- Authors:
- Zhang, Y.
- Wang, Q.
- Zhang, J. S.
- Yang, P. N.
- Wei, H. G.
- Source: Xinjiang Agricultural Sciences
- Volume: 47
- Issue: 12
- Year: 2011
- Summary: Objective: In order to discuss the effect of gentle salt-water irrigation on yield of cotton and its quality, a field experiment was conducted at the national irrigation experiment station of Kuerle city in 2008. The research has studied the effect of gentle salt-water alternated with fresh-water irrigation on cotton yield and yield component. Method: This experiment was carried out to use different gentle salt-water rate and different fresh-water rate to find out an appropriate amount of irrigation. Result: The results showed that the cotton yield and its fiber quality can be improved by gentle salt-water alternated with fresh-water irrigation of 3 g/L of mineralized degree in the south Xinjiang. Salt which was carried into soil could be rush into a deep layer of the soil profile by fresh-water irrigation and winter irrigation, and the total salinity of the soil generally kept its balance. Conclusion: By analyzing the tested index of every cotton growth stage, it was found out when gentle salt-water irrigation rate was 2 250 m 3/hm 2 and the fresh-water irrigation rate was 1 500 m 3/hm 2, cotton yield was higher.
- Authors:
- McClymont, L.
- McAllister, A.
- O'Connell, M. G.
- Whitfield, D. M.
- Abuzar, M.
- Sheffield, K.
- Source: Acta Horticulturae
- Issue: 922
- Year: 2011
- Summary: The METRIC algorithm (Allen et al., 2007) was applied to a Landsat 5 image to assess the range of vegetation cover (measured as Normalised Difference Vegetation Index; NDVI), and rates of evapotranspiration (ET), of major horticultural crops grown in the Sunraysia Irrigation Region of SE Australia. The image represented the period of maximum foliage cover of horticultural crops grown in the Region. The range in mid-season NDVI of almond, grape and citrus crops almost matched the whole-of-season range reported for broad-acre irrigated annual crops grown in Idaho, USA. Alfalfa reference ET (ETr) constituted the upper limit to ET rate seen in Sunraysia crops. The range of ET and NDVI observations in this study therefore complied with limits on ET and NDVI seen in irrigated crops in Idaho, USA. ET-NDVI relationships seen in USA crops appear to provide a useful reference framework for well-watered irrigated crops in cases where ETr is the upper limit on ET. ET rates in Sunraysia crops were strongly related to NDVI. The dependence of ET rates on NDVI, combined with the large range in NDVI, meant that irrigation water requirement varied widely within and between crop types in the Sunraysia region: results support the use of NDVI measures to account for site-specific differences in crop water requirement attributable to vegetation cover. Findings suggest that satellite-based METRIC methods of ET estimation may be used to formulate region- and crop-specific estimates of the crop coefficients (Kcb, Ke, and Kc) required for optimal irrigation water management of horticultural crops.
- Authors:
- Source: Journal of Research and Applications in Agricultural Engineering
- Volume: 56
- Issue: 4
- Year: 2011
- Summary: The aim of the study was to assess the dry matter, starch, vitamin C, glycoalkaloids and nitrates content in potato tubers from organic system cultivated in light, sandy soil of IHAR Jadwisin (Mazovia). The objective of this work was to evaluate the tuber chemical composition of 8 cultivars of potatoes under the influence of the irrigation. Irrigation had no effect on dry matter, starch and vitamin C, but significantly affected glycoalkaloids and nitrates. The study showed a significant effect of variety and years of research on the content of dry matter, starch, vitamin C, nitrates and glicoalkaloids. Genotypic differences were the most evident in the case of nitrates and glycoalkaloids content. Under the influence of irrigation decreased the nitrate content and increased content of glycoalkaloids.
- Authors:
- Chen, J. C.
- Baez, I.
- Takeuchi, Y.
- Sequeira, R. A.
- Ouyang, G. C.
- Xia, Y. L.
