Variation of leaf area index and leaf water potential of young dwarf apple trees under different irrigation methods

In this research which was carried out inSuleymanDemirel University Re-search and Application Farm during 2007 and 2008 years, apple leaf area index (LAI) and leaf water potential (LWP) were observed in Jersey Mac (V1) and Wil-liams Pride (V2) young apple varieties budded on M9 rootstock irrigated with dif-ferent irrigation methods. Drip (D), subsurface drip (SD), surface (S) and under-tree micro sprinkler (M) irrigation methods were used in the research. The amount of applied irrigation water was as much as 100% of Class A Pan evaporation measured during five days irrigation intervals. The amount of irrigation water was ranged between 348.3 (D, SD) - 1186 (S, M) mm depending on irrigation methods during the experimental years. Fur-thermore, maximum and minimum crop evapotranspiration values were determined as 426.1 (DV2) and 1334.7 (MV2) mm respectively.LAI values related to treatments ranged from 0.32 to 0.52 in 2007, 0.73 to 1.12 in 2008. LAI values increased by approximately 126.3% for all treatments. In both years, generally, the highest LAI values were observed in drip irrigation (D) for both varieties. Linear correlation (r=0.99, n=16) was obtained between fruit yields and leaf area index (LAI) values of the apple trees. Leaf water potential (LWP) measurements were repeated ...

EFFECT OF THE FORECAST CLIMATE CHANGE ON THE APPLE TREE WATER REQUIREMENTS IN THE BYDGOSZCZ REGION

The aim of the present research has been an attempt at evaluating the water requirements of apple trees over 2016-2050 in the Bydgoszcz region drawing on the forecast changes in temperature. The paper draws on the forecasting of mean monthly temperature for the Bydgoszcz region in 2011-2050 according to the climate change scenario for Poland SRES: A1B (Bąk, Łabędzki 2014). The water requirements of the apple tree have been determined based on the indispensable precipitation determined by Kemmer and Schulz. The water requirements were calculated for the period January through December and May through September for each year in the 35-year period (2016-2050). The reference period was made up by a 35-year period immediately preceding it (1981-2015). In the 2016-2050 period in the Bydgoszcz region, in the light of the temperature change scenarios, one could expect increased apple-tree water requirements. Determined with the Kemmer and Schulz method, the required annual (January-December) optimal precipitation will increase for the apple tree from 681 mm to 849 mm (by 168 mm, namely by 25 %). The optimal precipitation trend equations show that in the reference period (1981-2015), calculated with the Kemmer and Schulz numbers, the optimal annual precipitation for the apple tree was ...

COMPARISON OF APPLE TREE WATER REQUIREMENTS IN THE BYDGOSZCZ (POLAND) AND ISPARTA (TURKEY) REGIONS

The aim of the present research was an attempt to compare apple tree water requirements in the vegetation period in the Bydgoszcz region (Poland) and in the Isparta region (Turkey). The paper refers to the 1984-2014 temperature and precipitation values in the Bydgoszcz and Isparta regions. To determine the reference evapotranspiration (ET0), the calculation model by Hargreaves modified by Droogers and Allen was applied. Potential evapotranspiration, identified with apple tree water requirements, was determined using the method of plant coefficients proposed by Doorenbos and Pruitt. In each of the seven months considered (April-October) higher apple tree water requirements occurred in the Isparta region. The highest apple tree water requirements were noted in July and for that month during the thirty-year period they were 167.3 mm and 286 mm, on average, in the Bydgoszcz and Isparta regions, respectively. Daily water requirements of apple trees in July were more than 9.2 mm in the Isparta region and 5.4 mm in the Bydgoszcz region. Apple tree water requirements throughout the vegetation period (April-October) were much higher (by 120 %) in the Isparta region than in the Bydgoszcz region. The highest precipitation deficits occurred in July and amounted to 95.5 mm and 269.1 mm ...