Assessment of genotype x environment interaction on yield and yield components of durum wheat genotypes by multivariate analyses

Wheat breeders have to determine the new cultivars and lines responsive to the environmental changes for grain yield and yield components. Therefore, this study was conducted to evaluate 25 durum wheat (Triticum turgidum spp. durum) genotypes including 12 registered cultivars and 13 advanced breeding lines for their stability grown in three different locations (Tokat-Kazova, Diyarbakir and Sivas-Ulas) of Turkey for two growing seasons (2005-2006 and 2006-2007), and to select genotypes having desirable traits to be used in future durum wheat breeding program. Field trials were conducted in a randomized complete block design with three replications at each location. Days to heading, plant height, number of spikes per square meter, number of kernels per spike, spike weight, 1000 kernel weight and grain yield of the genotypes were evaluated in each location. The regression coefficient (bi) of Finlay and Wilkinson (1963) and mean square of deviation from regression (S2d) of Eberhart and Russell (1966) were used as the stability parameters. The results of combined analysis of variance showed a strong influence of the locations on plant height, number of spikes per square meter, number of kernels per spike,  spike weight, 1000 kernel weight and grain yield. Genotypic effects were mainly observed for spike length and test weight. Year had strong impact only on the days to heading. Ecological conditions of Diyarbakir among locations offer the better opportunity for production of durum wheat. Line 5 and cultivar Gidara were both stable in yield ability and also appeared the stable group based on the cluster analysis. In the first principal component days to heading, number of spikes per square meter and spike length  were the most important traits contributing to variation that obtained about 44.3%. There was a positive relationship between grain yield and number of spikes per square meter together test weight, whereas days to heading and spike length were negatively correlated to grain yield. The results of this study also imply that Line-5 and cultivar Gidara among genotypes were the most stable cultivars and can be used as breeding materials. The days to heading, number of spikes per square meter and spike length could be adequate to introduce the differences among genotypes.Key words: Durum wheat, stability, principal component analysis, cluster analysis

RESPONSE OF PEA (PISUM SATIVUM) TO SALINITY AND IRRIGATION WATER REGIME

The aim of this study was to determine the effects of different salinity and irrigation water regime on yield, plant growth and water consumption of pea (Pisum sativum). Commercial variety of Rona was used as plant material. Salinity and irrigation water regime experiments were set up in pots as randomized plot experimantel designs with five replications. The first experiment focused on pea responses to irrigation water salinity by irrigating the crops using five different levels of saline water (0.7, 2.0, 3.0, 4.0 and 7.0 dS m(-1)) with a constant leaching fraction (LF = 0.30). The other experiment was conducted to determine pea responses to irrigation regime

Análise produtiva e econômica do pepino japonês submetido a diferentes lâminas de irrigação Productive and economic analysis of japanese cucumber under different irrigation depths

Objetivou-se, com o presente trabalho, uma avaliação técnica e econômica da produtividade do pepino japonês (Cucumis sativus L.) em função de diferentes lâminas de irrigação. O experimento foi instalado em casa de vegetação, utilizando-se de um delineamento inteiramente casualizado (DIC), com cinco tratamentos de reposição de água no solo (50, 75, 100, 125 e 150%) e seis repetições. Os resultados permitiram concluir que, de maneira geral, o número e o peso dos frutos da cultura foram afetados pelo déficit e excesso hídrico, aplicados pelos tratamentos. A máxima produtividade obtida foi igual a 45.944 kg ha-1 com aplicação de 320 mm e a lâmina ótima econômica foi estimada em 319,5 mm, concluindose que, para o pepino japonês, maiores retornos econômicos são obtidos mantendo-se a cultura com umidade do solo próxima da capacidade de campo, repondo integralmente a quantidade de água consumida.<br>This study had the aim to verify the economic feasibility of japanese cucumber (Cucumis sativus L.) yield under different irrigation depths, cultivated in greenhouse. A completely randomized design (CRD), with five levels of replacement of irrigation water (50, 75, 100, 125 and 150%) and six replications was used. The results showed that the number and fruit weight of crop were affected by treatments of water deficit and excess used for treatments. The maximum productivity obtained was equal to 45,944 kg ha-1 for a depth of 320 mm and the economic optimum irrigation depth was estimated at 319.5 mm, concluding that for the japanese cucumber higher economic returns are obtained by keeping the crop with soil water content near field capacity, restoring the full amount of water consumed