Species composition, habitat structure and sedimentation in a Sonneratia caseolaris stand at the Lam River estuary, Vietnam
Kazuya Takahashi1,2, Tran Thi Tuyen1, Nguyen Huu Hien1, Nguyen Thuy Thi Ha1
1Vinh University, 182, Duan street, Vinh city, Nghe An province, VIETNAM.
2Mie Technology Licensing Organization Co., Ltd., 1577, Kurimamachiya-cho, Tsu city, Mie prefecture, JAPAN
This study aims to provide some information for development of silvofishery systems with a mangrove (S. caseolaris stand) for shrimp-culture ponds at the Lam River estuary, Vietnam. To achieve this objective, species composition, habitat structure and sedimentation effect in the S. caseolaris stand distributing along the canal for shrimp culture were surveyed. The study reveals that the stand contains four species or more under the canopy; dominant understory species are Aegiceras corniculatum, Cyperus malaccensis and Acanthus spp. (A. ilicifolius and A. ebracteatus). A. corniculatum was observed expanding its distribution area toward the low tidal zone. As a result, the habitat for seedlings/saplings of this species becomes significantly lower in land height than that of Acanthus spp. (ANOVA; p < 0.05), but not different from that of S. caseolaris. Sedimentation rates of A. corniculatum and Acanthus sp. recorded were 13.2 2.9 g m-2 hr-1 and 13.0 4.4 g m-2 hr-1, respectively. S. caseolaris sparsely grows with less developing of pneumatophore, which effectively traps sediment, at the early stage of succession. Considering reinforcement of sedimentation effect, especially right after restoration of the mangrove in the silvofishery systems, A. corniculatum and Acanthus spp. with S. caseolaris are recommendable to be introduced to the systems.
Keywords: Aegiceras corniculatum, Acanthus. understory species, low tidal zone, shrimp-culture pond
 Estimation of factors affecting Burundi’s sugar imports from East African community
Jean Claude Ndayisaba1, Job Kibiwot Lagat1, Symon Kibet Kiprop1
1Egerton University, Njoro Main Campus,KENYA
Around the world, the creation of regional economic communities attracted more attention in empirical analysis. Different techniques were used in order to assess the performances of trade taking place in the regional economic communities. This study applied such analysis to Burundi, concerning sugar imports from the East African Community. More specifically, this study determined the intensity of Burundi’s sugar imports and estimated the factors which influence Burundi’s sugar imports. Both the histograms and the gravity model were used to analyze the data collected from 2003 to 2018. In essence, the results indicated that Burundi intensively imported sugar from Kenya followed by Uganda. Moreover, the results revealed that the gross domestic products (GDPs), the distance and the exchange rates were the major factors influencing Burundi’s sugar imports. For instance, it was found that a 1% increase in the Burundian GDP leads to an expansion of sugar imports by 0.52%. Therefore, policy makers in Burundi should create a space that efficiently maximizes the intensity of sugar imports through attractive trade policies. Moreover, they should particularly put a rigorous control on GDPs, exchange rates and distance in order to enhance a smooth movement of sugar imports from the East African Community.
Keywords: sugar; gravity model; intensity of imports; regional economic community; trade flows.
