Volume 4 Issue 2
Investigating water productivity and yield of boro rice under conventional and conservation irrigation practices in Bangladesh
Md Maruf Hossain, Mohammed Mizanur Rahman, Md Touhidul Islam, Deen Islam, A K M Adham
>>doi: 10.5455/faa.34631 >>PP:867-872
Irrigation is one of the vital inputs to rice production in Bangladesh, where 78% of irrigation is dependent on groundwater (GW) resources. For the past two decades, GW level has been significantly declining across the country and on the other hand, surface water is limited in the dry season. This poses a great challenge to meet burgeoning irrigation demand of the country. Amid this situation, optimal and judicial use of water for irrigation is being thought to be a way out without compromising crop yield. In such context, an experiment was performed at the Field Irrigation Laboratory, Bangladesh Agricultural University, Mymensingh, Bangladesh to investigate the water productivity, growth and yield characteristics of ‘BRRIdhan 28’ under three different irrigation techniques i.e. alternate wetting and drying (AWD), raised bed (RB), and conventional continuous flooding (CF). Six treatments including four AWD variants with three replications for each treatment were laid out randomly in 18 plots. The highest yield was 6.63±0.65 t ha-1 under 10 cm disappearance AWD treatment (T2). But the lowest yield was (5.73±1.25) t ha-1 under mixed AWD treatment (T5) which did not show a significant variation on the yield of different techniques. CF treatment (T1) needed 68.94±3.44 cm of water and its water productivity was 0.48±0.08 kg m-3, where the T2 treatment needed average 52.10±3.21 cm of water and average water productivity was 0.59±0.04 kg m-3. The study revealed that 10 cm, 15 cm, 20 cm disappearance AWD and mixed AWD treatments (respectively, T2, T3, T4, and T5) saved 24.42, 24.28, 28.92 and 38.56% of irrigation water, respectively, and where the RB also saved 15.52% over the conventional method. On the basis of the above consideration, it can be mentioned that AWD technology can be adopted to increase the water productivity of dry season boro rice and thus to make its cultivation more profitable.
Keywords: Irrigation, water saving techniques, water productivity, yield
Heat stress alters chlorophyll fluorescence, photosynthesis and antioxidative enzyme activities in wheat cultivars
Md Sabibul Haque, Ummea Tanjima, Deboprio Roy Sushmoy, AKM Zakir Hossain
Heat stress becomes one of the most limiting factors to crop growth and yield. To investigate the impact of heat stress on physiological and biochemical responses in wheat cultivars, a pot experiment was conducted in the Department of Crop Botany, Bangladesh Agricultural University, Mymensingh, during November 2016 to March 2017. The experiment was laid out in a two factorial CRD design with three replications. The factors were i) four wheat cultivars (BARI GOM-25, BARI GOM-26, BARI GOM-27 and BARI GOM-28) and ii) heat stress (control and heat). The heat stress (38/25°C day/night) was imposed to the wheat plants for three days at early grain filling stage in a climate chamber. The control plants were remained in the field at around 20−25°C. Heat stress declined the leaf greenness (SPAD), the maximum photochemical efficiency of PSII (Fv/Fm), photosynthesis rate (A) and grain weight in all the cultivars in comparison to control. The leaf greenness (SPAD) and Fv/Fm were declined with the progress of heat stress treatment in all four cultivars. In both cases, lowest reduction was observed in BARI GOM-28 whereas, the highest reduction in SPAD and Fv/Fm were observed in BARI GOM-26 and BARI GOM-27, respectively. The percent reductions in photosynthesis and grain weight were significantly higher in BARI GOM-28 in comparison to other cultivars. Increased activities of catalase, peroxidase and ascorbate peroxidase enzymes were observed under heat stress in all four cultivars. Therefore, it may be concluded that the cultivar BARI GOM-28 showed more tolerance to heat stress than the other cultivars based on the measured physiological and biochemical traits.
Keywords: Heat stress, wheat, chlorophyll fluorescence, gas exchange, antioxidants.
