Monitoring of Artificial Nests in Horticultural Ecosystems-Observation of Woodpeckers Ethology

In order to increase the integrated protection of horticultural ecosystems by using the biological fight, the installation on artificial nests, is an important measure to help the insectivore birds. In a research program, a number of 166 artificial nets for Passeriformes birds were installed in different ecosystems as parks, botanical gardens and orchards in the South-Eastern part of Romania. During the nests monitoring period an interesting, but in the same time warring phenomenon, was noticed: a certain number of artificial nets were prayed by woodpeckers, especially by Dendrocopos major (Great Spotted Woodpecker). In Romania, all the ten European woodpecker species are nesting, nine being sedentary and one (Jynx torquilla) migratory, leaving the country in autumn. Woodpeckers in general, are very useful in woody plant biological protection, having a predominant insectivore nutrition and being the only one to keep under control the insects that are leaving on, inside and under the trees bark. The paper presents some data regarding the woodpeckers ethology in the studied ecosystems. More research are needed to understand the woodpeckers behaviour and to find protection methods of useful birds' nests against the woodpeckers attack. Keywords: useful birds;  Dendrocopos major;  Dendrocopos syriacus;  Passer montanus;  Picus viridis

On a divisibility relation for Lucas sequences

In this note, we study the divisibility relation U(m) | U(8/n+k) - U(8/n') where U := {Un}n>/-0s the Lucas sequence of characteristic polynomial x(2) - ax +/- 1 and k, m, n, s are fixed positive integers.Work of A.P. was partly financed by Project DIUV-REG no 25-2013Approved for public release; distribution is unlimited

The behavior of hazelnut cultivars in the eco-pedoclimatic conditions of the Bucharest area

Hazelnut is an essential species for nut production worldwide; extensive orchard areas have recently been planted in Romania. To choose the best cultivars to be grown in the future, a study was done on the behavior of seven hazelnut cultivars in the eco-pedoclimatic conditions of the Bucharest area. 'Hall’s Giant', 'Tonda Gentile delle Langhe', 'Romavel', 'Red Lambert', 'Tonda di Giffoni', 'Tonda Gentile Romana', and 'Vâlcea 22' were planted in the Experimental Orchard of the Faculty of Horticulture within the University of Agronomic Sciences and Veterinary Medicine of Bucharest. The results presented the behavior of hazelnut cultivars detailing the number of branches per tree, according to their age, and annually for each branch, length, and total cross-section area were measured. The influence of cultivars on yield and fruit characteristics at the harvest moment was detailed. 'Romavel' and 'Vâlcea 22' had the fruits with the highest weight, more than 3.3 g/fruit, while 'Red Lambert' and 'Tonda di Giffoni' presented the lowest values. 'Hall’s Giant' was the most vigorous cultivar, and 'Vâlcea 22' the less vigorous. Interesting growth dynamics for each cultivar and all studied branches in the two experimental years were detailed. First and second-year branches had the highest TCSA growth rhythm, but that was not maintained for the third to fifth-year branches

Management of Apple Scab and Powdery Mildew Using Bicarbonate Salts and Other Alternative Organic Products with Fungicide Effect in Apple Cultivars

The control of apple scab and powdery mildew is a challenge for organic fruit growing. Bicarbonate salts are already consecrate in reducing the attack of scab and powdery mildew in organic apple culture. In the current study the influence of some products accepted in organic apple production to control scab and powdery mildew (potasium bicarbonate, lime sulphur, wettable sulphur, potassium silicate, cooper ammonium-phosphate, potassium bicarbonate + potassium silicate, potassium bicarbonate + wettable sulphur) in comparison with untreated control, were used.  The biological material was represented by three scab resistant cultivars (‘Luna’, ‘Topaz’ and ‘Sirius’) and three scab susceptible cultivars (‘Elstar’, ‘Pinova’ and ‘Golden Delicious’). The experiments were carried out during 2014-2016 at Steluța LTD, Cluj-Napoca, N.W. Romania, as a bifactorial experiment arranged in randomized blocks. The trees were planted in 2011 at a density of 3,175 trees/ha. Depending of the year, a number of 18-22 treatments were made annually after each rain. It can be concluded that the combination of potassium bicarbonate + wettable sulphur significantly reduced the attack degree of scab and powdery mildew on leaves and fruits and increased the yield of the scab-susceptible and scab resistant cultivars. Good results were obtained in the case of treatment with potassium bicarbonate with potassium silicate, potassium bicarbonate and cooper ammonium phosphate. The treatments with the products used in the experiments did not register symptoms of phytotoxicity on leaves or fruits, except lime sulphur and wettable sulphur and cooper ammonium phosphates

