The response of two soya-bean varieties to the loss of apical dominance at the vegetative stage of growth

1980 ◽  
Vol 95 (2) ◽  
pp. 409-416 ◽  
Author(s):  
T. O. Tayo

SUMMARYIn three pot experiments and one field trial, the apical portion of the main stem of two soya-bean varieties (cv. Hampton and cv. Bossier) were removed at 3 weeks or 5 weeks after sowing in order to evaluate the response of the plants to the loss of apical dominance.The results showed that early loss of apical dominance in Hampton (an indeterminate variety) led to increased vegetative development but shorter plants, higher dry-matter accumulation and increased seed yield through the production of more and/or heavier pods. On the other hand, apical debudding of Bossier (a determinate variety) during the vegetative stage evoked no significant beneficial response and in the case of field debudding at 3 weeks after sowing, plant height was decreased and seed yield was significantly reduced.The response of soya bean to the loss of apical dominance therefore seems to be a function of the stage of vegetative development when the loss occurs as well as the growth habit of the variety.

1982 ◽  
Vol 98 (1) ◽  
pp. 71-77 ◽  
Author(s):  
T. O. Tayo

SUMMARYIn two field trials in 1980, 33, 67 or 100% of the leaves on pigeon pea (cv. Cita-1) plants were removed either at the vegetative stage, the onset of flowering, or at the rapid pod-filling stage, in order to evaluate the effect of reduced assimilatory capacity on the growth and yield characteristics of the crop.Reduction in the assimilatory capacity of the plant led to significant reduction in the vegetative growth, dry-matter accumulation and seed yield of the defoliated plants compared with the undefoliated control such that 33, 67 or 100% defoliation led to 15–55, 40–60 and 75–80% reduction in seed yield respectively, at both trials. Also, defoliation was more damaging to crop performance if carried out from the onset of flowering than at the vegetative stage. Thus, the seed yields of plants defoliated at the onset of flowering and the rapid pod-filling stage were 30–80 and 40–45 % lower than the yield from plants defoliated at the vegetative stage in both trials.


1981 ◽  
Vol 96 (2) ◽  
pp. 375-388 ◽  
Author(s):  
T. O. Tayo

SUMMARYIn three field trials, three varieties of cow pea (Prima, Ife Brown and Vita-5) grown as mono-crops or interplanted with maize (in one trial) were sprayed with a combination of PKS or NPKS in solutions containing 100, 100, 100 and 41 mg/1 of N, P, K and S respectively at the onset of flowering or 2 weeks later, in order to evaluate the effect of foliar spray of mineral nutrients on the performance of the crop.Early season sprayings of NPKS and PKS increased vegetative development and dry-matter accumulation in both mono- and mixed-croppings of Prima and Vita-5, but had little effect on Ife Brown. Seed yield was increased by 80–225 kg/ha in Prima and 160–218 kg/ha in Vita-5. In all cases of enhanced growth and yield, spraying at flowering was more beneficial than spraying 2 weeks later whilst NPKS evoked greater responses than PKS.In two late-season trials, all treatment combinations enhanced vegetative development and dry-matter accumulation in Ife Brown and Vita-5. Seed yield of Ife Brown was increased by 206 kg/ha in the first late season and by 550 kg/ha in the second late season whilst that of Vita-5 was increased by 226 kg/ha in the first late season, during which it was planted. In the first late season of Ife Brown, late spraying was more beneficial than early spraying, whilst plants sprayed with PKS out-yielded those sprayed with NPKS. On the other hand, in the second late season, Ife Brown responded more to early spraying than late spraying and NPKS was more beneficial than PKS: Vita-5 grown in the first late season responded similarly.In all cases of enhanced seed yield during the seasons, the pathway of response was through increased pod production and/or retention on the plants. The results therefore suggest that foliar spray of nutrients during the post-flowering period enhance seed yield in cow pea by ensuring prompt delivery of mineral nutrients to the site of photosynthesis at a time when nutrient depletion in the leaves and reduced efficiency of mineral nutrient uptake by the roots limit the supply of photosynthates to developing reproductive organs.


Author(s):  
Muhammad Zeeshan Mehmood ◽  
Ghulam Qadir ◽  
Obaid Afzal ◽  
Atta Mohi Ud Din ◽  
Muhammad Ali Raza ◽  
...  