Screening of local landraces of rice at the seedling stage for salinity tolerance based on genetic divergence analysis
Iffat Ara, Md Rasel, Lutful Hassan, Mirza Mofazzal Islam, Md Injamum Ul Hoque
>>doi: 10.5455/faa.30474 >>PP:849-857
The presence of genetic diversity is a prerequisite for improvement of any crops. Salinity is a severe threat for the production of rice which can be solved by improving tolerant variety through breeding programs. Twenty-five rice genotypes were evaluated to explore the genetic diversity of growth parameters by imposing three levels of salinity treatments (0 dS m−1, 7 dS m−1 and 12 dS m−1 EC) with three replications following completely randomized design (CRD).The genotypes were categorized into five major sub-clusters considering ten morphological traits using the non-hierarchical Euclidean distances revealed that maximum 10 genotypes viz., Moynamoti, Badshavog, Pangash, Suvash, Moghabalam,Sadaswarna, Bina dhan-8, Chinikani, Ashfailand and Rajashail were found in cluster III while lowest two genotypes namely, Lalbat and M-171 were found in cluster IV. The results of the cluster analysis also reported that the inter-cluster distances in all the cases were greater than the intra-cluster distances. The highest intra-cluster diversity was observed in cluster IV (6.30) whereas lowest intra-cluster diversity was found in cluster I (4.16). The maximum inter-cluster distance was found between cluster II and V (15.45) where minimum inter-cluster distance was observed between cluster I and II (6.39). Root fresh weight contributed greatest (19%) to the divergence of genotypes where root length contributed least (0.33%) to the total diversity of the genotypes. The cluster means value for most of the morphological traits was maximum in cluster II reflecting that the genotypes grouped in cluster II could be selected as salt tolerant genotypes at the seedling stages for the cultivation in the coastal area of Bangladesh.
Keywords: Rice, coastal area, genetic diversity, cluster analysis, Euclidean distances
Sharif Ahmed, Md Jahangir Alam, Tahir Hussain Awan, A K M Mominul Islam
>>doi: 10.5455/faa.34774 >>PP:839-848
Weeds are considered as one of the major factors responsible for current low wheat yield in Bangladesh. Although chemical weed control is well established in many wheat growing countries, in Bangladesh, the herbicides are typically not used by farmers to manage weeds in wheat. Hence, to evaluate the efficacy of pre- and post-emergence herbicides in mechanized drilled sown wheat, a two-year field study was conducted in southwest Bangladesh. The study evaluated the performance of four pre-emergence herbicides (oxadiargyl 80 g, pendimethalin 850 g, pyrazosulfuron 15 g, and mefenacet + bensulfuran methyl 550 g active ingredient ha−1) applied at 2 days after sowing (DAS) and four post-emergence herbicides (2,4-D 1400 g, ethoxysulfuron 18 g, penoxsulam 22.5 g, and fenoxaprop 56 g active ingredient ha−1) applied at 20 DAS, on weed control efficacy. A season long weed-free and a season long weedy plots were also maintained to compare the results. The weed control option using a single pre- or post-emergence herbicide was not adequate to control weed effectively when weed infestation was relatively higher. The best yield provided by pre-emergence (pendimethalin and oxadiargyl) and post-emergence (2,4-D and ethoxysulfuron) herbicide treatments were respectively 13-15% and 12-17% lower than the yield (4.1-4.2 t ha−1) of weed-free treatment. Post-emergence herbicides fenoxaprop was the best in controlling weeds; however, due to phytotoxic effects on wheat plants, the plots applied with fenoxaprop produced very low yield (2.6-2.8 t ha−1). Similarly, even after good weed control by the post-emergence application of penoxsulam, phytotoxicity on wheat resulting in low yield. The study suggested that the best weed control option for wheat is to use a pre-emergence (pendimethalin or oxadiargyl) followed by (fb) a post-emergence (2,4-D or ethoxysulfuron) herbicides depending upon weed species which would benefit the farmers by providing high weed control efficacy at lower cost compared to manual weeding.
