Physiological approaches to improving harvest index and productivity in sunflower

Factors associated with variation in harvest index and approaches to improve harvest index (HI) and productivity in sunflower are discussed in this article. In recent years, higher productivity in sunflower has been achieved mainly through increased crop growth rates. Besides, an improvement in harvest index also has contributed for improved productivity to a certain extent. In our study we observed that medium duration types (100 to 110 days) had high HI compared with early or long-duration varieties and we also attempted to understand the ways and means to improve HI in sunflower types with varied duration. Genotypes which had low partitioning of dry matter to stem plus thalamus had high HI. Genotypes which accumulated high biomass during post flowering stages of development also showed high HI and seed yield. In a few genotypes remobilization of photosynthates from vegetative plant parts to the seed resulted in high HI and seed yield. Among the sink characters, the number of seed per head, test weight and seed density (weight/volume) also contributed to achieving high HI values. Identification and selection of genotypes based on these criteria will increase the production further. Since large amount of biomass is still locked up in the vegetative plant parts, any practice to manipulate the mobilization of photosynthates from vegetative parts to head also improves HI and thus seed yield. In our experiment, we observed that foliar application of boron nutrient and application of growth regulators to the head improved the translocation of photosynthates to the head and thus increased the HI and seed yield

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Not AvailablePresence of abundant phytic acid in finger millet grain reduces the bioavailability of iron to the human body due to the higher molar ratio of phyticacid to iron, which is preferred to be less than 10:1. One of the traditional approaches being commonly used to reduce this ratio could be the germination process. Hence, the present study was undertaken to evaluate influence of germination on phytic acid and iron in finger millet germplasm. The molar ratio of phytic acid to iron was calculated both in raw and germinated form.Molar ratio of phytic acid to iron decreased from 17:1 in raw to 15:1 in the germinated seeds for 72 hrs with a progressive decrease from 24 hrs onwards. These results shows that the possibility of reduction in molar ratio of phytic acid to iron with one of the processing techniques like germination. Hence, this feasible and easy technique may be used to screen the large number of genotypes to arrive at lower molar ratio of phytic acid to iron.ICAR- Central institute for women in agriculture (CIWA

An improved non-destructive method for rapid estimation of leaf area in sunflower genotypes

Measurement of total leaf area per plant in crop improvement programmes for a variety of purposes is often very tedious and time consuming. In this paper, we offer a rapid and non-destructive method of estimating the total leaf area in sunflower at the time of anthesis. We show that multiplying the leaf area of a specific leaf position from the apex by the total number of leaves per plant yields total leaf area with more than 95 % accuracy. The specific leaf position for any given genotype in sunflower can be arrived at by multiplying the total number of leaves per plant by the factor 0.355 and rounding off to the nearest highest integer. This technique can be used for the rapid estimation of leaf area per plant at anthesis for any given genotype of sunflower