Sushil Kumar

An Assessment of Cytotoxic Potentiality of Plantago ovata Husk Aqueous Suspension on the Root Meristem Cells of Vicia faba L.

The seeds and husk of Plantago ovata of Plantaginaceae are used in traditional and modern systems of medicine. The aim of this study was to evaluate the cytotoxic potentialities of aqueous suspension of Planago ovata husk on Vicia faba root tip meristem cells using a cytogenetic approach. Treatments with various concentrations of Plantago ovata husk suspension to Vicia faba root meristem cells showed mito-inhibition and induced several chromosomal aberrations.

Adoption and impact assessment of weed management technologies in wheat and greengram under conservation agriculture system in central India

Rice-wheat is the major cropping system in the Indo-Gangetic plains and is also practiced on considerable area in Madhya Pradesh. Rice-wheat production system under conventional practices involves tedious and time-consuming methods of field preparation and weed management; increases cost of production, deteriorates soil fertility, and do not offer desired benefits for increasing the grain yields. In conventional agriculture, burning of crop leftover residue has become a major challenge that leads to loss of precious plant nutrients and deteriorates environmental quality. In order to mitigate these problems, technically-feasible, economically-viable and ecologically-permissible technologies need to be essentially adopted. A technology is required to facilitate timely sowing in standing stubbles, minimize weed infestation, lower cost of production, improve fertilizer/water-use efficiency and improve soil health. To reap the benefits of conservation agriculture (CA), studies were conducted at farmers ’fields in rice-wheat-greengram cropping system in black-cotton soils in Madhya Pradesh for consecutive five years. Sowing was done with Happy Seeder. Emergence of weeds from upper soil surface was effectively controlled by herbicides. Results showed that the benefits of CA can well be harnessed in black-cotton soils with rice-wheat-greengram cropping system. Retention of crop residues on soil surface provided an effective mulch cover for nutrient and moisture conservation, temperature moderation and weed control.

Tillage practices effects on winter crops weeds density and growth under rice based cropping system

Rice-based cropping systems are most predominant in India. Out of 139.9 million hectare (Mha) net cropped area, about 53% is rainfed and it produces almost 45% of food grains, 75-85% of pulses and oilseeds and significant amount of important industrial crops. Weeds are considered as one of the major limiting factors for efficient crop production in rainfed areas. Changes in tillage practices can cause shifts in weed species and densities. However, very little attention was given to understand effect of tillage practices on weed populations, as such information could be used to reduce populations of troublesome weed species (Peachey et al. 2006). So far much emphasis has been given on studying crop yields, weed emergence pattern and seed bank dynamics comparing zero tillage (ZT) and other conservation tillage practices with conventional tillage (CT) in rice based cropping systems across the world. However, meager efforts have been made on managing weed problem and improving yields by imposing diverse crops and designed tillage sequences within a cropping system. The present study was undertaken with the aim to understand effects of tillage practices on weed population in winter (Rabi) crops under rainfed rice based cropping system of Chhattisgarh.

Herbicides effect on fish mortality and water quality in relation to chemical control of alligator weed

Effect of three herbicides namely 2,4-D, metsulfuron-methyl and glyphosate was evaluated on fish mortality and water quality in relation to control of aquatic form of alligator weed (Alternanthera philoxeroides; Family, Amaranthaceae). All herbicides caused fish mortality and affected water quality after application, but it was highest in 2,4-D treated tanks followed by glyphosate and metsulfuronmethyl. Herbicide did not cause fish mortality at 1 DAA (days after application) but it caused at 7 DAA and increased corresponding to increase in concentration and days. Fish mortality was recorded lowest in herbicides treated tanks that were having only water but no weeds. Significantly higher fish mortality occurred in 2,4-D treated tanks having weeds. This reflected that fish mortality was more due to decaying of weeds, which decreased dissolved oxygen drastically in the water tanks. Herbicides did not affect fish development because growth and weight of fish was highest in water tanks treated with herbicides having no weeds. All the herbicides significantly decreased pH in treated tanks than control at 0 and 1 DAA, however, it was resumed towards normalisation in due course. The decrease in pH was least in the tanks having weeds and treated with metsulfuron-methyl followed by glyphosate and 2,4-D. Further, decrease in pH was less in water tanks having no weeds than having weeds. All the herbicides significantly decreased the dissolved oxygen (DO) at 0 day in water tanks with and without weeds except metsulfuron-methyl in the tanks having no weeds. Decrease in DO was more prominent in 2,4-D treated tanks followed by glyphosate and metsulfuron-methyl. Dissolved oxygen was least affected in tanks having no weeds.

Chemical control of duck weed and its effect on water quality and residue

Aquatic plants are necessary in aquatic ecosystem for survival of various aquatic lives (fish, crustacean etc.) to satisfy their respiration need. Aquatic vegetation helps in reducing the pollution load of water bodies by absorbing several pollutants. But excessive growth of these plants may cause several problems also that are mainly related to hindering transportation, water supply, lowering in water quality, fishing, energy production besides proliferation of disease. Lemna minor L. commonly called duck weed refers to a group of lentil shaped, free floating plants of the family Lemnaceae, which forms green carpet on the water surface. Duckweed is commonly used for toxicity testing of pollutants in waste waters (Soukupova and Beklova 2010). Duckweed plants are fast growing and widely distributed. They are easy to culture and to test. Some reports suggest that duckweed plants are tolerant to environmental toxicity (Verma 2007). Lemna minor represents a high growth rate and have been used for removal of heavy metals from polluted water bodies (Maine et al. 2001, Cardwell et al. 2002). In spite of beneficial aspects, it creates severe problems in respiration by clogging gills of fishes during fish culture. Small stagnated water bodies are favorite habitats of L. minor. Control of this weed by conventional manual and mechanical methods is most laborious, uneconomical and not suited for large water bodies, whereas biological control method has many limitations like lack of suitable natural enemies, culturing of agents, host specificity etc. Hence the chemical method appears quite suitable and cost effective to control duckweed. Although, no label claim is acclaimed for control of Lemna minor in India, application of oxadiargyl 450 mg/liter of water was found effective for controlling L. minor without showing any sign of harm to non-target organisms (Mandal and Nag 2014). Present study was conducted to evaluate most commonly used herbicides to control L. minor in wataer bodies in relation to its residue persistence and water quality. Experiment was carried out at ICAR-Directorate of Weed Research, Jabalpur during summer season of 2009 in 0.63 m2 water tank. A 25 cm soil layer was maintained in the bottom of the water tank. FYM was added in the soil to increase soil fertility. Culture of Lemna minor was added in the tank. It was allowed to establish well for one month to form a mat over the water surface. The experiment was laid out in complete randomized design with three replications and consisted of 10 treatments, viz. paraquat 0.25, 0.50, 1.0 kg/ha, glyphosate 0.50, 1.0, 1.5 kg/ha and metsufuron-methyl (MSM) 0,008, 0.012, 0.016 kg/ ha with unsprayed control. Spraying of herbicides was done on mat of L. minor with the help of knapsack sprayer fitted with flat fat nozzle using water 500 L/ha. Water samples were taken from treated and untreated water tanks before treatment and at 0, 1, 15 and 30 and 60 days after application. Water samples were filtered prior to extraction.