Saponin synthesis and cotton growth is antagonistically regulated by solar UV-B radiation

An article of Journal of Cotton Research has been published online.

[Background] Earlier we have reported that the exclusion of solar UV-B increased the growth and yield of cotton plants as compared with ambient UV-B. The UV-B radiation effects on the saponins and the impact of ambient and reduced UV-B on the accumulation of saponins has not been investigated yet. Thus a field experiment was conducted to study the influence of solar UV-B on the growth response and saponin synthesis in cotton (Gossypium hirsutum) var. Vikram plants by the exclusion of UV-B. The cotton plants were grown in specially designed iron chambers, wrapped with filters that excluded UV-B (<315 nm), or transmitted ambient UV-B. [Results] Exclusion of ambient UV-B enhanced the growth of cotton plants in terms of plant height and leaf area. Greater plant height in UV-B excluded plants was due to elongated internode and more number of nodes. Enhancement in growth was accompanied by a decrease in the accumulation of saponins, which was quantified by the spectrophotometric, TLC and HPLC methods. Solvent extraction of saponins from the internodes and leaves were used for the bioassay of Amaranthus hypocotyl growth and expansion of cucumber cotyledons. Extracts obtained from the UV-B excluded plants (leaves and internodes) promoted the growth to a larger extent as compared with the extracts obtained from ambient grown plants.

[Conclusions] The result indicates that solar UV-B may possibly suppress the plant growth by regulating the synthesis of natural growth inhibitor’s like saponin.

Saponin synthesis and cotton growth is antagonistically regulated by solar UV-B radiation
DEHARIYA Priti, KATARIA Sunita, GURUPRASAD Kadur Narayan, PANDEY Govind Prakash

Journal of Cotton Research, 2018, 1:14

https://jcottonres.biomedcentral.com/articles/10.1186/s42397-018-0014-x

Light and simplified cultivation of cotton, an approach of global relevance?

A paper recently published about China

In a recent visit to Shadong Cotton Research Institute, I was introduced to the approach of carrying out new cultivation techniques destined to adapt to the current context of labor scarcity and high production costs for cotton production in China. This approach is being elaborated in a recent paper by the research team led by Prof. Dong HeZhong who is also a member of the Executive Committee of our Association.

The paper titled ‘Technologies and theoretical basis of light and simplified cotton cultivation in China’ is available here. The paper is not in open access, if needed, the corresponding author can be contacted (donghezhong@163.com ).

To me, the paper is interesting at least for two reasons. One, it gives a good view on how cotton is being cultivated in China, through an intensive way, in terms of production chemicals and knowledge.

Machine to sow single seed of cotton after garlic
Machine to sow single seed of cotton after garlic

Second, it provides scientific basis to sustain why some techniques, already finalized along the approach followed, work.

Plantlet obtained from single seed sowing are shorter, stronger and have a more rooting system
Plantlet obtained from single seed sowing are shorter, stronger and have a more developed rooting system
Industrial nursery can prevent farmers from producing plantlets by themselves
Industrial nursery can prevent farmers from producing plantlets by themselves

Semi-mechanized transplanting

Semi-mechanized transplanting

Potential relevance to other contexts?

The issue of producing cotton in a competitive way, notably against alternative crops in a same country, is common to many producing countries. The concern to decrease costs is global however cotton cultivation is intensive in capital and/or in chemical use. The concern to reduce labor cost is particularly felt in countries with production which is little mechanized, if not manual.

China is probably producing cotton by farms of the smallest size in the world, with average farm size of less than one hectare in traditional production regions of Yellow River and Yangtze River valleys. The way China has succeeded to conceive adapted mechanization, although there are still many challenges ahead, is worth consideration in many developing countries where farmers grow cotton on a few hectares each.

Where cotton is grown under irrigation in large areas, the various techniques China has been developing if not adopting in its North-western region is worth of consideration as well. The combination of sowing, fertilizing and posing mulching film is an example.

Machine for several operations in one time
Machine for several operations in one time

Environmental considerations worth being more explicitly highlighted as well?

Nowadays, there is a worldwide consensus on reducing at most the potential negative impacts in agricultural production in general, not only in cotton cultivation. To capture furthermore the attention on the Light and Simplified Cultivation approach, probably the potential environmental impacts that could result, either positive or negative, should be addressed too.

Seventh ‘Asian Cotton Research and Development Network’ Meeting, 15-17 Sept 2017, Nagpur India.

The Seventh Meeting of the Asian Cotton Research and Development Network was held at Nagpur during 15-17 September 2017. The Indian Society for Cotton Improvement (ISCI), Mumbai hosted the meeting together with the ICAR-CICR (Central Institute for Cotton Research), Nagpur and ICAR-CIRCOT (Central Institute for Research on Cotton Technologies). The main theme of the meeting was PRODUCING QUALITY FIBRE & DOUBLING COTTON FARMERS INCOME. Cotton researchers from public and the private sector participated. Dr. C. D. Mayee, President, Indian Society for Cotton Improvement, was the chairman, of the organizing Committee. The meeting elected Dr. Prashant G. Patil as Chairman of the Network until the next meeting. Eminent cotton experts i.e., Dr. Timorthy Dennehy, Dr Judith Brown, Dr Albert Santos from US; Dr Derek Russell from Australia, Dr Negm from Egypt and several senior research leaders from India and Bangladesh attended the meeting. The proceedings, recommendations, presentations and abstracts of the meeting can be accessed here.

