عنوان مقاله [English]
نویسندگان [English]چکیده [English]
The lentil or masoor (Lens culinaris L.) is a brushy annual plant of the legume family, grown for its lens-shaped seeds. Lentil has been one of the first crops domesticated in the Near East. With 26% protein, lentil is the vegetable with the highest level of protein other than soybeans, and it is an important part of people’s diet in many parts of the world. It is reported that the average yield of lentil is considerably low compared to its potential yield of 1500-2000 kg ha-1, obtained in the research field. Such lower yield may be attributed to the poor management of the crop among which poor weed management is an important one. Lentil crop is not very competitive against weeds due to small and weak canopy. Weed reduces yield through competition with crop plants for space, moisture, light and plant nutrients. Generally 20 to 30% losses of grain yield are quite usual and may increase even 50%, if the crop management practices are not properly followed (Deihimfard et al., 2007). The modern lentil varieties give good yield if the land remains weed free for the first one month. However, most of the farmers are reluctant to control weeds in lentil field timely and finally, loses yield. Inadequate weed control was found to reduce the yield 40-66% in lentil (Erman et al., 2008; McDonald et al., 2007). A major component of integrated weed management is the use of more competitive crops, although the selection of better crop competitiveness is a difficult task. The use of competitive plants for weed control could be considered cost-effective and less labour-intensive, and thus reduces the amount of herbicides required. Therefore, the aim of this research was to evaluate lentil competitive ability and to compare the effects of cultivar selection.
Materials and methods
An experiment was carried out as a factorial based on a randomized complete block design (RCBD) with 10 treatments and three replications. Experimental treatments included hand weeding and weedy check and five lentil cultivars (Bilehsavar, Karalinta, Kimia, Seymareh and local). This experiment was studied at the Research Farm of Bu-Ali Sina University during the growing season of 2012-2013. Plots were not irrigated because lentil was grown under dry land conditions. Weeds were counted at their greatest intensity, and their identification was much easier. Three square meter samples were randomly collected from each sub-plot for evaluation the weed biomass. At harvest, two outer rows for each plot and 50 cm from each end of the plots were left as borders and the central rows were harvested. Yield and yield components of lentil were classified as biological yield, grain yield, 1000- seed weight, number of pods plant-1, number of seeds per pod and plant height.
Results and discussion
The results showed that the effects of weed control and cultivar was significant on all traits but plant height and chlorophyll meter reading was not affected by cultivar. Also, the effects of treatment interaction were significant on grain and biological yield. The highest grain and biological yield (110 and 338 g.m-2, respectively) was observed at local cultivar on hand weeding treatment. The lowest mean for these traits with a reduction of 82 and 70%, respectively, belonged to Karalinta cultivar on weedy control treatment. Weed interference decreased yield and yield component of all lentil cultivars significantly. Maximum and minimum weed dry matter and weed density belonged to Karalinta and local cultivars, respectively. The highest values for competition and ability of tolerance indices (2.02 and 52.82, respectively) belonged to Local cultivar and the lowest values of these indices (0.49 and 23.53, respectively) were achieved at Karalinta cultivar.
It can be concluded that local and Karalinta cultivars were the resistant and sensitive cultivars to weed presence, respectively.