USE OF SOME FUNGICIDES IN CONTROL OF APPLE SCAB AND STORAGE DISEASES

The paper present an analysis of the biological efficacy of some new experimented during 2008-2011 at RIFG Pitesti, in order to protect the stored apples against apple scab, brown rot and other damaging storage diseases. During the experiment, 11 fungicides, including 9 single active ingredients and 2 new actives mixes, were tested by preventive treatments applied in the orchards on 4 winter apple cultivars ‘Golden Delicious’, ‘Idared’, ‘Nured Jonathan’ and ‘Starkrimson’. The biological material was stored in the cold warehouse then assessed under lab conditions. The results obtained revealed that in control of brown rot, the best results were obtained with: Chorus 75 WDG - 0.3 kg/ha/treatment, Rovral 500 SC - 1.5L/ha/treatment, Switch 62.5 - 1kg/ha/treatment and Bellis 38 WG 0.8 kg/ha/treatment (F%: 0.75%; 0.25; 0%; 0%). As regard the control of apple scab, under storage conditions, the finest results were obtained with: Chorus 75 WDG - 0.3 kg/ha/treatment, Mystic Extra 0.75L/ha/treatment, Topsin M70 1kg/ha/treatment, Score 250 EC 0,2L/ha/treatment, Indar 5 EW 1,2 kg/ha/treatment, Toledo 430 SC 0.45L/ha/tratment, Folicur Solo 0.75L/ha/treatment (F%: 0%; 0.36%; 0.75%; 1.37%; 1.75%; 2.01%; 2.25%; 3.75%). Also, the treatments applied in 2011 with Bellis 38 WG 0.8 kg/ha and Switch 62.5 - 1kg/ha/treatment protected very well the stored apples against the apple scab and 4 other specific storage diseases (F%: 0)

THE EVALUATION OF FRUITS QUALITY IN SOME STRAWBERRY CULTIVARS (FRAGARIA X ANANASSA L. DUCH.)

The major factors influencing the strawberries quality are the genotype, culture technology, climatic conditions and harvest time. In Romania consumers like strawberry fruits especially picked in May to June season, in that period having better appearance, nutritional and organoleptic qualities, superior to those that ripen in summer and autumn. In 2012-2014 period at RIFG Pitesti was organized an experiment with seven strawberry cultivars to compare the quality of fruits, some cultivars being already in the commercial culture. The results showed significant differences between cultivars regarding the following quality parameters: the color of the fruits, determined by chroma (C*) recorded values ranging between 23.52 (Magic) and 32.92 (Premial) and the hue angle (hº), values between 21.74 (Clery) and 26.95 (Magic); fruit size determined by the size index registered values between 34.28 (Coral) and 39.2 (Record), average fruit weight ranging from 13.63 g at Coral cultivar and 25.02 g at Record cultivar. At the same time fruit firmness revealed the highest values for Alba (2.98 kgf/cm2) and Clery cultivars (2.78 kgf/cm2); The Coral cultivar noted the strongest aroma and the highest soluble solids content (10.33% Brix)

EVALUATION OF SOME PLUM CULTIVARS IN A HIGH DENSITY SYSTEM

Three plum cultivars bred in Romania (‘Carpatin’, ‘Centenar’ and ‘Tita’) were tested together with several standards (‘Cacanska Rodna’ and ‘Stanley’) in a high density experimental orchard established at Pitesti - Maracineni in the spring of 2009, with spacing 4 x 2.25 m. Trees were trained as spindles, grafted on ‘Saint Julian’ rootstock. In the orchard the following characteristics were evaluated: tree vigour based upon measuring of trunk-diameter, yields in kg/tree, time of fruit ripening and basic parameters of fruit quality. All Romanian varieties were characterized by earliness and large fruit, but production was relatively small. Instead, foreign varieties were characterized by high productivity in the 4th year after planting

INVESTIGATING SPATIAL DISTRIBUTION OF THE SOIL–WATER CHARACTERISTIC CURVES AND CONSEQUENCES IN IRRIGATION APPLICATION WITHIN A SANDY-LOAM SOIL IN AN INTENSIVE PLUM TREE ORCHARD

