Search

Search Results

• Analysing the plant density response of sunflower (Helianthus annuus L.) on heterogeneous production sites

  87-95

  Szabolcs Monoki

  Views:

  17

  Sunflower is considered a crop that uses soil moisture to the maximum, but it is true that the amount of available water is a limiting factor. Sunflower hybrids use soil water resources with varying efficiency, which is also greatly influenced by the number of plants sown per hectare. The use of satellite remote sensing and positioning, sensor-based measurement, GIS data analysis and processing software, and the emergence and use of technical solutions for differentiated sowing rates, open up the possibility of examining the possibility of site-specific plant density control in sunflower production. In this study, an attempt was made to determine the best sunflower plant density interval for the heterogeneous fertility zones of a given production area. The fertility zones were established using novel GIS methods. In the selected sample areas, three distinct fertility zones were defined. In each fertility zone, three plant density steps were used in four replicates. In the high and average fertility zones, increasing plant density resulted in slightly higher yields, while in the low fertility zones, sowing with reduced plant density did not cause a significant yield difference compared to the standard value. For moisture and oil content, no practical differences between plant density values could be detected.

• Comparative analyses of tetraploid genotypes produced by androgenesis

  113-126

  Árpád Székely

  Tímea Szalóki

  János Pauk

  Csaba Lantos

  Mihály Jancsó

  Views:

  14

  Plant breeding uses androgenesis-derived dihaploids for faster breeding. A small percentage of autotetraploids are also produced during the production of dihaploids. This paper presents a microplot field study of these tetraploids. The experiment used 6–6 diploid-tetraploid pairs, which are the results of three different combinations. In addition to phenological data (emergence, plant height, developmental stage on BBCH scale), yield and its components (panicle length, number of filled grains, number of unfilled grains, fertility) were also determined. The uniform vegetative development of tetraploids did not differ from that of diploids. However, they have a longer cropping period due to the prolongation of the reproductive phase. The least time delay was observed in line of 1087/8/35T, making it one of the shortest growing time tetraploid lines. In addition, this genotype has the highest number of filled grains and the second lowest unfilled grains, causing a very high fertility (~60%). This value is very encouraging, as conventional tetraploid lines have a fertility of 50%, while the new neo-tetraploid and PMeS lines have fertility in the range of 68–80%. With the expansion of experiments, hopefully, the genotypes with higher fertility will be identified.