No abstract

Wheat cultivars differ in their response to nitrogen (N) fertilizer, both in terms of its uptake and utilization. Characterizing this variation is an important step in improving the N use efficiency (NUE) of future cultivars while maximizing production (yield) potential. In this study, we compared the agronomic performance of 48 diverse wheat cultivars released between 1936 and 2016 at low and high N input levels in field conditions to assess the relationship between NUE and its components. Agronomic trait values were significantly lower in the low N treatment, and the cultivars tested showed a significant variation for all traits (apart from the N remobilization efficiency), indicating that response is genotype-dependent, although significant genotype × environment effects were also observed. Overall, we show a varietal improvement in NUE over time of 0.33 and 0.30% year–1 at low and high N, respectively, and propose that this is driven predominantly by varietal selection for increased yield. More complete understanding of the components of these improvements will inform future targeted breeding and selection strategies to support a reduction in fertilizer use while maintaining productivity.

No abstract

One of the most severe winter wheat (Triticum aestivum L.) diseases is Fusarium head blight (FHB). It is believed that selection for resistance to FHB is better in high disease pressure environments, for which various methods of artificial inoculation are used. The standard spray method of artificial inoculation is believed to be technically demanding and labour intensive. Therefore, scattering Fusarium-infected maize stalks onto trial plots after wheat emergence is suggested as a suitable alternative. The aim of this study was to compare the mean values and heritability of the visual rating index (VRI) and the percentage of Fusarium-damaged kernels (FDK) between the two abovementioned methods of artificial inoculation and natural infection, and to determine the phenotypic correlations between the three methods for the studied traits. The achieved levels of VRI and FDK were comparable for the two methods of artificial inoculation and considerably lower under natural conditions. Heritability for VRI ranged over four years from 0.68 to 0.91 for the spray method, from 0.73 to 0.95 for the infected maize stalks, and from 0.26 to 0.65 for natural infection, whereas for FDK it ranged from 0.56 to 0.85, 0.38 to 0.83, and 0.11 to 0.44 for the three inoculation methods, respectively. The strong positive correlation between the two applied methods of artificial inoculation for studied traits suggests that scattering infected maize stalks could serve as a reliable supplement for the technically and labor-intensive spray method of artificial inoculation.

Pšenica je po proizvodnji druga najvažnija ratarska kultura u Republici Hrvatskoj. Uvođenjem Kodeksa otkupa žitarica i uljarica, pored uroda zrna, sve veća važnost poklanja se parametrima kvalitete zrna pšenice, prvenstveno sadržaju proteina i hektolitarskoj masi, koji direktno utječu na cijenu pšenice prilikom otkupa. Genetski potencijal sorte kao i okolinski uvjeti izravno utječu na navedene parametre. Trogodišnjim istraživanjem provedenim na lokaciji Staro Topolje na 12 sorti ozime pšenice, uzgajanim pri tri različite razine gnojidbe dušikom, procijenjen je utjecaj godine, sorte i tretmana dušičnim gnojivom na sadržaj proteina, hektolitarsku masu i masu 1000 zrna. Prema dobivenim rezultatima utvrđen je signifikantan utjecaj godine, sorte i tretmana dušičnim gnojivom na sadržaj proteina. Najveći utjecaj na ovo svojstvo imala je godina, zatim tretman dušičnim gnojivom, a najmanji sorta. Signifikantan utjecaj godine i sorte utvrđen je i za hektolitarsku masu, dok tretman dušičnim gnojivom nije signifikantno utjecao na ovo svojstvo, uz činjenicu da je utjecaj godine bio znatno veći u odnosu na sortu. Također je utvrđeno da su sve testirane sorte jednako reagirale na tretman dušičnim gnojivom. Prosječni sadržaj proteina pri najnižoj količini primijenjenog dušičnog gnojiva iznosio je 11,08 %, pri srednjoj 11,95 %, a pri najvišoj 12,89 %.