203 Content list available at http://epubs.icar.org.in, http://www.icarneh.ernet.in; ISSN: 0970-6429 Indian Journal of Hill Farming Special Issue 2023, Volume 36, Pages 203-209 Response of summer blackgram (Vigna mungo L. Hepper) to planting geometry and weed management under Nagaland condition A. Thongni ∙ L. Tzudir* ∙ S. Kumari Department of Agronomy, SASRD, Nagaland University, Medziphema-797106, Nagaland, India ARTICLE INFO ABSTRACT Article history: Received: 31 January, 2023 Revision: 10 April, 2023 Accepted: 14 July, 2023 -------------------------------------- Key words: blackgram, growth attributes, planting geometry, spacing, weed management -------------------------------------- DOI: 10.56678/iahf-spl36.2023.25 In the present study, an attempt has been made to investigate the effect of planting distance and weed management practices on weed flora, growth and yield of summer black gram under mid hill conditions of Nagaland. Three planting distance i.e. 20 x 10 cm 2 (S 1 ), 30 x 10 cm 2 (S 2 ) and 40 x 10 cm 2 (S 3 ) and four weed management practices viz., Weedy check (W 1 ), Two hand weedings at 20 DAS and 40 DAS (W 2 ), Pendimethalin @ 1 kg a.i ha -1 + Imazethapyr @ 100 g ha -1 at 30 DAS (W 3 ) and Pendimethalin @ 1 kg a.i ha -1 + one hand weeding at 30 DAS (W 4 ), were evaluated and compared. Planting distance 40 x 10 cm 2 recorded the highest growth attribute and found to be at par with 30 x 10 cm 2 . Plant height and CGR however recorded to be highest at 20 x 10 cm 2 . Weed management with Pendimethalin @ 1 kg a.i ha -1 + one hand weeding at 30 DAS recorded lowest weeds, weed dry weight, highest weed control efficiency, growth and yield attributes and this treatment was found to be at par with two hand weedings at 20 DAS and 40 DAS. Combination of 30 x 10 c m 2 and Pendimethalin @ 1 kg a.i ha -1 + one hand weeding at 30 DAS recorded highest B:C ratio (1.32) among all the treatments and found to be an economically achievable treatment for summer blackgram. 1. Introduction Black gram (Vigna mungo L. Hepper) is an important drought resistance pulse crop grown throughout the country in all three seasons. It is a self-pollinated annual crop of fabaceae family. The stem is covered with brown hairs and much branched from the base. The leaves are large, hairy and trifoliate. The inflorescence consists of a cluster of 5-6 flowers at the top of a peduncle. The pods are about 4-6 cm in length with 4-10 seeds inside which are generally black or very dark brown in colour. It is a nutrient rich crop with about 24% protein and has significant quantities of vitamin B 1 , B 2 and niacin (Tiwari and Shivhare, 2016). It is commonly used as dal and is also consumed in a variety of ways in preparation of different dishes and snacks like dosa, idli, vada, papad, halwa and imarti in combination with other food grains. Being leguminous, it demands less nitrogenous fertilizers and it fits well in different crop rotation systems to maintain the fertility level of the soil (Nazir, 1994). Blackgram is mainly distributed in the tropical to sub-tropical countries like India, Pakistan, Sri-Lanka, Burma and some countries of South East Asia. India is the world’s largest producer as well as consumer and accounts of 29.03 m ha with production of 23.40 Mt at 806 kg ha -1 yield level (Directorate of Economics and Statistics, Govt. of India, 2019). In the North Eastern Region of India, the average productivity of pulses is 848 kg ha -1 which is higher than the national average (764 kg ha -1 ) thus indicates the potential of pulse production in this region. In Nagaland, the area under blackgram is about 830 ha with a total production of 680 Mt. The largest portion of the crop is grown in Dimapur and it leads both in area and production of black gram in the state with about 170 ha and 140 Mt respectively. It is followed by Peren, Phek and Wokha districts. (Directorate of Economics and Statistics, Govt. of Nagaland, 2020). Planting distance contribute substantially to the seed yield of blackgram. Many researchers obtained different response in blackgram to planting distance (Singh et al., 1994; Nagaraju et al., 1995). It is necessary to maintain optimum plant population by maintaining proper inter and intra row spacing. Maximum or minimum plant density may reduce the yield of blackgram causing different changes in the physiology of the plant. Maintaining optimum plant population is an important aspect ___________________ *Corresponding author: lanunola@nagalanduniversity.ac.in