CORRELATIONS BETWEEN MORPHOLOGICAL, AGRONOMIC AND CHEMICAL CHARACTERISTICS OF F₁ FLUE-CURED TOBACCO HYBRIDS

Istraživane su fenotipske koleracije morfoloških, gospodarskih i kemijskih svojstava F₁ hibridnih sorata duhana tipa „flue cured“. Za izračunavanje korelacije su korišteni dvogodišnji prosjek morfoloških, gospodarskih i kemijskih svojstava. Prinos je bio u najvisoj korelaciji sa duljinom srednjeg lista, duljinom vegetacije, zatim sa visinom biljke i brojem listova po biljci. Kvaliteta osušenog lista (indeks vrijednosti) nije bila u korelaciji s nijednim kemijskim ni morfološkim svojstvom. Isto tako, indeks vrijednosti nije bio koreliran s prinosom. Od kemijskih svojstava je sadržaj reducirajućih šećera bio u značajnoj pozitivnoj korelaciji s visinom biljke, duljinom srednjeg lista, duljinom vegetacije i prinosom.Phenotypic correlations between morphological, agronomic and chemical characteristics 12 F₁ flue-cured tobacco hybrids were calculated. The data of a two year variety test, conducted as a three replication rendomized complete block design Jezero near Vrgorac, were used for for the calculations. Yield was in the highest correlation with the lenght of the middle leaf, leniht of the vegetation period, plant hight and number of leaves per plant. Ouality of the cured leaves was very little in correlation with the morphological and chemical characteristic studied. Also, the cured leaf quality was very little in correlation with yield. Among chemical characteristics only content of reducing sugars was in a significant correlation with height of plant, lenght of middle leal, lenght ,of vegetation period and yield

Breeding field crops and vegetables in Croatia

Prva sorta poljoprivrednog bilja odabrana iz planskog međusortnog križanja u Hrvatskoj bila je sorta kukuruza Stražimirac. Autor sorte bio je Dragutin Stražimir iz Donje Zeline. Sorta se proširila u proizvodnji polovinom XIX stoljeća. Početak znanstvenog oplemenjivačkog rada u Hrvatskoj bio je vezan uz Kraljevsko gospodarsko-šumarsko učilište u Križevcima. G. Bohutinsky je prvi hrvatski biljni oplemenjivač i znanstvenik. Radio je na ovom učilištu od 1904-1914.g. Najviše je poznat po sorti pšenice Sirban prolifik. Bohutinsky i Mandekić već u prvoj dekadi XIX st. rade i na proučavanju samooplodnih linija i hibrida kukuruza. Ovaj problem su kasnije, prije II svjetskog rata, na Poljoprivredno-šumarskom fakultetu u Zagrebu proučavali Tavčar i Kvakan. Nakon Mandekića u Križevcima je radio na oplemenjivanju poljoprivrednog bilja Korić od 1922-1931., kada je prešao u Osijek. Najpoznatija mu je sorta pšenice U1. Bio je uspješan i u oplemenjivačkom radu na kukuruzu. Tavčar je bio autor više sorata poljoprivrednih kultivara iako je bio prvenstveno genetičar i pedagog. Prije drugog svjetskog rata na oplemenjivanju bilja rađeno je uspješno i na vlastelinstvima u istočnoj Hrvatskoj, već od 1909. na imanju grofa Pejačevića u Rumi, nešto kasnije na imanju grofa Eltza u Vukovaru i dr. Nakon II svjetskog rata oplemenjivački rad na poljoprivrednom i povrtnom bilju bio je najviše izvođen u Institutu za oplemenjivanje i proizvodnju bilja u Zagrebu (danas Bc Instutut) i na Poljopirvednom institutu u Osijeku. Na oplemenjivanju duhana radilo se u Duhanskom instutu u Zagrebu, a na šećernoj repi u Institutu za šećernu repu u Osijeku. Na oplemenjivanju povrća rađeno je u Institutu za povrće u Botincu. Na oplemenjivanju bilja rađeno je i na sadašnjem Agronomskom fakultetu u Zagrebu i na Poljoprivrednom instututu u Križevcima, a u novije vrijeme i u nekoliko privatnih tvrtki. Hrvatskim biljnim oplemenjivačima je do 1999. g. priznato ukupno 730 domaćih kultivara pretežno oraničnog bilja. Najpoznatija imena nakon II svjetskog rata su Potočanac, autor prvih visokorodnih polupatuljastih sorata pšenice i Palaveršić, autor prvog hrvatskog hibrida kukuruza. Selekcije oba autora su svojevremeno dominirala u proizvodnji u Hrvatskoj. Kod većine poljoprivrednih kultura domaće selekcije su i danas najviše tražene od strane hrvatskih proizvođača.The first field crop variety developed from a two variety cross was the maize variety Stražimirovac. Its author was Dragutin Stražimir, a priest in Donja Zelina. The variety became very popular among the maize producers around the middle of XIXth century. However, the beginning of scientifically based plant breeding was at the Royal High School for Agriculture and Forestry in Križavci during the first decade of XXth century. The first Croatian breeder scientist was Bohutinsky. He was best known by his wheat variety Sirban Prolifik. Bohutinsky worked on developing maize inbred lines and hybrids too, together with Mandekić. On the same topic worked Tavčar and Kvakan at the Faculty of Agriculture and Forestry in Zagreb, before the IInd World War. After Mandekić, the breeding program in Križevci was continued by Korić. He came to Križevce in 1922 and went to work in Osijek in 1931. His great success was the wheat variety U1, although he warked on several crop species. At the beginning of this century, breeding work was successfully done on large private farms in Eastern Croatia as well, i.e. on the farm of count Pejačević in Ruma, on the farm of count Eltz in Vukovar etc. After the II nd World war breeding work on field crop species was carried out mostly in the Institute for Plant Breeding and Production (Bc Institute) in Zagreb, and in the Agricultural Institute in Osijek. Tobacco breeding was done in the Tobacco institute Zagreb, sugar beet breeding in the Institute for Breeding Sugar Beet in Osijek and vegetable breeding in the Institute for Vegetable Breeding in Botinec. Also plant breeding was done at the Faculty of Agriculture in Zagreb, at the Agricultural High School in Križevci and at the Potato Breeding Station in Stara Sušica. More recently several private plant breeding firms have been established. Until 1999, 730 domestic varieties have been released from the Croatian plant breeding programs, mostly of the field crops. The most known names among the breeders after the IInd World war were Potočanac, author of first Croatian semidwarf high yielding wheats, and Palaveršić, author of first Croatian maize inbred hybrids. Domestic varieties of many field crop species were the only ones, that Croatian farmers preferred to grow

