<div>Effect of detopping and mepiquat chloride on morphological, physiological and yield attributes of soybean cultivar &lsquo;SL 544&rsquo; 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. &nbsp; &nbsp;&nbsp;</div>


<div>Source-sink optimization and morpho-physiological response of soybean [<em>Glycine max</em>] to detopping and mepiquat chloride application</div>


<div>The scope of increasing the cultivated area under forages is rather limited, because of mounting pressure on need for food and commercial crops, but there is a large demand for green and dry fodder from livestock industry. Hence, fodder production has to be increased per unit area per unit time. By practicing the de-topping in commercial grain maize we can increase the fodder production, quality and it also reduces the deficit of fodder to some extent. Reviews indicated that by de-topping of maize, there may be slight reduction in grain yield of maize but by doing it at right stage/time and at right plant height it gives highest net returns than no de-topped treatments. De-topping at 30 days after silking; removing the top 6 leaves or after physiological maturity; removing all the leaves above the cob or de-topping above 10th internode gives highest fodder yield and net returns with slight or no reduction in grain yield.&nbsp;</div>


Source-sink optimization and morpho-physiological response of soybean [Glycine max] to detopping and mepiquat chloride application

Detopping in Maize: A Review