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Background and Aim: Modern radiotherapy modalities, such as Intensity Modulated Radiotherapy and Volumetric Modulated Arc Therapy involve complex dose delivery. The dose delivery is complex as it involves beam modulation, hence, manual dose calculations for these techniques are not possible. Film dosimetry is commonly used method of dose verification for these modalities because of the advantages associated with it. The quantification of uncertainty associated with a film dosimetry system under clinical use becomes important for accurate dosimetry. The spread in the distribution of the pixel values (PV) of the irradiated film contributes to the uncertainty. The probability distribution (PD) of the PV was studied for the clinical photon beam energies of 6, 10, and 15 MV. Methods and Materials: Gafchromic EBT3 film and EPSON 10000XL flatbed scanner were used for this purpose and using the resulting PD, the uncertainty budgets for these energies in the red, green and blue color channels were estimated. Results: The PV of exposed films for the energies studied follows t distribution, the sum of the squares of the deviation of the measured data from the fitted value was of the order of 10-7, this indicates the goodness of fit. The "t" value corrected combined standard uncertainty (CSU) at 1σ, confidence level for exposed film and dose measurement at 200 cGy were 1.42%, 1.48%, and 1.63% and 1.99%, 3.23%, and 5.08% for 6, 10, and 15 MV energies, respectively, in the red colour channel. Conclusion: In the case of the limited number of measurements of a quantity, the SU values must be corrected using the "t" value to get the correct CSU. [ABSTRACT FROM AUTHOR]

A study was carried out in submountainous hill region of north Western Himalaya to assess the effects of seed rate and date of sowing on the incidence of cutworms in maize. It was observed that the incidence was significantly more in early sown (15th May) than the late sown crop (30th May or 15th June). Irrespective of date of sowing, crop sown at the recommended rate of 20kg/ha gave significantly less grain yield than those sown at higher seed rate of 25 kg/ha. On the basis of incidence, plant stand and grain yield under different dates of sowing, it could be concluded that in lower Kullu valley areas sowing should be delayed till the first fortnight of June and in case it has to be done early as in case of higher elevations (above 1300 masl) it can be done in the last week of May or first week of June at a higher seed rate of 25 kg/ha to compensate the damage caused by cutworms. [ABSTRACT FROM AUTHOR]