Effect of Within-Row Spacing on Agronomic and Morphological Characteristics of the Flue-Cured Tobacco Cultivars

In flue-cured tobacco (Nicotiana tabacum L.) production the aim is improvement of yield and quality (usability) of cured leaf. This has been achieved through development of new cultivars and adjustment of cultural practices. In Croatia, most of the flue-cured tobacco is grown at plant spacing of 45 cm within and 100 cm between rows, i.e. at planting density of about 22,000 plants per ha. In order to evaluate the effect of decreased planting density on agronomic and morphological characteristics of flue-cured tobacco, field experiments with six flue-cured tobacco cultivars and two within row plant spacings (45 and 55 cm) were conducted at two locations in the main Croatian flue-cured tobacco growing regions, over four years (2005 to 2008). Wider spacing within rows resulted in 396.12 kg ha-1 higher yield and 861.01 $ ha-1 higher value than the closer spacing. Change in price was not significant. Length, width, and leaf area of the 9th leaf also increased significantly at 55 cm within row spacing, while plant height and leaf number were unchanged. Cultivar x plant spacing and environment x plant spacing interactions were not significant for the studied traits. Results indicate that higher yield, higher value and good quality of cured tobacco leaf could be produced at 55 cm within row spacing (about 18,000 plants per ha)

Stalk rot resistance in Maksimir 3 synthetic maize population after four cycles of recurrent selection

Fusarium stalk rot (FSR) and anthracnose stalk rot (ASR), caused by Fusarium spp. and Colletotrichum graminicola (Ces.) G.W. Wils. respectively, are the two most important stalk diseases in maize which increase the incidence of stalk lodging and reduce grain yield. The aim of the present study was to (1) evaluate the effect of four cycles of recurrent selection in the Maksimir 3 Synthetic (M3S) maize population on ASR and FSR resistance and (2) to investigate the correlation among the different disease rating methods. The experiment included six M3S cycle populations per se and their test-crosses with a single cross hybrid. ASR resistance was estimated on artificially inoculated plant rows using three ratings (the number of infected internodes, the number of internodes rotten more than 75% and evaluation of outer stalk discoloration) whereas FSR resistance was estimated in artificially inoculated rows as well as in naturally inoculated rows by rating severity of disease symptoms on longitudinally cut stalks using the standard resistance scale. The results of the present study showed that four cycles of selection in the M3S maize population, conducted primarily for grain yield improvement, did not significantly affect its resistance to both ASR and FSR. Among the disease ratings a moderate positive correlation was found only between two ASR resistance ratings (the number of infected internodes and the number of internodes rotted more than 75%) in both population per se (r=0.49**) and population test-crosses (r=0.56**)