AbstractSeveral biotic and abiotic stresses significantly decrease the biomass accumulation and seed yield of sesame crops under rainfed areas. However, plant growth regulators (such as Paclobutrazol) can improve the total dry matter and seed production of the sesame crop. The effects of the paclobutrazol application on dry matter accumulation and seed yield had not been studied before in sesame under rainfed conditions. Therefore, a two-year field study during 2018 and 2019 was conducted with key objectives to assess the impacts of paclobutrazol on leaf greenness, leaf area, total dry matter production and partitioning, seed shattering, and seed yield of sesame. Two sesame cultivars (TS-5 and TS-3) were treated with four paclobutrazol concentrations (P0 = Control, P1 = 100 mg L−1, P2 = 200 mg L−1, P3 = 300 mg L−1). The experiment was executed in RCBD-factorial design with three replications. Compared with P0, treatment P3 improved the leaf greenness of sesame by 17%, 38%, and 60% at 45, 85, and 125 days after sowing, respectively. However, P3 treatment decreased the leaf area of sesame by 14% and 20% at 45 and 85 days after sowing than P0, respectively. Compared with P0, treatment P3 increased the leaf area by 46% at 125 days after sowing. On average, treatment P3 also improved the total biomass production by 21% and partitioning in roots, stems, leaves, capsules, and seeds by 23%, 19%, 23%, 22%, and 40%, respectively, in the whole growing seasons as compared to P0. Moreover, under P3 treatment, sesame attained the highest seed yield and lowest seed shattering by 27% and 30%, respectively, compared to P0. This study indicated that by applying the paclobutrazol concentration at the rate of 300 mg L−1 in sesame, the leaf greenness, leaf areas, biomass accumulation, partitioning, seed yield, and shatter resistance could be improved. Thus, the optimum paclobutrazol level could enhance the dry matter accumulation and seed production capacity of sesame by decreasing shattering losses under rainfed conditions.


2018 ◽  
Vol 44 (3) ◽  
pp. 479-482 ◽  
Author(s):  
Yubaraj Dhakal ◽  
RS Meena ◽  
Nirmal De ◽  
SK Verma ◽  
Ajeet Singh

Significant improvement in LAI, number of trifoliate, SPAD value of green leaf chlorophyll, dry matter accumulation, yield, harvest index (%) and nutrient content of mungbean were recorded due to application of 75% RDF + 2.5 t/ha vermicompost (VC) + Rhizobium (Rh)+ phosphorus solublizing bacteria (PSB), followed by 100% RDF + 2.5 t/ha VC and 100% RDF + Rh + PSB. The highest seed yield of mungbean was obtained with the application of 75% RDF + 2.5 t/ha VC + Rh + PSB (12.34 q /ha) followed by 100% RDF + 2.5 t/ha VC (12.05 q /ha) and 100% RDF + Rh+ PSB (11.95 q /ha).


Author(s):  
Manpreet Jaidka ◽  
J.S. Deol ◽  
Ramanjit Kaur ◽  
R. Sikka

Effect of detopping and mepiquat chloride on morphological, physiological and yield attributes of soybean cultivar ‘SL 544’ was studied. A two year investigation was conducted at Punjab Agricultural University, Ludhiana, during kharif seasons of 2014 and 2015. The experiment was laid-out in randomized complete block design (RCBD) with eight treatments viz. control, detopping (removal of 4-5 cm apical portion of main stem) at 50-55 days after sowing (DAS), mepiquat chloride @ 200 ppm (50-55 DAS), mepiquat chloride @ 200 ppm (50-55 + 65-70 DAS), mepiquat chloride 250 ppm (50-55 DAS), mepiquat chloride @ 250 ppm (50-55 + 65-70 DAS), mepiquat chloride @ 300 ppm (50-55 DAS) and mepiquat chloride @ 300 ppm (50-55 + 65-70 DAS) with four replications. Detopping had a non-significant effect on leaf area index, SPAD value, PAR interception, abscission of reproductive parts, seeds per pod, 100-seed weight, pod length and stover yield of soybean. It significantly decreased plant height, increased total dry matter accumulation/plant, number of flowers and pods/plant, pod setting percentage and seed yield over control during 2014 and 2015. At crop harvest, detopping developed optimized source-sink relationship by means of distribution of total dry matter between stem, foliage and pods by 20.4, 14.9 and 64.6 % during 2014 while 22.6, 20.1 and 57.4 % during 2015, respectively. Mepiquat chloride posed a non-significant effect on plant height, PAR interception, number of flowers/plant, number of seeds/pod, pod length and stover yield of soybean but it significantly decreased leaf area index, abscission of reproductive parts while increased the dry matter accumulation/plant, number of pods/plant, 100-seed weight and seed yield relative to control. At harvest, two foliar applications of mepiquat chloride @ 250 ppm resulted in optimized source-sink relationship by the distribution of total dry matter among stem, foliage and pods by 20.6, 10.9 and 68.5 % during 2014 while 19.5, 7.6 and 72.9 % during 2015, respectively. Occurrence of more rainfall during 2015 as compared to 2014 caused mepiquat chloride to hike seed yield as compared to detopping which is clearly witnessed by increase in pod dry weight per plant during 2015 than 2014. Conclusively, both detopping and mepiquat chloride resulted in enhancement in source-sink relationship and seed yield of soybean.


