Abstract
This study aimed to select productive soybean genotypes, adapted to the conditions of the “Cerrado” and with insect resistance. The experimental material involved 170 soybeans lines F 7:2 obtained from partial diallel crosses (4 x 4), that is, four parents with insect resistance and four other parents with high agronomic performance and the other three lines obtained from the plant breeding program of the ESALQ/USP. The F 7 , F 8 and F 9 generations were evaluated in Goiânia-GO, being the last one evaluated during three different sowing periods (October/21/98, November/09/98 and December/11/98). The following characters were evaluated: days to flowering; plant height at flowering; days to maturity; plant height at maturity; period of grain growth; spotted seeds; 100 seeds weight; foliar area sectioned; lodging; agronomic value; and grain yield. The augmented design was used for the F 7 generation while the complete randomized block design for the F 8 and F 9 generations. An analysis of variance was carried out for each generation and one joint analysis of variance was made for the three sowing periods with F 9 generation. Based on grain yield, through the different experiments, they were identified as to which were the most promising lines for the area, having the best combination of characteristics including insect resistance. The following results were obtained from the analysis: a) ten lines from the early cycle, with high yield, were considered favorable for the cultivation in the “cerrado”, showing high resistance to sucker and defoliator insect, and they involve the genitor IAC-100; b) the line 81-9-13 (OCEPAR-04 x IAC-100) had the best agronomic performance, because it was classified above the mean of the check for all characters evaluated in the F 9 generation; c) the second sowing period (11/09/98) was considered the most favorable for the cultivation of soybean in the region; d) the parental IAC-100 (used as the check) showed good characteristics for grain yield and insect resistance. So, evaluation of this parental should occur in the region, in order to recommend it for cultivation.
Highlights
The introduction of the long juvenile period trait is very important in adapting soybean to low latitude regions (>15o) and cropping outside the recommended period
The sowing period is defined by a set of environmental factors that jointly act and interact with the plant, promoting variation in yield and affecting other agronomic traits
Cultivars sown in different periods express their potential in response to the environmental stimulus, which depends on the latitude, sowing period and the cultivars itself (Urben Filho and Souza, 1993)
Summary
The introduction of the long juvenile period trait is very important in adapting soybean to low latitude regions (>15o) and cropping outside the recommended period. This trait that results in late flowering is economically important because it allows an extension of soybean sowing in terms of date and latitudes (Ray et al 1995; Destro et al, 2001). The photoperiod influences the soybean vegetative and reproductive period, affecting the duration of the crop cycle. The sowing period is defined by a set of environmental factors that jointly act and interact with the plant, promoting variation in yield and affecting other agronomic traits. Soybean is attacked by various insect species, especially the pod sucking stink bugs (Piezodorus guiildinii, Nezara viridula and Euschistus heros) and leaf feeder insects (Anticasia gemmatalis, Colaspis sp., Cerotoma arcuata, Diabrotica speciosa and Diphaulaca viridipennis)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
