Veli Uygur

RESPONSES OF GRAFTED WATERMELON ONTO DIFFERENT GOURD SPECIES TO SALINITY STRESS

The watermelon cultivar ‘Crimson Tide’ was grafted onto three different rootstocks and grown under saline conditions to investigate effects of salinity on grafted and non-grafted watermelon. One Cucurbita maxima and 2 Lagenarai siceraria landraces (Skp and Brecik) were used as rootstock. Plants were irrigated with two different saline solutions [0.5 (control) and 8.0 dS m−1] by two days interval at the first 15 days of experiment and one day interval at the last 15 days of experiment. The experimental design was randomized block. Each treatment was replicated three times with three plants. Grafted plants had higher plant growth parameter than non-grafted plant under saline conditions. Reduction in shoot dry weight was 41% in non-grafted plants while it was varied from 22% to 0.8% in grafted plants under saline conditions. Accumulation of sodium (Na+) was higher in non-grafted plants than grafted one. Calcium (Ca++) and magnesium (Mg++) concentration were higher in all grafted plants than non-grafted plants. Non-grafted plants had higher K+ concentration than other treatments under saline conditions. Ratios of Ca++/Na+, K+/Na+ and Mg++/Na+ were significantly affected by salt treatments and positively correlated with plant growth parameters. The ratios were lower in non-grafted plants than grafted plants under saline conditions.

Effects of rootstocks on some growth parameters, phosphorous and nitrogen uptake watermelon under salt stress.

ABSTRACT The uptake of phosphorous (P) and nitrogen (N) and some growth parameters of watermelon [Citrullus lanatus (Thunb.) Matsum and Nakai] cultivar ‘Crimson Tide’, grafted on gourd rootstock (Lagenaria siceraria) landraces and Cucurbita maxima, grown under five different saline conditions for 30 days were investigated. Salinity stress was induced by continuous irrigation with saline water having electrical conductivity (EC) of 0.5, 4, 8, 12, and 16 dS/m. Grafted watermelons showed better growth performance than non-grafted ones. Nutrient uptake was significantly affected by rootstocks and salinity levels. Salinity stress has resulted in an increase in P content of shoots as much as two fold. Total N uptake by shoots of both non-grafted and grafted watermelon on gourds gradually decreased above 8 dS/m salinity. This investigation showed that grafted plants had a better performance than the non-grafted watermelon cultivar. Therefore, gourds, especially those of Lagenaria type, may be used as a rootstock for watermelon under saline conditions.

Leaf Mineral Composition of Olive Varieties and Their Relation to Yield and Adaptation Ability

ABSTRACT The amount of yield and adaptation of a cultivar to a new environment is strongly related to nutrient uptake ability. The aim of this study was to compare nutrient uptake ability of 21 local and/or standard olive varieties grown under Mediterranean climatic conditions. Elemental compositions of olive leaves were determined for two consecutive years. The highest yields were obtained from ‘Gemlik’, ‘Manzanilla’, ‘Memecik’, and ‘Hojiblanca’ varieties. Nitrogen (N), phosphorus (P), potassium (K), magnesium (Mg), and manganese (Mn) content of leaves were comparatively higher in the high-yielding year (2004) whereas iron (Fe) and copper (Cu) contents were lower. Nutrient uptake ability and usage efficiency of olive varieties were different. Mineral composition of leaves was variety dependent and different groups of varieties showed higher leaf concentration for each element. Therefore, it can be concluded that the variation in the nutrient uptake ability may be used as a criterion for adaptation of a variety to a new ecological environment.