Keywords: Weed shift, weed control efficiency, herbicide toxicity, yield gap, wheat
Nahida Akter, Emrul Kayesh, M Mofazzal Hossain, Mohammad Saiful Alam
>>doi: 10.5455/faa.24065 >>PP:829-838
Burmese grape (Baccaurea ramiflora Lour.) is a popular minor fruit in Bangladesh. Morphological and physicochemical characterization of Burmese grape was conducted at Pirujali, Gazipur during 2017-18 in eighteen Burmese grape genotypes. Wide variation was observed in case of growth, yield contributing characters, yield and fruit quality of the germplasm studied. Correlation study among different growth parameters of the genotypes was done to know the relationships so that superior genotypes can be selected for further experiment. Fruit set (%) was the highest in BS09 (77.27%) genotype and the lowest was in BS02 and BS03 and it was 36.84%. Zero percent fruit drop was observed in BS06, BS07 and BS17 and the highest fruit drop was in BS08 (50%) genotypes. The days to fruit maturity was the lowest (100 d) in BS12 genotype followed by BS13 (103 d) and the highest maturity days was in BS18 (132 d). For most of the desirable attributes BS02 showed better response such as maximum leaf length (28.31 cm), leaf breadth (9.02 cm), fruit length (34.1 mm), fruit diameter (33.9 mm), juice content (38 mL 20 seeds−1), total soluble solids (18%), and ascorbic acid (13.2 mg 100g−1). BS03 ranked the second among the genotypes on the basis of these parameters. Fruit number had negative correlation with fruit length, single fruit weight and juice content.
Keywords: Burmese grape, physiochemical, fruit quality, correlation
Mohammad Rashidul Haque, Razia Sultana, Md Habibur Rahman, Syful Islam, Ahmed Khairul Hasan
>>doi: 10.5455/faa.19122 >>PP:823-828
Rice cultivation in saline prone area is very difficult. Some recently developed salt tolerant rice varieties are introduced in the coastal zone of Bangladesh. But their impact on income analysis is not done yet. The present study was designed to assess the adoption and impact on income of salt tolerant rice varieties viz., Binadhan-8 and Binadhan-10 cultivation in coastal areas of Bangladesh. In total 300 farmers from six salt tolerant rice growing areas, namely Patuakhali, Cox’s Bazar, Chittagang, Bagerhat, Khulna and Sathkhira districts were taken to conduct the present study. Profitability analysis was done to achieve the objectives of the study. The major findings of the study revealed that the average cost of production of salt tolerant rice variety (Binadhan-8 and Binadhan-10) was Tk 62670 ha−1. Average cost of production for Binadhan-8 was Tk 61729 ha−1 and it was Tk 63611 ha−1 for Binadhan-10. Per hectare gross return of Binadhan-8 and Binadhan-10 were Tk 81934 and Tk 94786, respectively. Therefore, per hectare average cost as well as gross return of Binadhan-10 was higher than that of Binadhan-8. Average ha−1 net return received by adopting farmers was Tk 25690 and it was higher in case of Binadhan-10 (Tk 31175) than Binadhan-8 (Tk 20205). In the study area, the average yield of Binadhan-10 (5.45 t ha−1) was higher than Binadhan-8 (4.92 t ha−1). The undiscounted benefit cost ratio (BCR) was 1.40 which indicates that cultivation of these varieties is profitable to the farmers when all sorts of cost were taken into consideration. Results also revealed that most of the farmers are not using the recommended technologies regarding input usage and agronomic practices. The highest area coverage of salt tolerant rice varieties (Binadhan-8 and Binadhan-10) was in Cox’s Bazar district which is 3.7% of total cultivated area followed by Chittagong (2.62%), Bagerhat (2.40%), Patuakhali (2.18%) and Khulna (1.53%), respectively. In the study area, the highest income impact (27.1%) was in Sathkhira district, and it was the lowest (12.91%) in Patuakhali district.
