<div>Background: Globally, grain legumes are the paramount family of agricultural crops following cereals. Generally, sequence cropping has manifested effectual in increasing farm productivity and profitability. However, sometimes herbicides administered in previous crop may be associated with phytotoxic effects that can later cause damage to the succeeding crops. The present study aimed to understand the residual effect of extreme levels of atrazine on succeeding cowpea under maize-cowpea cropping system. 
 
Methods: Field experiments were conducted during Kharif and rabi season of 2019-20 and 2020-21 in a randomized block design with eleven treatments, replicated thrice. 
 
Result: Residual effect of pre-emergence atrazine at 0.50 kg a.i. ha-1 followed by tembotrione at 120g a.i. ha-1 as post-emergence at 25 DAS recorded the lowest total weed density (4.41), total weed dry weight (9.81 g m-2) and highest weed control efficiency (39.25%) during rabi 2019-20 while during rabi 2020-21 lowest total weed density (5.03), total weed dry weight (10.68 g m-2) and highest weed control efficiency (39.65%) were noticed in pre-emergence atrazine 50% WP at 2.00 kg a.i. ha-1. Highest seed yield (788.67 and 842.33 kg ha-1) was obtained in weed free treatment.</div>

Response of Cowpea [Vigna unguiculata (L.) Walp.] as Succeeding Crop to Residual Effect of Extreme Levels of Atrazine Administered in Preceding Maize (Zea mays L.)

<div style="text-align:justify">Background: Weeds are one of major threats to crop yield and quality. Weeds compete with cane crop and reduce the yield significantly in a very short period. Planned use of all available farm resources leads to integrated control strategy. The current study aimed to study the use of inter row rotary weeder for integrated weeds management to control population dynamics of weeds in sugarcane crop. The objective of experiment is to find out economical, feasible and easy to use approach to minimize the weed density below the threshold level in sugarcane crop and to minimize the use of chemicals for weeds control to promote organic farming. Methods: In this research experiment, at Sugarcane Research Institute, Faisalabad during 2017 and 2018, the treatment includes viz. Application od Click (atrazine and acetochlor) @ 3.75 Liter per hectare as Pre-emergence, Ametryn + Atrazine 80 W.P @ 2.50 kg per hectare as post-emergence, Machanical Inter-culture with Rotary weeder and cultivator plough and earthing up. These treatments in different combinations were compared with control. Result: The application of Pre-emergence weedicide Click (atrazine and acetochlor) @ 3.75 Liter per hectare + Inter culture with Rotary weeder 50 days after planting (DAP) + Inter culture with cultivator plough before earthing up (100 DAP) produced significantly higher cane yield of 105 t. ha-1 and highest net benefits per hectare of Rs. 156250/-. The lowest cane yield of 70 t. ha-1 was noted from the experimental units with Weedy check / control. If farmers use this approach, the use of post emergence weedicides will be minimized and will encourage organic farming with safe and healthy environment.</div>

<div style="text-align: justify;">Valuation of Weed Control Methods by using Inter Row Rotary Weeder in Sugarcane Crop</div>

<div style="text-align: justify;">A field experiment was conducted to study the effect of pre-emergence, post emergence and combination of atrazine with post emergence herbicides on soil enzyme urease activity(expressed as &micro;g of NH4+ released g-1 soil h-1) at College Farm, College of Agriculture ,Professor Jayashankar Telangana State Agricultural University (PJTSAU), Rajendranagar, Hyderabad, India during kharif 2014. The experiment was laid out in randomized block design (RBD) using six herbicide treatments un weeded control and hand weeding at 20 and 40 DAS with three replications. Maize was sown as test crop(variety &ndash;DHM-117).The soil samples were collected at 15 days intervals ie: 0, 15,30,45, 60, 75 and 90 days, to assay the enzyme activity. The pre-emergence herbicides were sprayed at zero days after sowing where post- emergence herbicides were sprayed after 15 days after sowing. The enzyme activity in the control increased from 0 days to 60 days and then decreased but the activity in the pre- emergence herbicide pendimethalin showed the same phase as that of control and showed higher activity over the control at each stage where as atrazine showed decrease in activity at 0 days (8.71) and latter it revoked the activity and reached maximum at 60 days (12.35). When compare to pendimethalin the activity was less at each and every stage. In case of post &ndash; emergence herbicides the activity showed mixed responses to at different stages Tembotrione showed higher activity when compare to Topramezone. In combination of Tembotrione and Topramezone with atrazine showed mixed responses.</div>