EFFECT OF CITRUS ROOTSTOCKS ON LEAF MINERAL COMPOSITION OF ‘OKITSU’, ‘CLAUSELLINA’, AND ‘SILVERHILL’ MANDARIN CULTIVARS

Citrus performance is strongly related with rootstock. This study was conducted to investigate leaf nutrient contents of ‘Okitsu’, ‘Clausellina’ and ‘Silverhill’ mandarin cultivars budded onto sour orange, ‘Carrizo’ and ‘Troyer’ citrange rootstocks in Dörtyol, Turkey in 2004 and 2005. The maximum nitrogen (N), potassium (K), and copper (Cu) contents were determined for ‘Clausellina’; phosphorus (P) for ‘Okitsu’; and sodium (Na) for ‘Silverhill’. Calcium (Ca), magnesium (Mg), iron (Fe), manganese (Mn), and zinc (Zn) uptake were similar for the mandarin cultivars. ‘Carrizo’ citrange at N, K, Mg, Mn, and Cu uptake; ‘Troyer’ citrange at N, P, K, and Fe uptake; and common sour orange at Ca, Zn, and Na uptake was superior on the other rootstocks. It was observed that ‘Carrizo’ and ‘Troyer’ citrange rootstocks had advantages over sour orange in nutrient uptake. Thus, growth performance, yield, and quality parameters considered, ‘Carrizo’ and/or ‘Troyer’ citranges could be suggested as rootstocks for the studied mandarin cultivars under similar ecological conditions.

LEAF MINERAL COMPOSITION OF ‘NOVA’, ‘ROBINSON’ AND ‘FREMONT’ MANDARIN CULTIVARS ON DIFFERENT ROOTSTOCKS

Rootstock selection has a critical importance for mineral nutrition of budded cultivars. This study was conducted at the experimental farm of Mustafa Kemal University, Dörtyol, Turkey. The aim of this study was to investigate the effect of sour orange, Troyer and Carrizo citrange rootstocks on the leaf nutrient contents of ‘Nova’, ‘Robinson’, and ‘Fremont’ mandarin cultivars in the 2004 and 2005 growing seasons. Carrizo citrange was examined for nitrogen (N), potassium (K), magnesium (Mg), sodium (Na), and manganese (Mn); Troyer citrange for iron (Fe); and sour orange for calcium (Ca) and zinc (Zn) were superior on the others. Nitrogen, phosphorus (P) and Mg levels of mandarin leaf budded on sour orange were under or just above the deficiency threshold. Potassium, Mn, and Zn content of ‘Robinson’; P, Ca and Fe content of ‘Fremont’; and Cu content of ‘Nova’ were statistically higher. Therefore, it can be concluded that Carrizo rootstock may be suggested for the region and regions with similar ecological conditions.

Effects of low-molecular-mass organic acids on P nutrition and some plant properties of Hordeum vulgare

ABSTRACT One of the strategies of the plants growing in phosphorus (P)-deficient environments is to exudate low-molecular-weight organic acids (LMWOA). Thus, we aimed to investigate the effect of LMWOA on phosphorus uptake of barley from either fertilizer or inherited soil phosphorus. The experiment was set up in full factorial arrangement in completely randomised design with two phosphorus (0 and 50 mg P kg−1), five organic acids, LMWOA (malic acid, oxalic acid, citric acid, acetic acid, ascorbic acid), and four organic acid rates (0, 10, 20, and 30 mmol kg−1). The effects of LMWOA on yield in descending order were: oxalic acid > ascorbic acid > malic acid > acetic acid > citric acid. The maximum P concentration in grain was obtained at 30 mmol kg−1 LMWOA treatments. As a result, it was found that oxalic acid was the most effective LMWOA in increasing nutrient uptake induced grain yield with and without phosphorous fertilizer application.

