Evaluation Yield of Sunflower (Farrokh cultivar) under Effects of Conventional Deficit Irrigation and Partial Root Zone Drying

Deficit irrigation is an optimization strategy for water use efficiency in irrigation. This research was conducted to evaluation effect of deficit irrigation (DI) and partial root zone drying (PRD) on yield, yield components and water use efficiency of corn. Research was conducted on Shahid Bahonar University of Kerman in the spring of 2010 using a completely randomized block design with one control, 18 deficit irrigation treatment and three blocks. Deficit irrigation treatments were included: mild water stress (irrigation with درصد75 ETP), high water stress (irrigation with %50 ETP), fixed every other furrow irrigation and three partial root zone drying (Change the wet furrows in every irrigation, Change the wet furrows in every other irrigation and change the wet furrows in every second irrigations). Every treatment was applied at three growth stages of corn (all periods of growth, vegetative growth stage and reproductive growth stage). The highest biological yield obtained 32431 and the lowest was 17654 kg per hectare. The highest grain yield was 12115 kg per hectare and the lowest was 7163. Water use efficiency (km grain yield per cubic meter of water) for the control treatment was equal to 1.16 and for partial root zone drying with change the wet furrows in every irrigation (14 days) in all periods of growth treatment was equal to 2.13. Results showed that partial root zone drying with one interval irrigation (14-day) was the best choice to apply deficit irrigation on corn.

This work examines the effects of two deficit irrigation strategies, conventional deficit irrigation (DI) and partial root-zone drying (PRD), on mature navel orange trees. The study carried out during two consecutive years (2008 and 2009) in a semi-arid climate on a silty–clay–loam soil in the north of Iran. Both DI and PRD trees were irrigated at two levels, 75 and 50% (DI75, PRD75, DI50 and PRD50) of the full irrigation (FI). In DI, irrigation water was applied to both sides of the tree rows, similar to FI. In PRD, irrigation water was applied alternately to only one side, at each irrigation event. Results showed that DI treatments reduced fruit yield by ∼30% compared with FI, but PRD treatments caused no reduction in fruit yield. No negative impact was detected in fruit quality after applying DI and PRD treatments. Shoot growth decreased in all DI and PRD treatments in both years. In DI, stomatal resistance was higher (50%) than in FI, but it was not significantly affected in PRD. The irrigation water use efficiency of PRD trees increased to nearly twice that of FI. According to these two years' results, we recommend PRD as an acceptable deficit irrigation strategy in the region.

This study investigated the comparative effects of reduced irrigation regimes—partial root-zone drying (PRD) and conventional deficit irrigation (DI)—on the incidence of blossom-end rot (BER) in tomato (Solanum lycopersicum L.) under three Ca-fertilization rates: 0, 100, and 200mg Ca kg–1 soil (denoted Ca0, Ca1, and Ca2, respectively). The plants were grown in split-root pots in a climate-controlled glasshouse and treated with PRD and DI during early flowering to the fruit maturity stage. The results showed that, in comparison with DI treatment, PRD significantly reduced BER incidence. A greater xylem sap abscisic acid concentration, lower stomatal conductance, and higher plant water status in the PRD in relation to the DI plants might have contributed to the increased fruit Ca uptake, and could have reduced BER development in tomato fruits. Therefore, under conditions with limited freshwater resources, application of PRD irrigation could be a promising approach for saving water and for preventing BER development in tomatoes.

Alternate partial root-zone drying irrigation improves nitrogen nutrition in maize ( Zea mays L.) leaves

Nitrogen dynamics in the soil-plant system under deficit and partial root-zone drying irrigation strategies in potatoes

