Mahmud Tengku Muda Mohamed

Spent Mushroom Waste as a Media Replacement for Peat Moss in Kai-Lan (Brassica oleracea var. Alboglabra) Production

Peat moss (PM) is the most widely used growing substrate for the pot culture. Due to diminishing availability and increasing price of PM, researchers are looking for viable alternatives for peat as a growth media component for potted plants. A pot study was conducted with a view to investigate the possibility of using spent mushroom waste (SMW) for Kai-lan (Brassica oleracea var. Alboglabra) production replacing peat moss (PM) in growth media. The treatments evaluated were 100% PM (control), 100% SMW, and mixtures of SMW and PM in different ratios like 1 : 1, 1 : 2, and 2 : 1 (v/v) with/without NPK amendment. The experiment was arranged in a completely randomized design with five replications per treatment. Chemical properties like pH and salinity level (EC) of SMW were within the acceptable range of crop production but, nutrient content, especially nitrogen content was not enough to provide sufficient nutrition to plant for normal growth. Only PM (100%) and SMW and PM mixture in 1 : 1 ratio with NPK amendment performed equally in terms of Kai-lan growth. This study confirms the feasibility of replacing PM by SMW up to a maximum of 50% in the growth media and suggests that NPK supplementation from inorganic sources is to ensure a higher productivity of Kai-lan.

Integration of agronomic practices with herbicides for sustainable weed management in aerobic rice

Till now, herbicide seems to be a cost effective tool from an agronomic view point to control weeds. But long term efficacy and sustainability issues are the driving forces behind the reconsideration of herbicide dependent weed management strategy in rice. This demands reappearance of physical and cultural management options combined with judicious herbicide application in a more comprehensive and integrated way. Keeping those in mind, some agronomic tools along with different manual weeding and herbicides combinations were evaluated for their weed control efficacy in rice under aerobic soil conditions. Combination of competitive variety, higher seeding rate, and seed priming resulted in more competitive cropping system in favor of rice, which was reflected in lower weed pressure, higher weed control efficiency, and better yield. Most of the herbicides exhibited excellent weed control efficiency. Treatments comprising only herbicides required less cost involvement but produced higher net benefit. On the contrary, treatments comprising both herbicide and manual weeding required high cost involvement and thus produced lower net benefit. Therefore, adoption of competitive rice variety, higher seed rate, and seed priming along with spraying different early-postemergence herbicides in rotation at 10 days after seeding (DAS) followed by a manual weeding at 30 DAS may be recommended from sustainability view point.

Antimicrobial Compounds from Leaf Extracts of Jatropha curcas, Psidium guajava, and Andrographis paniculata

The present research was conducted to discover antimicrobial compounds in methanolic leaf extracts of Jatropha curcas and Andrographis paniculata and ethanolic leaf extract of Psidium guajava and the effectiveness against microbes on flower preservative solution of cut Mokara Red orchid flowers was evaluated. The leaves were analyzed using gas chromatography-mass spectrometry. A total of nine, 66, and 29 compounds were identified in J. curcas, P. guajava, and A. paniculata leaf extracts, with five (88.18%), four (34.66%), and three (50.47%) having unique antimicrobial compounds, respectively. The experimental design on vase life was conducted using a completely randomized design with 10 replications. The flower vase life was about 6 days in the solution containing the P. guajava and A. paniculata leaf extracts at 15mg/L. Moreover, solution with leaf extracts of A. paniculata had the lowest bacterial count compared to P. guajava and J. curcas. Thus, these leaf extracts revealed the presence of relevant antimicrobial compounds. The leaf extracts have the potential as a cut flower solution to minimize microbial populations and extend flower vase life. However, the activities of specific antimicrobial compounds and double or triple combination leaf extracts to enhance the effectiveness to extend the vase life need to be tested.

Enhancing the Efficacy of Burkholderia cepacia B23 with Calcium Chloride and Chitosan to Control Anthracnose of Papaya During Storage