<div style="text-align: justify;">Effect of herbicides on the activity of soil enzymes urease in maize crop</div>

Background: Maize, being highly productive and versatile cereal crop, is influenced by various biotic and abiotic stresses. Among biotic stresses, weed infestation is one of the serious concerns in maize cultivation. Weeds can affect maize by competing for light, water and nutrients resulting in yield loss of up to 70% in severe cases.&nbsp; 
 
Methods: A field experiment was conducted during kharif season for two consecutive years of 2019 and 2020 in agriculture farm of Palli Siksha Bhavana (Institute of Agriculture), Visva-Bharati, Sriniketan, West Bengal, India.&nbsp; The experiment was laid out in randomized block design and replicated thrice. The experiment comprised of seven weed management treatments viz. T1 (tembotrione 9% + atrazine 45% WG @ 1000 g/ha), T2 (tembotrione 9% + atrazine 45% WG @ 1250 g/ha), T3 (tembotrione 9% + atrazine 45% WG @ 1500 g/ha), T4 (Tembotrione 34.4% SC @ 286 ml/ha), T5 (Atrazine 50% WP), T6 (Hand weeding), T7 (Weedy check).&nbsp; 
 
Result: Experimental results revealed that among different herbicide mixtures, tembotrione + atrazine 1500 g/ha was found to be effective in suppressing the weeds growth and found no residual effect on soil chemical and biological properties during both the years of the experiment.

Effect of Ready Mix Application of Herbicide on Weed Dynamics and Productivity of Maize in Lateritic Belt of West Bengal

<div>Background: Maize (Zea mays L.) is the most versatile and emerging food crop of global importance. Weeds are ubiquitous but their presence in wide spaced and initially slow growing crop like maize acts as an obstacle for plentiful harvest. Nutrient uptake by weeds during the first thirty days of maize growth was 59 kg N, 10 kg P2O5 and 59 kg K2O per ha, which was 7-10 times higher than the nutrient uptake by maize. 
 
Methods: The present field experiment was conducted during Rabi, 2018-19 under irrigated conditions at wetland farm of S.V. Agricultural College, Tirupati andhra Pradesh, with ten treatments and three replications in a randomized block design. 
 
Result: Lower density and dry weight of weeds with higher weed control efficiency, lower nutrient uptake by weeds and higher nutrient up take by maize at 80 DAS, kernel and stover yield was recorded with hand weeding twice at 15 and 30 DAS, which was statistically at par with atrazine 1.0 kg ha-1 as PE fb topramezone 30 g ha-1 or tembotrione 120 g ha-1 as PoE or atrazine 1.0 kg ha-1 as PE fb HW at 30 DAS, while these were lowest with weedy check. Higher benefit cost ratio of maize was noticed with both atrazine 1.0 kg ha-1 as PE fb topramezone 30 g ha-1 as PoE (T3), which was in parity with atrazine 1.0 kg ha-1 as PE fb tembotrione 120 g ha-1 as PoE (T2) and hand weeding twice at 15 and 30 DAS (T9). From the present study it may be concluded that atrazine 1.0 kg ha-1 as PE fb topramezone 30 g ha-1 or tembotrione 120 g ha-1 as PoE were considered to be the most effective and economic weed management practices to increase the productivity of Rabi maize at times of labour scarcity.</div>

<div>Weed Dynamics and Nutrient Uptake of Maize as Influenced by Different Weed Management Practices</div>

