Abstract
A survey was conducted among the farmers and pesticide dealers about pesticide use in crop (vegetable-brinjal) production at Mymensingh district. It revealed that brinjal was the most popular and main vegetable and its major insect-pest was brinjal shoot and fruit borer (BSFB). The most commonly used pesticides were diazinon, malathion and fenitrothion. The farmers purchased pesticides from dealer shops of local market and used in their crop field unscrupulously and haphazardly due to illiteracy and lacking of knowledge about pests and pesticides management. So, training and creation of awareness among them are most essential for proper selection and judicial use of effective pesticide (Study 1). To study the quality control and assessment of pesticides, samples of diazinon, malathion and fenitrothion of different brands were collected from different formulation factories existing in Bangladesh and pesticide dealer shops of Mymensingh district and tested in the laboratory. Analytical results of those samples indicated that insecticides collected from factory found comparatively better than field samples. Quality of Sabion 60 EC, Malataf 57 EC, Malatox 57 EC and Sovathion 50 EC collected from dealer shops found unsatisfactory in respect of their standard specification. So, strengthening of inspection, monitoring and quality control activities are most important for quality assurance of pesticides (Study 2). The situation of pesticides import, production and use in Bangladesh during last ten years (1991-2000) have studied and found that the trend and quantity of different pesticides import, production and utilization are gradually increased. Total quantity of pesticide utilization was 7055.04 MT (1991) and 15631.24 MT (2000) respectively. The quantity of used insecticide was 13808.18 MT (2000), which was maximum and equivalent to 93% of the total pesticide consumption. Granular insecticide used more than liquid or other type of insecticide. Thus, the government directives as per provisions mentioned in the pesticide ordinance, 1971 and the pesticide rules, 1985 might be properly maintained and implemented during registration, import, production and use in the country (Study 3). Field experiments were conducted with diazinon (Rison 60 EC), malathion (Cyfanon 57 EC) and fenitrothion (Sumithion 50 EC) on brinjal (variety: Uttara) to find out the effectiveness of 4-different treatments having 4- different doses of each insecticide to control BSFB at flowering and fruiting stage. The doses rate of each insecticide was fixed on the basis of national standard as 1.7 L/ha for diazinon and 1.12 L/ha for both malathion and fenitrothion respectively. The results of those 4-treatments for every insecticide on shoot, fruit and yield performance of brinjal plant against infestation of BSFB found statistically insignificant, except the treatment D, having DR @ 3.4 L/ha of diazinon and F. having DR @ 2.24 L/ha of fenitrothion on shoot were found statistically significant. The F. treatment of fenitrothion was the best with lowest shoot infestation (5.57%) and found superior to control BSFB than all other insecticide treatments comparatively (Study 4). Analytical results of brinjal plant samples under those treatments and their residual situation of 3-selected organophosphorus insecticides under field condition were found as follows: (i) Quantity of diazinon under all those treatments after both 48 and 120 hours found 0.61 mg/kg (min.) to 4.15 mg/kg (max.) respectively, which were more than MRL value of 0.5 mg/kg. So, it was not safe for harvest and consumption of brinjal fruit before 120 hrs of single spraying with diazinon. (ii) Quantity of malathion under all those treatments after both 48 and 120 hours found 0.04 mg/kg (min.) to 0.74 mg/kg (max.) respectively, which were less than MRI. value of 3.0 mg/kg. So, it was safe for harvest and consumption of brinjal fruit before 120 hrs of single spraying with malathion. (iii) Quantity of fenitrothion under all those treatments after both 48 and 120 hours found 0.005 mg/kg (min.) to 0.16 mg/kg (max.) respectively, which were less than MRL value of 0.5 mg/kg. So, it was safe for harvest and consumption of brinjal fruit before 120 hrs of single spraying with fenitrothion. Therefore, strengthening of over all pesticide administration and quality control system of Bangladesh are immediately needed to ascertain the judicial use of pesticide and pest management in agriculture for maximum crop production (Study 5).