The efficacy of the combination of Burkholderia cepacia B23 with 0.75% chitosan and 3% calcium chloride (CaCl2) as a biocontrol treatment of anthracnose disease of papaya caused by Colletotrichum gloeosporioides, was evaluated during storage. The growth of B. cepacia B23 in papaya wounds and on fruit surfaces was not affected in presence of chitosan and CaCl2 or combination throughout the storage period. The combination of B. cepacia B23 with chitosan-CaCl2 was more effective in controlling the disease than either B. cepacia B23 or chitosan or other combination treatments both in inoculated and naturally infected fruits. Combining B. cepacia B23 with chitosan-CaCl2 gave the complete control of anthracnose infection in artificially inoculated fruits stored at 14 oC and 95% RH for 18 days, which was similar to that obtained with fungicide benocide¢c. Moreover, this combination offered a greater control by reducing 99% disease severity in naturally infected fruits at the end of 14 days storage at 14 oC and 95% RH and six days post ripening at 28i¾2oC, which was superior to that found with benocide¢c or other treatments tested. Thus, postharvest application of B. cepacia B23 with chitosan-CaCl2 as enhancers represents a promising alternative to synthetic fungicides for the control of anthracnose in papaya during storage.

Opportunities of marker‐assisted selection for rice fragrance through marker–trait association analysis of microsatellites and gene‐based markers

Developing fragrant rice through marker-assisted/aided selection (MAS) is an economical and profitable approach worldwide for the enrichment of an elite genetic background with a pleasant aroma. The PCR-based DNA markers that distinguish the alleles of major fragrance genes in rice have been synthesised to develop rice scent biofortification through MAS. Thus, the present study examined the aroma biofortification potential of these co-dominant markers in a germplasm panel of 189 F2 progeny developed from crosses between a non-aromatic variety (MR84) and a highly aromatic but low-yielding variety (MRQ74) to determine the most influential diagnostic markers for fragrance biofortification. The SSRs and functional DNA markers RM5633 (on chromosome 4), RM515, RM223, L06, NKSbad2, FMbadh2-E7, BADEX7-5, Aro7 and SCU015RM (on chromosome 8) were highly associated with the 2AP (2-acetyl-1-pyrroline) content across the population. The alleles traced via these markers were also in high linkage disequilibrium (R(2) > 0.70) and explained approximately 12.1, 27.05, 27.05, 27.05, 25.42, 25.42, 20.53, 20.43 and 20.18% of the total phenotypic variation observed for these biomarkers, respectively. F2 plants harbouring the favourable alleles of these effective markers produced higher levels of fragrance. Hence, these rice plants can be used as donor parents to increase the development of fragrance-biofortified tropical rice varieties adapted to growing conditions and consumer preferences, thus contributing to the global rice market.

Preharvest calcium applications improve postharvest quality of papaya fruits (Carica papayaL. cv. Eksotika II)

ABSTRACT This research was conducted to evaluate the effects of calcium chloride (CaCl2) and calcium nitrate Ca(NO3)2 on nutrient concentrations and postharvest quality of papaya fruits. In the first experiment, plant stem height increased significantly after Ca(NO3)2 application compared to CaCl2. The calcium content in the peel and pulp for both sources [CaCl2 and Ca(NO3)2] significantly rose with increasing calcium concentrations, but there was a significantly higher content of calcium in fruit peel and pulp in the CaCl2 treatment. Magnesium and potassium in fruits decreased with increasing calcium concentrations. A reduction in anthracnose lesion diameter in the infected fruit with increasing calcium was observed in both CaCl2 and Ca(NO3)2 treatments. Ethylene production in fruits decreased with increasing calcium concentrations. In the second experiment, only CaCl2 was used as the calcium source, and results showed that the calcium content in fruit peel and pulp significantly increased at higher CaCl2 levels, whereas ethylene production, anthracnose lesion diameter, and magnesium content decreased compared to control.

Application of an Effective Statistical Technique for an Accurate and Powerful Mining of Quantitative Trait Loci for Rice Aroma Trait

When a phenotype of interest is associated with an external/internal covariate, covariate inclusion in quantitative trait loci (QTL) analyses can diminish residual variation and subsequently enhance the ability of QTL detection. In the in vitro synthesis of 2-acetyl-1-pyrroline (2AP), the main fragrance compound in rice, the thermal processing during the Maillard-type reaction between proline and carbohydrate reduction produces a roasted, popcorn-like aroma. Hence, for the first time, we included the proline amino acid, an important precursor of 2AP, as a covariate in our QTL mapping analyses to precisely explore the genetic factors affecting natural variation for rice scent. Consequently, two QTLs were traced on chromosomes 4 and 8. They explained from 20% to 49% of the total aroma phenotypic variance. Additionally, by saturating the interval harboring the major QTL using gene-based primers, a putative allele of fgr (major genetic determinant of fragrance) was mapped in the QTL on the 8th chromosome in the interval RM223-SCU015RM (1.63 cM). These loci supported previous studies of different accessions. Such QTLs can be widely used by breeders in crop improvement programs and for further fine mapping. Moreover, no previous studies and findings were found on simultaneous assessment of the relationship among 2AP, proline and fragrance QTLs. Therefore, our findings can help further our understanding of the metabolomic and genetic basis of 2AP biosynthesis in aromatic rice.

