This study was conducted to investigate the root and foliar application of soluble silicon on plant growth, fruit quality parameters and anthracnose disease development in fruits of Capsicum annuum L. 'Muria F1'. Silicon as potassium silicate (75 mg/l) was provided to root by amending the nutrient solution (T Root) at weekly interval or to foliage by spraying (T Foliar) daily, as two separate treatments. Control plants were not treated with Si. Disease resistance in fruits was assessed by artificial inoculation of Colletotrichum gloeosporioides. Plant growth and fruit quailty parameters were not significantly affected by Si treatments except firmness and cuticle thickness of fruits which were significantly greater in both T Root and T Foliar treated fruits than the control. This increase in fruit firmness and cuticle thickness possibly may be attributed to mechanical strength occurred by Si treatment. Sensory evaluation was carried out by a trained panel and there was no significant difference in sensory properties among the Si treated and control fruits. The fruits harvested from T Root or T Foliar treated plants developed significantly smaller lesions (67% and 39% respectively) as compared to the control. Further, the disease incidence was delayed by 2 days in both root and foliar treatments compared to the control. However, the effect of Si root treatment was significantly higher than the foliar spray against the disease.

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Introduction Silicon is beneficial for many plants for growth, yield and enhancing resistance to biotic and abiotic stresses. In the present study, silicon as a form of rice hull sand mixture (3:2 v/v) was used in simplified hydroponic system to evaluate the performance and disease resistance of Capsicum annuum L. The nutrients were supplied by NF (New Formula) or Albert's solution. Results Continuous monitoring of soluble silicon content in the simplified hydroponic boxes revealed that a high amount of silicon was leached by the rice hull sand medium. Disease resistance was assessed by challenge inoculation of harvested fruits with anthracnose-causing fungi, Colletotrichum gloeosporioides, and it was observed a significant disease reduction (over 83 %) in fruits harvested from simplified hydroponic system compared to that of liquid hydroponic system. Shoot length, root length, fruit length, fruit weight and fruit firmness were also increased significantly in simplified system compared to the liquid system. However, the results were not significantly affected by the nutrient solutions used in these two systems. Conclusions In conclusion, the simplified hydroponic system composed of rice hull, as a natural silicon supplement could be used as a low-cost environmental friendly growing method of capsicum to enhance resistance against anthracnose disease, and to improve plant growth and fruit quality.

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Ixora or Jungle Geranium (Ixora coccinea) is an invaluable plant in tropical landscapes for its beautiful foliage, easiness of growing and fabulous flowers freely formed and artfully presented. Sri Lanka exports Ixora hybrids as planting materials after rooting the Ixora cuttings on a coir dust media. Exporting potted Ixora plants with flowers is more beneficial than that without flowers as flowers increase product quality and gain customer attraction. In commercial floriculture venture, flower induction at young age using plant growth regulators and fertilizers is a popular practice. An experiment was conducted to investigate the most effective combination of a plant growth regulator and fertilizers for early flower initiation of Ixora hybrids; Vulcanus, Chanmai, Nora grant and Kontiki under outdoor and shaded conditions. Six-month-aged healthy plants of Ixora hybrids grown in containers were treated with a flowering hormone containing Nitrobenzene in combination with two fertilizer types: F1-Bloom special and F2-Krista K 44. Flowering hormone was sprayed in four concentrations; H1= 0.075% (V/V), H2 = 0.100% (V/V), H3 = 0.125% (V/V) and H4 = 0.150% (V/V) once in two weeks. Both fertilizers were applied as a liquid spray in same concentration (1 g/L of water) once a week. All the cultural practices were similarly applied to the plants under two light levels (outdoor light 'L1'and shaded conditions 'L2'). There were 16 treatment combinations and control, each with five replicates. Each treatment combination consisted of three plants. The number of flower-initiated plants per treatment combination was recorded as a percentage for five weeks. Percentage values after five weeks of treatments were transformed into log values and used for the analysis of variance. All the hybrids except Vulcanus showed a significant flower induction compared to the control. Outdoor light and shaded conditions were not significantly different to each other showing the potentiality of early flower initiation of hybrids under shaded condition. However, no significant difference in flower induction was observed among four levels of the flowering hormone and the two types of fertilizers (p> 0.05) in all four Ixora hybrids despite differences among the hybrids. Therefore, it could be concluded that the least expensive combination of hormone and fertilizer type could play a profitable and a positive role in early flower induction of Ixora at an age of six months.