Mohammad Mahbub Islam
Research Associate, Land Zoning Project, Ministry of Land, Dhaka
Arifur Rahman
Quarantine Entomologist, Plant Quarantine Wing, Department of Agricultural Extension, Khamarbari, Dhaka
Eggplant, Lowerstoried, Agroforestry, Terrace ecosystem, Jackfruit
Belabo Upazila under Narsingdi district.
Farming System
Eggplant, Jackfruit, Agroforestry
The experiment was carried out at Abdullahpur farmer's field belonging to the Belabo Upazila under Narsingdi district during the period from September 2011 to January 2014. The place is geographically located at 23°46 to 24°14' north latitude and 90°35' to 90°60' east longitude. The climate of the locality is sub-tropical in nature. It is characterized by high temperature and heavy rainfall during the Kharif season (April to September) and scanty rainfall during the rabi season (October to March). The topography of the field was medium high land above flood level belonging to the Madhupur Tract in Agro-Ecological Zone 28. It is characterized by shallow Red-Brown Terrace soil, which is nearly equivalent to Ustocharepts suborder under the order Inceptisol of USDA Soil Taxonomy having pH 5.5 and soil texture was clay loam being acidic in nature, poor infertility status, and impeded internal drainage. The experiment was laid out following Randomized Complete Block Design (RCBD) with three replications. Each jackfruit tree was considered as a unit plot for a single replication. Five treatments of this study are used covering agroforestry (four orientations) and traditional farming (open field) such as Open (control): Non-agroforestry (Farmer’s practice), AF-S: Agroforestry-south orientation, AF-N: Agroforestry-north orientation, AF-E: Agroforestry-east orientation, AF-W: Agroforestry-west orientation. The earlier established Jackfruit orchard was transformed into a multistoried agroforestry system. Jackfruit trees were considered as an upper storied crop; lemon, sweet orange, mandarin, and papaya were established as middle stories crops; and eggplant, ash gourd, and bottle gourd were grown as lower stories crops. Thirty-five days old seedlings of eggplant collected from the local nursery which is locally called Singnath were transplanted at 75 cm x 75 cm spacing on May 17, 2012; and May 05, 2013, respectively. The recommended doses of fertilizers were applied @ 5000 kg of cow dung, 115 kg N, 75 kg P, and 78 kg K per hectare. The entire quantity of cow dung, P, and half of N and K fertilizers were applied as basal doses at the time of final land preparation. The remaining N and K were applied in two equal installments at the time of flowering and fruiting. Thinning, gap filling, and the first wedding was done 20 days after transplanting. After thinning, one seedling per hill was retained. Gap filling was done to ensure a uniform stand. Uprooting was done since there were possibilities of injuring the adjacent seedlings that were left behind. Hand weeding was done to keep the plots free from weed infestation. Weeding was done at 20, 40, and 60 days after transplanting (DAT). The plants were irrigated whenever required to supply sufficient soil moisture. Some seedlings of eggplant were invaded by virus. Affected plants were uprooted and burnt immediately. Malathion 57 EC was applied at the rate of 2 ml l-1 for virus vector control each 25 days interval. Dithene M 45 was also applied at the rate of 2g lit-1 for protection against fungal disease after one month of seedling transplanting. Vilumeflexi Poison bait and sex pheromone were also used to reduce the infestation of insects especially whitefly and fruit borer had invaded on leaves and fruits, respectively. To control those insects, malathion 57 EC @ 2 ml /L water and cypermethrin 40 EC 1 ml /L water was applied twice per week and thrice for cropping life. Dursbern 20 EC @ 2 ml /L water and Asataf 75 SP @ 1g /L water were applied to control soil-borne insects. The harvesting started at 70 days and ended at 180 days after transplanting during both the years of experimentation and three or five times per month. The harvesting was done by handpicking and cutting with a sharp knife. Fruit per plant, fruit yield per plant, fruit weight, length, and diameter of the sample fruits were taken immediately after harvesting. Five representative plants were selected from each orientation for data collection of vegetative growth. Samples were collected at every month interval in both years. Ten representative eggplants were selected from each orientation for yield and yield attributes. SPAD value of eggplant leaves was measured by SPAD 502 plus chlorophyll meter and the light was measured above the canopy of plants by sunfluxceptometer at one time per month and the collected data were averaged and expressed as µmm-2 s-1 in agroforestry plots and in the respective control plots at 11:00 am-12:00 pm. Soil moisture (%) and temperature (°C) were measured by PMS-714 Soil Moisture Meter (model) and Temp 4/5/6 Thermistor Thermometer (model), respectively. Soil moisture and temperature were measured at 10 cm deep soil adjacent to the main root of vegetable crops in agroforestry plots and in the respective sole crop plots at 9:00-10:00 and 10:00-11:00 AM respectively, once per month and the collected data were averaged. It was done 3 days after irrigation. Cost and benefit analyses were done to compare the benefits of the tested agroforestry system with the monoculture tree or annual crop systems. Benefit-cost ratio (BCR) and land equivalent ratio (LER) are the two measurements of productivities that are normally used in agroforestry. The benefit-cost ratio is the ratio of gross return with a total cost of production. It was calculated by using the following formula (Islam et al., 2004), BCR=Gross return (Tk. ha-1 year-1 )/ Total cost of production (Tk. ha-1 year-1 ). The term land equivalent ratio (LER) is derived from its indication of relative land requirements for intercrops versus monocultures. LER helps find the relative performance of a component of a crop combination compared to the sole stands of that species (Mead and Willey, 1980). In simple Agroforestry situations, LER can be expressed as LER=Ci/Cs + Ti/Ts, Where: Ci=crop yield under agroforestry, Cs=crop yield under sole cropping, Ti=tree yield under agroforestry, and Ts = tree yield under sole cropping. Data were analyzed statistically by ANOVA to examine whether treatment effects were significant. Mean differences were adjusted by Least Significant Different (LSD) at a 5% level of significance (Gomez and Gomez, 1984). The software package “Statistics 10.0” was followed for statistical analysis.
International Journal of Natural and Social Sciences, 2021, 8(2): 24-36
Journal