1997 ◽  
Vol 48 (1) ◽  
pp. 91 ◽  
Author(s):  
A. Hardy ◽  
C. Huyghe ◽  
J. Papineau

Despite the high oil and protein content of the seeds, the agronomic potential of Lupinus mutabilis Sweet, a South American lupin species, is limited because of its low seed yield and its uncertain maturity. Dry matter accumulation and partitioning, and seed yield, of 2 genotypes (early-maturing LM34 and late-maturing LM268) were studied in 2 seasons at 2 densities at Lusignan, France. Total dry matter at harvest was, on average, 680 g/m2. The mainstem and first-order branches mainly contributed to total plant biomass but pods were only produced on the mainstem. On average, across the different crops, the maximum leaf area index (LAI) was 2· 8. The duration of LAI above 2·5 was short and not correlated with the total dry matter production. The partitioning of the dry matter varied according to the genotype. LM34 showed enhanced pod growth, its harvest index (HI) was 0·32, and seed yield averaged 1·28 t/ha. LM268 showed enhanced vegetative growth, both HI and seed yield were lower (0·16 and 1·13 t/ha, respectively), and whole plant maturity was never reached. For both genotypes during the pod filling, no remobilisation of assimilates occurred from stems to pods.


1984 ◽  
Vol 35 (4) ◽  
pp. 511 ◽  
Author(s):  
RW Downes ◽  
JS Gladstones

Plants of Lupinus angustifolius cv. Unicrop were raised at 27/22 or 21/16�C dayhight temperatures until flowering. They were then either grown on to maturity at these conditions or moved to the other regime. Branches were removed as they started to develop and leaves were removed at the start of flowering so that 0, 3, 6, 9, 12 upper leaves or all 21 leaves were retained. Conditions before flowering determined potential pod number. Defoliation treatments revealed that under favourably cool conditions all leaves contributed to seed yield but in treatments involving 27/22'C there was no seed yield response to more than about six leaves, emphasizing the significance of environmental conditions rather than current assimilate on pod set and other yield components. In another experiment, plants were raised to flowering at 27/22, 21/16 or 15/10�C before flowering, when all were moved to 21/16�C. Half the plants were allowed to develop branches and on the remainder branch buds were removed. Branch and stem growth appeared to provide severe competition for the development of the primary inflorescence. Though branching was much more pronounced in plants at 15/10�C before flowering than in other treatments, vegetative development exceeded reproductive investment and harvest index was low under these conditions. It was suggested that there appears to be a need to develop and evaluate unbranched or less-branched lupin genotypes.


1980 ◽  
Vol 94 (1) ◽  
pp. 137-144 ◽  
Author(s):  
G. S. Chaturvedi ◽  
P. K. Aggarwal ◽  
S. K. Sinha

SummaryCowpea is an important food legume crop of arid and semi-arid regions of the tropics. In such climates whether a determinate or indeterminate type of growth habit would be more useful is not clear. In the present study a determinate and indeterminate cultivar of cowpea were grown at two population densities under rainfed conditions for 2 years. Grain yield was higher in the indeterminate variety for both years. At higher density more dry matter was produced but it had no effect on grain yield. Nitrogen analysis showed that it moved from leaves to developing pods. However, a large amount of nitrogen was still left in vegetative parts in contrast to cereals. Pod development was completed in 19 days and the rate of dry-matter accumulation during the peak period of growth was as high as 120 mg/day per fruit. It was difficult for the plant to cope with this high demand for photosynthates. It is suggested that more pods can develop on a plant provided the growth rate of individual pods is slower and extended to a longer period.


1985 ◽  
Vol 77 (5) ◽  
pp. 675-679 ◽  
Author(s):  
J. S. Beaver ◽  
R. L. Cooper ◽  
R. J Martin

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