Background: Pesticides have been used extensively in agriculture to control pests, plants, weeds, insects and other species that can harm crop plants. Pesticides are wide words for substances that are used to eradicate undesired organisms from crops in order to preserve or increase crop yield. Herbicide application requires technical ability in the selection of a specific herbicide, the safe application dose and the application method. The current study aimed to study the effect of pre-emergence and post-emergence herbicides on the growth and soil attributes of maize. 
&nbsp; 
Methods: The experimental site was East which falls under the central plain zone of agro-climatic zones of Punjab. It comprised 10 treatments of different herbicide combinations. The experiment was laid out in a randomized block design with three replications. Maize variety PMH-13 was used as a test crop and sown in July 2022 at a row spacing of 60 x 20 cm. Results revealed that (T8) Atrazine @ 0.50 kg ai/ha + pendimethalin @ 1 kg ai/ha (Tank mix) (PE) fb HW at 20 DAS was the most superior herbicide treatment in increasing plant height, number of leaves, crop dry matter accumulation, stem girth, chlorophyll content, cob length, cob girth, with soil attributes. 
&nbsp; 
Result: The highest grain yield (59.0 q/ha) and stover (117.06 q/ha) of maize were also recorded under Atrazine @ 0.50 kg ai/ha + pendimethalin @ 1 kg ai/ha (Tank mix) (PE) fb hand weeding at 20 DAS. Atrazine pre-emergence application at a dosage of 1 kg ai/ha resulted in faster growth and lower weed density at 20 DAS. T8, which is atrazine @ 0.50 kg ai/ha + pendimethalin @ 1 kg ai/ha (Tank mix) (PE) fb HW at 20 DAS, is suggested for increased grain yield in the Trans Gangatic region based on performance. 
&nbsp; 
&nbsp;

Evaluating the Effects of Herbicide on Growth, Yield and Soil Attributes of Maize Crop in the Trans-Gangetic Region

Background: Cereal-legume cropping system is considered to be one of the better alternatives for sustaining soil fertility and increasing the yield. At present maize-groundnut cropping system is gaining importance under both rainfed and irrigated situations. Maize, being an exhaustive and weed-sensitive crop, is supplied with large doses of fertilizers and new herbicide molecules.Since maize is exhaustive and weed sensitive crop, there was a usage of excessive fertilizers and new herbicides. There is a need to assess the carry over effect of fertilizers and new generation herbicides in leguminous crops like groundnut. 
 
Methods: The experiment was conducted during two consecutive rabi seasons of 2019-20 and 2020-21 on sandy loam soils of S.V. Agricultural College, Tirupati, Andhra Pradesh. Maize hybrid DHM -117 was sown and maintained with general cultivation practices except for nitrogen and weed management methods was raised after harvest of maize in undisturbed layout to study the residual effect of different nitrogen and weed management practices imposed in maize. 
 
Result: Residual effect of nitrogen and weed management practices imposed in preceding maize did not exert any significant influence on germination percentage, phytotoxicity and SPAD chlorophyll meter reading (SCMR) values but efficacy of herbicide residue found to be significant with weed management practices. Growth parameters, yield attributes pod yield, haulm yield and economics were higher in groundnut with brown manuring, which was however, in parity with hand weeding twice at 15 and 30 DAS, pre emergence application of atrazine 1.0 kg ha-1 fb post emergence application of topramezone 30 g ha-1 and pre emergence application of atrazine 1.0 kg ha-1 fb post emergence application of tembotrione 120 g ha-1 and lower with unweeded check and it was remained in parity with application of parthenium water extract15 lha-1 twice at 15 and 30 DAS, application of sunflower water extract 15 lha-1 twice at 15 and 30 DAS, pre emergence application of atrazine 1.0 kg ha-1 fb post emergence application of parthenium water extract 15 lha-1 and pre emergence application of atrazine 1.0 kg ha-1 fb post emergence application of sunflower water extract 15 lha-1 in the order of ascent.&nbsp; None of their interaction effects were found to be significant during both the years of study and in pooled mean.

