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Organic cucumber production in the greenhouse: A case study from Turkey

Organic farming seems to be a solution in environmentally sensitive zones such as the protection zone of Tahtali Dam, which supplies fresh water to Izmir, the third largest city in Turkey. Greenhouse vegetable production is the major agricultural activity in this area (Menderes Township). However, due to the pollution risk from agriculture, governmental authorities have issued a regulation discouraging the use of chemicals within the collection basin of the dam. An on-farm project was conducted in 2001 to introduce organic greenhouse vegetable production in the Tahtali Dam preservation area and to serve as a model for other areas in Turkey facing similar ecological problems. Two irrigation levels and four organic fertilizers were tested on the growth of cucumbers (Cucumis sativus cv. Sardes). The four fertilizers were two rates of farmyard and poultry manure (30 and 50 tons ha -1 ) with and without two organic fertilizers based on either bacteria or algae. During the growing period, pests and diseases were monitored weekly and preparations allowed in organic agriculture were used when necessary. Plant diseases did not create any significant problem, but the pest population, in particular spidermites, increased. No significant differences in cucumber yield were found between the fertilizer and irrigation treatments tested. However, it should be noted that yields from the addition of 30 tons ha -1 of farmyard or poultry manure and organic fertilizers were the same as those for 50 tons ha -1 of manure alone. The average total yield was 13 kg m -2 , within an acceptable range for short-term crop production in this region, but 55% lower than a conventional substrate culture trial nearby. However, due to reduced production costs and a price premium for organic products, the organic produce yielded a net return of US

Sweet Basil (Ocimum basilicum L.) and Potassium Fertilization

1.12-1.79 per m 2 whereas that for conventional bag culture produce was US

The use of industrial wastes as manures: A case study with effluent mud from an olive oil processing plant

0.55 per m 2 . Our results indicate that, under present conditions, organic greenhouse cucumber production has less environmental impact and is more economic than conventional bag culture, due to reduced chemical input and reduced operating and initial investment costs.

Soil properties and mineral content of leaves in fig orchards producing high-quality fruits

ABSTRACT The objective of the present study was to examine the effect of potassium (K) fertilization and soil texture on total yield (1st and 2nd cuttings) and yield components of sweet basil (Ocimum basilicum L.) A greenhouse pot experiment was conducted in a completely randomized statistical design. Basil growth was examined in two different textured soils under three different doses of K fertilization. Generally, for the basil grown under clay soil conditions, moderate amounts of K fertilization is proposed to be sufficient if higher linalool contents are wanted. However, if the growing conditions are sandy loam in texture, it is suggested that higher doses of K be used. Results also highlighted the contribution of second cut as an important cultural practice in the cultivation of an annual basil.

Effect of combined N and K nutrition on yield and quality of spinach

The effect of different effluent mud (EM) and nitrogen (N) combinations on biomass production, major and minor nutrient and toxic element concentrations of maize were studied. Nitrogen enriched EM applications improved the yield and lowered toxic element and sodium concentrations. Excluding the lowest rate of EM, all tested effluent doses resulted in poor growth.

Effects of compost material on yield and quality of glasshouse tomatoes grown in different textured soils

Soil, leaf and fruit samples from Big and Small Meander Valleys, the main dried-fig producing region in Turkey, were analysed and evaluated. Quality parameters were determined as size, colour, acidity, soluble solids and ratio of defects, and were classified according to their relevance in fresh- and dried-fig production. The five top-ranking orchards were selected according to their overall quality. Soil properties and leaf nutrient status were also determined. Evaluations brought out the significance of nitrogen and potassium fertilization in commercial dried-fig production.

Effect of saline conditions on nutritional status and fruit quality of satsuma mandarin cv. Owari

Vegetables require a balanced fertilization in order to achieve higher yields and good quality as for taste, vitamin, nitrate and mineral contents are concerned. These issues are very important for human health and conservation during storage and transportation. Spinach is one of the highly consumed leafy vegetables in Turkey. Considering that potash fertilizers could increase the quality of vegetables through a better balanced fertilization, a field trial was performed to evaluate the use of different doses of N and K on yield and some quality criteria of spinach. Two rates of N on K2O were applied, 80 and 160 kgha−1 of each respectively. Highest yield was obtained at highest N-K treatments. Vitamin C contents were the highest in parcels that received less N but more K. Potassium applications significantly decreased NO3 concentrations in leaves. Leaf total N and K concentrations increased with respect to treatments. No steady changes were measured in the case of leaf P, Cl, Fe, Cu, Mn, Zn, contents. The effect of K nutrition on leaf Mg was negative, contradicting to leaf SO4 content which increased by K levels.

Performance of purslane (Portulaca oleracea L.) as a salt-removing crop

This research was established to study the effects of compost material, a supplement of organic matter, on tomato yield and fruit quality. Tomato plants were grown up in plastic bags (25 kg) containing different textured soils (sandy and clay) and different amounts of compost material (15–30 and 60 ton ha−1). The highest yield was determined in the clay soil+I dose compost parcel as 3.91 kg m−2. From fruit characteristics, total soluble solids, dry matter content and titratable acidity increased by compost applications, but pH and Vitamin C values were not affected by the treatments.

Effect of nutrient sources on cucumber production in different substrates

Citrus are grown in subtropical and tropical regions of the world. Mediterranean basin is the main region for citrus growing with irrigation. In the Mediterranean countries, due to the shortages of water, quantity and quality of irrigation water create problems. In Turkey, satsuma mandarins are mainly grown in the western part of the country. Gumuldur-Buyukalan, the main satsuma-growing region in Turkey is threatened by groundwater salination due to seawater intrusion. Citrus species are generally considered as sensitive to salt. Saline irrigation water reduces the vegetative and generative growth of trees, as well as yield and quality. In Buyukalan-Gumuldur/Turkey, 12 satsuma orchards were sampled in 1996 and 1997. The aim of the researchwork was to determine the effect of salinity on fruit quality and to find out its relationship with the nutritional status of the trees. As fruit quality parameters, average fruit weight, total soluble solids (TSS %) titratable acidity (as % citric acid) and Cl content of the fruit juice and crude fibre of the pulp were analysed. In addition, sugar composition was determined by gas chromatography. Sodium, potassium, calcium and chloride contents were analysed in leaf and irrigation water samples. Water samples were taken towards the end of the irrigation period. Leaf samples were taken during the fruit ripening period (end of October). In the statistical evaluation of the results, the effect of salinity on the analysed quality parameters were defined.