PHYTODIVERSITY AND ECOLOGICAL FEATURES OF WEED SPECIES OF SUFAID SUNG, PESHAWAR

Field surveys were carried out to assess the phytodiversity, phenology, leaf size, leaf shape, life form and ethnobotany of weed flora of village Sufaid Sung, Peshawar from March 2017 to June 2019. Overall, 95 species have been reported associated with 31 families. Dominant families were Poaceae (22 species), Asteraceae (10 species) followed by Amaranthaceae and Papilionaceae (6 species each), Brassicaceae and Polygonaceae (5 species each), Euphorbiaceae and Solanaceae (4 species), Apiaceae, Caryophyllaceae, Cyperaceae, Malvaceae and Verbenaceae added 2 species, Chenopodiaceae and Convolvulaceae contributed 3 species, Apiaceae, Caryophyllaceae, Cyperaceae, Malvaceae and Verbenaceae added 2 species while the rest of 16 families contributed a single species each. The dominant life form was therophytes (76 species) followed by hemicryptophytes (11 species) and geophytes (8 species). Leaf size of the flora showed that the most dominant leaf size class was mesophyll (38 species) followed by macrophyll and microphyll (18 species each), nanopohyll (15 species) and leptophyll (5 species) while a single aphyllous. Simple leaf species were 68 while 26 species had dissected leaves. This study shows a detailed phytodiversical situation of weeds that may be important as reference work for future ethnobotanical, ecological, weed management and conservational studies.

INFLUENCE OF MIXED CROPPING OF CABBAGE AND MUSTARD ON WEED DYNAMICS AND YIELD OF POTATO (SOLANUM TUBEROSUM)

A field experiment was conducted in Horticulture farm of Agriculture and Forestry University, Chitwan, Nepal during September 2018 to January 2019 to evaluate the influence of mixed cropping of cabbage and mustard in weed dynamics and yield of potato. The experiment was carried out in a split-plot design with three replications. The treatment consists of with mustard (M1) and without mustard (M2) as main plot factor and eight treatments namely, sole potato at 0.7m (T1) and 1.4m (T5) inter-row spacing, sole cabbage at 0.35m (T2) and 0.7m (T3) inter-row spacing, potato at 1.4 m row spacing with one (T4), two (T7) and three (T8) row cabbage, and potato at 0.7m row spacing with one-row cabbage (T6), as subplot factor. Effect of broadcasting mustard was found significant in the dry weight of broadleaf weed, the height of cabbage and potato, cabbage canopy, and net production of potato. Net production was calculated by converting the yield of all the three crops in the monetary value of potato. Similarly, the effect of different intercropping of cabbage and potato was found significant on cabbage and potato height, cabbage canopy, dry weight of weed, the yield of cabbage and potato, and net production of potato. The interaction of main plot factors and sub-plot factors was found statistically significant; mustard broadcasting on intercropping of 35cm cabbage within 70cm row to row spacing of potato (M1×T6) was found superior in terms of yield of all the three crops and net production of potato. Similarly, (M1×T6) had a lower dry weight of broadleaf; Solanum nigrum and Chenopodium album were major weeds—both being a broadleaf weed. Thus, it would be better to suggest vegetable growing farmers, to follow mixed cropping of cabbage, mustard and potato for higher return and sustainable ecological weed management.

Challenges of weed management in rice for food security in Africa: A review

Rice is one of the most important crops for food security in Africa. However, there is a large gap between its present demand and supply. Weed competition is basically one of the major constraints in rice systems in Africa, leading to 48–100% yield reduction and sometimes complete crop failure, thereby threatening food security. Weed control methods currently employed to avoid such losses are predominantly hoe-weeding and herbicide application. Hoe weeding is tedious, inefficient, time consuming, associated with high labour demands and often too expensive for the average farmer to afford. Herbicide use on the other hand, does not provide season-long weed control. Moreover, there are not many herbicides that can control different kinds of weeds with one application. Thus, to optimise yield, financial, social and environmental costs and benefits, integrated and ecological weed management approaches are advocated. Future weed research should therefore be focused on delivering information for the implementation of these approaches. This would require improved knowledge of weed biology and ecology, prioritization of problematic weed species, development of competitive rice cultivars and timely weed control. To address the diversity of weed problems in rice systems in Africa, however, research innovations must take full account of farmer’s local conditions using farmers’ participatory approaches. This review suggests that knowledge-based integrated novel approaches must be developed to assist farmers in coping with the challenges of weed management for sustainable rice production.

An online decision support tool to evaluate ecological weed management strategies

Weeds remain the most commonly cited concern of organic farmers. Without the benefit of synthetic herbicides, organic farmers must rely on a host of ecological weed management (EWM) practices to control weeds. Despite EWM’s ability to improve soil quality, the perceived rate of integrated EWM strategy adoption remains low. This low adoption is likely a result of the complexity in designing and evaluating EWM strategies, the tendency for outreach to focus on the risks of EWM strategies rather than their benefits, and a lack of quantitative measures linking the performance of EWM strategies to farmers’ on-farm objectives and practices. Here we report on the development and deployment of an easy-to-use online decision support tool (DST) that aids organic farmers in identifying their on-farm objectives, characterizing the performance of their practices, and evaluating EWM strategies recommended by an expert advisory panel. Informed by the principles of structured decision making, the DST uses multiple choice tasks to help farmers evaluate the short- and long-term trade-offs of EWM strategies, while also focusing their attention on their most important objectives. We then invited organic farmers across the United States, in particular those whose email addresses were registered on the USDA’s Organic Research Integrity Database, to engage the DST online. Results show considerable movement in participants’ (n = 45) preferences from practices focused on reducing weeding costs and labor in the short term to EWM strategies focused on improving soil quality in the long term. Indeed, nearly half of those farmers (48%) who initially ranked a strategy composed of their current practices highest ultimately preferred a better-performing EWM strategy focused on eliminating the weed seedbank over 5 yr.

In the weeds: distinguishing organic farmers who want information about ecological weed management from those who need it

The benefits of farming organically in the USA are increasingly known; however, organic farmers also encounter considerable risks, especially from weeds. Without herbicides, organic farmers can rely only on crop rotations, mechanical cultivation, manual weeding, beneficial insects and other cultural practices, termed ecological weed management (EWM), to control weeds. Despite promising results and the many ways in which EWM can be employed, it remains poorly adopted by the organic community. Organic farmers resist research and recommendations from University scientists and Extension, instead preferring to rely on local family and friends and their own experience to guide decisions. Here we investigate factors that may lead organic farmers to recognize that they need additional information about EWM and to seek that information out. Using a national survey of organic farmers (n = 554) and a risk-information seeking and processing model, we show that farmers’ risk and benefit perceptions, worry, social norms encouraging seeking out information, and farmers’ own perceived knowledge gaps, particularly with respect to their most problematic weed, influence information-seeking behavior. Identifying characteristics that may distinguish those organic farmers who need and want additional information, we provide recommendations to Extension and University scientists about how best to communicate, build trust and provide decision support to the organic community with respect to EWM.