Keywords: Salt tolerant rice varieties, adoption, benefit cost ratio, coastal area, Bangladesh
Nur-e-Jannat, Mahfuza Begum, Md Abdus Salam, Sirajam Monira
>>doi: 10.5455/faa.19969 >>PP:815-822
The seed banks are the sole source of future weed populations and enhance the survival of a species by buffering against harsh environmental conditions or drastic weed control measures. Seed bank allows weed species to germinate over a period of many years. This experiment was undertaken with a view to evaluating the weed seed distribution pattern at different soil depths in order to estimate the potential weed population in the crop field. The experiment was conducted at the net house of the Department of Agronomy, Bangladesh Agricultural University during April to September 2014. Soil samples were collected from 12 plots at three depths viz. 0-5, 5-10 and 10-15 cm of Durba Chara village of Mymensingh district. A total of 33 weed species belonging to 17 families were found of which 23 species were broadleaved, 6 grasses and 5 sedges. Thirty weed species from 19 annuals and 11 perennials belonging to the 15 families, 23 weed species from 15 annuals and 8 perennials belonging to 10 families andonly 19 weed species from 13 annuals and 6 perennials belonging to 11 families were identified at 0-5, 5-10 and 10-15 cm soil depth, respectively. The seven dominant weed species i.e. Fimbristylis miliacea L., Lindernia antipoda L., Lindernia hyssopifolia L., Cyperus difformis L., Eleusine indica L., Hedyotis corimbosa L. and Eclipta alba L. were found at different soil depths. The result revealed that weed density decreased with increase of the soil depth. The higher number of weed species and density were observed at 0-5 cm depth of soil followed by 5-10 cm and 10-15 cm depth of soil, respectively. All weed types viz. grasses, sedges and broadleaves were found in abundance at 0-5 cm depth than 5-10 cm and 10-15 cm depth. Annual and perennial weeds were also higher at 0-5 cm depth and annual weeds were dominant over perennial weeds at each of the three soil depths. Out of the total number of weed seedlings emerged from three soil depths, about 65% of seedlings emerged within first two months (April-May) of commencement of germination trial and rest 35% seedlings emerged within last 4 months (June-September). Based on Sorenson’s Index of Similarity, the diversity of occurring weed species between 5-10 cm and 10-15 cm depths was lower as Sorenson’s Index of Similarity was the highest (81%) as well as between 0-5 cm and 10-15 cm depths was higher as Sorenson’s Index of Similarity was the lowest (69%).
Keywords: Floristic diversity, seed bank, crop field, Sorenson’s Index of Similarity
Totan Kumar Ghosh, Samia Haque Binto, Jalal Uddin Ahmed, S M Zubair Al-Meraj, Mohammad Zahangeer Alam
>>doi: 10.5455/faa.24912 >>PP:806-814
Paederia foetida L. is an important medicinal herb harboring lots of essential drug producing metabolites and the plant has been going to be endangered due to lack of proper strategies for conservation. Since, indirect organogenesis by tissue culture is considered as the valuable tools for rapid multiplication and improvement of plant genetic resources, application of this technique should be very imperative for the conservation of this valuable and rare medicinal plant. Hence, the research effort was made to develop a suitable protocol for indirect organogenesis in vitro using nodal explants of P. foetida. After surface sterilization, the explants were submitted to Murashige and Skoog (MS) medium supplemented with different concentrations and combinations of plant growth regulators for showing the performance in terms of callus induction, shoot proliferation and root initiation. Among the surface sterilants used, 0.1% HgCl2 treated for 2 min and 3% NaOCl treated for 10 min showed better performance and maintained 100% and 80% survivability respectively. MS medium supplemented with 2,4-Dichlorophenoxyacetic acid (2,4-D) at 1.5 mg L−1 showed better performance than others in terms of initiation of callus from nodal explants. In contrast, naphthaleneacetic acid (NAA) at 0.5 mg L−1 and 6-benzylaminopurine (BAP) 0.2 mg L−1 showed highest rate of callus proliferation with somatic embryos from proliferated callus. During shoot organogenesis, MS medium supplemented with BAP 2 mg L−1 showed better results for the regeneration of shoots from embryogenic calli. The shoots derived from callus produced roots by half strength MS medium supplemented with indole-3-acetic acid (IAA). After acclimatization, the plantlets were allowed to ambient condition for further establishment. Our findings claim the establishment of a suitable protocol for indirect organogenesis of P. foetida that could be employed for rapid multiplication, conservation and sustainable utilization of P. foetida as valuable genetic resource.