Residual Effect of Nitrogen and Weed Management Practices in Maize on Succeeding Groundnut

<div>Background: Maize followed by summer pulses is the emerging cropping system in many places in India. Herbicides are the efficient tools for checking weed infestation and their usage is increasing throughout the globe due to increased labour cost and quick weed control. Some herbicides do not degrade quickly and may remain in the soil for weeks, months or years after application and may inhibit the growth of succeeding crops.&nbsp; 
 
Methods: Field experiment was conducted in a randomized block design (RBD) during rabi and summer seasons of 2017-18 and 2018-19 to know the residual effect of different herbicides applied in maize on succeeding greengram.&nbsp; 
 
Result: The present study revealed that lower density and dry weight of total weeds and higher yield attributes and yield was recorded with the practice of adopting two hand weedings at 15 and 30 DAS, which was however, at par with atrazine 1.0 kg ha-1 as PE fb one HW at 30 DAS, atrazine 1.0 kg ha-1 as PE fb topramezone 30 g ha-1 as PoE and atrazine 1.0 kg ha-1 as PE fb tembotrione 120 g ha-1 as PoE, without any significant disparity among them. Herbicides applied in maize did not alter statistically the enzyme activity and microbial count in the soil at harvest of succeeding greeengram.&nbsp;</div>

<div>Residual Effect of Weed Management Practices Executed in Preceding Maize on Succeeding Greengram</div>

<div>Background: Weeds are the most critical pest, which cause the highest yield reduction in food grain crops. Weeds interfere with maize growth by competing one or more growth limiting factors, controlling of weeds in maize during the critical period assumes great importance for realizing higher yield. Unavailability of relatively cheap labour in time necessitated the use of herbicides in maize. Residual impact of herbicides caused significant influence on germination and growth of succeeding crop. 
 
Methods: The field experiment was carried out during kharif 2019 at Agricultural College and Research Institute, Madurai to evaluate the residual effect of herbicides used in preceding maize on succeeding blackgram. Treatments were application of pre emergence herbicide atrazine at 0.25 kg ha-1 or pendimethalin 1 kg ha-1 applied singly on 3 days after sowing and in combination with post emergence herbicide tembotrione 120 g ha-1 or halosulfuron methyl 90 g ha-1 on 25 DAS, weed free check, unweeded check in maize crop. 
 
Result: Among the weed control treatments, pre emergence herbicides atrazine 0.25 kg ha-1 or pendimethalin 1 kg ha-1 singly and in combination with post emergence herbicides tembotrione 120 g ha-1 or halosulfuron methyl 90 g ha-1 applied in maize crop did not caused any phyotoxicity and residual impact on succeeding blackgram. However, the highest plant height (29.5 cm), dry matter production (1.17 g plant-1) and seedling vigour index (1473) of succeeding blackgram was recorded in atrazine at 0.25 kg ha-1 as pre emergence at 3 DAS followed by tembotrione at 120 g ha-1 as post emergence at 25 DAS.</div>

​​Preceding Maize Crop Herbicide Residual Effect on Germination, Growth and Vigour of Succeeding Blackgram

<div>Background: Maize popularly known as &ldquo;Queen of cereals&rdquo;. Weeds resulted in the highest crop loss (33%), followed by pathogens (26%), insects (20%), storage pests (7%), rodents (6%) and others (8%) in India. Application of herbicides will affect various soil microbial processes and enzymatic activities in the soil, whose activity is very important for maintaining the soil fertility. 
 
Methods: The present field experiment was conducted during Rabi, 2017-18 and 2018-19 under irrigated conditions at wetland farm of S.V. Agricultural College, Tirupati Andhra Pradesh, with ten treatments and three replications in a randomized block design.&nbsp; 
 
Result: Higher kernel and stover yield of maize was recorded with hand weeding twice at 15 and 30 DAS and the yield loss was comparatively lower with atrazine 1.0 kg ha-1as PE fb topramezone 30 g ha-1or tembotrione 120 g ha-1 as PoE or atrazine 1.0 kg ha-1as PE fb HW at 30 DAS, while these were lowest with weedy check. Soil microbial count and enzyme activity was statistically comparable in all the pre followed by post emergence herbicide treatments.&nbsp;</div>