Ananta Vashisth

Effect on germination and early growth characteristics in sunflower (Helianthus annuus) seeds exposed to static magnetic field.

Seeds of sunflower (Helianthus annuus) were exposed in batches to static magnetic fields of strength from 0 to 250mT in steps of 50mT for 1-4h in steps of 1h. Treatment of sunflower seeds in these magnetic fields increased the speed of germination, seedling length and seedling dry weight under laboratory germination tests. Of the various treatments, 50 and 200mT for 2h yielded the peak performance. Exposure of seeds to magnetic fields improved seed coat membrane integrity and reduced the cellular leakage and electrical conductivity. Treated seeds planted in soil resulted in statistically higher seedling dry weight, root length, root surface area and root volume in 1-month-old seedlings. In germinating seeds, enzyme activities of alpha-amylase, dehydrogenase and protease were significantly higher in treated seeds in contrast to controls. The higher enzyme activity in magnetic-field-treated sunflower seeds could be triggering the fast germination and early vigor of seedlings.

Exposure of Seeds to Static Magnetic Field Enhances Germination and Early Growth Characteristics in Chickpea (Cicer arietinum L.)

Seeds of chickpea (Cicer arietinum L.) were exposed in batches to static magnetic fields of strength from 0 to 250 mT in steps of 50 mT for 1-4 h in steps of 1 h for all fields. Results showed that magnetic field application enhanced seed performance in terms of laboratory germination, speed of germination, seedling length and seedling dry weight significantly compared to unexposed control. However, the response varied with field strength and duration of exposure without any particular trend. Among the various combinations of field strength and duration, 50 mT for 2 h, 100 mT for 1 h and 150 mT for 2 h exposures gave best results. Exposure of seeds to these three magnetic fields improved seed coat membrane integrity as it reduced the electrical conductivity of seed leachate. In soil, seeds exposed to these three treatments produced significantly increased seedling dry weights of 1-month-old plants. The root characteristics of the plants showed dramatic increase in root length, root surface area and root volume. The improved functional root parameters suggest that magnetically treated chickpea seeds may perform better under rainfed (un-irrigated) conditions where there is a restrictive soil moisture regime.

Growth characteristics of maize seeds exposed to magnetic field

Standardization of magnetic field was done for maximum enhancement in germination characteristics of maize seeds. Seeds of maize were exposed to static magnetic fields of strength 50, 100, 150, 200, and 250 for 1, 2, 3, and 4 h for all field strengths. Results indicate that magnetic field application enhanced seed performance in terms of percentage germination, speed of germination, seedling length, and seedling dry weight significantly compared to unexposed control. Among the various combinations of field strength and duration, 200 mT for 1 h exposure gave best results. Exposure of seeds to magnetic fields improved seed coat membrane integrity as it reduced cellular leakage and, consequently, electrical conductivity. Experiments conducted at a research farm as well as farmers field showed that plants raised from seeds exposed to 200 mT for 1 h had higher values of leaf area index, shoot length, number of leaves, chlorophyll content, shoot/root dry weight, and root characteristics as compared to corresponding values in untreated control. From the studies, it may be concluded that exposure of dry seeds to static magnetic field of 200 mT for 1 h improved shoot and root growth. Improved root system and biomass led to increased seed yield. Improved functional root parameters suggested that magnetically treated maize seeds could be used under moisture stress conditions. Bioelectromagnetics. 38:151-157, 2017.

Effect of Weather Variability on Growth Characteristics of Brassica Crop

A field experiment was conducted at research farm of IARI, New Delhi with an aim to study the effect of weather variability on crop growth and seed yield. Three cultivars of Brassica were sown on three dates at an intervals of 15 days during 2007–2008 rabi season. The leaf area index, biomass, chlorophyll concentration index and aphid infestation were measured at different stages of crop growth. Study revealed that all the growth parameters were affected due to the change in the weather conditions. First sown crop experiences 2–3°C lower temperature as compared to late sown crop during maturity and more temperature during field emergence, vegetative and flowering. Because of more favorable weather conditions and less aphid infestation crop growth and seed yield were relatively more in the first sown crop as compared to late sown crop.