RELATIVE TOXICITY OF SOME CHEMICAL PESTICIDES AGAINST JUTE HAIRY CATERPILLAR (SPILOSOMA OBLIQUA W.) IN TOSSA JUTE (CORCHORUS OLITORIUS L.)

Pesticides have been a major contributor to the growth of agricultural productivity and food supply. Pesticides were a key factor in significant agricultural productivity growth during the last century and continue to be a critical factor in reducing crop damage. Fifteen insecticides were investigated to select their effective and economic doses against Hairy caterpillar in a Tossa Jute variety during April-October’ 2020 at the Department of Entomology, Manikganj and Narayanganj, Bangladesh Jute Research Institute (BJRI), Bangladesh following Randomized Completely Block Design with three replications. All new insecticides with a standard were found effective for controlling jute hairy caterpillar giving 95.38, 94.55, 95.19, 92.85, 93.59, 94.22, 93.49, 93.62, 89.84, 95.72, 93.56, 93.38, 94.42, 95.39, 91.34 and 95.41 % at Manikganj; 95.78, 93.32, 93.97, 93.18, 92.09, 92.49, 93.74, 92.93, 92.29, 93.69, 93.95, 93.17, 95.31, 94.99, 92.11 and 94.53 % reduction of infestation at Narayanganj at 5th day after spray over control plot respectively. In Manikganj, the highest fibre yield (3.66 t/ha) was found in the plot treated with Rock 20 EC and the lowest (2.96t/ha) was found in Reset 20WDG treated plot. In case of Narayanganj, the highest fibre yield (3.85 t/ha) was found in the plot treated with Proxy 20 EC and the lowest (2.79t/ha) was found in Daman treated plot. These insecticides can be recommended for the farmer’s use to control jute hairy caterpillar.

Combining Ability and Gene Action for Yield Improvement in Kenaf (Hibiscus Cannabinus L.) Under Tropical Conditions Through Diallel Mating Design

Nine morphologically distinct kenaf genotypes were hybridized to produce 36 hybrids following a half diallel mating design. The combining ability and gene action of 15 yield and yield components were assessed in hybrids and their parents across two environments. Except for the mid diameter and plant height traits, there were highly significant differences (p ≤ 0.01) between both the analysis of variance of environments and the interaction of genotype and environment. For the inheritance of these traits, additive gene effects were considerable, and the expression of these additive genes was heavily influenced by the environment. Significant differences were found for all studied traits for GCA except top diameter, and SCA except plant height and top diameter, implying the presence of both additive and non-additive gene action for the inheritance of the concerned characters. For all features except top diameter and number of nodes, the magnitude of GCA variation was significantly higher than that of SCA variance, indicating the additive gene's predominance. The parental lines P1, P3 and P4 were determined to be outstanding general combiners for fibre yield and yield-related parameters. Considering combining ability and genetic analysis study together, the crosses P1 × P4, P1 × P9, P2 × P3, P2 × P5, P4 × P6, P4 × P7, P4 × P9, P5 × P8, and P7 × P9 were found promising for their heterotic response to higher fibre yield, stick yield, seed yield and and could be useful by adopting proper strategies for future improvement in kenaf breeding programmes.

PLANT SPACING AND ITS EFFECT ON YIELD, FIBRE QUALITY AND PHYSIOLOGICAL PARAMETERS IN COTTON

The purpose of this study was to see how changing plant spacings affected cotton yield, yield components, fibre quality traits, and physiological parameters. In this study, six plant spacings (no thinning, 5, 10, 15, 20, and 25 cm) were investigated. Plant density caused significant differences in the number of first fruiting branches, number of bolls, ginning percentage, seed cotton yield, fibre yield, and normalised difference vegetative index (NDVI). Plant height, the number of sympodial branches, number of monopodial branches, boll weight, seed cotton weight/boll, number of 100-seed weight, seeds/boll, canopy temperature, chlorophyll content, leaf area, and fibre quality properties (micronaire, length, strength, elongation, uniformity, short fibre index, reflectance, yellowness, and spinning consistency index [SCI] were non-significant. The highest values of seed cotton yield, fibre yield, ginning percentage, number of first fruiting branches, and NDVI were obtained in the no thinning and 5 cm plant spacing applications, while the highest boll number was obtained at 20 and 25 cm plant spacings. In this study, physiological parameters, such as canopy temperature, leaf area, chlorophyll content, and fibre technological traits, were not affected by plant spacing. The highest seed cotton yield, fibre yield, ginning percentage and NDVI were obtained from no thinning and 5 cm intra-row spacing, indicating their impact on examined characteristics. Therefore, a yield estimation can be made in the flowering period with the NDVI in different plant densities in cotton.

