Weed infestation is affected by chickpea farmer demographics and agronomic practices

To investigate the effects of agronomic practices and farmer demographics on levels of weed infestation in chickpea fields, a survey was conducted during 2015 in Sanjabi district, Kermanshah, Iran. Two sets of data were collected: (a) weed sampling from the selected chickpea fields, and (b) questionnaire recording of farmer demographics and agronomic management. The farmers were asked about their residence status (resident or migrant), occupation (farming only, farming plus a second job), experience and education levels, as well as seedbed preparation, sowing date and method, source of seed supply, crop cultivar, sowing seed rate, weed control operation and crop rotation history. The results showed that weed species composition was similar across the studied fields. The use of a row crop planter, a sowing rate of 45 kg ha^‐1, and weed control resulted in 30.2, 23.03 and 34.2% reductions in weed infestation compared with hand sowing, a sowing rate of 30 kg ha^‐1 and lack of weed control, respectively. Weed density decreased with increasing farmer experience and decreased by 33.0% and 23.5% in chickpea fields of resident farmers and owners whose sole occupation was agriculture. We found that 89.5% of the most experienced farmers adopted weed control operations and most resident landowners (77.4%) opted for crop planter (77.4%) and weed control (90.3%) compared to migrant farmers (50 and 68.5%, respectively). More landowners who were exclusively farmers performed weed control (90.6%) than owners who had a second job (67.9%).     

Effect of crop plant density on critical period of weed competition in potato

A field study was conducted in Hamedan western Iran in 2006 to establish the critical period of weed competition (CPWC) in potato (Solanum tuberosum L.) for commercial and seed production plant densities. A quantitative series of treatments concerned with both increasing duration of interference and length of weed-free period were imposed within each commercial and seed potato production plant density. The beginning and end of the CPWC based on a 10% loss of tuber yield was determined by fitting logistic and Gompertz equations to the relative tuber yield data representing increasing duration of weed interference and weed-free period, respectively. At a 10% tuber yield loss level, the duration of weed interference for 571 and 676 growing degree days (GDDs) from crop emergence, corresponding to 40% and 50% canopy closure, marked out the beginning of the CPWC for commercial and seed production plant densities, respectively. When maintained weed-free for 1163 and 1014 (GDD), corresponding to 100% and 80% canopy closure, weed emerging later caused tuber yield losses of less than 10% for commercial and seed production plant densities, respectively. Practical implications of this study are that post-emergence herbicides or other weed control methods should be used in western Iran to eliminate weeds from 19–24 days post-crop emergence up to 43–51 days. Such an approach would keep yield loss levels below 10%. Interactions between plant density and weed competition durations indicated that weed management in commercial plant density of potato could be less intensive than that of seed production plant density, reducing herbicide use and risk of herbicide carryover to sensitive rotation crops.     

Chemical and biological control of Fusarium species involved in garlic dry rot at early crop stages

European Journal of Plant Pathology - The aim of the study was to test in vitro and in vivo the efficacy of triazoles and biocontrol agents (BCAs) against Fusarium proliferatum and F. oxysporum,...