Partial root-zone drying improves irrigation water productivity (IWP, yield per unit applied irrigation water) with respect to controls receiving substantially more water, but similar gains are often achieved with conventional deficit irrigation. This paper presents a meta-analysis of IWP for a broad range of horticultural crops and environments. Two comparisons were preformed: (a) crops managed with either partial root-zone drying or conventional deficit irrigation against controls receiving substantially more water than the two water-saving techniques, (b) crops managed with partial root-zone drying and their counterparts with conventional irrigation where both received similar amounts of irrigation. In relation to controls receiving substantially more water, conventional deficit irrigation increased IWP by an average 76% and partial root-zone drying by 82%; the gains from both water-saving methods were statistically undistinguishable. Yield per unit applied irrigation water of crops under partial root-zone drying was significantly (P = 0.007) but modestly (5%) higher than in their counterparts with conventional irrigation where both received similar amounts of irrigation. In 80% of cases the difference in IWP between the two methods was in the ±20% range. Considering the cost and management complexity of implementing partial root-zone drying, it is critical to identify the rare conditions where this method could be economically justified.

Soil microbial response, water and nitrogen use by tomato under different irrigation regimes

Combining cover cropping with deficit irrigation in a Mediterranean low vigor vineyard

Evaluation of soil chemical properties irrigated with recycled wastewater under partial root-zone drying irrigation for sustainable tomato production

آگاهی از تأثیر تنش کم آبی بر کمیت و کیفیت گیاه توت فرنگی به منظور مدیریت آبیاری و محصول ضروری است. پژوهش حاضر به منظور بررسی اثر کم آبیاری تنظیم شده و کم آبیاری ناقص ریشه روی خصوصیات کمی و کیفی گیاه توت فرنگی در سال 1391 در یکی از مزارع توت فرنگی شهرستان بابلسر انجام شد. 3 تیمار آبیاری مطالعه شد: آبیاری کامل، کم آبیاری تنظیم شده و کم آبیاری ناقص ریشه در سطح 75% نیاز آبی گیاه. پژوهش در قالب طرح بلوک های کامل تصادفی با سه تکرار مورد بررسی قرار گرفت. آبیاری تا رسیدن رطوبت خاک به نقطه ظرفیت زراعی ادامه پیدا می کرد. با داشتن منحنی رطوبتی خاک و اندازه گیری مکش خاک به وسیله تانسیومتر وضعیت رطوبت خاک تعیین شد. عمق آب آبیاری طی کل فصل آبیاری در تیمارهای آبیاری کامل و کم آبیاری به ترتیب 341 و 256 میلی متر بود. بررسی اثر تیمارها با اندازه گیری خصوصیات کمی و کیفی نمونه های میوه در مرحله رسیدگی انجام شد. از نظر خصوصیات کمی صفات وزن تر، وزن خشک، سطح برگ، شاخص سطح برگ و عملکرد در تیمار آبیاری کامل به طور معنی داری بیشتر از تیمارهای کم آبیاری بود. در مقایسه صفات کیفی اسید قابل تیتر، اسیدیته و شاخص طعم میوه اختلاف معنی داری بین تیمارها مشاهده نشد. مقدار قند کل و آنتوسیانین در تیمار کم آبیاری تنظیم شده به طور معنی داری بیشتر از دو تیمار دیگر بود. با در نظر گرفتن صفات کمی و کیفی، روش کم آبیاری ناقص ریشه نزدیک ترین نتایج به تیمار آبیاری کامل را دارا بود. در شرایط استان مازندران استفاده از این روش برای به حداقل رساندن تلفات کمی و افزایش کیفیت میوه ها در شرایط تنش آبی توصیه می شود.

The effects of partial rootzone drying (PRD), deficit irrigation (DI) and control irrigation (CI) on fruit quality during storage of ‘Granny Smith’ apples were studied during a two-year period. Trees were planted in 120-L plastic pots. Fruits achieved earlier maturing at DI treatment, compared with fruits from PRD and CI treatments. Regulated drought has a positive effect on fruit firmness and weight loss during storage. After six months of cold storage, the highest decrease of flesh firmness was found in fruits from CI treatment. Effect of irrigation on changes in contents of soluble solids and total acids during storage were not found. Positive effect of DI on fruit firmness, compared with PRD, was not determined. The weight loss on PRD and DI was similar. Positive effects of DI on fruit storage were not found compared with PRD. Contrary, PRD showed good effects on fruit size and yield, compared with DI treatment.

