnoće (od 205 do 207 g). Najkrupnije plodove, mase 220 g razvio je kultivar Buran uz primjenu standardne hranjive otopine. Kultivar Buran je ostvario 7,24 % viši ukupni tržni prinos od kultivara Belle (21,40 kg/m2) dok je primjenom standardne hranjive otopine ostvaren 13,79 % viši prinos u odnosu na otopinu s povećanom koncentracijom NH4NO3 (20,74 kg/m2). Najviši ukupni tržni prinos ostvario je kultivar Buran uz primjenu standardne hranjive otopine (24,55 kg/m2), a najniži kultivar Belle uz primjenu hranjive otopine s povećanom koncentracijom amonijevog nitrata (20,13 kg/m2). Zbog razvijenih krupnijih plodova i višeg ostvarenog prinosa te manjeg udjela netržnih plodova prilikom primjene standardne otopine za krupnoplodne kultivare se ne preporučuje povećanje koncentracije amonijevog nitrata u hranjivoj otopini.The aim of this research was to determine the agronomic traits of two tomato cultivars grown in soilless culture on rockwool, fertigated with the standard and 50 % increased ammonium nitrate concentration in the nutrient solution. During the harvest period, fruits from 8 clusters shortened to 5 fruits were harvested. Fruit weight and marketable yield per cluster and in total, the number of marketable and unmarketable fruits per m2 and share of unmarketable fruits with blossom-end rot symptoms were determined. Between 99.2 and 112.0 marketable fruits was harvested per m2, while the share of unmarketable fruits varied from 5.42 to 8.38 %. Both cultivars developed larger fruits in all clusters when they were fertigated with the standard nutrient solution. During the harvest period they developed fruits which weighed between 205 to 207 g, respectively. Cv. ‘Buran’ fertigated with the standard nutrient solution has developed the highest fruit weight (220 g). The same cultivar has achieved a 7.24 % higher marketable yield than cultivar Belle (21.40 kg/m2). Fertigation with the standard nutrient solution resulted in 13.79% higher yield compared to the solution with higher NH4NO3 concentration (20.74 kg/m2). The highest total marketable yield (24.55 kg/m2) was achieved by cv ‘Buran’ fertigated with the standard nutrient solution, while the lowest (20.13 kg/m2) was achieved by cv. ‘Belle’ fertigated with nutrient solution that contained higher concentration of ammonium nitrate. Because of the higher fruit weight and marketable yield, and also the lower unmarketable fruits share was achieved with the standard nutrient solution, increasing the ammonium nitrate concentration for beefsteak cultivars is not recommended