PERFORMANCE OF MAIZE AS INFLUENCED BY DIFFERENT LEVELS OF NITROGEN AND SPACING

Abstract

An experiment was conducted during April to July 2010 at the Agronomy field laboratory of Sher-e-Bangla Agricultural University, Dhaka to evaluate the performance of maize as influenced by different levels of nitrogen under different spacings. The experiment comprised two different factors; (1) four levels of nitrogen application viz. N1 (180 kg N/ha), N2 (220 kg N/ha), N3 (260 kg N/ha) and N4 (275 kg N/ha) and (2) three different plant spacings viz. S1 (60 cm × 25 cm), S2 (75 cm × 25 cm) and S3 (90 cm × 25 cm). The experiment was set up in randomized complete block design (factorial) with three replications. Results revealed that both nitrogen and plant spacing significantly affected growth, yield and yield contributing characters of maize. The highest nitrogen level N4 (275 kg N/ha) recorded the highest value of all growth parameters at all data recording days whereas the lowest nitrogen level N1 (180 kg N/ha) recorded the lowest values of all the growth parameters. In respect of yield contributing characters and yield, results revealed a different scenario where nitrogen level N2 (220 kg N/ha) obtained the highest values of cob length, number of grains/cob, weight of grains/cob, 1000- grain weight, grain yield and harvest index and the corresponding lowest values were obtained from the lowest nitrogen level N1 (180kg N/ha). The highest spacing S3 (90 cm × 25 cm) though produced the shortest maize plant but it produced the highest number of leaves/plant, leaf area and dry weight/plant and all corresponding lowest values were recorded from the lowest spacing S1 (60 cm× 25 cm). The medium spacing S2 (75 cm × 25 cm) compared to S4 produced lower values in growth parameters but it recorded the highest values in yield contributing characters and grain yield and the lowest values of yield contributing characters and grain yield were recorded from the lowest spacing S1 (60 cm × 25 cm) but the highest stover yield was recorded from S1 and the lowest from S3 spacing. The N2 (220 kg N/ha) in combination with S2 (75 cm × 25 cm) performed the best and obtained the highest cob length (23.40 cm), number of grains/cob (515.76) weigh of grains/cob (146.10 g), 1000- grain weight ( 269.30 g) which contributed to obtain the highest grain yield (4.79 t/ha) and harvest index (38.71%). The corresponding lowest values were obtained from N1 × S1 but the highest stover yield (6.19 t/ha) and lowest stover yield were obtained from N4 × S1 and N1 × S3, respectively.