Efficient Exploitation of Local Fruit Resources Through Sustainable Production and High Added Value Processing

Fruit production in Europe has a dual system organization: an industrial type with high density planting systems in large extension farms and a small size orchard type in family owned farms. Certainly, the two systems are quite different in terms of fruit varieties, planting systems, orchard management and fruit production valorisation. In recent years, the smart family fruit farms became more and more important for the rural economy by increasing the efficient use of local resources, by offering social security and comfort and by reducing the environmental fruit finger print. Besides the already existing orchards, new ones are planted with trees produced using local species and varieties, better adapted to soil and climate conditions, grafted on resistant rootstocks. Low input orchard technologies, organic fertilization and integrated pest management are generally used. Natural windbreaks and shelters, grass soil cover management are generalized in order to ensure a higher biodiversity and the protection of wild life. Local fruits are produced in many cases under registered Protected Designation of Origin (PDO), Protected Geographical Indication (PGI), and Traditional Specialties Guaranteed (TSG). Those insure the product authenticity, a quality control system and a better marketing. Fruits are sold fresh on the local markets and in modern distribution network but also processed in the farm or in cooperative processing units. Special products are obtained following traditional recipes, some of the being sugar free, rich in vitamins, active principles and considered functional food. Continuous science and technology development brings innovation also in orchard technologies in European small fruit farms aiming to maintain their sustainability and competitiveness, by producing top quality fruits, with nearly to zero residues and no environmental negative impact. The European model of small smart fruit farms could be introduced and tested to Indonesian condition

A journey through Galois groups, irreducible polynomials and diophatine equations

Computing the Galois group of the splitting field of a given polynomial with integer coefficients over the rationals is a classical problem in modern algebra. A theorem of Van der Waerden [Wae] asserts that almost all (monic) polynomials in Z[x] have associated Galois group Sn, the symmetric group on n letters. Thus, cases where the associated Galois group is different from Sn are rare. Nevertheless, examples of polynomials where the associated Galois group is not Sn are well-known. For example, the Galois group of the splitting field of the polynomial xp − 1, p 3 prime, is cyclic of order p − 1. For the polynomial xp − 2, p > 3, the Galois group is the subgroup of Sp generated by a cycle of length p and a cycle of length p − 1. One interest in this paper is to find other collections of polynomials with integer or rational coefficients whose Galois groups are isomorphic to these groups.Natonal Science Foundation (Filaseta)Grants SEP-CONACyT 37259 E and 37260E (Luca

On a divisibility relation for Lucas sequences

The article of record as published may be found at http://dx.doi.org/10.1016/j.jnt.2015.11.011 0022-314XMax-Planck Institut für MathematikHubei provincial Expert Program in ChinaProject DIUV-REG N◦25-2013Max-Planck Institut für MathematikHubei provincial Expert Program in ChinaProject DIUV-REG N◦25-201

Compositions with the Euler and Carmichael Functions

Abstract. Let ϕ and λ be the Euler and Carmichael functions, respectively. In this paper, we establish lower and upper bounds for the number of positive integers n ≤ x such that ϕ(λ(n)) = λ(ϕ(n)). We also study the normal order of the function ϕ(λ(n))/λ(ϕ(n)).