Response of tomato growth to continuous elevated CO_(2)concentration 2 under controlled environment

CO_(2)fumigation has been extensively used in greenhouses cultivation to enhance crop yield.The effects under the precise level of elevated CO_(2)(e[CO_(2)])on crop morphology,yield,and fruit quality remain largely elusive yet.To explore the response of plant growth to the continuous RCPs(Representative Concentration Pathways)projected CO_(2)concentration[CO_(2)],tomato(Hezuo 908)plants were grown under ambient CO_(2)(a[CO_(2)],462μmol/mol)and e[CO_(2)](550,700,850 and 1000μmol/mol):named as EC550,EC_(700),EC_(850),and EC_(1000),respectively,under uniform environmental condition for two planting seasons.Collective growth of tomato plants(plant height,stem diameter,and leaf area index)was significantly enhanced under EC_(700)and showed a slightly negative response under EC_(850).The optimum yield was stimulated under EC_(700)by 74.05%and 55.91%,while maximum total dry weight(DW_(t))was enhanced under EC_(1000)by 58.23%and 39.78%during autumn-winter and spring-summer planting seasons,respectively,as compared to a[CO_(2)].The greatest yield and least DWt stimulated under EC_(700)for both seasons indicated that EC_(700)improved the ability of the tomato plants to translocate carbohydrates to fruits.Optimum water use efficiency related to yield(WUE_(y))was enhanced by 55.91-210.87%under EC_(700)compared to a[CO_(2)].The titratable acid(TA)was improved by 19.94%(EC_(700)),29.17%(EC_(850)),and 97.92%(EC_(1000)),and the lycopene(Lp)was increased by 2.22%(EC_(700))and reduced by 2.28%(EC_(1000)).Thus,the overall optimum impact on tomato growth was explored under EC_(700).Super e[CO_(2)]did not positively influence the tomato growth process and yield under adequate water and fertilizer conditions.The present study results are beneficial for greenhouse crop production and might be used as a reference to validate the climate change influence modeling.

Review of electrostatic system parameters,charged droplets characteristics and substrate impact behavior from pesticides spraying

Electrostatic spraying application is adopted in crop protection to prevent pest infestation,to improve product quality and to maximize yield.It involves a superposition of charges to pesticide spray droplets to attract substrate ions at obscured surfaces.The droplets wraparound effect reduces off-target deposition,enhances on-target spray and invariably improves spray efficiency.Electrostatic spraying system works effectively at optimum parameters in combination with charging voltages,application pressures,spraying height regimes,flow rate,travel speed,electrode material,and nozzle orientation.Many combinations of the system parameter settings have been systematically used by researchers for the electrostatic application,but there are unknown specific optimum parameters combinations for pesticide spraying.Since droplets chargeability influences the effectiveness of electrostatic spraying system,the parameters that produce ideal charge to mass ratio determine the functionality of the spraying deposition,retention and surface coverage.This article,therefore,analyses electrostatic system parameters that produce suitably charged droplets characteristics for effective impacting behavior of pesticides on substrates.Increasing applied voltages consequently maximizes charge-mass ratio to optimum and starts declining upon further increase in voltages beyond a critical point.This review further proposes the selection of an optimum electrostatic parameters combination that yields optimum droplets chargeability in pesticide application.Also,it is necessary to investigate the charge property of substrates prior to pesticide application in order to superpose the right opposite charge on spray droplets at rupture time during electrostatic spraying system.