 Evaluation of Agronomic Characters of Soybean Varieties and Bambara Groundnut Landraces Cultivated on Different Soils of Lake Victoria Basin
Benson O. Onyango1, Fredrick Otieno Ogolla2
1Department of Biological Sciences, Jaramogi Oginga Odinga University of Science and Technology, P.O. Box 210 40601, Bondo, KENYA
2Department of Biological Sciences, Chuka University, P.O. Box 109 60400, Chuka, KENYA
Neglect and under-utilization of legumes such as soybeans and bambara groundnuts are the reason for increased food insufficiency in the Lake Victoria basin. Diversification of legumes into the cropping systems of Lake Victoria basin ensures protein rich diets and improved soil fertility. This study was carried out to evaluate agronomic characters of two soybean varieties and two bambara groundnut landraces cultivated on different soils of Lake Victoria basin. Seeds of two bambara groundnut landraces; Kakamega Cream (KAKC) and Busia Brown (BUSB) were collected from farmers in Kakamega and Busia counties, respectively in Kenya. Soil sampling was done at selected farmers’ fields with no history of inoculation in Kisumu, Port Victoria, Kendu bay and Karungu within Lake Victoria basin. Screen house experiment was performed in plastic pots with two plants of each cultivar. Randomized Complete Block Design was used. Experiments data were organized into a matrix and subjected to two- and three-way analysis of variance using Genstat 16th Edition and significant means separated using Least Significant Difference at [LSD5%] and Dancun Multiple Range Test. Agronomic characters of BUSB and KAKC landraces differed significant (p<0.05). Bambara groundnuts performed better in Port Victoria and Kendu bay soils than Kisumu and Karungu. Agronomic performance of two soybean varieties SB19 and ‘Safari’ on soils from four sites in Lake Victoria basin was significant (p<0.05). Soybeans yield in Port Victoria and Kendu bay soils was better compared to Kisumu and Karungu soils. Agronomic performance of bambara groundnuts and soybeans were influenced by soil type. Port Victoria and Kendu bay soils resulted in better growth compared to Kisumu and Karungu soils. Landrace KAKC and SB19 had better agronomic performers and are recommended to farmers and seed companies for certified seed production.
Keywords: Bambara Groundnuts, Rhizobia, Nodulation, Effectiveness, Soybeans
 Weed management in sugar beet: A review
Tamalika Bhadra1, Chandan Kumar Mahapatra1, Swapan Kumar Paul1
1Department of Agronomy, Bangladesh Agricultural University, Mymensingh-2202, BANGLADESH
Sugar is an essential commodity and an integral part of the food chain which is the cheapest source of energy. Sugar plays a vital role in the development of taste, texture, colour and keeps baked goods soft and moist. Sugar beet ranks second as a sugar producing crop in the world. Weeds in beet crops reducing the yield in the field level as well as making the harvesting and processing difficult. The weed seeds in soil bank are detrimental as they germinate in subsequent crop cultivation. Weed control failure causes severe yield loss in sugar beet. However, several weed control measures along with herbicides provide a significant increase of average yields in sugar beet. It has become necessary to reduce the use of them in order to protect the human health as well as the other living organisms. For this reason, alternative ways of controlling weeds are being practiced all over the world. The efficient way of reducing the use of herbicides with the revaluation of agronomic techniques is replacing herbicide treatments. Thereby weed control combine herbicidal and nonherbicidal methods in an integrated manner. Basically, integrated weed control approach provides a potential reduction in weed population. However, this system is not as efficient to minimize the herbicide utilization in larger-scale sugar beet production.
Keywords: Sugar crops, Sugarbeet, cultivation, yield loss, weed management
 Screening of the sunflower genotypes for drought stress under polyethylene glycol at seedling stage
Uzma Ayaz1, Sanam Bashir1, Shahid Iqbal Awan1, Muhammad Ilyas1, Muhammad Fareed Khan2
1Department of Plant Breeding and Molecular Genetics, The University of Poonch Rawalakot, Azad Jammu & Kashmir, PAKISTAN
2Faculty of Management Sciences, University of Poonch Rawalakot, Azad Jammu & Kashmir, PAKISTAN
Drought stress directly affects growth along with productivity of plants by altering plant water status. Sunflower (Helianthus annuus L.) an oilseed crop, is adversely affected by abiotic stresses. The present study was carried out to characterize the genetic variability for seedling and morpho-physiological parameters in different sunflower genotypes under well watered and water stressed conditions. A total of twenty seven genotypes including two hybrids, eight advanced lines and seventeen accessions of sunflower (Helianthus annuus L.) were tested against drought stress at germination and seedling stages in Polyethylene glycol (PEG). Significant means were calculated among traits using analysis of variance (ANOVA) whereas, correlation and principle component analysis also confirmed that germination percentage, root length, proline content, shoot length, chlorophyll content, stomatal frequency and survival percentage are positively linked with each other hence, these traits were responsible for most of variation among genotypes. The cluster analysis results showed that genotypes Ausun, line-2, line-8, 17559, 17578, Hysun-33, 17555, and 17587 as more diverse among all the genotypes. These most divergent genotypes could be utilized in the development of drought tolerant inbreed which could be subsequently used in the Heterosis breeding.
