Salinity, chitin and GA 3 effects on seed germination of chervil (Anthriscus cerefolium)

Abstract The seed germination observation of chervil (Anthriscus cerefolium) lasted 35 days at a temperature of 20 ο C. The effect of sodium chloride (NaCl), chitin and gibberillic acid (GA 3 ) on seed germination of chervil was studied for 35 days at a temperature of 22 ο C under controlled growth chamber conditions. For this, various aqueous solutions of NaCl (80, 120, 180, 240 mM NaCl), chitin (1, 2, 3, 4% ) and GA 3 (100, 200, 500, 1000 ppm GA 3 ) were used as germination substrates. The above solutions used solely or combined and added on Petri dishes containing fifty chervil seeds. The seed germination of chervil in the control (H 2 O) was 44%. In the 80 mM NaCl concentration there was an increase in the germination (64%) while in higher NaCl concentrations the germination reduced. The seed germination percentage of the chervil in the substrates with 1% and 2% chitin as the 200, 500 and 1000 ppm GA 3 was increased than the corresponding one in H 2 O. With increasing rate of chitin and GA3 the seed germination of the chervil was reduced. In the combinations of 80 mM NaCl+ 1% Chitin, 120 NaCl + 1% chitin, 120 NaCl + 100 GA 3 , 180 NaCl + 2% chitin and 180 NaCl + 200 GA 3 germination increased and the Timson Index of germination velocity was higher than the corresponding velocity in H 2 O

Effects of biochar on pepperoncini (Capsicum annuum L cv. Stavros) germination and seedling growth in two soil types

Abstract Biochar is a solid material obtained from the carbonization of biomass. The effect of biochar on the germination and seedling growth of pepperoncini pepper (Capsicum annuum L. cv. Stavros) was studied under controlled growth chamber conditions in two experiments. The substrates in the pre-test experiment (first experiment) were 2%, 4%, 6%, 8%, and 10% biochar (at 24°C or 28°C), while in the second experiment they were acidic (pH 6.1) or alkaline soil (pH 7.2), with or without biochar at 24°C. Three replicates (Petri dishes) for each treatment were placed at random in a growth chamber for 12 days at a 16/8h light/dark photoperiod, 12 klx light intensity and 80% relative humidity. In biochar substrates the seed germination percentage in Η 2 Ο-control was high at 24°C and low at 28°C. At 28°C it was also increased (4°C) and it was higher than the corresponding one in the Η 2 Ο-control. At both temperatures (24°C and 28°C) there was a tendency for increased height growth. The percentage of seed germination in acidic soil substrates was low (42%), while in alkaline soil substrates high (82%). All biochar applications in acidic soil substrates increased the seed germination percentage, which varied between 53% and 67%. Biochar application in alkaline soils substrates did not influence seed germination. Seedling height in acidic soil substrates was 0.15cm, while in alkaline soil substrates it was 1.63cm. Biochar application in acidic soils increased the seedling height, while in alkaline soils it was reduced when compared to the control

Interactions between salinity and irrigation frequency in greenhouse pepper grown in closed-cycle hydroponic systems

Two different irrigation regimes with two different salinity levels were applied to peppers (Capsicum annum L.) grown in closed hydroponic systems in a glasshouse. The two salinity levels were attained by adding NaCl to the irrigation water used to prepare nutrient solution to obtain concentrations of 0.8 and 6 mol m(-3), and allowing the salts to progressively accumulate in the recycled nutrient solution. The two salinity levels were combined with two different levels of irrigation frequency in a two-factorial experimental design. Initially, the Na and Cl concentrations increased rapidly in the recycled effluents, but nearly three months after treatment initiation they converged gradually to maximal levels depending on the NaCl treatment. The low irrigation frequency imposed a more rapid salt accumulation in the root zone, which was ascribed to restriction of the volume of drainage solution. However, the maximal salt concentrations in the root zone were independent of the watering schedule. This finding agrees with previous research revealing that the maximal salt accumulation in the root zone of plants, grown in closed hydroponics, is dictated merely by the NaCl concentration in the irrigation water. Total and Class I yields were suppressed by salt accumulation but the high irrigation frequency significantly mitigated the deleterious salinity effects. At low salinity, the low irrigation frequency raised significantly the weight percentage of fruits with blossom-end rot (BER), whereas at high salinity the incidence of BER was further increased without significant differences due to the irrigation regime. Frequent irrigation resulting in high drainage fractions in closed hydroponic systems may delay the rate of salt accumulation in the root zone, thereby enhancing yield and improving fruit quality, without increasing the discharge of polluting fertigation effluents to the environment