density in the cultivar-specific maize production technology.) Növénytermelés , 44 , 261-270.
A tőzám szerepe a fajtaspecifikus kukorica-termesztési technológiában. (The role of plantdensity in the cultivar-specific maize
Diepenbrock, W., Long, M., Feil, B. (2001): Yield and quality of sunflower as affected by row orientation, row spacing, and plantdensity. Die Bodenkultur (Austrian J. Agric. Res.) , 52, 55-62.
Yield and quality of sunflower as
The study reports the effect of the planting density of wild thyme (Thymbra spicatavar. spicata) on plant height, fresh herbage yield, dry herbage yield, dry leaf yield, essential oil content and essential oil yield. The results show that the highest fresh and dry herbage, dry leaf yield and essential oil yield were obtained from narrow row spacing and in-rows. However, fresh herbage, dry leaf yield and essential oil yield showed a variation of 0.993-1.463 kg m-2, 0.179-0.279 kg m-2and 33.6-50.9 L ha-1, respectively.
In maize, plant density has a considerable influence on the rate of dry matter accumulation and on its partitioning between vegetative and reproductive sinks. The aim of the present research was to use the first, second and third derivatives of the Richards function (RF) for growth analysis on maize hybrids grown at various densities. In two-factorial split-plot experiments carried out in Martonvásár, Hungary in 1997–1999 the growth analysis method was used to examine the effect of six plant densities (20, 40, 60, 80, 100 and 120 thousand plants ha
) on the growth of three maize hybrids (Mara, Mv 355, Florencia) with different vegetation periods. Plant density had a significant effect on the dynamics of dry matter accumulation, absolute growth rate (AGR) and absolute acceleration rate (AAR). There was a significant reduction in the asymptotic maximum (A) and growth parameters (AGR, AAR) of the whole plant and of the individual plant organs (stalk, leaf, ear and grain yield), while the parameters of the leaf area index (LAI) increased significantly with a rise in the plant density. The usefulness of the RF for approximating the growth processes of maize plants and individual plant parts was confirmed statistically.
Authors:Z. Gyenes-Hegyi, I. Pók, L. Kizmus and et al.
The plant height and the height of the main ear were studied over two years in twelve single cross maize hybrids sown at three different plant densities (45, 65 and 85 thousand plants/ha) at five locations in Hungary (Keszthely, Gönc, Gyöngyös, Sopronhorpács, Martonvásár). The results revealed that plant height and the height of the main ear are important variety traits and are in close correlation with each other. It was found that the hybrids grew the tallest when the genetic distance between the parental components was greatest (Mv 4, Mv 5). The height of the main ear was also the greatest in these hybrids, and the degree of heterosis was highest (193% for plant height, 194% for the height of the main ear). The shortest hybrids were those developed between related lines (Mv 7, Mv 11). In this case the heterosis effect was the lowest for both plant height (128%) and the height of the main ear (144%). The ratio of the height of the main ear to the plant height was stable, showing little variation between the hybrids (37–44%). As maize is of tropical origin it grows best in a humid, warm, sunny climate. Among the locations tested, the Keszthely site gave the best approximation to these conditions, and it was here that the maize grew tallest. The dry, warm weather in Gyöngyös stunted the development of the plants, which were the shortest at this location. Plant density had an influence on the plant size. The plants were shortest when sown at a plant density of 45,000 plants/ha, and the main ears were situated the lowest in this case. At all the locations the plant and main ear height rose when the plant density was increased to 65,000 plants/ha. At two sites (Gönc and Sopronhorpács) the plants attained their maximum height at the greatest plant density (85,000 plants/ha). In Keszthely there was no significant difference between these two characters at plant densities of 65 and 85 thousand plants/ha, while in Gyöngyös and Martonvásár the greatest plant density led to a decrease in the plant and main ear height. The year had a considerable effect on the characters tested.
Győrffy, B. (1979): Fajta-, növényszám és mutrágyahatás a kukoricatermesztésben. (Effect of variety, plantdensity and fertiliser in maize production.) Agrártudományi Közlemények , 38 , 309-331.
Fajta-, növényszám és
Roupakias, D.G., Zesopoulou, A., Kazolea, S., Daskalitses, G., Mavromatis, A., Lazaridou, T. 1997. Effectiveness of early generation selection under two plantdensities in faba bean ( Vicia faba L.). Euphytica 93 :63
Authors:T. Kiss, K. Balla, J. Bányai, O. Veisz and I. Karsai
The yield potential of wheat depends not only on genetic × environmental interactions, but also on various agronomic factors such as sowing date or the seed rate used for sowing. The main aim of this work was to determine possible correlations between the effects of different sowing dates and plant densities on the yield components of a collection of 48 wheat genotypes. Two-way analysis of variance on the data revealed that both sowing date and plant density, as main components, only had a minor effect on the yield component patterns. Correlation analysis, however, indicated that the sowing date had a greater effect on the yield components, while plant density was in closer correlation with the heading time (r = 0.90). The patterns determined for individual yield components at two different sowing dates and plant densities showed significant differences for spike length, spike fertility, grain number in the main spike, number of productive tillers, grain number on side tillers, mean grain number and grain weight. Genotypes that carry the winter (recessive) alleles of genes regulating vernalisation processes (VRN-A1, VRN-B1, VRN-D1) and the sensitive (recessive) alleles of the two genes responsible for photoperiod sensitivity (PPD-B1, PPD-D1) may have better tillering and consequently higher grain yield, though this may depend greatly on the year.
Field experiments were conducted during 1998 and 1999 in June-September with rice variety ASD18 at the wetland farm, Tamil Nadu Agricultural University, Coimbatore, India to find out theeffect of N management approaches and planting densities on N accumulation by transplanted rice in a split plot design.The main plot consisted of three plant populations (33, 66 and 100 hills m-2) and the sub-plot treatments of five N management approaches. The results revealed thatthe average N uptake in roots and aboveground biomass progressively increased with growth stages. The mean root and aboveground biomass Nuptake were 26.1 to 130.6 and 6.4 to 17.8 kg ha-1, respectively. The N uptake of grain and straw was higher in theSesbania rostratagreen manuring + 150 kg N treatment, but it was not effective in increasing the grain yield. The mean total N uptake was found to be significantly lower at 33 hills m-2(76.9 kg ha-1) and increased with an increase in planting density (100.9 and 117.2 kg ha-1at 66 and 100 hills m-2density). N application had a significant influence on N uptake and the time course of N uptake in all the SPAD-guided N approaches. A significant regression coefficient was observed between the crop N uptake and grain yield. The relationship between cumulative N uptake at the flowering stage and the grain yield was quadratic at all three densities. The N uptake rate (µN) was maximum during the active tillering to panicle initiation period and declined sharply after that. In general, µNincreased with an increase in planting density and the increase was significant up to the panicle initiation to flowering period.thereafter, the N uptake rate was similar at densities of 66 and 100 hills m-2.
Babu, N.K.-Vyakaranahal, B.S.-Shashidhara, S.D.-Giriraj, K. (1993): Effect of plantdensities on seed quality in parental lines of BSH-I hybrid and cv. Morden of sunflower. Karnataka Journal of Agricultural