Keywords: Callus, conservation, explants, growth regulators, organogenesis, Paederia foetida
Md Shirajul Islam Sarkar, Md Kamal, Muhammad Mehedi Hasan, Md Ismail Hossain
>>doi: 10.5455/faa.21851 >>PP:798-805
Culture of seaweed is expanding globally due to wide range application of seaweeds including human consumption as nutritious food. Despite the availability of naturally occurring seaweeds, utilization is scarcely noticed in Bangladesh. Therefore, some value added seaweed food and functional food products were experimentally manufactured and those products were found to be promising for commercial production. Proximate composition and shelf life determination by organoleptic evaluation were conducted on four value added seaweed food products viz., seaweed jelly, soup, ice cream, curd and two functional food products viz., seaweed singara, samosa. Crude protein, lipid, moisture and ash content of above mentioned food and functional foods items were analyzed. To study shelf life, two sets of sample; each set of sample included previously mentioned 4 value added seaweed food items and 2 value added seaweed functional food items stored both in ambient condition and in freezer at −18 °C were investigated for 1 month. Crude protein content of seaweed jelly, soup, ice cream and curd was 8.71%, 9.04%, 14.96% and 16.60%; lipid content was 6.76%, 12.67%, 10.33% and 1.10%; moisture content was 42.75%, 56.94%, 51.68% and 58.06%; ash content was 19.05%, 16.27%, 8.02% and 9.10%, respectively. Average proximate composition value of seaweed singara, samosa was found respectively as 9.80% and 10.01% crude protein, 6.88% and 6.17% lipid, 32.08% and 27.44% moisture, 13.20% and 10.01% ash. All value added seaweed food and functional food products kept open in ambient condition had a shelf life of not more than three days. Shelf life of seaweed food and functional foods in freezer was at least 1 month. Determination of optimum use of seaweeds in product development, spoilage mechanism, development of more new products, effect of these products on human health, seaweed culture technique etc. should be investigated in future.
Keywords: Seaweed product quality, macro algae, food security, Blue economy, Hypnea, Bangladesh
Biorational management of tomato fruit borer, Helicoverpa armigera (Hübner) in winter under field condition of Bangladesh
Dinasree Biswas, Mohammad Mahir Uddin, Masum Ahmad
>>doi: 10.5455/faa.20352 >>PP:792-797
An experiment was conducted during the period of December 2014 to March, 2015 in the Entomology Field Laboratory, Department of Entomology, Bangladesh Agricultural University on the management of tomato fruit borer, Helicoverpa armigera (Hübner) using different biorational insecticides on winter tomato variety BARI-2 in Bangladesh. Efficacy of seven different biorational insecticides viz. Neem oil, Mahogany oil, Karanja oil, Ambush 1.8EC, Libsen 45 SC, Emamectin benzoate 5 SG and Beauveria bassiana were evaluated on the basis of percentage of fruit damage and percentage increase/decrease of yield. All the biorational insecticides were significantly effective in comparison to control treatment. Besides, among seven insecticides; Emamectin benzoate 5 SG provided the best result with the lowest cumulative mean percentage fruit infestation (20.95% and 17.24% based on number and weight, respectively). Percentage reduction of infested fruit was the highest (57.50 and 62.38%, by no. and weight, respectively) in Emamectin treated plots. Similarly the highest percentage protection (58.99 and 63.06% by number and weight, respectively) of infested fruit was also found from the Emamectin benzoate treatment. But Libsen 45 SC revealed the highest efficacy on marketable fruit yield (20.23 t ha−1) compared to other treatments. So, Emamectin benzoate and Libsen both might be used to manage tomato fruit borer effectively.
Keywords: Management, tomato fruit borer, Spinosad, Emamectin benzoate, Abamectin, Beauveria bassiana
Growth and yield of transplanted Aman rice cv. Binadhan-16 as influenced by seedling age and nitrogen fertilization at staggered transplanting
Jannatul Ferdous, Md Delwar Hossain, Md. Parvez Anwar, Zannatun Tazri
>>doi: 10.5455/faa.26627 >>PP:785-791
An experiment was conducted at the Agronomy Field Laboratory of Bangladesh Agricultural University to find out the effect of age of seedlings and level of nitrogen on growth and yield of transplant Aman rice cv.Binadhan-16. T. Aman rice seedlings of four different ages (15, 20, 25 and 30-day old) were examined with four levels of nitrogen (0, 50, 70 and 90 kg N ha−1). The experiment was laid out in a randomized complete block design (RCBD) with three replications. The results revealed that the effect of age of seedlings and level of nitrogen and their interaction was significant on growth, yield and yield contributing characters of transplant Aman rice. The highest plant height and total dry matter production hill−1 were recorded in the plots of 15-day old seedlings with 70 kg N ha−1. Grain yield gradually increased with the use of relatively younger seedlings and with 15-day old seedlings produced the highest number of effective tillers hill−1 (8.583) and grains panicle−1 (122.7) as well as the highest grain yield (4.265 t ha−1) and straw yield (5.392 t ha−1). In case of level of nitrogen, 70 kg N ha−1 produced the highest grains panicle−1 (114.1), grain yield (4.539 t ha−1) and straw yield (5.623 t ha−1). Interaction effect showed that, 15-day old seedlings with 70 kg N ha−1 produced the highest number of effective tillers hill−1 (9.71), grain yield (5.17 t ha−1) and straw yield (6.20 t ha−1). Therefore, 15-day old seedlings with 70 kg N ha−1 appeared as the promising technique to obtain the highest grain yield.
