Status of Dhaincha incorporated soil after rice harvest in (Boro) rice–Dhaincha–rice (T. Aman) cropping pattern

An experiment was conducted at Field Laboratory of the Department of Crop Botany, Bangladesh Agricultural University, Mymensingh, to find out the effect of dhaincha incorporation on subsequent rice crop yield and postharvest soil nutrient status. The experiment was laid out in a randomized complete block design having three replications. Nine dhaincha accessions were used as experimental materials along with a control (without dhaincha plant). Seeds of dhaincha accessions were sown in experimental plot @ 60 kg ha-1. Sixty days old dhaincha plants were mixed up with soil. Soil samples were collected twice, before sowing of dhaincha seeds and after rice crop harvest. Forty five days old healthy rice seedlings were transplanted in the well prepared dhaincha incorporated plots at the spacing of 15 cm x 25 cm (plant-plant x row-row). The pH and nutrient status were improved in dhaincha incorporated soil over the control. The highest grain yield (5.81 t ha-1) was obtained from dhaincha Acc. 33 incorporated plot followed by Acc. 25 (5.73 t ha-1) and the lowest in control (4.35 t ha-1). Due to the incorporation of dhaincha biomass in soil, the rice grain yield increased 7.82% to 33.56% over the control. Among the dhaincha accessions, number 33 showed the best performance in terms of influencing grain yield. A precise conclusion to be built up through collection of large number of germplasms from Bangladesh is needed

Screening of Sesbania accessions based on seed germination and seedling biomass

Seedling emergence and germination percentage of seeds play a vital role for optimum plant population and biomass yield maximization of a crop in the field. An experiment was carried out at Plant Systematics Laboratory of the Department of Crop Botany, Bangladesh Agricultural University, Mymensingh, during the month of April to May 2016 for the screening of Sesbania accessions based on seed germination, vigour index and initial biomass yield. The experiment was laid out in a completely randomized design with four replications. One hundred and ten Sesbania accessions were used as experimental materials. Four hundred healthy seeds, 100 seeds as one replication, of each accession were spread uniformly on containers for the germination test. Cumulative germination percentage of seeds was counted daily up to 10 days. After 10 days, 40 seedlings (10 from each replication) were taken from each accession and measured. Quantitative descriptors viz. emergence (%) and germination (%) of seeds, vigour index, shoot length, root length, base diameter and biomass yield, varied significantly. Based on quantitative descriptors, Agglomerative Hierarchical Clustering (AHC) and Principal Component analyses (PCA) were conducted. In PCA, the first three principal components explained 82.64% of the total variations. In AHC, three individual clusters were developed and six accessions always remained in the same cluster. These six accessions could belong to same species. Based on their seed germination and initial seedling growth, five accessions performed better and selected for further study. Field trials of these accessions are needed to recommend one or more accessions as cultivar(s)