5 June 2018
Crop Diversity = Minting Money
Agriculture in the Gangetic Plains
The farmers in the subtropical plains of North India traditionally practice rice-wheat cropping. Productivity of rice under rainfed conditions is low. A new study suggests that there are more diverse and profitable crop combinations that the farmers could use.
“The use of aromatic crops in traditional cropping systems increases the biodiversity of the farms and improves farmers’ income under rainfed conditions”, says Khushboo Khan, CIMAP, Lucknow.“We evaluated the economic feasibility of integrating basil and menthol mint into the conventional cropping systems” Rajesh Kumar Verma.
The scientists conducted field trials with eight different crop combinations for four consecutive years from 2012 to 2016. In summer, the scientists cultivated cowpea and menthol mint. The winter crops included wheat, potato and lentils. All the annual crop combinations had basil as the rainy season crop instead of rice.
The team followed standard agronomic practices and harvested the crops 90-140 days after planting/sowing.“We then calculated the input costs, and the agricultural income generated from the cropping systems with basil and menthol mint as constituents”, says Khushboo Khan.The researchers used various indices – including net returns, gross returns, Benefit Cost Ratio and Marginal Benefit Cost Ratio – and arrived at the best cropping system for the region.
They found basil-pea-menthol mint the best annual inter cropping system with maximum net returns. The basil-lentil-cowpea combination gave the worst results.Crop diversification enables efficient utilisation of available resources. It also improves soil health and sustainability.
The Higher Benefit Cost Ratio for crop combinations, with aromatic crops as substitutes for rice in arable lands, may prompt farmers to experiment with these combinations, hopes the team.
Ind. Crops Prod., 115: 104-110
Smitha G Nair
23rd October 2017
Drought Tolerance – Pea Gene in Rice
Water scarcity and increasing temperature affect rice cultivation. Scientists from various parts of the world are trying to develop rice cultivars which can cope with these stress conditions.
Recently, research groups from the Assam Agricultural University and the ICGEB, New Delhi collaborated to develop a drought tolerant transgenic rice cultivar.
They isolated PDH47 – Pea DNA Helicase 47 – a gene that plays an important role to overcome cold stress in the pea plant, Pisum sativum. The scientists introduced this gene into the rice cultivar ASD16. This cultivar is popular in South India but is susceptible to drought stress.
The scientists used a soil bacterium, Agrobacterium tumefaciens, to introduce PDH47 gene into immature embryos of rice. They were successful in developing transgenic rice plants. The team grew these transgenics till second generation in a greenhouse. Then they withheld water for 30 days and tested the plants for drought tolerance. The team used relative water content, proline and hydrogen peroxide as proxies to evaluate the drought tolerance of the plants.
The team observed that the expression of the PDH47 gene is greater in the shoots and roots of transgenic plants than in control plants. Moreover, upregulating the gene induced expression of other endogenous rice genes under drought stress.
This is the first time PDH47 gene is used to develop drought tolerant rice plants. This gene can be exploited to develop other tolerant transgenic crops.
The results of this research give hope to scientists and farmers. However, since GM crops are facing severe opposition from the public, there might be a resistance when it comes to field trials.
Plant Cell Tissue Organ Cult., 130: 577-589 (2017)
G. Prem Kumar
27 October 2017
Rise, Paddy, Rise!
Fluoride in rice
Rice cultivation requires a huge amount of water. Unfortunately, most of the water bodies in our country are polluted by fluoride. When paddy fields are irrigated with fluoride contaminated water, the fluoride may accumulate in straw. Is it safe to feed cattle such straw?
Naba Kumar Mondal from the University of Burdwan, West Bengal investigated the effects of fluoride on the growth of four rice varieties – MTU-1010, IET-4786, IET-4094 and GB-1 – cultivated in India.
He germinated the seeds in different petri plates, grew them in a greenhouse and then added sodium fluoride. Mondal studied the growth parameters of the seedlings. He observed a reduction in shoot and root lengths, a loss of green colour and the appearance of dark spots on leaves.
When he examined the fluoride uptake in the seedlings and fluoride concentration in the tissues, he found that fluoride accumulated in roots more than in shoots.
His observations on the biochemical changes, lipid peroxidation, root ion leakage, and catalase activity due to fluoride accumulation were identical to those from similar works on wheat, bengal gram, mustard and tomato.
The scientist suggests the use of surface water or fluoride-free water for irrigation. In areas with fluoride pollution, crops having low capacities to accumulate fluoride may be cultivated. By employing these methods, farmers can overcome the problems caused by fluoride in irrigation water and thereby improve the yield.
Ecotoxicol. Environ. Safety. 14: 36-44 (2017)
Anoop Kumar V
Moolah from linalool
The fragrance from jasmines gives is enchanting. Why are these flowers so fragrant?
It is because of the linalool – a flower volatile emitted from the flowers. It is a top note component in many perfume compositions.
It is reported that 8000 tons of linalool is consumed the world wide alone in fragrance compositions. Linalool is an ingredient in many brands of body lotions, shampoos, shower gels, soaps and household detergents. It is also an important intermediate in the synthesis of vitamins E and A.
linalool is an open chain monoterpene alcohol, produced in floral and nonfloral tissues of jasmine. It contains terpenoids, phenylpropanoids and fatty acid-derivatives. It is produced in floral and nonfloral tissues and exists as two enantiomers, namely R-linalool and S-linalool. Molecultes which are mirror images of each other. Their smells are diferent: S-linalool is sweet, herbaceous, with citrus fruits notes whereas R-linalool has a woody, lavender-like aroma.
Last fortnight, a research team from the CSIR-Central Institute of Medicinal and Aromatic plants, Lucknow investigated the change in linalool enantiomers of jasmine at various developmental stages using chemical and molecular methods. They found that R-linalool was major enantiomer in bud stage and S-linalool is maximum at flowering stage.
They concluded that variation in enantiomeric ratio of linalool enantiomers is the unique feature and the emission of flower volatiles. Iand its effect on pollinators has yet to be studied with special emphasis on the volatile characteristics, floral scent profiles and ecological interaction of the plant with the environment.
Phytochemistry, 140: 83-94 (2017)