region of Shaanxi, and it was not only subject to extreme rainfall, but due to the lack of water transportation, it was also fairly difficult to mobilise massive aid there from outside in case of serious famine. Improvements in the physical efficiency of irrigation systems are often suggested as a means of coping with short water supplies. When surface water resources were scarce, some people thought of using underground water.
The wellirrigation campaign in the Qing dynasty
There were two well drilling campaigns sponsored by the Qing government: one during the
Safflower is originated from Iran and is tolerant against water deficit stress. However, in semi-arid Mediterranean climate terminal drought and heat stress adversely affect the safflower production. In order to investigate the influence of foliar application of proline (Pr) (10 and 20 mM) and glycinebetaine (GB) (2 and 4 mM) under well and deficit irrigation (37.23° N,46.16° E). Foliar spray of compatible organic solutes started from middle vegetative growth and continued till seed filling stage. Comparison of well irrigated and stress conditions revealed that severity of water deficit stress (SI) was 0.25. Evaluation of growth-related morphological characteristics such as plant height, leaf area, canopy spread and percent ground cover showed that they considerably reduced by water deficit stress. However, foliar application of compatible solutes could somewhat increase growth related parameters. Results showed that water deficit stress noticeably reduced the chlorophyll content, while foliar spray could alleviate the water deficit stress effects when compared with intact plant (non-sprayed plants). The beneficial effect of GB was more prominent than Pr, especially under deficit irrigation condition. Principal component analysis (PCA) indicated that the best performance under well irrigated condition was obtained by application of 4 mM GB while under deficit irrigation condition the best performance was recorded for plants treated with 2 and 4 mM GB and 20 mM Pr. Overall, results of current experiments showed that foliar spray with high concentration of GB may can significantly alleviate the adverse effects of water deficit stress.
Dust pollution can negatively affect plant productivity in hot, dry areas with high insolation during summer. To understand the effect of water-deficit and its interaction with dust pollution on vegetative and physiological changes in grapevine ʻBidaneh Sefidʼ, two-year-old plants were subjected to drought stress (-0.1 and -1 MPa) and dust treatment in a greenhouse during 2013 and 2014. The results showed that dust had a significant negative effect on the number of leaves, shoot length, root and shoot dry weights, and total dry weight under both drought and well-irrigated conditions. Dust, when applied in combination with drought, caused severe growth reduction. Leaf relative water content (RWC) and membrane stability index (MSI) were reduced under dust and drought stress, while soluble carbohydrate, proline, malondialdehyde (MDA) and H2O2 concentrations increased. Furthermore, dust application resulted in characteristics similar to those induced by water-deficit stress and intensified vegetative and physiological changes when applied together. Dust and drought treatments increased peroxidases and ascorbate peroxidase activities when compared to the control. The results indicate that dust has an adverse effect on the growth and physiology of grapevine and plays a negative role in the response of grapevine to drought stress.
This study aimed to investigate the effects of drought stress on Amsonia orientalis, an endangered ornamental plant with a limited natural distribution in Europe. Effects of polyethylene glycol (PEG)-mediated drought stress (-0.15, -0.49, -1.03 and -1.76 MPa osmotic potentials) were tested on in vitro cultures. In general, root lengths and numbers, total protein, chlorophyll a and carotenoid contents were negatively influenced at elevated levels of the stress factor. The successive decrease in the tested osmotic potentials resulted in gradually higher H2O2, malondialdehyde (MDA) and proline contents. Activities of the antioxidant enzymes, peroxidase (POD) and catalase (CAT), were found to be enhanced in response to the decreasing osmotic potential tested, whereas increased superoxide dismutase (SOD) activity was observed at the -0.15 MPa osmotic potential. Strong activation of POD enzymes under drought stress suggests that POD enzymes might have a major role in regulating the H2O2 content, while CAT has only a supplementary role in A. orientalis. These results indicated that although A. orientalis is susceptible to long-term drought, the species may survive during mild drought stress because the development of the plant was not totally inhibited but only limited. Nevertheless, the species should be introduced to well-irrigated lands, after evaluation of the soil’s water status, in order to ensure the continuation of its generations.
Sher Ali Khan, Xiaoyu Liu, Bakht Ramin Shah, Wenting Fan, Hong Li, Sher Bahadhar Khan and Zahoor Ahmad
Vegetables are important source of nutrients for human body. Wastewater irrigation may lead to contamination of these vegetables and cause possible health risk. In the present study impact of waste water irrigation on metals uptake (Fe, Mn, Ni, Co, Zn, Cd, Cr and Pb) by five commonly consumed vegetables (radish, cabbage, lettuce, cauliflower and spinach) grown in the suburbs of Peshawar were investigated using AAS (Atomic Absorption spectrophotometer). The uptake and accumulation of metals for vegetables irrigated with wastewater were significantly (p < 0.05) higher than tube well irrigated vegetables and permissible limits of WHO/FAO. Among the edible parts of vegetables maximum accumulation of Mn, Pb and Cd occurred in radish followed by Ni and Fe in spinach while Cr and Zn were high in cauliflower and cabbage. The estimated daily intake of metals (DIM) revealed that at present the consumption of studied vegetables were under the tolerable limits of (US-EPA, IRIS), however intake of metals in waste water irrigated vegetables were significantly high and can cause health hazards in the long run
Irrigation and Drainage Engineering. Vol. 117. Iss. 4 p. 567-577.
PAPADEMETRIOU M.K., DENT F.J. 2001. Grape production in the Asia-Pacific region. Bangkok, Thailand. Food and Agriculture Organization of the United Nations, Regional Office for Asia and the Pacific. No. 7 pp. 104.
ROBY G., MATTHEWS M.A. 2004. Relative proportions of seed, skin and flesh, in ripe berries from Cabernet Sauvignon grapevines grown in a vineyard either wellirrigated or under water deficit. Australian Journal of Grape and Wine Research. Vol. 10 p. 74