Isparta-Atabey ovası topraklarında mikro element yarayışlılığı ile toprak özellikleri arasındaki ilişkilerin temel bileşen analizi ile belirlenmesi

Soil properties influenced by soil formation processes and land use affect micro nutrition availability in soils. This study aims to reveal relationships between 24 measured soil parameters and micro element availability through descriptive statistics, Pearson correlation and principal analysis techniques, in 70 surface samples (0-20 cm) taken from the 21 soil series of Isparta-Atabey plain. Positive and high skewness coefficients indicated that organic matter and available concentrations of phosphorus (P), copper (Cu), iron (Fe), and zinc (Zn) increased due to mainly agricultural practices and/or to relatively lesser extent soil forming processes. Principal component (PC) analysis indicated that seven components explained about 80% of total variance and two of these components were responsible for the variation in microelement concentrations. The principal component related to Cu and Zn in soils showed positive loading with available P, Cu, Zn, ammonium acetate extractable Mg; and negative loading with only clay content of soils. The PC 5 explained the variation in Fe and Mn concentrations in relation to negative loading of soil pH. Consequently, it was determined that the DTPA extractable concentrations of Cu and Zn in some sampling sites have reached environmentally risky levels.Toprak olusum sureclerine ve arazi kullanimina bagli olarak ortaya cikan toprak ozellikleri topraklarda mikro element yarayisliligi uzerine etki etmektedir. Bu calismada Isparta-Atabey ovasindaki 21 toprak serisinden alinan 70 toprak ornegi incelenen 24 parametre ile topraklarin yarayisli mikro element konsantrasyonlari arasindaki iliskiler tanimlayici istatistikler, Pearson korelasyonu ve temel bilesen analiz yontemleri kullanilarak incelenmistir. Tanimlayici istatistik analizlerden carpiklik katsayisinin yuksek ve pozitif olmasi, organik madde, fosfor (P), bakir (Cu), demir (Fe) ve cinko (Zn)’ nun buyuk oranda topraklarda tarimsal uygulamalarin ve/veya kismen de toprak olusum sureclerinin etkisiyle arttigini gostermistir. Temel bilesen analizi, topraklarin davranislarinin tanimlanmasinda yedi bilesenin toplam varyansin yaklasik %80’nini aciklayabildigini ve bu bilesenlerden iki tanesinin ise topraklardaki mikro elementlerin konsantrasyonundaki degisimi aciklayabildigini belirlemistir. Topraklardaki Cu ve Zn konsantrasyonundaki degisimle iliskili temel bilesenin yarayisli P, Cu, Zn, amonyum asetat ile ekstrakte edilebilir Mg ile pozitif; kil miktari ile negatif iliskili oldugu belirlenmistir. Temel bilesen 5 ise topraklardaki Fe ve Mn konsantrasyonundaki degisimi pH’nin negatif etkisiyle iliskilendirmistir. Sonuc olarak bazi topraklarin Zn ve Cu mikroelementleri acisindan gubreleme ve zirai mucadele pratiklerinin etkisiyle DTPA ile ekstrakte edilebilen konsantrasyonlarinin cevresel acidan risk olusturabilecek seviyelere ulastigi belirlenmistir.

Chemical Fractions of Phosphorus: The Effect of Soil Orders, Soil Properties, and Land Use

ABSTRACT Low availability of phosphorus (P) in Turkish soils is a significant problem of agricultural production depending on carbonates in slightly weathered and iron/aluminum oxides in highly weathered soils. Thus, crop-based P fertilization along with inherited nature of P partition can lead to changes in the amounts and geochemical fractions of phosphorus. For this reason, horizon-based surface samples were taken from 16 soil series that belong to four orders with different pedotransfer functions. The geochemical phosphorus fractions were sequentially extracted by sodium bicarbonate (NaHCO3), sodium hydroxide (NaOH), citrate-dithionite-bicarbonate buffer system (CBD), hydrochloric acid (HCl), and aqua-regia. Results indicated that weathering sequence was inversely related to plant available P fractions. The fertilizer P was possibly converted to HCl-extractable (Ca-Pi) fraction in calcareous soils through NaOH-Po and NaHCO3-Po fractions whereas it accumulated in the CBD-P fraction in relatively weathered soils. The carbonates and Al/Fe oxides were most significant constituents in P partitioning as consequences of parent material and weathering chronosequence.