Dissipation kinetics, decontamination, consumer risk assessment and monitoring of flonicamid and imidacloprid residues in capsicum under open field and polyhouse condition.

Liquid chromatography mass spectrometry (LC-MS)-based detection of flonicamid, imidacloprid and 6-chloronicotinic acid residues was validated and analysed in capsicum fruit, processed products and soil. The standard concentrations (0.0025 to 0.25 µg mL-1) of insecticides had a good linear curve (r2>0.99). Limit of detection and limit of quantification values were 0.0025 and 0.01 mg kg-1, respectively. The accuracy (80.53 to 100.33 %) of capsicum matrices and soil (89.41 to 100.52 %) and precision (RSD <10%) were established. Dissipation of imidacloprid (20 and 40 g a.i. ha-1) and flonicamid (75 and 150 g a.i. ha-1) at single (X) and double dose (2X) was studied under open field and polyhouse conditions. Under open field conditions, the flonicamid and imidacloprid residues persisted with half-life of 1.98, 2.90 days (X) and 2.80, 3.14 (2X) days, respectively. While under polyhouse conditions, the flonicamid and imidacloprid residues persisted with a half-life of 2.84, 3.66 (X) and 3.24, 3.97 (2X) days, respectively. The metabolite, 6-CNA, was not detected in any samples under open field and polyhouse condition. Among decontamination treatments, cooking in boiling water for 10 minutes reduced 78 to 81.60 percent of imidacloprid and flonicamid residues in both doses. The estimated dietary risk assessment of imidacloprid and flonicamid residues (RQ <1) indicated that the risk is within the acceptable limit. In farmgate capsicum samples, residues of flonicamid (7 samples) and imidacloprid (11 samples) were detected. Market samples of capsicum products (powder, flakes and sauce) were not detected with residues of selected insecticides.

Early flowering, good grain quality mutants through gamma rays and EMS for enhancing per day productivity in rice (Oryza sativa L.).

PURPOSE: Rice is the prominent crop of world and it frames the important component of food chain. But, long duration of highly preferred rice varieties requires more water and are prone to biotic and abiotic stresses. Short duration rice varieties serve as a promising alternative in such cases. Hence, the present study was taken up to induce early flowering mutants in popular rice variety Bapatla 2231 (BPT 2231), a long duration medium slender rice variety using gamma rays and Ethyl Methane Sulfonate (EMS) treatment combinations. MATERIALS AND METHODS: Five hundred well filled and viable grains of optimum moisture content (12%) were subjected to irradiation with 8 doses comprising 100 Gy, 200 Gy, 300 Gy, 350 Gy, 400 Gy, 450 Gy, 500 Gy and 600 Gy treatments. For combination treatments, the irradiated seeds of gamma rays were further treated with 30 mM concentrations of Ethyl Methane sulfonate (EMS). The irradiated population were raised up to M3 generation for the identification of early maturing mutants. The isolated early maturing mutants in M3 generation were characterized for phenotypic, biochemical and grain qualities. RESULTS: The frequency of desirable early maturing mutants was observed more in combination treatments than the individual treatments of gamma rays. A total of 34 early maturing mutants (M) with variation for grain quality and biochemical traits were obtained. The mutants M-1, M-3, M-5, M-32, and M-34 were high yielding with fine grain type. The mutants M-4, M-17, M-18, M-19, M-20, and M-26 were high yielding with bold grain type. The mutants M-22, M-23, M-24, M-27, and M-28 were high in nutrient content. The early mutants matured 40-50 days earlier than control. CONCLUSION: In this variety, the combination treatments showed higher mutation frequency, mutagenic effectiveness and efficiency than the gamma rays in induction of both chlorophyll and viable mutants. This study revealed that the combination treatments were more effective in inducing early mutants than the gamma ray treatments alone. The early maturing mutants can be released as variety after evaluation under different yield trials and the mutants with increased nutrient content and varied grain quality can be utilized in hybridization/heterosis breeding programs for rice crop improvement.