SUMMARYThe effects of partial rootzone drying (PRD) and rootstock vigour on dry matter accumulation and partitioning among leaves, shoots, fruits, frame and roots of apple trees (Malus domesticaBorkh. cvar Pink Lady) were investigated in 2005 near Caltavuturo, in Sicily. In a first field trial, trees on MM.106 rootstock were subjected to: conventional irrigation (CI), maintaining soil moisture above 0·80 of field capacity; PRD irrigation, where alternating sides of the rootzone received 0·50 of the CI irrigation water; and continuous deficit irrigation (DI), where 0·50 of the CI water was equally applied to both sides of the rootzone. In a second trial, trees on M.9 or MM.106 were subjected to CI and PRD irrigation. In trial 1, dry matter accumulation was markedly reduced by DI irrigation and to a lesser extent by PRD; PRD trees partitioned 20% less to leaves, 31% less to fruits and 24% more to woody components than CI trees; DI trees partitioned 14% less to current shoots and 18% more to fruits than CI and had the highest fruit:leaf ratio. In trial 2, there was no interaction between rootstock and irrigation treatments. MM.106 induced greater leaf, shoot, frame and root dry weights (DWs) than M.9, resulting in more vegetative growth and larger trees. PRD reduced leaf, shoot, frame and fruit DWs, while root DWs were similar to CI, and thus PRD trees were 18% smaller than CI trees. Neither rootstock nor irrigation affected dry matter partitioning among organs or root:canopy ratio, whereas PRD trees or trees on MM.106 showed better water use efficiency than CI and M.9, respectively. The results show that PRD trees did not activate drought tolerance strategies in terms of dry matter allocation that could improve acquisition of water resources, regardless of rootstock. PRD irrigation increased above-ground dry matter partitioning towards woody components at the expense of leaves and fruits.

A study was conducted to compare two water-saving practices, deficit irrigation (DI) and partial root zone drying (PRD), and to examine how they affect water use, growth and yield of greenhouse grown capsicum compared to control irrigation (CI). The effect of PRD on the growth of capsicum plant was significant. The results showed that capsicum fruit yield was highest for control (full irrigation), followed by the deficit irrigation treatment (DI-75 %) and then 1 PRD treatment. The analysis suggested that the treatment 1 PRD outperformed 2 PRD and DI-50 in terms of fruit yield. The yield loss in PRD treatment was only 11.1 % compared to control, whereas amount of water applied was 50 % less than through control irrigation. The highest water use efficiency was achieved for treatment of 1 PRD with 63 % improvement in irrigation efficiency over control. The treatment 1 PRD used 20.60 litres of water to produce 1 kg capsicum as against 33.61 litres under control treatment.

Fruit yield and quality of 4 year old “Williams Pride” apple trees on M9 rootstock under partial rootzone drying (PRD) were studied over 2 years. Irrigation treatments were control irrigation (CI), conventional deficit irrigation (DI), and two different partial rootzone drying (PRDI and PRDII). In PRD, irrigation water was applied alternately on one side of the tree’s rows and the other side was not irrigated. While the irrigated side was changed at every irrigation in PRDI, the side that was not irrigated was changed at every other irrigation in PRDII. Total irrigation water amount was 324.1 and 314.2 mm for CI in 2009 and 2010, respectively. Applied irrigation water amount for DI, PRDI and PRDII was 50% of the CI. The ranking of water use efficiency (WUE) and irrigation water use efficiency (IWUE) values was maintained as PRDII>PRDI>DI>CI in average, in 2009 and 2010. Consequently, minimal or no differences between PRDII and CI treatments were determined in vegetative growth, some yield components and fruit quality. These results recommended that PRD treatments are more effective water saving irrigation technology with a higher WUE and not reduce fruit quality for apple trees compared to regulated deficit irrigation.   Key words: Apple, yield, irrigation water, partial rootzone drying, water use efficiency.

Grain yield response and N-fertiliser recovery of maize under deficit irrigation