Reza Fifaei; Reza Fotouhi Ghazvini; Behrooz Golein; Yusef Hamidoghli
Abstract
Citrus often were encountered with periodic droughts. For this reason, drought effect on six-month-old seedlings of Poncirus (PT) (Poncirus trifoliata Raf.),Troyer citrange (TC) (Citrus sinensis Osbec. × Poncirus trifoliata Raf.),Citrumello (CR) (Citrus paradisi M. × Citrus sinensis Osbec.),Sour ...
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Citrus often were encountered with periodic droughts. For this reason, drought effect on six-month-old seedlings of Poncirus (PT) (Poncirus trifoliata Raf.),Troyer citrange (TC) (Citrus sinensis Osbec. × Poncirus trifoliata Raf.),Citrumello (CR) (Citrus paradisi M. × Citrus sinensis Osbec.),Sour orange (SO) (Citrus aurantium L.),andCleopatra mandarin (CM) (Citrus reshni L.) were tested on 2014 in Ramsar Citrus Research Institute. This research was conducted as factorial experiment based on completely randomized design with three replications. The factors included commercial Citrus rootstocks and two level of irrigation. The results showed that maximum quantities of proline, total soluble sugars, malondialdehyde and carotenoid and minimum quantities of total, b and a chlorophyll were observed in drought stress. Maximum accumulation of proline (ordered 306.41 and 281.65 µmol/gdw) and total soluble sugars (ordered 233.79 and 137.9 mg/gdw) and minimum accumulation of malondialdehyde (ordered 179.21 and 204.1 µmol/gdw) were observed in SO and CM rootstocks under drought stress. Decreasing amount of total and chlorophyll a in CM and chl b in SO rootstock was more than other rootstocks and decreasing amount of total and b, a chlorophyll in CR was least. Furthermore, increasing amount of carotenoid in SO and CM was most and the least amounts in PT was observed. On the basis of the study, trifoliate rootstocks as Poncirus, Troyer citrange and Citrumello tolerate as much as drought.
mojgan sanjari; Alireza Siroosmehr; Baratali Fakheri
Abstract
To study the effect of humic acid and drought stress on some physiological characteristics of roselle (Hibiscus sabdariffa) an experiment was conducted in the research field of Agricultural Education Centre of Jiroft in 2013. Field experiment was carried out as split plot design with three replications. ...
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To study the effect of humic acid and drought stress on some physiological characteristics of roselle (Hibiscus sabdariffa) an experiment was conducted in the research field of Agricultural Education Centre of Jiroft in 2013. Field experiment was carried out as split plot design with three replications. Water deficit stress as main factor with three levels (A1 = Irrigation after 50, A2 = 100 and A3 = 150 mm evaporation from pan class A) and humic acid was sub plots in four methods of application (B1 = non humic acid, B2 = with irrigation, B3 = with irrigation + once spraying, B4 = with irrigation + twice spraying). Humic acid was used with irrigation at 10kg/ha and for spraying at 250ml/100l. Drought stress had significant effect on chlorophyll a, chlorophyll b, carotenoids, relative humidity content and proline of roselle leaves. Interaction effect of humic acid and drought stress was only significant for total chlorophyll and soluble carbohydrate. Drought stress decreased chlorophyll a (48.22 percent), chlorophyll b (32.77 percent), carotenoid content (79.64 percent) and relative humidity (12.59 percent), while increased proline content (12.59 percent). Humic acid increased chlorophyll a, chlorophyll b and carotenoids but reduced proline content (15.04 percent).
Maryam Haghighi; Hossein Behboudian
Volume 13, Issue 1 , August 2011, , Pages 1-8
Abstract
The world is facing a dwindling supply of water, therefore deficit irrigation is becoming more of a necessity than a choice. Partial rootzone drying (PRD) is a new water saving irrigation technique where at each irrigation time only one part of the rootzone is watered. The un-irrigated part is watered ...
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The world is facing a dwindling supply of water, therefore deficit irrigation is becoming more of a necessity than a choice. Partial rootzone drying (PRD) is a new water saving irrigation technique where at each irrigation time only one part of the rootzone is watered. The un-irrigated part is watered during the next irrigation. We explored the potential of PRD for `Petopride´ processing tomato. There were two treatments: control (C, normal irrigation) and PRD. We collected data on water relations of vegetative and reproductive organs. PRD saved water by 50% and increased water use efficiency of the plant compared to C. Leaf water potential was more negative under PRD compared to C. Irrigated and non-irrigated roots of PRD had similar water potential and this could have happened by water movement between the two sides of root system. Water potential of fruit was lower in PRD than in C. But pressure potential (turgor potential) was similar between PRD and C fruit. This was indicative of osmotic adjustment (osmoregulation) in PRD fruit. To our best knowledge, this is the first report of osmotic adjustment of fruit under PRD treatment.