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Calcium and humic acid affect seed germination, growth, and nutrient content of tomato (Lycopersicon esculentum L.) seedlings under saline soil conditions

The effects of calcium and humic acid on seed germination, growth and macro- and micro-nutrient contents of tomato (Lycopersicon esculentum L.) seedlings in saline soil conditions were evaluated. Different levels of humic acid (0, 500, 1000 and 2000 mg kg−1) and calcium (0, 100, 200 and 400 mg kg−1) were applied to growth media treated with 50 mg NaCl kg−1 before sowing seeds. Seed germination, hypocotyl length, cotyledon width and length, root size, shoot length, leaf number, shoot and root fresh weights, and shoot and root dry weights of the plant seedlings were determined. Macro- and micro-nutrient (N, P, K, Ca, Mg, S, Cu, Fe, Mn and Zn) contents of shoot and root of seedlings were also measured. Humic acid applied to the plant growth medium at 1000 mg kg−1 concentration increased seedling growth and nutrient contents of plants. Humic acid not only increased macro-nutrient contents, but also enhanced micro-nutrient contents of plant organs. However, high levels of humic acid arrested plant growth or decreased nutrient contents. Levels of 100 and 200 mg kg−1 Ca2+ application significantly increased N, Ca and S contents of shoot, and N and K contents of root.

Phosphorus and humic acid application alleviate salinity stress of pepper seedling

Humic acid is a commercial product that contains many elements which improve the soil fertility and increase the availability of nutrient elements. It consequently affects plant growth and yield and ameliorates the deleterious effects of salt stress. The objective of the study was to determine the effect of humic acids and phosphorus on growth and nutrient content of pepper seedlings (cv. Demre) grown under moderate salt stress in growth chamber conditions. Applications of different levels of phosphorus [0 (P 0 ), 50 (P 1 ), 100 (P 2 ) and 150 (P 3 ) mg kg -1 ] and humic acid [0 (HA 0 ), 750 (HA 1 ) and 1500 (HA 2 ) mg kg -1 ] to growing media containing moderate salt dose (8 mM NaCl treatment) were studied. The study was replicated four times with 20 plants in each replicate. Humic acid (HA) and phosphorus applications increased the growth and growth parameter of plants. In company, effects of HA and P application was more effective on growth and growth parameter than each separate effect. The optimum total yield was obtained from 69 mg kg -1 P application with HA 2 doses according to regression analysis. Humic acid application significantly increased N, P, K, Ca, Mg, S, Mn and Cu contents of shoot of pepper seedling. Also, N, P, K, Ca, S, Fe, Mn, Zn and Cu contents of root were increased with humic acid application. Na contents of both shoot and root of pepper decreased with increased humic acid doses. It can be concluded that high humic acid doses has positive effects on salt tolerance based on the plant growth parameters and nutrient contents. The present study suggests that HA treatments can ameliorate the deleterious effects of salt stress on pepper plants and HA could offer an economical and simple application to reduce problems of pepper production in moderately saline soil. Keywords: Nutrient uptake, plant growth parameter, salt stress, pepper African Journal of Biotechnology Vol. 9(36), pp. 5845-5851, 6 September, 2010

Sewage sludge as a substitute for mineral fertilization of spinach (Spinacia oleraceae L.) at two growing periods

Abstract.

Türkiye’den Toplanan Popülasyonlardan Elde Edilen Çerezlik Kabak Çeşit Adaylarının Mineral Madde İçerikleri

Turkiye, cerezlik kabak uretiminde en onemli ulkeler arasindadir. Calismanin amaci, ulkenin farkli bolgelerinden toplanan ve S5 kademesine ulastirilan cerezlik kabak islah hatlarinda tohum kabugu ve tohumdaki bazi mineral maddelerin miktarini ortaya koymaktir. Bu calismada, S5 kademesinde yirmi yedi kabak genotipi ve genotip olarak karakterize edilmis iki yerel populasyon kullanilmistir. Tohum kabugu ve tohumda P, K, Ca, Fe, Mg, Mn, Cu, S ve Zn minerallerinin icerigi ayri ayri belirlenmistir. Arastirma sonuclarinda, tohum icerisindeki en yuksek mineral madde icerigi P icin “A14” ve “A25”, K icin “A14”, Ca icin “B17” ve “A8”, Fe icin “B33” ve “C24”, Mg icin “A14”, Mn icin “C30” ve “A32”, Cu icin “A14”, S icin “A14” ve Zn icin “A14” hatlarinda belirlenmistir. Tohum kabugunda ise P icin “B14”, K icin “A14”, Ca icin “A11”, Fe icin “B25” ve “C25”, Mg icin “A11”, Mn icin Urgup Sivrisi (populasyon), Cu icin “A33”, S icin “C18” ve Zn icin “A14” hatlarinda en yuksek degerler gozlenmistir. Sonuc olarak A14 en yuksek mineral madde icerigine sahip genotip olarak tespit edilmistir.