Key words: Screening, Sunflower, Genotypes, drought stress, polyethylene- glycol
 Heterosis in maize hybrids at farmer’s field in Dang district of Nepal
Jeevan Upreti1, Prashiksha Acharya1, Jharana Upadhyaya2, Jiban Shrestha3
1Tribhuvan University, Institute of Agriculture and Animal science, Prithu Technical College, Lamahi, Dang, NEPAL
2Nepal Agricultural Research Council, National Maize Research Program, Rampur, Chitwan, NEPAL
3Nepal Agricultural Research Council, Agriculture Botany Division, Khumaltar, Lalitpur, NEPAL
This experiment was conducted at the farmer’s field at Bangaun, Dang, Nepal during summer season from 18th May to 21st September 2018 to estimate heterosis in maize hybrids. Seven maize hybrids were evaluated in a randomized complete block design with three replications. The results revealed that all the maize hybrids showed significant positive heterosis over mid parents and better parent for grain yield. High level of heterosis was found for grain yield followed by plant height. The hybrids RH10 and RML86/RML96 produced significantly the highest mid parent heterosis and heterobeltiosis for grain yield. The hybrids RH10 and RH6 produced higher positive heterosis over both check varieties (Rajkumar and Subarna) for grain yield. Hybrid RH10 produced the highest standard heterosis (39.39%) for grain yield over Rajkumar; followed by RH6 (38.45%) and RML86/RML (22.48%), respectively. Mid and better parent heterosis were significantly higher for yield and yield attributes viz cob length, cob diameter, number of kernel rows per cob and number of kernels per row. The highest positive mid parent heterosis for grain yield was found in RML96/RML86 (466.91%) followed by RH10, RH8 and RH4. For the grain yield, the heterobeltiosis was found to be the highest in RH10 followed by RML96/RML96. These results suggested that maize hybrids RH10 and RML96/RML86 could be exploited for commercial cultivation and their parental lines could be used for hybrid seed production.
Keywords: Heterobeltiosis, hybrid maize, summer season, grain yield, Nepal
 Varietal Response of Sesame to Different Weed Management
Md. Shoyeb Hossain1, Afrina Rahman1, Muhammad Salim1, Mozammel Hoque2, Ahmed Khairul Hasan1
1Department of Agronomy, Bangladesh Agricultural University, Mymensingh, BANGLADESH
2Department of Agronomy and Haor Agriculture, Sylhet Agricultural University, Sylhet, BANGLADESH
An experiment was conducted at the Agronomy Field Laboratory, Bangladesh Agricultural University during February to May 2019 to study the effect of weed management practices on the yield of different sesame varieties. The experiment comprised two factors; factor A: sesame varieties viz.,Binatil-2, BARI Til-3 and BARI Til-4; factor B: weed management practices viz. no weeding, one hand weeding at 15 days after sowing (DAS), two hand weeding at 15 and 30 DAS, three hand weeding at 15, 30 and 45 DAS and post-emergence herbicide application at 10 days after emergence (DAE). The experiment was laid out in a randomized complete block design with three replications. Weed parameters and most of the yield contributing characters and yield were significantly influenced by sesame varieties and weed management practices. Among the varieties, the highest seed yield (1.01 t ha-1) was recorded in BARI Til-4, whereas for weed management practice, the highest seed yield (1.26 t ha-1) was obtained in three hand weeding. In interaction, the highest seed yield (1.54 t ha-1) was found in BARI Til-4 with three hand weeding which was statistically similar to two hand with the same variety (1.48 t ha-1). Therefore, BARI Til-4 with two hand weeding at 15, and 30 DAS might be taken in consideration for obtaining higher seed yield in sesame.
Keywords: Weed management, sesame varieties, hand weeding, herbicide, yield