- Source: Plant Health Progress - Peer-Reviewed Journal of Appied Plant Health
- Issue: October
- Year: 2011
- Summary: The Asian form of huanglongbing (HLB) is caused by ' Candidatus Liberibacter asiaticus (Las),' a phloem-limited bacterium transmitted by the Asian citrus psyllid, Diaphorina citri Kuwayama. Nutrient management, together with other cultural practices such as pruning and irrigation, for mitigation of the disease has been practiced in China for many years. Our literature review, field survey, and interviews with Chinese scientists and growers indicate that these cultural practices were generally ineffective for the disease management. However, a nutritional approach in conjunction with other cultural practices such as irrigation can maintain grove productivity for a certain time depending on the type of citrus species/cultivars, the age of the trees, the propagation method of the plants, the Asian citrus psyllid (ACP) ( Diaphorina citri Kuwayama) population, and other factors. Symptomatic mature pommelo ( Citrus maxima Merr) and sweet orange ( C. sinensis L. Osbeck) plants can commonly survive and maintain a certain level of productivity for an additional 4 to 5 years, even longer assuming vigorous ACP control.
- Authors:
- Jin, L. P.
- Pang, W. F.
- Duan, S. G.
- Bian, C. S.
- Liu, J.
- Xu, J. F.
- Source: Chinese Potato Journal
- Volume: 25
- Issue: 1
- Year: 2011
- Summary: Drought stress (DS) is considered to be one of main constraints of potato ( Solanum tuberosum) production. A pot trial with a total of 42 potato varieties was conducted in a rain-proofed shed in Hebei, China, to evaluate their drought tolerance (DT) under two water regimes (well irrigated and DS). Under DS conditions, some varieties, such as Hutou, Gaoyuan 7, CE 66 and HS 66, showed good DT. Gaoyuan 7 and Hutou maintained higher tuber yield even under the DS, and so they could be applied for the DT breeding. Plant height was sensitive to drought, but the drought had less effect on plant height of the varieties with strong DT. Drought conditions induced an increase in the tuber number of varieties with strong DT, and a decrease in the number of varieties with weak DT. The specific gravity of tubers was insignificantly affected by the drought. The ratio of variable to maximum chlorophyll fluorescence (Fv/Fm) changed insignificantly under DS, but the effective quantum yield (qY) of leaves decreased sharply.
- Authors:
- Niu, X. X.
- Wang, B.
- Ma, X. W.
- Xue, X. R.
- Yao, Q. Q.
- Chen, B. Y.
- Yang, T.
- Source: Xinjiang Agricultural Sciences
- Volume: 48
- Issue: 5
- Year: 2011
- Summary: Objective: To improve cotton planting technology according to cotton canopy characteristics. Method: Adopt the way, in film with drip irrigation relatively high and low two irrigation quantities, design such 5 different nitrogen strategy plan, completely combination of 10 treatments, determine and analyze the 10 with cotton canopy characteristic and yield growth the variation characteristics. Result: Whether irrigation level is high or low, LAI value and K value each of them with "behind the front less" application of N fertilizer was significantly higher in the bud stage; In the bloom stage under the high irrigation, LAI value was significantly higher with "behind the front less" application of N fertilizer; in the Bud stage, bloom stage, boll stage under high irrigation, with "behind the front less "application of N fertilizer, LAI value was relatively fast increased, but the TC value and T value were decreased relatively quickly; in the bud stage, bloom stage, boll stage under low irrigation, MFIA value was decreased relatively quickly with "front behind much less" application of N fertilizer, but the K value was increased relatively quickly; when the irrigation is higher, the fine under the control of water and nitrogen yield with LAI value was positively related to change, LAI value and seed cotton yield each of them with "behind the front less application of N fertilizer was significantly higher. Conclusion: When the Irrigation is relatively high, the LAI of cotton in bud stage and bloom stage showed the highest value when using two top-dressing with the behind the front less" strategy of nitrogen, to the effect of LAI value, TC value, T value, K value, and yield in growth stage was stronger than that "front behind much less" strategy of nitrogen.
- Authors:
- Zhang, Y. L.
- Luo, H. H.
- Hu, X. B.
- Yang, M. S.
- Feng, G. Y.
- Cui, S. Q.
- Yao, Y. D.
- Zhang, W. F.
