The effects of integrated management on yield, yield components and weed control of bean

Bean is one of the most important legumes worldwide for direct human consumption and is a rich source of protein and carbohydrates. Bean is weak to compete with weed because of the retard growth at the early stages. Therefore, weed control at this time plays an important role to gain high priduction. Yield crop depends on weed number, and size after germination. Weed control depends on integration of prevalent methods application along with desirable agronomical operations. Selection of the best sowing method, plant density and application of chemical weed control methods plus weeding can effectively control weeds. It is shown that weed dry weight decreased in wet sowing method as compared with dry sowing. Using higher plant density increased the yield bean by 16% as compared to ordinary density. Application of Trifloralin at the rate of 2 lit/ha controlled weeds in bean field without any reduction for yield bean. This study tries to find the effects of irrigation before and after sowing and integrated management on yield, yield components and weed control of Chiti bean.
Field experiment was carried out as factorial split plot based on complete randomized block design with four replicates during 2011 at Shazand city in Markazi province, Iran (34˚ 3' N latitude; 49˚ 48' E longitude; altitude of 2010 m above sea level). The factors were two sowing methods (wet and dry sowing), three levels of plant density (12.5, 17 and 25 plant/m2) and three levels of methods of weed control (weed infest, twice hand weeding, and Trifloralin plus once hand weeding). Seeds of KS2189 genotype were sown by hand at rows spaced at 40 cm. Trifloralin was applied as soil-mixed pre-planting treatment at the rate of 2 lit/ha. The first and second weeding were done at 30 and 40 day after sowing, respectively. Sampling weeds were done 60 day after sowing. Agronomic traits were measured based on the mean of 15 plants/plot. At harvest, plants were removed from 3 m2 of the middle of each plot and the grain and biological yield were measured. The data were subjected to the analysis of variance using SAS. Means were compared using Duncan's Multiple Range test at P=0.05 level of significance.
Results showed that decreasing the plant density significantly increased the number of pods per plant. Application of Trifloralin plus once hand weeding caused to increase the number of pods per plant by 62% as compared to control. The interactive effect of sowing method and weed control treatment showed that the number of pods per plant was higher in weed control treatments than weed infest treatment for both wet and dry sowing. The maximum number of grains per pod was observed for plant density of 17 plant/m2. Wet sowing increased grain yield by 14% as compared to dry sowing. Previous studies showed that wet sowing can increase grain yield by 18%. It seems that high moisture content of soil make higher possibility of emergence and seedling establishment in wet sowing treatment that dry sowing. The shoot growth increased by increasing of photosynthesis and thus increased final grain yield. The maximum grain yield (4667.3 kg/ha) was observed in plots which were wet sown as method, in plant density of 17 plant/m2 and applied Trifloralin plus once hand weeding. In both sowing method, with decreasing of plant density weed density and biomass increased. The minimum of weed density (37.80 plants/m2) and buimass (96.96 g/m2) was obtained from wet sowing method and plant density of 25 plant/m2. Results showed that in both sowing method, the minimum weed density and biomass was obtained from application of Trifloralin plus once hand weeding. Comparison among treatment means showed that the maximum of weed biomass (711.92 g/m2) and total number (239.2 plants/m2) was obtained in dry sowing condition with plant density of 12.5 plant/m2 and weed infest treatment.
In general, the best integrated treatment to more suppression of weeds and to obtain optimum grain yield of chiti bean is using plant density of 17 plant/m2 on wet condition and applying of Trifloralin plus once hand weeding.