scholarly journals Morphological Studies on the Regularity of Shoot Development in Rice Plant. V. The regular modification in changes of organ length on main shoot with the same total leaf number.

1996 ◽  
Vol 65 (3) ◽  
pp. 479-486 ◽  
Author(s):  
Katsuya MATSUBA
Genetika ◽  
2003 ◽  
Vol 35 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Nada Hladni ◽  
Dragan Skoric ◽  
Marija Kraljevic-Balalic

The main goals of sunflower breeding in Yugoslavia and abroad are increased seed yield and oil content per unit area and increased resistance to diseases, insects and stress conditions via an optimization of plant architecture. In order to determine the mode of inheritance, gene effects and correlations of total leaf number per plant, total leaf area and plant height, six genetically divergent inbred lines of sunflower were subjected to half diallel crosses. Significant differences in mean values of all the traits were found in the F1 and F2 generations. Additive gene effects were more important in the inheritance of total leaf number per plant and plant height, while in the case of total leaf area per plant the nonadditive ones were more important looking at all the combinations in the F1 and F2 generations. The average degree of dominance (Hi/D)1/2 was lower than one for total leaf number per plant and plant height, so the mode of inheritance was partial dominance, while with total leaf area the value was higher than one, indicating super dominance as the mode of inheritance. Significant positive correlation was found: between total leaf area per plant and total leaf number per plant (0.285*) and plant height (0.278*). The results of the study are of importance for further sunflower breeding work.


1977 ◽  
Vol 28 (2) ◽  
pp. 183 ◽  
Author(s):  
MS Rahman ◽  
JH Wilson

The effects of adding phosphorus (40 kg of phosphorus ha-1) at sowing on rate of development, spikelet number per ear, rate of spikelet initiation, apex length at floral initiation, and leaf number at ear emergence of the main shoot of seven wheat cultivars were studied under a 16 hr photoperiod at a constant temperature of 20°C. Phosphorus additions increased the spikelet number per ear, rate of spikelet initiation, and apex length significantly in all wheats, but had no effect on the duration of the vegetative phase, spikelet phase or elongation phase, or on leaf number. The increase in spikelet number was due to an increase of spikelet initiation. All wheats responded similarly to addition of phosphorus.


1970 ◽  
Vol 5 (1) ◽  
Author(s):  
Lia Karlina Br Sembiring ◽  
Rosita Sipayung ◽  
Irsal

Massive breeding is often the case with the availability of the amount of water that can be stored on the media. The aim of this research is to know the influence of media and the frequency of watering on the growth of robusta coffee seedlings and to find the best media and optimum watering frequency. This experiment was conducted at the Faculty of Agriculture, University of Sumatera Utara, Medan from June to September 2017. The experimental method used was Factorial Randomized Block Design with 2 treatment factors, ie 1: planting medium ie, topsoil ; topsoil: sand (2: 1); topsoil: rice husk (2: 1), topsoil: charcoal husk (2: 1) and factor 2: watering frequency ie, watered once a day; watered every 4 days; watered 7 days and watered once every 10 days. The variable was plant height, stem diameter, total leaf number, total leaf area, fresh crown weight, canopy dry weight, fresh root weight, root dry weight, longest root, and canopy and root ratio. The results showed that planting media treatment had a significant effect on plant height variables, stem diameter increase, leaf number, total leaf area, fresh crown weight, canopy dry weight, fresh root weight, root dry weight, and root canopy ratio. The best treatment of planting medium was found in topsoil treatment: rice husk (2: 1). The treatment of watering frequency had a significant effect on the stem diameter 2 - 12 of the week after planting move observation variable, total leaf area, fresh crown weight, dry crown weight, fresh root weight, and dry weight of roots. The best treatment frequency of watering hose is watering every 4 days. The interaction between the two treatments had a significant effect on the diameter of the stem diameter variable, the total leaf area and the fresh weight of the canopy.