Production system and harvesting stage influence on nitrate content and quality of butterhead lettuce

Leafy vegetables such as lettuce grown under different production systems may accumulate different concentrations of nitrate which may reach to the levels potentially toxic to humans. Moreover, nitrate accumulation varies in various plant parts and physiological age of the plant. Therefore, to determine the effect of production system and harvesting stage on nitrate accumulation and quality of butterhead lettuce, a study was conducted considering two lettuce production systems namely hydroponic and organic, and four different harvesting stages such as 35, 38, 41 and 44 days after transplanting (DAT). The experimental design was complete randomized design (CRD) with four replications. Hydroponic and organic systems performed similar in terms of yield, quality and nitrate content of butterhead lettuce. Delaying harvesting can not only increase yield but also can minimize nitrate accumulation and health hazard risk as well. Delay in harvesting stage may result in quality deterioration of lettuce and increased production cost. Thus, a compromise is necessary to consider 41 DAT as the optimum stage to harvest butterhead lettuce with significantly higher reduction of nitrate content in both outer adult leaf blades and young leaves of hydroponic lettuce. Fresh weight, firmness and color of butterhead lettuce at this stage were still acceptable.

Metaheuristic approaches for optimizing agricultural land areas

Metaheuristic approaches are the most selected technique to find optimization solution intelligently in many areas of timetabling and scheduling, space allocation, decision making and others. These approaches have promised a better solution in single objective optimization problem. However, there is no revealed discussion on the issue that has more than one problem. In agricultural land use planning, we found that there are two related problems need to be solved intelligently before obtaining the main objective of optimal solution for the land. The problems are i) to allocate the resources into agricultural land optimally, then ii) to arrange the plant in the planting area in order to find an optimal layout. The solution of the both problems will utilize the land and consequently maximize number of plant to be planted in an area respectively. This paper is preliminary investigation towards optimizing agricultural land, in order that we focus on the understanding of the issues in agricultural land and solution methods by referring to the similarity of the previous researches. We also promote the solutions idea and show the complexity of the problems, and finally find that the metaheuristic approaches are a necessity.

Use Of Absolute Function And Its Associates In Formation And ‘Redevelopment’ Of Mathematical Models In Some Plant‐Related Quantitative Physiology: Salinity Effects On Leaf Development Of Schefflera arboricola And Harvest Index In Rice

The roles of quantitative physiology are becoming more apparent and crucial in the era of ICT recently. As based on the rate‐related variables, most of the mathematical models are in the form of ‘non‐linear’ function in describing the responses or the observed within‐plant processes outcomes versus time. Even though if some responses change in a drastic manner at certain response point within a biological unit or space of a plant system, the response curve ‘should’ be dependent on a continuous independent variable range in a specified period of determination where biologically ‘should not’ functioned by independent variable range having ‘IF’ statement(s). Subjected to nutrient concentration of high salinity (6.0 mS cm−1), the leaf turgidity (measured as leaf surface area) of S. arboricola which initially was described by one form of the logistic growth functions [(y = 1/(a+be⎯cx)] abruptly reduced as explained by a model having terms of Absolute function (ABS) containing tan−1(x) and its parameter of leaf life expectancy as affected by high salinity growing medium at a certain point of days after planting. This yielded an overall function of y = 1/(a+be−cx)−A[tan−1{(x⎯B)/D}+ABS(tan−1{(x⎯B)/D})]E, where a, b, c, A, B, D, and E are constants that most of them can be ‘biologically’ interpreted. The constant B is the point similar to ‘IF statement’ as normally used in other mathematical functions. Plants subjected to lower salinity status (<3.0 mS cm−1) were only having function of y = 1/(a+be−cx). In the harvest index or HI (economic yield/above ground biomass) study of 20 rice varieties grown over two planting seasons, the long flattened tails at both sides of a peak in the middle of function of y = R+B(T+ABS(B⎯x))e⎯k(T+ABS(B⎯x)) had indicated that those varieties maturing at 123 to 133 days after transplanting were having high HI values. In our observation, Absolute (ABS) function coupled with some terms could be used in the formation of some mathematical functions having biological meaningful constants in explaining some quantitative physiological and biological responses vs. independent variables studied.