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Wheat Information
Service
Number 74: 9-11 (1992)
Effect
of photosynth "Mixtalol" on grain improvement and yield in
triticale
R. Rao and V. K. Khanna
Department of Plant Breeding, G. B. Pant Agrivarsity, Pantnagar,
India
Plant breeders produce high yielding varieties by having genotypes
possessing combinations of efficient physiological processes capable
of producing higher yields. An enormous amount of information has
been collected on the effect of mineral nutrition, water relations,
growth regulators and herbicides on various physiological processes
for increasing crop productivity. However, specific attention to
photosynthesis in plants as means of increasing crop productivity has
not been sufficiently stressed in agriculture.
While increasing crop productivity by use of nutrients alone seems to
have reached a plateau, there is an enormous scope of improving the
yields through the photosynthetic route. The upper limit for maximum
photosynthetic efficiency for terrestrial plants has been calculated
to be of the order of 6.6% (Basshan 1977), but most crop plants
achieve photosynthetic efficiencies only of the order of 0.15-0.2%
(Boardman 1980), suggesting a possibility of increasing the rate many
folds more and, consequently, yields. A study on the effects of
"Mixtalol" which is a mixture of aliphatic alcohols, on improvement
in grain shrivelling, yield contributing characters and yield is
reported here. Mixtalol at the optimum dilution is absorbed throuth
leaves as well as through roots and acts rapidly in the plant system
(Menon and Srivastava 1984). It increases photosynthesis,
C02 uptake, nutrient uptake and decreases
photorespiration. It improves plant stature, flowering, rooting and
tillering and general plant vigour. Some constituents seems to have
an effect which simultaneously helps the growth of a deeper and
better root system.
Materials and Methods
The experimental material used in the present study comprised of
five strains of hexaploid triticale namely UPT 72142, UPT 78268, UPT
79245, UPT 79339 and UPT 79347. Plants were grown in four row plots,
following a split plot design, with four replications and treated
with Mixtalol, which is a mixture of a spectrum of aliphatic alcohols
with chain lengths C-24 to C-34 (Menon and Srivastava 1984). Mixtalol
has the following composition (%): C-24 Tetracosanol: 7-10; C-26
Hexacosanol: 12-16; C-28 Octacosanol: 15-20; C-30 Triacontanol:
24-30; C-32 Dotriacontanol: 11-14; and C-34 Tetratriacontanol: 4-5.
Mixtalol treated and control plants were allotted to main plots and
five strains were taken as sub-plots. Each strain was sown in four
rows with a row-to-row distance of 23 cm and each row was 2.5 m long.
4.5 ml of Mixtalol was mixed in 1.5 litres of water and sprayed in
about 9.2 square meters area. Spraying was done after 31 and 65 days
of sowing. Ten plants were randomly selected from each replication
and data was recorded on heading date, maturity date, plant height,
number of tillers per plant, spike length, 100-seed weight and yield
per hectare.
Results and Discussion
Table
1 shows the
effect of Mixtalol spray on various characters. The analysis of
variance is given in Table
2. Mixtalol
treatment did not show any significant effect on days to 75 percent
heading and maturity, though it increased plant height significantly
as compared to control. This increase may be due to an increased dry
matter in the treated plants as a result of increased mitotic
activity imparted either directly or possibly through a change in
endogenous levels of auxins/cytokinins. The number of tillers per
plant increased significantly after Mixtalol treatment as compared to
control. Menon and Srivastava (1984) found an increase in the number
of tillers per plant in rice, which is indicative of initial vigour
due to Mixtalol application. Hundred grain weight and yield per
hectare also increased significantly due to Mixtalol treatment. Menon
and Srivastava (1984) attributed this to an increase in the rate of
photosynthesis and a decrease in photorespiration rate. Grain type
showed improvement which may have resulted because of an improvement
in mitotic activity during grain formation and also improved
photosynthesis. Extensive field trials with Mixtalol have shown yield
increases of 14-27% in paddy, 13-27% in wheat, 33% in maize, 21-29%
in potatoes and 48% in sorghum (Menon and Srivastava 1984). Mixtalol
may prove to be very useful in increasing plant productivity by
improved photosynthesis.
References
Bassham JA (1977) Increasing crop production through more
controlled photosynthesis. Science 197: 630-638.
Boardman NK (1980) In: Solar energy (eds). G. Porter and W.
Hawthorne, London Royal Society, pp. 132-145.
Menon KKG and Srivastava HC (1984) Increasing plant productivity
through improved photosynthesis. Proc. Ind. Acad. Sci. (Plant Sci.)
93: 359-378.
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