Effect Of Weed Management Strategies Research Articles

Monitoring the effects of weed management strategies on tree canopy structure and growth using UAV-LiDAR in a young almond orchard

The primary objective of this study was to assess the potential effect of integrated weed management (IWM) on canopy structure and growth in a young almond orchard using unmanned aerial vehicle (UAV) LiDAR point cloud data. The experiment took place in the Neve Ya’ar Model Farm, with four IWM strategies tested: (1) standard herbicide, (2) physical-mechanical, (3) cover crops, and (4) integrated management combining herbicide and mowing. One pre-treatment sessions in 2019 and two experiment sessions in 2020–2021 were conducted. During these three experimental sessions, manual measurements, including trunk diameter (TD), were taken for all trees in the orchard. Six canopy growth parameters (e.g., tree height and volume), and functionality parameters (e.g., leaf density, gap fraction profile (GFP) and entropy) were calculated for individual trees using UAV-LiDAR data and were compared to manual measurement (i.e., TD). The results indicated that the herbicide treatment enabled effectively maintained weed coverage at approximately 5–10 % throughout the experiment, demonstrating successful control over weed growth. In contrast, the integrated weed management strategy yielded the highest weed cover (∼50 %). With the view of replacing ground manual measurements with UAV-LiDAR-derived measurements, we explored the relationships between TD and UAV-LiDAR-derived volume and GFP. The relationships between TD and GFP were with R2 values of 0.43 and 0.57 for 2021, respectively. The relationship between GFP and volume showed an R2 value of 0.65 for both years. We observed significant differences between IWM for TD, volume, and GFP in both years, indicating on higher tree development in the herbicide and integrated management treatments. The standard herbicide-based management yielded the highest crop yield, while the cover crop strategy yielded the lowest per plot. Finally, random forest (RF) model was used to identify key factors that significantly influence tree volume, TD, and GFP. The RF results showed that IWM explained about 30 % of tree structural changes, while the rest were attributed to environmental factors (i.e., topographical and climatic). The RF model R2 values ranged between 0.79 and 0.86, representing the topographical and climatic effects on tree structural parameters and growth, reflecting the natural field variability. Our study designed and successfully implemented a framework for estimating canopy characterization in young almond orchards subjected to varied IWM treatments. Ensuring the precise calibration of the LiDAR system and validating data, especially in complex canopy structures, can be challenging since the accuracy of ground-truth data has its errors. For future study, the fusion of LiDAR data with multispectral imagery or terrestrial LiDAR data can be considered, as well as more frequent UAV-LiDAR re-visits, offering insights into phenological states and higher resolution of canopy characteristics in orchards. This research enhances our understanding of the advantages and challenges of using UAV-LiDAR point cloud data analysis to assess the impact of IWM on young almond tree growth.

Effects of Weed Management Strategies and Organic Matter in Plantain (Musa paradisiaca L. ABB) Yield in Agricultural Research Farm, Afaha Nsit, Akwa Ibom State, Nigeria

Effects of weed infestation on plantain bunch yield in Nigeria is very alarming coupled with low nutritional status of the tropical soil. Therefore, field experiments were carried out in 2016/2017 and 2017/2018 to investigate the effects of weed management strategies and organic manure on the performance of plantain (Musa paradisiaca L.ABB). The experiments were carried out in Agricultural Education Research Farm, College of Education, Afaha Nsit. Seven treatments were replicated three times. These were sweet potato (20,000 plants/ha) + poultry manure (20t/ha); sweet potato (20,000plants/ha) + sawdust (40t/ha); hand-slashing at three months interval + poultry manure (20t/ha); hand-slashing at three months interval + sawdust 40t/ha; sweet potato + egusi-melon + poultry manure (20t/ha); sweet potato + egusi-melon + sawdust (40t/ha) and weedy + no organic manure. The experiment was laid out in randomized complete block design. Analysis of variance was carried out on data obtained on weed studies and plantain performance. Means were separated using Duncan Multiple Range Test at 5% probability level. The unfertilized weedy plot reduced plantain bunch yield by 89.7% followed by 41.9% and 43.0% obtained from the sawdust treatment plots integrated with egusi-melon plus hand-slashed and sweet potato respectively. The treatment plot of sweet potato integrated with egusi-melon plus poultry manure (20t/ha) significantly controlled weeds satisfactorily, accelerated plantain growth, reduced 50% flowering time by 23.5% and significantly enhanced plantain bunch yield hence; it is recommended.
 Keywords: Plantain, sweet potato, hand-slashing, organic manure.

Effect of weed management strategies on weed count and yield attributes of apple (Malus × Domestica) under high density orchard system

A field experiment was conducted during 2018 to assess the effect of different weed management strategies on weed count and yield attributes of apple under high density orchard system. The said investigation was carried out in experimental fields of Division of Fruit Science, SKUAST, Kashmir. One year old trees of exotic apple cv. “Elstar” grafted on M-9 T337 rootstock, introduced from Holland in March 2017, were selected for experimentation. Thirteen selected treatments were laid in randomized complete block design, with each treatment replicated thrice. The results revealed that the use of the combination of pre and post emergent herbicide was significantly effective in controlling weeds. Minimum weed count (0.25) was found under T12 (Oxyfluorfen followed by Glufosinate ammonium). Maximum incidence of weeds was recorded under unweeded control. Furthermore significant influence of different weed management strategies was observed on initial and final fruit set in high density apple trees. Maximum final fruit retention was obtained under paddy straw mulch. The highest fruit yield per tree was recorded under T12 (Oxyfluorfen followed by Glufosinate ammonium) which was statistically at par with T5 (paddy straw mulch). Minimum final fruit retention, fruit yield and yield efficiency was recorded under control indicating that weed management strategies are very much essential under high density orchard system for obtaining higher yield.

Management of an ACCase‐inhibitor‐resistant Lolium rigidum population based on the use of ALS inhibitors: weed population evolution observed over a 7 year field‐scale investigation

A 7 year experiment was set up in 2002 to evaluate the long-term effects of weed management strategies based on graminicidal sulfonylureas (SUs) on the evolution of a Lolium rigidum population resistant to ACCase inhibitors in a continuous wheat cropping system. The strategies included the continued use of ALS inhibitors, the continued application of ACCase inhibitors and a simple resistance management strategy based on a biennial rotation of herbicide mode of action (MoA). The efficacy of the tested SUs in the field decreased significantly, starting from the fourth treatment in all control strategies. Regardless of control strategy, the few survivors of the ALS treatment in the third season produced a significant number of ACCase- and ALS-resistant (multiple-resistant) progeny. Continuous ALS and biennial rotation of herbicides reduced weed densities, but L. rigidum conserved its ACCase resistance trait. Enhanced metabolism was detected in ALS-resistant plants, whereas target site was primarily involved in the ACCase-resistant individuals. At the end of the experiment, multiple-resistant individuals were found in all samples coming from the control strategies investigated. The biennial rotation between ALS and other MoA appeared to delay the development of resistance to SUs over continuous treatments, but additional measures will likely need to be taken in order to make this sustainable in the long term, whereas the field efficacy of SUs remained relatively high until the end of the experiment. Integrated weed management with more diversity should be introduced in oversimplified cropping systems in order to sustainably manage resistant L. rigidum populations.

Effect of weed management strategies on some soil-associated arthropods in maize and asparagus ecosystems

Effect of weed management strategies on some soil-associated arthropods in maize and asparagus ecosystems