The orchard plot has plum trees (Stanley cultivar grafted on Saint Julien rootstock), six years old, with 4 m between tree rows (ITR) and 2.25 m between trees in the row (IR). The relief is a gentle hillside with a slope of 0.075 m m-1 . Undisturbed soil samples were taken at field capacity (FC) from both IR and ITR positions, between 0 and 1 m depth, with a 0.1 m depth step, in cylinder metal cores of 0.05 m in both sizes. Soil water characteristic curves between the matric potential (soil suction, ψ, expressed as pF) and SWC (m3 m ) were determined in the lab according to van Genuchtenʼs method. BD for each sample was also determined. Highly significant correlations were found between the main soil physical indices used in irrigation application and bulk density. Thus, soil compaction in orchards deteriorates soil structure and decreases water supply to the fruit trees. Only about one quarter of the total water capacity of a soil is usually used as available water for plants. Most of this capacity for the investigated soils contains either immobile water (equivalent of the wilting point) or drainage water (from total capacity to field capacity). From the available soil water capacity, only half (i.e. 12.5% of total soil water capacity) is easily available, the rest being increasingly more difficult available to plants. Soil matric potential is lower and lower with decreasing soil water content within the available soil water capacity, or otherwise soil suction increases more and more under the same conditions. Thus, soil water availability decreases dramatically from field capacity to the wilting point, for uniform decreases in soil water content, and irrigation application under water stress reduces dramatically soil water availability for plants compared to fully irrigation

STUDIES ON THE EVOLUTION OF APPLE FRUITS QUALITY DURING THE PRESERVATION PERIOD IN COLD STORAGE FACILITIES

The apple fruits harvest maturity is very brief and does not coincide with the consumption maturity. The process of ripening continues after fruit harvesting, and the consumption maturity is achieved earlier or later in the storage period. Present paper highlights the evolution of some apples characteristics (penetration resistance, chlorophyll fluorescence), in the storage period,the characteristics that define the quality fruits consumption. The study was carried out at the Research Institute for Fruit Growing Pitesti-Maracineni where the fruits of two apples varieties ('Dalinred', and 'Goldrush') that have been harvested in October and stored in cold storage. After four months of storage (January) and after five months of storage (February), determinations of penetration resistance and chlorophyll fluorescence were carried out. The results obtained have shown that penetration resistance of the 'Goldrush' fruits variety in January had higher values than penetration resistance of the 'Dalinred' fruits variety and the values of resistance decrease with increasing storage period. Regarding chlorophyll fluorescence, the values have the same tendency as well as those of penetration resistance, a small decreasing of values, with the increasing storage period. Both, the penetration resistance values as well as the chlorophyll fluorescence values, proved a good duration for maintaining fruit quality, and the decreasing values in the two periods of determination (January and February), was insignificant

ESTIMATING SOIL MOISTURE STATUS IN PEACH TREE ORCHARDS BY USING CROP WATER STRESS INDEX

Soil moisture content (SMC), in addition to soil water potential, is an important soil index in irrigation application. However, SMC is difficult to determine in field and its estimation can be done by various methods. The objective of this paper is to estimate volumetric soil moisture status by using crop water stress index (CWSI) in a peach orchard for irrigation scheduling. Tree canopy temperature (Tc) was measured by using thermal images in a peach orchard for irrigation scheduling. Tc was investigated in three irrigation regime treatments (factor A) that produced various SMC values, three cardinal points (factor B): South, North and East-West aspects combined, and five up-down vertical position measurements (factor C: upper, middle upper, middle, middle lower and lower) across the tree canopy thermal images. The standard errors of the estimate (SEE) between measured and estimated SMC values range from 1.7 to about 2.2 % of volume. These values essentially show the approximate size of SMC. However, this method can be promising if it is improved by reducing differences between the conditions of determining CWSI and farming conditions. Consequently, the method could be used in orchard region or countries with similar soil and climate conditions

Canopy temperature for peach tree at various soil water contents

Canopy temperature measurements with infrared thermometry have been extensively studied as a means of assessing plant water status for field and row crops. Achieving high quality peach fruit depends on the ability to maintain mild to moderate levels of water stress in the crop during the growing season. The paper examined the spatial distribution of tree canopy temperature (Tc) using thermal images in a peach orchard for irrigation scheduling. The variation of Tc was investigated in three irrigation regime treatments (factor A) that produced various soil moisture content (SMC) values, three cardinal points (factor B): South, North and East-West aspects combined, and five up-down vertical position measurements (factor C: upper, middle upper, middle, middle lower and lower) across the tree canopy thermal images. It was found that Tc was significantly influenced by the irrigation regime. Cardinal point showed a significant Tc difference between South on the one hand and the other aspects. The vertical position within canopy image did not significantly influence Tc