Open Access Original Research Article

Drought Stress Effects on Plant Water Relations, Growth, Fruit Quality and Osmotic Adjustment of Tomato (Solanum lycopersicum) under Subtropical Condition

Kamrun Nahar, Shah Muhammad Ullah

Asian Journal of Agricultural and Horticultural Research, Page 1-14
DOI: 10.9734/AJAHR/2018/39824

The pot experiments were conducted in 2 subsequent years in the net house of the Dept. of Soil, Water and Environment, Dhaka University to evaluate the effect of water stress on the growth, plant water relations, fruit quality and osmotic adjustment of seven tomato cultivars. The percentage of field capacity levels were 40, 70 and 100. The tomato plants subjected to water stress during their growth period had decreased relative water content (RWC) of leaves and moisture content in tomatoes compared with the plants supplied with adequate moisture. Water use efficiency (WUE) also decreased with increasing moisture stress. A significant increase in organic solutes, glucose (85%), fructose (62%), sucrose (121%) and proline (103%) at 40% F.C. compared with 100% F.C. showed a tendency of these plants to adjust osmotically. Ascorbic acid, citric acid and malic acid were also significantly enhanced by water stress treatments. The quality of fruits was improved as a result of the synthesis of these acids.

Water stress did not affect the height of plants and no physical damage due to stress was observed in fruits and were over 90% red. Ripening and fruit quality showed that none of the stress-treated tomatoes deteriorated in quality. On the other hand, water stress enhanced the sweetness of the tomatoes by increasing their glucose, fructose, and sucrose contents and improved the quality by increasing the amount of important acids such as ascorbic acid, malic acid and citric acid.

Open Access Original Research Article

Use of Organic Compost and Residues as an Alternative to Commercial Substrate for Lettuce Cultivation (Lactuca sativa L.)

G. M. B. Bohm, L. N. Bierhals, S. M. Schwanz, S. L. Lanius, E. B. Moraes

Asian Journal of Agricultural and Horticultural Research, Page 1-10
DOI: 10.9734/AJAHR/2018/40262

Aims: The objective of this work was to evaluate the physical and biological characteristics of the substrates formulated from organic compost (OC), carbonized rice husk (CRH), sewage sludge (SS) and commercial substrate, as well as the vegetative development of lettuce seedlings cultivated in the compositions.

Study Design:  Eight treatments were studied in a completely randomized design: TO- commercial substrate (CS), T1- 50% OC & 50% CRH, T2 – 75% OC & 25% CRH, T3- 50% SS & 50% CRH, T4- 75% SS 25% CRH, T5- 100% SS, T6- 100% OC and T7- 30% SS, 30% OC & 40% CRH, being carried in box of expanded polystyrene (PEE) with four replicates.

Place and Duration of Study: The experiment was conducted in an experimental area of Campus Pelotas, Federal Institute Sul-rio-grandense, Pelotas, Brazil, period from November until December 2015.

Methodology: The physical characteristics evaluated were: total porosity, macroporosity, microporosity, water retention capacity and density. The microbiological analysis as carbon in the microbial biomass (Cmic), basal respiration (BR) and metabolic quotient (qCO2). Also, organic matter, electrical conductivity and dry matter and plant growth.

Conclusion: The addition of organic compost, treated sewage sludge and carbonized rice husk are suitable for the formation of alternative substrate for the cultivation of lettuce seedlings. The T2 (75% OC & 25% CRH) and T7 (30% SS, 30% OC & 40% CRH) treatments were the most promising in relation to physical characteristics resulting in good microporosity, total porosity,             water retention capacity and density, but low macroporosity. Regarding the microbiological characteristics the T2 treatment presented greater microbial activity and ideal electrical conductivity. For vegetative growth and dry matter T2 and T7 presented similar results to the commercial substrate.

Open Access Original Research Article

Effects of Different Soil-biochar on Physico-Chemical Soil Properties, Rooting and Growth of Bougainvillea glabra and Ficus benjemena Using Stem Cuttings

I. Iddrisu, H-V Adzraku, P. K. Tandoh

Asian Journal of Agricultural and Horticultural Research, Page 1-16
DOI: 10.9734/AJAHR/2018/40318

