CORRELATION AND PATH ANALYSIS ESTIMATION FOR PLANT CHARACTERS OF MAIZE INFLUENCED BY WEEDING AND NITROGEN PRACTICES THROUGH SUPPRESSING APHID INFESTATION
Authors: Alam Md. Jewel , Faysal Md. Mostofa , Paul Dhipak Kumer , Razzaque M M Abdur , Tareq Md. Zablul 
Published: February 2025

Maize aphid, Rhopalosiphum maidis Fitch. is one of the most serious pests of maize in Bangladesh as well as worldwide. This pest was controlled using a lot of techniques. A field research was conducted at the Entomology Field Laboratory, Department of Entomology, Bangladesh Agricultural University, Mymensingh during the period of October 2022 to March 2023 in order to investigate the impact of different techniques of weeding and nitrogen levels on morpho-physiological traits, yield and yield attributes of maize with aphid infestation. The experiment comprised three techniques of weeding (viz., W1=No weeding, W2= one time of weeding at 20 DAS and W3= two times of weeding at 20 and 40 DAS) and nitrogen levels (N1=240kg/ha, N2= 250kg/ha and N3= 260kg/ha at respective days of weeding). BARI hybrid butta-9 was used as an experimental crop. The two-factorial experiment was laid out in Randomized Complete Block Design (RCBD) with three replicates. From the results of this study, it revealed that the application of single or combined methods of weeding and nitrogen levels adversely affected on aphid infestation in plants, which ultimately caused a significant increase in grain yield per hectare. Among different tested techniques, the combined two-times application of weeding at 20 & 40 days after the sowing of seed (W3) and nitrogen at rate of 250 kg/ha (N2) significantly influenced on the highest plant height, maximum length & diameter without husk, number of grain rows per cob, number of grains per cob, grain weight per cob, and consequently, increased yield of BARI Hybrid butta-9 through the highest suppressing of aphid infestation. In case of the single effect, weeding (W3) and nitrogen (N2) was the best practice than others, where returned higher yield and the lowest infestation. Correlation and regression coefficients, path analysis was carried out based on average plant character values and percentage of aphid infestation. The results from correlation coefficient indicated that all parameters are shown positive correlation with each other except plant infestation caused by aphid. Among the seven variables, plant height, number of grain rows per cob, number of grains per cob, grain weight per cob and 100 seed weight had more direct effects than their indirect effect while cob length and diameter without husk had more indirect effects than their direct effects on aphid infestation. It is evidence from aphid infestation model that in case of maize the plant that contained higher plant height, higher length & diameter of cob without husk, maximum number of grain row per cob, higher number of grains per cob, maximum weight of grain & 100 seed weight and the highest yield of maize can easily minimize the infestation of aphid. Based on the results of this research, therefore, it may be concluded that to obtain a higher yield of maize through suppressing aphid infestation, it should be applied two times of weeding at 20 & 40 days after the sowing of seed and nitrogen at rate of 250 kg/ha in the research area.