The dominant role of animal social status in vertebrate seed dispersal

Seed dispersal directly affects plant establishment, gene flow, and fitness. As a result, understanding patterns in seed dispersal is fundamental to understanding plant ecology and evolution, as well as addressing challenges of extinction and global change. Our ability to understand dispersal is limited because few frameworks have emerged that provide a means for predicting dispersal across time and space. We provide a novel framework that links seed dispersal to animal social status, a key component of behavior. Because social status affects individual resource access and movement, it provides a critical link to two factors that determine seed dispersal: the quantity of seeds dispersed and the spatial patterns of dispersal. Moreover, individual social status may have unappreciated effects on post-dispersal seed survival and recruitment when social status affects individual habitat use. Hence, environmental changes, such as selective harvesting and urbanization, that affect animal social structure may have unappreciated consequences for seed dispersal. The framework we present highlights these exciting new hypotheses linking environmental change, social structure, and seed dispersal. By outlining experimental approaches to test these hypotheses, we hope to facilitate studies across a wide diversity of plant-frugivore networks, which may uncover emerging hotspots or catastrophic losses of seed dispersal.

Pulsed magnetic field impact on adaptation and vegetation of strawberry microplants (Fragaria×ananassa Duch.)

Microplant adaptation to non-sterile conditions is critical in clonal micropropagation providing for plant establishment and the overall method efficiency. Various techniques are employed to facilitate microplant establishment, including physical exposures like pulsed magnetic field. The study aimed to investigate the effect of pulsed magnetic field on establishment during adaptation to non-sterile conditions and subsequent vegetation of adapted strawberry plants. Research focused on strawberry microplants of the Tsaritsa and Nashe Podmoskovye cultivars originated by the All-Russian Horticultural Institute for Breeding, Agrotechnology and Nursery. Magnetic pulse treatment (MPT) was carried out with an AMIS-8 magnetic stimulator developed at the Institute. A positive impact of some MPT modes on microplant establishment, leaf and stolon formation was registered during strawberry adaptation to non-sterile conditions. Relatively low frequencies of 0.8-21 Hz exerted best effect in strawberry for most criteria. MPT contributed to an 11.5 % improvement in microplant establishment in Nashe Podmoskovye and 23.1 % — in Tsaritsa cultivars vs. no treatment. In best MPT assays, the number of leaves increased by 9.2—15.4 % and of stolons — 6.2-6.5 times in adapted strawberry plants compared to control. No significant inter-varietal differences were observed in Nashe Podmoskovye and Tsaritsa for vegetation criteria during adaptation to non-sterile conditions.

Substrate Stratification: Layering Unique Substrates within a Container Increases Resource Efficiency without Impacting Growth of Shrub Rose

Nurseries rely on soilless substrates to provide suitable growing media for container grown crops. These soilless substrates have been developed to readily drain water to prevent issues with waterlogging and associated soil-borne disease. A negative consequence of high porosity and subsequent drainage throughout the container profile is the required high or frequent irrigation rates with poor retention of applied nutrients. Substrates with relatively high levels of moisture and nutrient retention placed on top of a coarse and freely draining substrate could further optimize water and nutrient retention, while allowing for needed gas exchange for plant establishment and growth. Containerized Red Drift® rose (Rosa ‘Meigalpio’ PP17877) plants were grown under 16 mm or 12 mm daily irrigation, utilizing a traditional pine bark substrate or stratified substrates with either a conventional bark, bark fines, or a bark–peat mixture on top of a coarse bark within a container. The stratified substrates received 20% less controlled-release fertilizer; however, the fertilizer in the stratified treatments was concentrated in the upper strata only. During the first growing phase or season, plants grown in stratified substrates outperformed those grown in conventional, non-stratified bark substrates under normal irrigation. The stratified substrates did not reduce growth under reduced irrigation regimes. Overall, crop growth was equal or superior for stratified substrates when compared to the non-stratified controls, even with a 20% reduction of fertilizer. This research suggests that stratified substrate systems can be used to reduce fertilizer and irrigation rates while producing crops of similar or superior quality to conventionally grown containerized crops.

A comparative analysis of the efficacies of six selected herbicides for effective control of spear grass (Imperata cylindrical Linn) in cassava production in Obudu, Northern Cross River State

A two-year, (2015 and 2016) field trial was conducted in Obudu Local Government Area of Cross River State to compare the efficacies of six (6) selected herbicides in controlling spear grass (Imperata cylindrical Linn) in cassava farm. The main treatments were the three cassava varieties: TMS 30572, TMS 50395 and NR 8082, while the sub treatments were six herbicides: Primextra, Igrancombi Gold, and Paracot as pre-emergence, Touchdown Forte Hi Tech, Galex and Fusilade Forte as post-emergence herbicides. The result showed that cassava establishment did not differ significantly among the cassava varieties, whereas herbicide type significantly (p<0.05) affected cassava establishment. High plant establishment was recorded in plots treated with Paracot, followed by plots treated with Igrancombi compared to high mortality rate recorded in plots treated with primextra as pre-emergence application. The tuber yield did not differ significantly among the cassava varieties. However, on the basis of average for both years, the trend was as follows: TMS 30572 (2.81 t/ha-1) > NR 8082 (2.75 t/ha-1)> TMS 50395 (2.56t/ha-1). On the contrary, tuber yield differed significantly (p<0.05) among herbicide types irrespective of the cassava variety, although no well-defined trend was established.