1998 ◽  
Vol 49 (2) ◽  
pp. 249 ◽  
Author(s):  
C. J. Birch ◽  
G. L. Hammer ◽  
K. G. Rickert

The ability to predict leaf area and leaf area index is crucial in crop simulation models that predict crop growth and yield. Previous studies have shown existing methods of predicting leaf area to be inadequate when applied to a broad range of cultivars with different numbers of leaves. The objectives of the study were to (i) develop generalised methods of modelling individual and total plant leaf area, and leaf senescence, that do not require constants that are specific to environments and/or genotypes, (ii) re-examine the base, optimum, and maximum temperatures for calculation of thermal time for leaf senescence, and (iii) assess the method of calculation of individual leaf area from leaf length and leaf width in experimental work. Five cultivars of maize differing widely in maturity and adaptation were planted in October 1994 in south-eastern Queensland, and grown under non-limiting conditions of water and plant nutrient supplies. Additional data for maize plants with low total leaf number (12-17) grown at Katumani Research Centre, Kenya, were included to extend the range in the total leaf number per plant. The equation for the modified (slightly skewed) bell curve could be generalised for modelling individual leaf area, as all coefficients in it were related to total leaf number. Use of coefficients for individual genotypes can be avoided, and individual and total plant leaf area can be calculated from total leaf number. A single, logistic equation, relying on maximum plant leaf area and thermal time from emergence, was developed to predict leaf senescence. The base, optimum, and maximum temperatures for calculation of thermal time for leaf senescence were 8, 34, and 40ºC, and apply for the whole crop-cycle when used in modelling of leaf senescence. Thus, the modelling of leaf production and senescence is simplified, improved, and generalised. Consequently, the modelling of leaf area index (LAI) and variables that rely on LAI will be improved. For experimental purposes, we found that the calculation of leaf area from leaf length and leaf width remains appropriate, though the relationship differed slightly from previously published equations.


Weed Science ◽  
2011 ◽  
Vol 59 (4) ◽  
pp. 489-494 ◽  
Author(s):  
Marisa Alcorta ◽  
Matthew W. Fidelibus ◽  
Kerri L. Steenwerth ◽  
Anil Shrestha

Horseweed is a common pest in vineyards of the San Joaquin Valley (SJV) of California. Interest in controlling this weed has increased with the recent discovery of a glyphosate-resistant (GR) biotype that has been observed to be more vigorous than a glyphosate-susceptible (GS) biotype in the SJV. However, the impact that either biotype may have on grapevine growth has not been assessed. Therefore, two glasshouse experiments were conducted to characterize the competitiveness of GR and GS horseweed biotypes from the SJV with young grapevines. ‘Syrah’ grapevines grafted to Freedom rootstocks were planted in 8-L plastic pots, alone, or with a single GR or GS horseweed. Additional GR and GS horseweeds were also planted separately in individual pots, and all plants were grown for 14 and 16 wk in 2006 and 2007, respectively. Grapevines grown with either biotype of the weed produced fewer leaves and amassed approximately 20% less dry mass (DM) than vines grown alone. The GR biotype reduced grapevine stem DM and length by 30%, but the GS biotype did not. The GR biotype accumulated more than twice the DM as the GS biotype, whether in competition with grapevine or not. Grapevines reduced the total leaf number of both horseweed biotypes by almost 50% and aboveground DM of GR and GS biotypes by 50 and 75%, respectively. These preliminary findings indicate that competition from horseweed can substantially reduce the growth of young grapevines and that the GR biotype may be more competitive than the GS biotype.


HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 592e-592
Author(s):  
John E. Erwin ◽  
Nina Glomsrud

Rose plants (cvs `Royalty' and `Lovely Girl') in an established canopy were cut back to node 1, 3, 5, 7, 9, 11, or 13 from the base of the stem at harvest. Harvest was defined as the reflexing of the outermost petal. Most rose stems were composed of 13 nodes, therefore, pruning to the 13th node involved removing the flower only. Three leaf removal techniques were evaluated: 1) no leaf removal, 2) removing the node leaf only, or 3) removing all leaves on the stem. Total break number increased as the node position which stems were cut back to increased. For instance, break number increased on `Lovely Girl' from 1.8 to 2.6 breaks as node position increased from 1 to 13. The number of lateral breaks which developed into marketable flowers also increased as the node position which stems were cut back to increased. `Lovely Girl' flower number increased from 0 to 2.6 flowers per stem as node position increased from 1 to 13. Leaf removal reduced the number of marketable flowering shoots. For instance, flowering shoots decreased from 2.6 to 1.4 per stem on stems cut at the 13th node following removal of all leaves on that stem. `Royalty' had more lateral breaks than `Lovely Girl' but also had more non-flowering lateral breaks following pruning. Commercial implications of this research will be discussed.


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