No abstract

No abstract

In Turkey, the majority of medicinal plants at the selling points are wildly harvested. Therefore, no control exists during their growth and development. The public awareness on effects of environmental pollution in this regard especially with respect to heavy metals in the herbs is increasing. With this objective, medicinal and aromatic plants were collected from herbalists in different, densely populated districts of Izmir Municipality. The concentrations of some essential plant nutrient elements (N, P, K, Ca, Mg, Na, Fe, Mn, Cu, Zn, B, and Mo) and toxic heavy metals (Co, Cd, Cr, Ni, and Pb) and Al were measured. Results showed that herbs are rich in the investigated mineral elements; however, some of the heavy metals are found to be at concentrations above the reported critical levels. ÖZETTürkiye'deki satış noktalarından alınan tıbbi bitkilerin çoğu doğadan toplama yoluyla sağlanmaktadır. Bu nedenle bitkilerin gelişim ve büyümesi kontrol altına alınamamaktadır. Özellikle çevresel kirliliğin tıbbi bitkilerin ağır metal içeriği üzerine yapabileceği olası etkiler ile ilgili toplumsal farkındalık her geçen gün artmaktadır. Bu amaçla İzmir'de nüfusun yoğun olarak bulunduğu ilçelerdeki farklı satış noktalarından tıbbi ve aromatik bitkiler toplanmıştır. Bazı bitki besin elementi konsantrasyonu (N, P, K, Ca, Mg, Na, Fe, Mn, Cu, Zn, B ve Mo) ile toksik ağır metal (Co, Cd, Cr, Ni, Pb ve Al) içerikleri ölçülmüştür. Sonuçta tıbbi bitkilerin zengin mineral içeriğine sahip olduğu ancak bazı ağır metallerin kritik düzeylerin üzerinde bulunduğu saptanmıştır. Anahtar Kelimeler: Tıbbi ve aromatik bitkiler; Ağır metal; Temel besin elementleri; Makro besin elementleri; Mikro besin elementleri

Organic farming seems to be a solution in environmentally sensitive zones such as the protection zone of Tahtalı 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 Tahtalı 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$1.12–1.79 per m2 whereas that for conventional bag culture produce was US$0.55 per m2. 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.

No abstract