Engin Yurtseven

INTERACTIVE EFFECTS OF SALINITY AND N ON PEPPER (CAPSICUM ANNUUM L.) YIELD, WATER USE EFFICIENCY AND ROOT ZONE AND DRAINAGE SALINITY

The aim of this study was to determine the salt tolerance of pepper (Capsicum annuum L.) under greenhouse conditions and to examine the interactive effects of salinity and nitrogen (N) fertilizer levels on yield. The present study shows the effects of optimal and suboptimal N fertilizer levels (270 kg ha−1 and 135 kg ha−1) in combination with five different irrigation waters of varying electrical conductivity (EC) (ECiw = 0.25, 1.0, 1.5, 2.0, 4.0, and 6.0 dS m−1) and three replicates per treatment. At optimal N level, yield decreased when the irrigation water salinity was above ECiw 2 dS m−1. At the suboptimal N level, a significant decrease in yield occurred only above ECiw 4 dS m−1. At high salinity levels the salinity stress was dominant with respect to yield and response was similar for both N levels. Based on the results it can also be concluded that under saline conditions (higher than threshold salinity for a given crop) there is a lesser need for N fertilization relative to the optimal levels established in the absence of other significant stresses.

Orta Anadolu Koşullarında Aşılı ve Aşısız Domateste (Lycopersicon esculentum) Damla ve Karık Yöntemlerinin Toprakta Tuz Dağılımı, Meyve Verimi ve Su Kullanım Etkinliği Üzerine Etkileri

A field study with tomato was carried out at Ankara University, Horticultural Research Station in two consecutive years. The aim of the study is to determine the effects of grafting and irrigation methods on yield and water use of tomato and salinity distribution within the soil. Grafted and ungrafted tomato cultivars were grown using drip and furrow irrigation methods. Salinity of irrigation water (electrical conductivity) was 1.9 dS/m and the SAR (sodium adsorption ratio) was below 1.0. The mean fruit yields were 4671, 4391, 4109 and 3457 g/plant for drip-grafted, drip-ungrafted, furrow-grafted and furrow-ungrafted treatments, respectively. Seasonal total evapotransprations were 810.0 and 771.5 mm under drip irrigation, 957.0 and 928.2 mm under furrow irrigation in 2005 and 2006, respectively. Total irrigation water requirement (applied water) were 731 and 714 mm under drip irrigation, 881 and 871 mm under furrow irrigation in 2005 and 2006, respectively. Water use efficiencies (WUE) were 12.92, 12.14, 9.38 and 7.90 kg/m3 for drip-grafted, drip-ungrafted, furrow-grafted and furrow-ungrafted treatments, respectively. Monthly soil samplings indicated that the salinity distribution decreased towards the root zone (wetted area beneath the emitters and plants) with drip irrigation and increased towards the root zone (furrow ridges and plants) with furrow irrigation.