197 Short Communication J. Hortl. Sci. Vol. 13(2) : 197-201, 2018 Seed yield and quality as affected by weed management practices in bitter gourd P. Anitha*, S. Nirmala Devi and P. Sainamole Kurian All India-Co-ordinated Vegetable Improvement Project, College of Horticulture, Kerala Agricultural University Vellanikkara, Thrissur - 680 656. *Email: anitha.p@kau.in ABSTRACT Effect of weed management practices on seed yield and quality of bitter gourd var. Preethi was studied during 2016-17. The results showed that highest seed yield (0.73t/ha) was recorded in the treatment Pendimethalin @0.75 a.i. /ha plus one hand weeding at 40 DAS followed by mulching using black polythene (0.65t/ha) which were on par. The lowest seed yield (0.18t/ha) was in weedy check. Weed control efficiency was highest (100%) in mulching with black polythene followed by application of pendimethalin +one hand weeding at 40DAS (97.97). Seed quality in terms of percentage germination (82.52) , vigour index I(1924.15) and Vigour index II ( 27.24) were significantly superior in mulching with black polythene and was on par with weed free check and application of Pendimenthalin + one hand weeding at 40 DAS. Highest seedling length (26.10cm) and seedling fresh weight (2.45g) were also recorded in the same treatment. However, there was no significant difference between treatments for seedling dry weight. Key Words: Bitter gourd, weed, seed quality, seed yield, germination, vigour index INTRODUCTION Seed quality plays an important role in the production of agronomic and horticultural crops. Characteristics such as trueness to variety, germination percentage, purity, vigour, a nd appearance a re impor ta nt to fa r mer s pla nting cr ops. A close understanding of weed management is essential for obtaining higher crop yields and preserving seeds quality. Weed management is the most important aspect while producing good quality seed and maximizing crop yields. Producing a competitive and high-yielding crop begins with the seed. It is important to begin with seed that will germinate and emerge uniformly and quickly, producing a vigorous seedling that can compete with emerging weeds (Duar y, 2014). Her bicides are chemicals that are normally used to combat weeds present in a crop and an ideal herbicide should be highly effective at the same time conserve seed quality. Rapid germination of seeds and emergence of seedlings is a n impor ta nt deter mina nt of successful cr op establishment (Hydecker et al., 1973). Seed quality is one of the key factors affecting successful farming. Poor quality seeds genera lly show decrease in germination and emergence of seedlings. Weed management in seed production is important to avoid weed competition and to get seeds of high quality and purity. Vegetable seed growers employ various weed ma na gement pr a ctices. T he effect of weed management practices on efficiency of weed control and purity and quality of produced seeds is a matter of concern to the seed growers. Therefore, the present study was undertaken to find out the effect of various weed management practices on the seed yield and seed quality in bitter gourd var. Preethi. The study was conducted with nine treatments and three replications in randomized complete block design in the year 2016-17. The plot size consisted of 4.5mx 3m. The experiment consisted of following treatments namely, T1 - Pre emergent application of Pendimethalin@0.75 a.i/ha T2 - T1+one hand weeding at 40DAS T3 - Stale seed bed by Glyphosate @1kg a.i./ha 15 days before sowing 198 Anitha et al J. Hortl. Sci. Vol. 13(2) : 197-201, 2018 T4 - T3+one hand weeding at 40DAS T5 - Mulching with black polythene T6 - Straw mulch T7 - Hand weeding at 20, 40, 60 DAS T8 - Weed free check T9 - Weedy check The bitter gourd var. Preethi was raised during 2016-17 as per the Kerala Agricultural University Package of Practices Recommendations, Cr ops (2011). Percentage weed control was estimated over the weedy check, by counting the number of weeds present in each plot. Ripe fruits were harvested for seed extraction, seeds extracted were dried to moisture content of 8.0% and per hectare yield was computed and seeds stored in plastic containers in the AC with a temperature of 22 ± 5 ºC. Stored seeds were kept for germination study after three months in a sterile sand medium and percentage germination was computed. Twenty days after germination, twenty seedlings were up rooted and average fresh weight, seedling length, were noted and kept for drying in an oven. After attaining constant weight, average seedling dry weight was measured. Seed quality parameters such as vigour index I and vigour index II were estimated as detailed by per Abdul- Baki and Anderson, 1972. The effect of weed management practices on seed yield and quality is presented in Table 1. Highest seed yield (0.73t/ha) was recorded in the treatment Pendimethalin @0.75 a.i./ha + one hand weeding at 40 DAS (T 2) followed by mulching using black polythene (0.65t/ha) (T5), straw mulch(T6) ( 0.56t/ha) and these were on par. The lowest seed yield (0.18t/ ha) was in weedy check (T9) followed by T3 (Stale seedbed by Glyphostae@1.0kga.i//ha 15 days before sowing (0.36t/ha). Application of Pendimethalin as pre- emergent @0.75kg a.i/ha alone (T1) for weed control, recorded seed yield on par (0.54t/ha) with weed free check (T8) (0.51t/ha). It was clear that application of herbicides alone for weed control (T1 and T3) resulted in reduction in seed yield in bitter gourd. Similar