Diversity Assessment of Indian Sunnhemp (Crotalaria juncea L.) Accessions for Enhanced Biomass and Fibre Yield using Geographic Information System Approach

Background: Sunnhemp, a rapid growing, high biomass yielding bast fibre crop has a tremendous potentiality in biofuels sector as a lignocellulosic substrate. In order to capitalize the new found area there is a need to identify high biomass and fibre yielding sunnhemp genotypes. The present study provides details of morphological diversity and geographical distribution pattern of Indian sunnhemp accessions. Methods: A total of 42 germplasm accessions collected from ten different states were evaluated for fibre yield and attributing traits in April-June cropping season. Based on phenotypic data agglomerative hierarchical cluster analysis was performed. Geographical coordinates of germplasm collection site were utilized to derive the spatial genetic diversity pattern for green biomass yield and fibre yield.Result: Phenotypic evaluation revealed significant genetic variability among the genotypes for biomass and fibre yield leading to identification of several promising accessions. Cluster analysis and PCA grouped the 42 sunnhemp accessions into three clusters. Cluster II and III are highly divergent harboring contrasting phenotypes. DIVA-GIS approach identified eastern Rajasthan, western Jharkhand and border area between Bihar and Jharkhand as sites of highest sunnhemp diversity.

Rank correlation of seed and Fibre Yield Characters in Jute (Corchorus olitorius)

The present study aimed to explore the Rank correlation of seed and fibre yield characters in Jute (Corchorus olitorius). Jute cultivation availability of quality seed remains a potential factor as it deals with the fibre. Studying the correlation between both seed and fibre characters at the same time in jute is a complex matter since the sowing season, agricultural practices vary in both the cases. Varieties producing high fibre and seed yield are necessary to meet the deficit in seed supply for the jute producing farmers of West Bengal, India. In this study, the experimental material consisted of thirty six jute (Corchorus olitorius L) crosses along with two check varieties. Fibres were harvested at 120 days and the seeds at maturity. The variability in most of the yield (fibre and seed) contributing characters was mainly due to genotype with some extent of environmental influence. To obtain a clear understanding of the inter-relationship between seed and fibre characters a rank correlation was performed instead of simple correlation. A strong positive correlation was found which helped us in finding lines with both high seed and fibre yield. Furthermore, a fibre quality test was also conducted for estimating the fineness and strength of the fibre.

Heterosis and Combining Ability for Yield and Yield Attributing Traits in Tossa Jute (Corchorus olitorius L.)

Jute is one of the important bast fibre crop in the World next to cotton. Yield potential of this fibre crop is still under exploited and this natural fibre is facing challenges from synthetic products which calls for immediate attention to restore breeding works in a comprehensive manner. The present research has been contemplated with ten hybrids evolved from five lines of Tossa jute following half diallel matting design to ascertain gene action, combining ability and heterotic potential of the hybrids in respect of fibre yield and yield attributing traits. Methods comprised of growing of parents as well as F1s along with standard check in randomized complete block design (RCBD) maintaining three replications followed by recording observation on fibre yield and other yield attributing traits. Results revealed that most of the studied traits were governed by non-additive gene action which justified exploitation of heterosis utilizing these traits in this crop. The specific combining ability (SCA) components of variance (σ2 SCA) were larger than the general combining ability (GCA) components of variance (σ2 GCA) for all of the five traits under study which further implied the preponderance of non-additive components of variance towards the expression of these traits. JRO 524 was detected as the best general combiner considering the economically important trait. Finally, considering dry fibre and stick yield, three hybrids, namely OIN 24 × JRO 524, OIN 39 × OIN 46 and OIN 39 × JRO 524 has been identified to be superior over their better parent as well as standard check regarding these traits. Additionally, all these three hybrids exhibited positive and significant SCA effects. These three promising specific combiners can be advanced to get better Tossa jute lines for bolstering economic returns of the farming community in future.