- Source: Xinjiang Agricultural Sciences
- Volume: 48
- Issue: 5
- Year: 2011
- Summary: Objective: The purpose of this program is explore the formation rule of the yield and the canopy structure of hybrid cotton at low density and with less seeds to seek high yield and efficiency. Method: Two hybrid cotton cultivars, xinluzao 43 and lumianyan 24, were grown under-mulch-drip irrigation to study various low-densities' influence on the canopy structure, photosynthetic characteristics and the yield of hybrid cotton. Result: The results showed that the lint yield of hybrid cotton reached 3 300 kg/hm 2 ultra-high levels at the density of 10. 5*10 4 plants/hm 2, through individual and group coordinated production advantage. The leaf area index LAI, canopy openness (DIFN) rising fast. The higher light absorption and the more photosynthesis products will be, which contributes to the dry matter production capacity and conversion rate, thus helping reach the purpose of increasing yield and efficiency. However, the yield of hybrid decreased less than 2 700 kg/hm 2 levels at the density of 45 000 plants/hm 2, decreased rage up to 18.1%-21.7%. Conclusion: The aim of saving cost, improving the yield and efficiency can be actualized by exerting individual potential and by relatively reducing the density of hybrid cotton.
- Authors:
- Wang, J.
- Li, X. M.
- Liu, M. X.
- Yang, J. S.
- Yu, M.
- Source: Journal of Northwest A & F University (Natural Science Edition)
- Volume: 39
- Issue: 6
- Year: 2011
- Summary: Objective: The study was done to explore the effects of different mulched drip irrigation modes on cotton evapotranspiration, and to provide reference for design of technical parameters of drip irrigation and determination of irrigation schedule. Method: A laboratory simulation experiment was carried out to obtain the cotton evapotranspiration by weighing method, and then the effects of different emitter discharges (0.3, 0.8 L/h), irrigation water qualities (0.40, 2.47, 3.50 g/L), and irrigation amounts (321,386 mm) on cotton evapotranspiration were analyzed. Result: The cotton evapotranspiration under small emitter discharge (0.3 L/h) is higher than that under large emitter discharge (0.8 L/h) when the cotton is irrigated with sufficient fresh water. For the same irrigation amount and emitter discharge, the cotton evapotranspiration is almost the same under fresh water (0.40 g/L) and brackish water irrigation (2.47 g/L), which is obviously lower than the cotton evapotranspiration under saline water irrigation (3.50 g/L). For the same emitter discharge, the cotton with sufficient water supply has higher evapotranspiration than that with deficient water supply. Conclusion: The cotton evapotranspiration decreases with the increase of emitter discharge or mineralization degree of irrigation water, increases with the increase of irrigation amount. The blackish water irrigation with proper amount can not influence the cotton evapotranspiration significantly.
- Authors:
- Source: BIULETYN INSTYTUTU HODOWLI I AKLIMATYZACJI ROÅLIN
- Issue: 259
- Year: 2011
- Summary: The investigation, carried out in the years 2008-2009, aimed an assessment of effects of four factors: place of growing, irrigation, presprouting of seed potatoes and use of effective microorganisms on marketable quality of potatoes grown under organic farming system. Eight cultivars, representing different earliness groups, were tested. Genotype had the largest influence on occurrence of external and internal tuber disorders. The place of growing (soil type) affected occurrence of common scab, black scurf, deformations and rust spot. Drip irrigation reduced incidence of common scab, tuber deformations and rust spot. Presprouting of seed potatoes and effective microorganisms exerted the smallest influence on the marketable tuber quality.
- Authors:
- Zhang, P.
- Yan, J. P.
- Xu, H. L.
- Zhao, X. F.
- Source: Acta Pedologica Sinica
- Volume: 48
- Issue: 6
- Year: 2011
- Summary: After comparative analysis of the distribution characteristics of soil water and salt in farmlands (3 cotton fields and 1 orchard) and their shelterbelts in drip irrigation prevailing Kalamiji Oasis in the lower reaches of Tarim River, Northwest China through comparative tests and field monitoring, effects of the current drip irrigation pattern on farmlands within forest networks and their shelterbelts and main factors affecting salt-water dynamics in the soil within the forest network were studied and analyzed with the following conclusions obtained. (1) In Kalamiji oasis, the groundwater table in the fields lowers at a rate of 0.5 m a -1 as a result of popularization of drip irrigation and varies seasonally; it is relatively shallow in non-irrigation season and relatively deep in irrigation season; and over 1 m deeper in the latter than in the former. (2) As the impact of drip irrigation on soil never goes deeper than 80 cm, the irrigation supplies little water, almost nil, to groundwater, while the roots of farmland shelterbelt have to go deep into the soil to absorb water, thus leading to significantly lower soil water content in the shelterbelt than in farmland ( p