results are reported by Young and Yenish (2000) in wheat, Smith and Wilson (2002) in Phaseolus vulgaris, Khan, et al., (2006) in green gram. Weed control efficiency was 100% in mulching with black polythene (T5) followed by T2, (Pendimethalin +1 hand weeding at 40DAS) i.e. 97.97% which were on par. The remaining treatments differed significantly with respect to efficiency of weed control. The lowest weed control efficiency (54.53) was noted in weedy check (T9). Bowman et al., (1986) and Ismail et al., (2009), reported similar results. Va r iou s w eed ma na gement t r ea t ment s affected seed quality significantly. Mulching with black polythene (T5) was significantly superior with respect to percenta ge germination (82.52) a nd vigour index I (1924.15) and vigour index II (27.24) and this was on par with Pendimenthalin + one hand weeding at 40 DAS (T2). Highest seedling length (26.10cm) and seedling fresh weight (2.45g) were also recorded in the same treatment. Seed quality p a r a met er s s u c h a s p er c ent a ge g er mina t ion (58%,45.9%), seedling dry weight,(0.35g, 0.29g), vigour index I (1040.60, 1146.82) and vigour index II (20.06, 13.41) respectively were significantly low in T1 and T3 treatments where herbicide only wer e used for weed contr ol. I t s howed tha t application of herbicide alone considerably reduced the seed yield and other seed quality parameters in bitter gourd. Shalno and Zheljazkov (2011) also r epor t simila r r esults in cor ia nder, Sha w a nd Ratnayake (2017) in Cassia obtusifolia, where normal seedlings, seedling emergence and seedling length were consider ably reduced by herbicide a p plic a t ion. I t wa s a lso c lea r t ha t her b ic ide application along with one hand weeding at 40 DAS (T2 and T4) recorded seed quality characters such as germination % (74.7%, 74.12%) seedling length (24.85cm, 24.82cm), seedling fresh weight (2.14g, 2.19g) seedling dry weight (0.36g, 0.32g), vigour index I (1854.00, 1638.47) and vigour index II (26.61, 23.52) which are on par. However, T2 and T4 differed significantly with respect to seed yield and percentage weed control where T2 performed superior in these characters. Similar results were obtained by Drew. J.L and Robert, G. W (2005) where they found that pendimenthalin applied as pre-emergent herbicide provided acceptable weed control in the irrigated chickpea. However, seedling dry weight did not vary significantly in various weed control treatments. 199 Seed yield and quality in bitter gourd Table.1. Effect of weed management treatments of seed quality in bitter gourd var. Preethi Treatments Seed Germi- Seedling Seedling Seedling Vigour Vigour % yield nation length fresh dry index I index II weed t/ha (%) (cm) weight weight control (g) (g) T1 Preemergent application of Pendimethalin@0.75 a.i/ha 0.54 58.00 17.90 2.00 0.35 1040.60 20.06 88.57 T2- T1+one hand weeding at 40DAS 0.73 74.70 24.85 2.14 0.36 1854.00 26.61 97.97 T3 -Staleseedbed by Glyphosate @1kg a.i./ha 15 days before sowing 0.36 45.90 19.74 2.19 0.29 1146.82 13.41 67.50 T4 T3+one hand weeding at 40DAS 0.48 74.12 24.82 1.91 0.32 1638.47 23.52 72.73 T5 Mulching with black polythene 0.65 82.52 26.10 2.45 0.33 1924.15 27.24 100.00 T6 Straw mulch 0.56 51.58 22.80 2.44 0.23 1178.80 11.66 91.48 T7 Hand weeding at 20, 40, 60 DAS 0.49 62.67 16.85 2.00 0.34 1057.20 21.20 71.73 T8 Weed free check 0.51 70.90 19.75 1.15 0.42 1185.77 29.66 81.43 T9 Weedy check 0.18 62.77 16.83 2.11 0.32 1057.73 20.26 54.43 CD (P=0.05) 0.13 4.74 3.54 0.27 NS 238.73 7.43 3.08 The study revealed that there was significant influ- ence of various weed management treatments on seed yield and quality of bitter gourd. There was 100% weed control efficiency in mulching with black polythene (T5). Among the treatments with herbicides and its combinations, Pendimethalin + one hand weeding at 40DAS gave 97.7% weed control efficiency along with high seed yield and seed quality parameters and hence can be recommended for weed control in the seed production plot of bitter gourd (Fig.1 and Fig.2). J. Hortl. Sci. Vol. 13(2) : 197-201, 2018 ACKNOWLEDGMENT The authors are thankful to the Project Co- ordinator, All India Co-ordinated Research Project (Vegetable Crops), Varanasi for the financial support rendered and the College of Horticulture, Kerala Agricultural University, Vellanikkara, Thrissur for the facilities provided during the course of the study. 200 Fig.1. Seed yield affected by weed management in bitter gourd Fig.2. Germination of seeds affected by weed management in bitter gourd J. Hortl. Sci. Vol. 13(2) : 197-201, 2018 Anitha et al 201 (MS Received 31 August 2017, Revised 14 October 2018, Accepted 24 December 2018) REFERENCES Abdul- Baki and Anderson, 1972. Vigour deterioration in soybean by multiple criteria. Crop. Sci. 13:630-637. Bowman, J.E. Hartmen, G; Mc Clay, R.P. Sinclair J.R. Hummel J.W. and Wax L.M. 1986. Effect of weed control a nd Row spa cing in conventional tillage, reduced Tillage and Non Tillage on Soybean Quality. Plant Disease 70: 673-676 Drew. J.L and Robert. G.W. 2005. Chemical weed control in dry land and irrigated chickpea. Weed Technology: 19(4): 959-965. Duary, B. 2014. Weed Prevention for Quality Seed Production of Crops. S ATSA Mukhapatra - Annual Technical Issue 18: 2014 Heydecker W; Higgins.J. and Gulliver R.L.1973. Acceler a ted ger mina tion by osmotic treatment. Natura : 246: 42-44 Isma il. C; Atilla , Y; Yusuf. T; Leuvent. O 2009. 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