Energy Inputs, Output and Productivity in Organic and Conventional Maize and Tomato Production, under Mediterranean Conditions

Maize (Zea mays L.) and tomato (Solanum lycopersicum L.) are two important crops in Mediterranean countries. The objectives of this study were to evaluate the differences and similarities in energy flow between conventional and organic tomato and maize crops. Our results indicated that the total energy input in the conventional system was higher than in organic system and for individual crops was 25.90 and 29.34% higher for tomato and maize, respectively, than the organic system. Of the inputs for the different operations, fertilizers consumed the bulk of the energy for all crops. In maize crop, human labour had little impact on total energy use both in organic and conventional system. In addition, seed inputs in maize production had corresponded to 11.44% of the total energy requirement. Concerning the pesticides inputs, there were significant differences between organic and conventional systems. In both crops, the pesticides energy input was higher in conventional production compared to organic system. Moreover, irrigation inputs were 13-23% of the total energy use in the organic system and 12-20% in the conventional system. In both crops, the energy output and energy productivity were also higher in conventional production compared to organic system. Our study shows that the adoption of organic cultural system could reduce energy inputs.

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Determination of Tolerance Levels of Cotton Genotypes Obtained from F6-F7 Generation against Verticillium Wilt Disease Caused by Verticillium dahliae Kleb.

The susceptibility of cotton genotypes obtained from F6 and F7 generations to Verticillium wilt (VW) disease (Verticillium dahliae Kleb.), was studied under artificial and natural infestation during 2009 and 2010 growing seasons at the Cotton Research Institute, Nazilli, Turkey. In this study, fifteen cotton breeding lines and two control varieties were used as plant material. During the cotton growing season, foliar disease index (FDI), vascular disease index (VDI) and pot disease index (PDI) were observed in addition to seed cotton yield and some fiber quality characteristics. According to the obtained results, disease severity (DS) values observed in pot experiments were higher than field trials. In terms of DS, Tamcot CD3H— Tamcot Luxor-III, MaraÅŸ92— Tamcot Sphinx and Sayar 314— Stoneville 453-I breeding lines exhibited similar values with tolerant Carmen variety. Tamcot CD3H— Tamcot Sphinx Sayar 314— Stoneville 453-I, Sayar 314— Stoneville 453-II and Stoneville 453— Tamcot Sphinx breeding lines which gave similar DS values with tolerant Carmen variety were statistically on the same group with Carmen variety suitable to seed cotton yield. In this study, the disease tolerant breeding lines had higher fiber strength values than susceptible lines, the lowest fiber strength value obtained from Cukurova 1518 susceptible variety.

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Genetic Stability of In vitro Multiplied Phalaenopsis gigantea Protocorm-like Bodies as Affected by Chitosan

Chitosan is a carbohydrate polymer derivative of chitin which presents in shell of crustaceans. This biopolymer is a non toxic and environmentally friendly, considered as a plant growth stimulator in some plant species. The present study investigates the effects of chitosan and media types on multiplication and genetic stability of Phalaenopsis gigantea protocorm-like bodies (PLBs). PLBs were inoculated in liquid New Dogashima Medium (NDM) and Vacin and Went (VW) supplemented with various concentrations of chitosan (0, 5, 10, 15, 20 and 25 mg/L). The highest PLB multiplication was observed on VW and NDM supplemented with 10 mg/L chitosan with mean number of PLBs 177 and 147, respectively. Chitosan promoted the formation of juvenile leaves and the highest number was observed in NDM supplemented with 20 mg/L chitosan with mean number of 66 leaves after 8 weeks of culture. Genetic stability was assessed among mother plant and secondary PLBs after 2, 4, 6, and 8 weeks of culture in liquid media. 8 out of 10 ISSR markers produced a total of 275 clear and reproducible bands with mean of 6.9 bands per primer. The secondary PLBs produced during sub-culturing process of chitosan treated liquid culture were genetically uniform and similar to mother plant.

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