Search
Search Results
-
The effect of day and night temperatures on apple skin colour formation
21-25.Views:1120The colour of fruits is considered to be an important quality indicator. Saleability greatly depends on how well covered the colour is of the specific type of fruits. It is a well-known phenomenon by growers that apples get nicer colours in one year while in other years the basically red and green colour cultivars can be differentiated only by morphological characteristic features. Cover colour is one of the phenometric variables and it is a well-known fact that significant differences can be experienced year by year. The experienced oscillation can be the cause of inappropriate water- and nutriment supply, however it can be the result of some kind of plant disease, extremely high or low temperature, setting rate above the average and outstanding fruit density. In the present examination it is postulated that the degree of cover colour is mostly influenced by day and night temperature. Therefore, our study aims to find out whether it is true or not. Cover colour belongs to those phenometric characteristic features, only the final value of which is taken into consideration; due to their nature of establishment or forming time it seems useless to follow closely the change in the time of vegetation. However, determining the start of colouring and knowing the dynamics of full colouring could carry very important information for growers. If it is possible to determine the curve describing the time change of colouring, we have a possibility to estimate it by means of enviroment variables. So it is also possible to model pigmentation in the future. Knowing this, colouring irrigation could be made more efficient in the future. For this, as a first step, it is inevitable to find out what the relationship is between the main meteorogical variables, namely day and night temperature and the difference between day and night temperature, and colour cover. In this study we summarize and show these interrelations.
-
Evaluation of Colour Versions of Wild Sage (Salvia nemorosa L.)
111-115.Views:442In the continental weather zone, more and more frequently occurring extreme conditions require continuous renewal of the market which generates constant challenge for the ornamental plant breeders. Most of the traditionally used decorative ornamental plants are sensitive to these extreme conditions. In 2001, Department of Plant Biotechnology, Debrecen University initiated an interdisciplinary breeding program in collaborations with Zoltan Kovats (he dealt with hungarian drought-tolerant plant species) to produce new or reintroduce forgotten drought-tolerant ornamental species into public parks and roadsides. From ~900 species of Salvia genus, Salvia nemorosa L. has been known as a medical plant, however, because of its high adaptation ability and decorative nature it is a highly recommended ornamental plant as well. Salvia nemorosa L. has a low maintenance, extremely droughttolerant, fast growing plant, generates proper cover, and highly competing weeds on roadsides. Nowadays, 50-60 varieties are available; however this number could be increased by new hybrids. Great morphological and colour variation could be seen within the species, from different white to deep violet. The main goal of this research is the production of elite lines with wide colour and morphological variation in wild sage. We have already obtained 25 different clones for further investigation without eliminating the original plants generating an in vitro gene bank as it has been done by Italian breeders.
-
Alternate bearing of 'Golden Reinders' and 'Summered' apples
77-85.Views:995The aim of the present study was to study the effect of biennial bearing (irregular yields) on the generative production of apple cultivars 'Golden Reinders' and 'Summerred' on M.9 rootstock. The observations were made at Nagykutas in West-Hungary for four years. The authors have studied the flowering time, flower density, fruit density, fruit drop, seed content, yielding and fruit quality in the on-year and off-year. Based on the results, it can be stated that the alternation does not cause a significant change in the flowering time of cvs. 'Golden Reinders' and `Summerred': the difference between the flowering time of trees in the on-year and off-year period was 0-1 day. However, there were significant differences in the flower density. 'Golden Reinders' proved to have a weaker tendency to alternation similarly to the statements of the literature. Alternation (off-year) was observed only in three years from the studied four years. While in the case of `Summerred', strong alternation was observed in all four years. In fruit density, there were differences among the cultivars and among the different cycles of biennial bearing. Fruit density (and its opposite, fruit drop) changed inconsistently in the period between flowering and harvest. In the case of 'Golden Reinders' and 'Summerred' 2 and 4 fruit drop periods were detected, respectively. In the off-year, the different periods were less distinct, in most cases they were overlapping each other. The dynamics of fruit drop was related to seed content per fruit. The lower the seed number was, the higher the degree of fruit drop was. In both the high- and off-year cycles, the number of seeds in fruits on the tree and on the ground increased with time. In the yield parameters (fruit number, fruit load, yield efficiency), the differences were greater among the yields of trees in the high- and off-year cycles for 'Summerred'. The fruit quality parameters were greatly influenced by the fruit load of the trees in the different alternation cycles. In general, it can be stated that fruit mass, diameter and height were lower on trees in the on-year. A similar trend could be observed in flesh firmness, cover colour and dry matter content, but the differences were smaller. 'Summerred' was more sensitive to the differences in fruit load.
-
The impact of location, row direction, plant density and rootstock on the sunburn damage of apple cultivars
19-30.Views:1150The effect of row direction (N-S, E-W), plant density (conventional and intensive) and rootstock (M9, MM106 and crab apple) on the sensitivity of 41 apple cultivars to sunburn injury was studied at 6 locations (Derecske, Kálmánáaza, Nagykutas, Nagylapos, Siófok, Tornyospálca).
During the observations the cultivars had rootstock-specific properties in respect of sunburn-susceptibility. Accordingly, the injury was decreased in the order: M9, MM106 and seedling rootstocks. The differences in sensitivity depend on the canopy of trees, caused finally by the growing vigour of rootstocks. Accordingly, the highest value of sunburn injury was observed on M9 rootstock, because this rootstock has a dwarfing effect upon the scion cultivars. Thus, vegetative area of these trees grow very slowly and the foliage is not enough compact to protect the fruit from solar radiation. The size and density of the foliage increased in the order: M9, MM 106 and crab apple seedling as rootstock. Moreover, relationships were demonstrated between the diameter of upper part of the crown, the leaf area, the number of fruits per tree and the injury of sunburn.
Authors categorized the cultivars in respect of values of sunburn incidence: 1. „Not sensitive", II. „Moderately sensitive" and HI. „Strongly sensitive" categories were constituted. Generally, Topaz and Gala cultivars showed low damage (or were free from symptoms), in contrast to this, Golden mutants suffered relatively much. The most sensitive cultivar was Jonica on all the three rootstocks. We searched for relationship between the fruit quality parameters and the frequency of sunburn. Significant correlation was found in the cases of fruit size and the extent of cover-colour. The latter is interpreted with the fact that the best coloured fruits are found on the periphery of crown as a consequence of more intense irradiation.
-
Microclimatic studies on different aged apple plantations
7-11.Views:1021The purpose of measuring parallel canopy and out of canopy microclimates was to find out in what extent climatic parameters measured in different aged canopis differ from each other and from the values characteristic to out-of-canopi areas. The importance of phytoclimatic researches seems to lie in the fact that if the reactions of fruit trees towards meteorological elements are continuously followed, we have the possibility to provide growers with information. These pieces of information are like defining the optimum time of phitotechnical interventions (summer pruning, sorting sprouts, thinning fruits, etc.), the necessity of applying mulching, defining the method and time of irrigation and applying plant protection activities. By means of phytoclimatic researches, it is possible to react to unfavourable meteorological impacts within a certain extent. It is also possible to successfully reduce the risks of late spring and early autumn frost damage, as well as the risks, content and measure of experienced heat and water stress conditions by finding out about the physical characteristics of the canopis' internal area.