Keywords: Seedling age, nitrogen level, growth, yield, transplant aman rice
Comparative studies on germination and seedling growth of on-season and off-season produced jute seeds
Rashidul Islam, Md Solaiman Ali Fakir, M Abul Hossain
To overcome the problems of crop loss and prolonged period of land engaged for jute seed production in on-season, the off-season production of jute seeds is being practiced but the seed quality of both these systems has not been thoroughly compared to get better seeds for higher yield in jute. Considering the above facts, the present research was carried out to perform a comparative study among different parameters, such as, germination and seedling growth of on-season and off-season produced seeds of Corchorus capsularis (Variety CVL-1) and Corchorus olitorius (Variety O-9897). In this study, signiﬁcant inﬂuence of production period of seeds on germination percentage, seedling vigor index, germination co-efﬁcient, shoot length, root length, shoot and root dry weight, ratio of root dry weight and shoot dry weight was observed. The highest seed germination percentage, seed germination co-efﬁcient, seedling vigor index, shoot and root length, shoot and root dry weight, ratio of root dry weight and shoot dry weight were found in off-season Deshi jute seeds followed by on-season Deshi and off-season Tossa jute seeds. The lowest value of each of these properties was found in case of on-season Tossa jute seeds and seedlings. Based on the ﬁndings of this study, it may be concluded that off-season produced jute seeds showed better performance than those of on-season jute seeds in both the species in terms of seed germination and other relevant characters.
Keywords: Jute seeds, Corchorus, germination, seedling growth
Genetic variability, correlation and path coefﬁcient analysis for yield and yield components of selected lentil (Lens culinaris M.) genotypes
Md Mahmuduzzaman Chowdhury, Md Ashraful Haque, Md Abdul Malek, Md Rasel, Kamal Uddin Ahamed
Genetic variability, correlation coefﬁcient and path coefﬁcient were estimated for different morpho-physiological traits of 20 lentil genotypes. A signiﬁcant genetic variation was observed for all the observed traits. Signiﬁcantly higher PCV values than those of GCV for all the traits indicated that the traits are more inﬂuenced by the environment. The highest estimates of GCV and PCV were observed for seed yield plant −1 (23.80% and 24.03%, respectively) followed by number of pods peduncle −1 (16.91% and 19.80%, respectively). All the studied traits expressed high heritability ranging from 64.89% to 98.46% and the maximum was recorded for seed plant−1 (98.46%) followed by pod plant −1 (98.35%) and seed yield plant −1 (98.10%). High heritability along with high genetic advance was noticed for number of pods plant −1 (98.35% and 50.63, respectively) and number of seeds plant −1 (98.46% and 96.01, respectively) and high heritability coupled with high genetic advance as per cent of mean was observed for number of seeds plant −1 (98.46%, 39.80%) followed by number of pods plant−1 (98.35%, 33.03%) reﬂected the accumulation of additive gene and phenotypic selection for these characters will be effective for seed yield improvement. The study of associations among the different traits revealed that seed yield plant −1 was signiﬁcantly and positively correlated with number of primary branches plant −1 , pods plant −1 and seeds plant −1 and 100-seed weight. Path analysis also reported that number of pods plant −1, seeds pod−1 and 100-seed weight was related to the seed yield mostly through the direct positive effect. So, the traits viz., number of primary branches plant −1 and pod plant −1 and 100-seed weight should get the major importance during traits selection for lentil yield improvement as those traits had positive and signiﬁcant correlation as well as direct positive effect with seed yield plant −1 and the information of wide genetic diversity for this traits could be used in future systematic lentil breeding programs for the improvement of seed yield.
