Modeling of transpiration of paprika (Capsicum annuum L.) plants based on radiation and leaf area index in soilless culture

Abstract

Modeling of crop transpiration is important to manage the irrigation strategy in soilless culture. In this study, the transpiration of paprika plants (Capsicum annuum L.) grown in rockwool was analyzed considering the relationship between incident radiation (RAD) and leaf area index (LAI). Coefficients of the simplified Penman-Monteith formula were calibrated in order to calculate the transpiration rate of the crop (Tr). Transpiration rate per floor area was measured by weighing plants with load cells. The following model was developed: Tr = a [1 exp(-k × LAI)] × RAD / + b for estimating transpiration of paprika. Determination coefficient for the linear regression between estimations and measurements of daily transpiration was 0.80 with a slope of 0.93. In validation, the model showed high agreement between estimated and measured values of daily transpiration. Radiation showed a great effect on transpiration of paprika plants. The results indicated the simplified PenmanMonteith formula could be used to predict water requirements and improve irrigation control in soilless culture. However the model coefficients require parameter adjustments for specific climate and crop conditions.

Irrigation water consumption modelling of a soilless cucumber crop under specific greenhouse conditions in a humid tropical climate

“…There was a poor relationship between the WU and the incoming radiation under greenhouses in tropical climate conditions opposed to other climatic conditions (FERNÁNDEZ et al 2010;TA et al 2011). This fact may be partly explained by the steadiness of the radiation inside the greenhouse due to the low temporal variation of the solar radiation in tropical climates, the high fraction of diffuse radiation due to the high cloudiness of the atmosphere in equatorial areas (SHARMA & PAL, 1965) and the low transmissivity of the plastic film to the radiation, in general, and to the diffuse radiation in particular.…”

Influences of technologies of cultivation of perennial bluegrass herbs on their transpiration in the conditions of water meadows

“…Сравнительная оценка двух способов обработки пойменного луга, вспашки и дискования показала их разную эффективность. Расчеты транспирации и ее количественных показателей как полевых культур (Ben-Asher et al, 2008;Ta et al, 2011;Beggi et al, 2015), так и мятликовых трав, а именно продуктивности, относительной транспирации, транспирационного коэффициента, коэффициента использования ФАР, доказывают, что наибольшая эффективность вспашки по сравнению с дискованием заметно проявляется в засушливые годы при дефиците влаги.…”

“…Известны работы, посвященные исследованию транспирации древесных (Petzold et al, 2011;Espadafor et al, 2015;Taylor et al, 2015), кустарниковых (Barman et al, 2008;Suvočarev et al, 2013) и полевых культур (Penka, 1963;Ben-Asher et al, 2008;Ta et al, 2011;Beggi et al, 2015) при глубоком залегании грунтовых вод (3-5 м) в период вегетации. Для многих культур определены транспирационные коэффициенты, продуктивность транспирации, относительная транспирация, при которой посевы нуждаются в дополнительном увлажнении (Torikov et al, 2014;Pakshina et al, 2016).…”

Changes in electrical conductivity and moisture content of substrate and their subsequent effects on transpiration rate, water use efficiency, and plant growth in the soilless culture of paprika (Capsicum annuum L.)

“…To determine transpiration for irrigation control, aerial environmental factors, such as accumulated radiation, and root-zone environmental factors including moisture content (MC) in substrate, have been considered. In particular, the relationships between aerial environmental factors and transpiration have been studied, and various irrigation methods have been proposed (Patane, 2011;Rao and Bhatt, 1988;Rogiers et al, 2011;Ta et al, 2011;Tai et al, 2010). However, even under the same aerial environmental conditions, the transpiration rate can be affected differently by root-zone factors, for example the moisture content and electrical conductivity (EC) in the substrate.…”