Agricultural Research Management Information System

Home
Research Summary
Search
About Us
- ARMIS
- Brochure
Contact Us
Report
User Request
Data Input
Help
- Operation Manual
  - PDF
  - Video
- Program Area & Commodity
We have reached 37600 number of research entries at this moment.

- Logout

Research Detail

Home
Research
Detail

Defoliation and Its Effect on Morphology, Biochemical Parameters, Yield and Yield Attributes of Soybean

M. R. ALI
Department of Crop Botany, Bangladesh Agricultural University, Mymensingh-2202, Bangladesh

M. ASHRAFUZZAMAN
Professor
Department of Crop Botany, Bangladesh Agricultural University, Mymensingh-2202, Bangladesh

M. A. MALEK
Chief Scientific Officer
Bangladesh Institute of Nuclear Agriculture, Mymensingh-2202, Bangladesh

M. M. A. MONDAL
Principal Scientific Officer
Bangladesh Institute of Nuclear Agriculture, Mymensingh-2202, Bangladesh

M. Y. RAFII
Professor
Institute of Tropical Agriculture, University Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia.

Abstract/ Executive Summary:

Experiment was conducted at the experimental field of Bangladesh Institute of Nuclear Agriculture, Mymensingh. Loss of foliage in soybean crop through leaf eating insects and diseases is common in tropical and sub-tropical countries where farmers do not protect their crops adequately. Experiment was performed under sub-tropical condition (24^o8' N, 90^o0' E) with four levels of defoliations (0, 25, 50 and 75% from base of the canopy). Defoliations were imposed at the visible bud initiation stage to investigate the growth and yield attributes in two popular soybean varieties during January to April 2011. Results revealed that degrees of defoliations simultaneously decreased leaf area and total dry matter (TDM) production irrespective of varieties. Defoliation not only reduced source sizes but also decreased total sink (pod) production resulting in lower seed yields. However, basal 25% defoliation did not decrease TDM, seed weight/plant and seed yield/ha significantly indicating the fact that the soybean plant, in general, can tolerate 25% basal leaf loss of the canopy. Exceeding this threshold limit (>25%) of the canopy defoliation reduced TDM and seed yield significantly. Implication of the results in relation to pest management was also discussed.

Keywords: Canopy structure, Dry matter production, Seed yield, Sink, Source, Soybean

Location: Experimental field of Bangladesh Institute of Nuclear Agriculture, Mymensingh

Start Date: 00-01-2011

End Date: 00-04-2011

Program Area: Crop-Soil-Water Management

Commodity: Soybean

Objectives:

To investigate the growth and yield attributes in two popular soybean varieties

Methodology:

Experimental Site and Conduction of Experiment: Experiment was conducted at the experimental field of Bangladesh Institute of Nuclear Agriculture, Mymensingh (24^o8´N, 90^o0´E), Bangladesh during January to April 2011. The soil of the experimental area was silty loam having a total of 0.06% nitrogen, 1.15% organic matter, 18.5 ppm available phosphorus, 0.28% meq exchangeable potassium, 18 ppm sulphur and 6.8 pH. Two popular soybean varieties viz., BARISoybean-5 and BARISoybean-6 were used for investigation. The experiment was laid out in a randomized complete block design with four replicates. Urea, TSP, MP and gypsum were used as a source of nitrogen, phosphorus, potassium and sulphur at the rate of 40, 120, 80 and 30 kg/ha, respectively, at the time of final land preparation. Unit plot size was 5 × 4 m. Distance between two blocks and two plots was 1.0 and 0.5 m, respectively. Seeds were sown on 12 January 2011. Row to row distance was 35 cm and plant to plant distance was maintained 9-11 cm in rows. After germination, the plants were thinned to a density of 26-30 plants/m². Intercultural operations were done as and when necessary for proper growth and development of the plants. First weeding was done followed by thinning at about 21 days after sowing (DAS). A single irrigation was given at 25 DAS. Insecticide (Ripcord 50 EC @ 0.025%) was sprayed at flowering and fruiting stages (55 and 65 DAS) to control shoot and fruit borer. Data Recording: The four levels of defoliation treatments employed at the beginning of opening of flowering stage (50 days after sowing) were : (i) control (no leaf removal), (ii) 25% leaves removed from bottom (basal 25%), (iii) similarly bottom 50% and (iv) bottom 75%. Total leaf area (LA)/plant from 10 randomly selected plants of each plot was determined by measuring leaf area at individual node in the main stem using automatic leaf area meter (Model : LI 3000, USA). At harvest, seed yield and yield components and dry matter production and its partitioning into plant parts were recorded. The TDM/plant was estimated by summing dry matter of root, stem, leaves and pods dry weight per plant. Harvest index was determined.Statistical Analysis: Data were analyzed statistically as per the design used following the analysis of variance (ANOVA) technique and the mean differences were adjusted with DMRT at 5% level of significance using the statistical computer package programme, MSTAT-C.

Source of Information: Res. on Crops 14 (2) : 500-506, (2013)

Article Link (Online Journal):

Funding Source:

1. Government

Budget:

Total Budget (Tk.) :

Achievement/Findings:

Loss of leaves through insect attack, disease and other environmental hazards reduces assimilatory surface. Such leaf loss at bud initiation stage up to 25% may not affect seed yield in soybean as was investigated in the current experiment. Therefore, it may not be advisable to spray pesticide for controlling pests in soybean variety at one-fourth loss of leaf surface to make cost effective and to save environment from pollution.

Knowledge Management: Journal