Keywords: Lentil, genotype, genetic variability, correlation, path analysis
Efﬁcacy of 1-MCP on controlling ethylene sensitivity and extending vase life of sensitive and less sensitive cut orchid ﬂowers
Parviz Almasi, Mahmud Tengku Muda Mohamed, Siti Hajar Ahmad, Alireza Noroozisharaf
>>doi: 10.5455/faa.16194 >>PP:759-768
This study was conducted to investigate the effects of 1-MCP on the sensitivity to ethylene and postharvest quality of selected cut orchid ﬂowers. Cut orchid ﬂowers are considered as the ethylene sensitive but there are apparently variation in sensitivity among species, cultivars and hybrids. Low effective concentration of 1-MCP and its minimum residues have caused that 1-MCP been viewed as an important and safe candidate for replacing STS. Inﬂorescences of each Dendrobium ‘Darren Glory’ (DDG), D. ‘Sonia Bom’ (DSB), Mokara ‘Calypso Jumbo’ (MCJ) and M. ‘Chiti Gold’ (MCG) hybrids were purchased from a commercial farm. After harvest and transport to the Postharvest Lab they were divided into two groups and placed in two chambers. They exposed to 0 and 300 nL L-1 1-MCP for 4 hours. The chambers were opened for 1 hour airing. Then inﬂorescences of each chamber divided to two subgroups and treated with 0 and 1 µL L-1 ethylene gas, balanced with nitrogen. After 24 hours the chambers were opened and the inﬂorescences were taken out from them. The inﬂorescences were kept in the laboratory with normal condition. The most weight loss and longest vaselife was recorded in DDG and MCG with 44% and 14 days respectively. Meanwhile, maximum postharvest quality improvement was obtained by 1-MCP pretreatment in very sensitive cut orchid hybrids.
Keywords: Inﬂorescence, Dendrobium, Mokara, postharvest quality, bud opening
Md Moshiur Rahman
>>doi: 10.5455/faa.16534 >>PP: 744-758
Puddled transplanting is the major system of rice cultivation in many parts of the world. Transplanting system provides a high and stable yield. It is labour intensive and requires huge amount of irrigation water (1500-2000 mm). The increasing scarcity of irrigation water and labour acted as a major driver to the adoption of the wet direct seeding system in many Asian countries. Wet direct seeding saves substantial amount of labour but it has very low water saving potential. Dry direct seeding is another rice establishment method that has potential to save both water and labour in rice culture. Seedling raising, puddling and transplanting of seedling into the puddle are omitted in the dry direct seeding system, rather primed seeds are directly sown on the dry cultivated land by hand or seeder or directly by seeder without tillage. Direct seeding contributes to saving of 50% labour requirement in crop establishment. The labour saving could be even more if seeding is done by machineries. Dry direct seeding gives comparable or even higher yield than that of puddle transplanted rice. It reduces greenhouse gas emission, buildup of arsenic and other heavy metals and improves soil health compared with the conventional system. Dry direct seeded rice based cropping system offers the scope of increasing cropping intensity and diversity and farm income. Yield decline in dry direct seeded system has been reported elsewhere and the reduction of yield was mainly related with inadequate agronomic management and under continuous mono-crop upland condition. However, trials at farmers’ field in Bangladesh proved that dry direct seeded rice can give better harvest than the conventional puddle transplanted rice with proper agronomic management. The adoption of dry direct seeded rice culture in Bangladesh is mainly constrained by the present irrigation water sharing system and unavailability of good quality seeding machineries. The present review focuses on the effect of dry direct seeded rice on water requirement, yield performance, cropping intensity and diversity, soil physical and chemical properties, greenhouse gas emission, labour and economic issue so that dry direct seeding can be used as a tool for increasing crop productivity with less water with minimal adverse effect on soil and environment.
Keywords: Puddle transplanted rice, flood irrigation, wet direct seeded rice, crop intensification, greenhouse gas emission