Combined effect of genotype and inter-row tillage on yield and weed control of chickpea (Cicer arietinum L.) in a rainfed Mediterranean environment

Chickpea is an important pulse crop in the rainfed Mediterranean area, but its competitiveness against the weeds is very low. The combination of high competitive chickpea genotypes and inter-row cultivations could be a feasible strategy for increasing weed control. A 2-year field experiment in a typical rainfed Mediterranean environment of Central Italy was carried out to assess the competitive ability of selected chickpea genotypes grown as pure stand and in mixture with natural weed infestation partially suppressed by inter-row tillage. Experimental treatments consisted in six chickpea genotypes (Alto Lazio, C1017, C133, C134, C6150 stable lines and cultivar Sultano) and four different weed managements [no weed control (weedy); 1-hoeing performed at 25 DAE (days after chickpea emergence); 2-hoeings, one performed at 25 and one at 50 DAE; weed-free]. Chickpea aboveground biomass at 25 and 50 DAE, chickpea traits at harvesting, weeds, and competition parameters were recorded at final chickpea harvesting. C6150, C1017, Sultano, and Alto Lazio gave the best seed yield in the absence of weeds (on average 2.30 t ha−1 of DM). In weedy field conditions, the natural weeds reduced seed yield from 56.1% to 75.1%, while the1-hoeing and 2-hoeing treatments reduced the yield loss from 32.5% to 56.9% and from 5.3% to 54.9%, respectively depending on the chickpea genotypes. A good level of competitive ability combined with an elevated yield potential allowed Alto Lazio to reach the highest grain yield production in weed presence. The competitive balance index (Cb) was positively correlated with the chickpea aboveground biomass and ground coverage especially in the early stage (25 DAE), and with the chickpea plant height. 2-hoeings were more effective in reducing weed infestation than 1-hoeing, even if at chickpea harvesting the weed infestation was however high (on average 223 g m−2 of DM and 65 plants m−2 of weed aboveground biomass and density, respectively). The weed aboveground biomass was mainly made up of Polygonum aviculare L. and it was positively correlated with the number of chickpea fruitless pods and negatively correlated with the chickpea seed yield. Our findings suggest that in the rainfed Mediterranean environment of Central Italy, combining highly yielding competitive chickpea genotypes with 2 inter-row hoeings, applied at 25 and 50 DAE, is a feasible strategy in order to prevent consistent chickpea seed yield reduction caused by the weeds.