Seventh Meeting of the ACRDN

Proceedings are available

The Seventh Meeting of the Asian Cotton Research and Development Network was held at Nagpur, India during 15-17 September 2017. The Indian Society for Cotton Improvement (ISCI), Mumbai hosted the meeting together with the ICAR-CICR (Central Institute for Cotton Research), Nagpur and ICAR-CIRCOT (Central Institute for Research on Cotton Technologies).

The main theme of the meeting was  “PRODUCING QUALITY FIBRE & DOUBLING COTTON FARMERS INCOME.” Cotton researchers from public and the private sector participated. Dr. C.D. Mayee, President, Indian Society for Cotton Improvement, was the Chairman of the Organizing Committee. The meeting elected Dr. Prashant G. Patil as Chairman of the Network until the next meeting. Eminent cotton experts like Dr. Timorthy Dennehy, Dr Judith Brown, Dr Albert Santos from US; Dr Derek Russell from Australia; Dr Negm from Egypt and several senior research leaders from India and Bangladesh attended the meeting.

The proceedings, recommendations, presentations and abstracts of the meeting are now available at the ICAC website.

FOLIAR APPLICATION FOR YIELD AND QUALITY OF COTTON GROWN ON KAMPANG SAEN SOIL IN THAILAND

Abstract                                                                         Back to Table of contents

A comparative study on conventional fertilizer application and foliar fertilizer application of cotton grown on Kampaeng Saen soils (Udic Haplustalffs) was conducted for five years during 1986-1990. The results revealed that fertilizers applied at the recommended rate (37.5-37.5-37.5 kg/ha of N-P205-K20) in the first and second year could increase cotton growth, yield and quality over the unfertilized control and had residual effects on the third, fourth and fifth year. Cotton growth and yield of combined applications of conventional and foliar application were not different from conventional.

Foliar applications of the four grades of foliar fertilizer 16-48-0 (DAP), 30-20-10, 16-32-6 and 16-5-5 could increase cotton yield and quality over the unfertilized control.  The most economical foliar fertilizer was 16-48-0 (DAP).

Conclusions 

  1. Foliar fertilizer application integrated with soil fertilizer application was not necessary because the growth and the quality of cotton was not significantly different to soil application alone.
  2. It was possible to use foliar fertilizer application with cotton. Foliar fertilizer application increased plant growth and cotton quality. In term of economics, using foliar fertilizer application would take less risk than the other methods.
  3. Soil fertilizer application or conventional fertilization was the suitable method and it was cheap for the farmers in the long term. The study indicated that soil fertilizer application for two in five years is not adequate for nutriont replenishment but it returned a good income and also had residual affects for subsequent crops compared with other treatments.
  4. Soil properties: pH, organic matter, available P and exchangeable K were variable, but all showed a trend to be reduced after five years of cotton cropping.

 

Future Considerations

The study indicated that foliar fertilizer application could be used with cotton and recommended to farmers.

Future research should concentrate on the fertilizers that are not expensive and are found easily in the market, such as urea and DAP. The rate of fertilizer, time of application and the number of times of application should be studied on fertile and infertile soils.

                                                                                Back to Table of contents

MANAGING SOIL MECHANICAL STRESSES FOR COTTON PRODUCTION

Abstract                                                                         Back to Table of contents

Soil mechanical stresses are detrimental to root and shoot growth in cotton when threshold values are exceeded.  Soil surface, mechanical stresses are manifested either as crusts or seals formed when rain or irrigation is followed by rapid drying, while at shallow depths a dense hard layer is formed due to either clay accumulation or calcification. Cotton seedling emergence was reduced from 58 to 10% when surface crust strength increased from 0.25 to 1.20 kg cm-2 in a sandy loam soil. Mechanical disruption of soil crust and seedline mulch application with farm yard manure (FYM) overcame the adverse effect of surface mechanical stresses on seedling emergence. A 5 cm thick layer of about 1.9 Mg m-2 at 15 to 20 cm depth decreased the plant height, root growth and yield of seed cotton. The growth of the tap root completely ceased when it encountered the dense layer and reduction in yield was about 16%. Deep tillage alleviated the adverse effect of a dense layer at shallow depths.

Conclusion

Surface and sub-surface mechanical impedance reduced seedling emergence, growth and yield of cotton. Seedline mulch with FYM, mechanical breaking and deep tillage is useful for managing soil mechanical stresses and for increasing cotton yield.

                                                                                 Back to Table of contents