A study was conducted at the Department of Horticulture, KNUST, to determine the effect of biochar-soil mixes on the soil physico-chemical properties for rooting and growth performance using air-layering. A 2X5 Factorial Randomized Complete Block Design which consisted of five soil-biochar amendments (2 part Coconut husk biochar: 1 part Topsoil, 2 part Maize stover biochar: 1 part Topsoil, 2 part Rice husk biochar: 1 part Topsoil, 2 part Paspalum conjugatumbochar: 1 part Topsoil and only Topsoil) and the two plant type (Bougainvillea glabra and Ficus benjamena). Parameters measured for the air layers included; days to root emergence, number of survived air layers, number of rooted air layers and root length (cm) per air layer. The 2Rhb: 1Tp mix recorded the highest water holding capacity of 601.70%, 21.8 times greater than the Tp. The 2Pcb:1Tp recorded the highest percentage increase of air porosity of 10.6%, better than Tp. The total nitrogen in 2Pcb:1Tp at 4WAP recorded an increase of 38.7% as the highest among the media 4WAP. 2 part Maize stover biochar: 1 part Topsoil recorded 23.0% increase in organic matter 4WAP which was the highest among the media. 2Msb: 1Tp had a slight percentage increase of 6.0% as the highest among the media 4WAP.There was an increase of 45.7% 0f calcium content in 2Pcb: 1Tp which was the highest among the media at 4WAP. The results indicated that, significant (p<0.05) interaction between media and plant material type for the number of days to sprouting of Bougainvillea glabra air layers in 2Pcb:1Tp and 2Msb: 1Tp, 2Rhb: 1Tp1 and 2Pcb:1Tp, 2Rhb: 1Tp and 2Pcb:1Tp and 2Msb:1Tp and 2Pcb:1Tp influenced the number of fully developed leaves 5 WAP, 6 WAP and 7 WAP respectively. There were significant differences in the number of roots per air- layer of Bougainvillea glabra in 2Msb: 1Tp, 2Rhb: 1Tp and 2Pcb: 1Tp. Root length per air layers for Bougainvillea glabra was also significantly influenced by 2Msb:1Tp and 2Pcb: 1Tp.

Open Access Original Research Article

Effect of Plant Extracts on the Postharvest Quality and Management of Pepper Anthracnose Incited by Colletotrichum capsici (Synd) Butler and Bisby on Pepper (Capsicum frutescens L.) Fruits

Chigoziri Ekhuemelo, Richard Isa Bwala, Daniel Terfa

Asian Journal of Agricultural and Horticultural Research, Page 1-7
DOI: 10.9734/AJAHR/2018/40392

The experiment was conducted using the stem and root bark extract of Azadirachta indica and the root bark extract of Vernonia amygdalina at 10% concentration. The pepper fruits were dipped in each extract for five minutes and air dried after which 1mm agar plugs of Colletotrichum capsici were used to inoculate the fruits. The root, stem bark extract of A. indica and the root bark extract of V. amygdalina significantly (P ≤ 0.05) reduced the lesion diameter of C. capsici by 94%, 68% and 20% respectively. Pepper fruits treated with the root bark extract of A. indica had a severity of 2.05 while pepper fruits treated with the root bark extract of V. amygdalina and A. indica both had a severity value of 2.33. Capsicum frutescens fruits inoculated with C. capsici alone had the highest severity value of 4.47. Treating pepper fruits with the root bark extract of V. amydalina and A. indica significantly (P≤ 0.05) reduced decay of C. frutescens by 76% and 86% respectively. Total soluble solid (TSS) of pepper fruits treated with the root bark extract of A. indica was significantly (P≤0.05) lower (7.50°brix) compared with the TSS value of the control (9.20°brix). The root and stem bark extract of A. indica can be utilized as an alternative to synthetic chemicals in the treatment of pepper fruits to reduce pepper anthracnose and increase pepper fruit quality.

Open Access Short Research Article

Rooting Ability of Cocoa (Theobroma cacao L.) Stem Cuttings: Effect of Genotype, Cutting Type, Hormone Concentration and Their Interactions

K. M. D. Kamga, D. T. Tchatchoua, R. G. Caspa, G. Yombo A. Bessa, L. J. Baleba

Asian Journal of Agricultural and Horticultural Research, Page 1-10
DOI: 10.9734/AJAHR/2018/40168

Aims: This study aimed to evaluate the rooting ability of stem cuttings of eight-year-old cocoa hybrids disseminated in the 5th agroecological zone of Cameroon.

Study Design: The experiment was a 6 x 2 x 3 randomised complete block design with three replications.

Place and Duration of Study: The study was conducted at the multipurpose agricultural research station Nkoemvone – Ebolowa from February to September 2017.

Methodology: The studied factors were six genotypes (G1 = IMC67 x SNK 64, G2 = SNK 620 x MA 12, G3 = T79/501 x SNK 109, G4 = T79/501 x SNK 64, G5 = SNK 413 x UPA 143 and G6 = UPA 143 x SNK 64), two Cutting types (C1 = Orthotropic and C2 = Plagiotropic) and three rooting hormone concentrations (H1 = 2 tablets per liter of water, H2 = ½ tablet per liter of water and H3 = 1 tablet per liter of water). Rooting ability was evaluated by assessing percentage of rooted cuttings, number of root per rooted cutting and the length of the longest root per rooted cutting.

Results: Analysis of variance results indicated that genotype, hormone concentration and most of their interactions were highly significant while cutting type was not significant on the measured traits. The best rooting was obtained with genotype G4 for all the measured parameters. It was shown in this experiment that genotype G4 could be propagated using Rhizopon hormone, with a concentration of ½ tablet per litre of water and plagiotropic cutting type. This is also noticed in their interaction terms, where genotype G4/Hormone concentration 2 and 3 were the best combinations for all parameters. 

Conclusion: Significant differences among genotypes are an indication that different genotypes may require different conditions for their propagation. As such investigations into the requirement for the propagation of the other genotypes should be considered in the future.