• Title, Summary, Keyword: Semi-Arid

Search Result 98, Processing Time 0.054 seconds

Prevalence of Phytophthora Blight of Pigeonpea in the Deccan Plateau of India

  • Sharma, M.;Pande, S.;Pathak, M.;Rao, J. Narayana;Kumar, P. Anil;Reddy, D. Madhusudan;Benagi, V.I.;Mahalinga, D.M.;Zhote, K.K.;Karanjkar, P.N.;Eksinghe, B.S.
    • The Plant Pathology Journal
    • /
    • v.22 no.4
    • /
    • pp.309-313
    • /
    • 2006
  • Phytophthora blight(PB), caused by Phytophthora drechsleri f. sp. cajani is the third potentially important disease of pigeonpea in the Deccan Plateau(DP) of India after wilt and sterility mosaic. In the rainy-season of 2005, an outbreak of PB was seen throughout DP. To quantify the incidence and spread of the disease, a systematic survey was conducted in the major pigeonpea growing regions of DP during the crop season 2005. Attempts were made to determine the effect of cropping systems on the PB development and identify resistant cultivars, if any, grown by farmers and on research farms. Widespread incidence of PB was recorded on improved, and or local cultivars grown in different intercropping systems. Majority of improved cultivars grown at research farms were found susceptible to PB(>10% disease incidence). Pigeonpea intercropped with groundnut, black gram and coriander had less disease incidence(${\leq}10%$). Three wilt and SM resistant pigeonpea cultivars KPL 96053, ICPL 99044, and ICPL 93179 were found resistant(<10%) to PB as well. However, their resistance to PB needs confirmation under optimum disease development environments.

Constraints and opportunities to sustain future wheat yield and water productivity in semi-arid environment

  • Ahmad, Mirza Junaid;Choi, Kyung-Sook
    • Proceedings of the Korea Water Resources Association Conference
    • /
    • /
    • pp.185-185
    • /
    • 2019
  • Sustaining future wheat production is challenged by anthropogenically forced climate warming and drying led by increased concentration of greenhouse gases all around the globe. Warming stresses, originating from the elevated $CO_2$ concentration, are continuously reported to have negative impacts on wheat growth and yield. Yet, elevated $CO_2$ concentration, despite being disparagingly blamed for promoting warming, is also associated with a phenomenon called $CO_2$ enrichment; in which wheat yield can improve due to the enhanced photosynthesis rates and less water loss through transpiration. The conflicting nature of climate warming and $CO_2$ enrichment and their interplay can have specific implications under different environments. It is established form the field and simulation studies that the two contrasting phenomena would act severely in their own respect under arid and semi-arid environments. Wheat is a dietary staple for masses in Pakistan. The country's wheat production system is under constant stress to produce more from irrigated agricultural lands, primarily lying under arid to semi-arid environments, to meet the rapidly growing domestic needs. This work comprehensively examines the warming impacts over wheat yield and water productivity (WP), with and without the inclusion of $CO_2$ enrichment, under semi-arid environment of Punjab which is the largest agricultural province of Pakistan. Future wheat yields and WPs were simulated by FAO developed AquaCrop model v 5.0. The model was run using the bias-correction climate change projections up to 2080 under two representative concentration pathways (RCP) scenarios: 4.5 and 8.5. Wheat yield and WPs decreased without considering the $CO_2$ enrichment effects owing to the elevated irrigation demands and accelerated evapotranspiration rates. The results suggested that $CO_2$ enrichment could help maintain the current yield and WPs levels during the 2030s (2021-2050); however, it might not withhold the negative climate warming impacts during the 2060s (2051-2080). Furthermore, 10 - 20 day backward shift in sowing dates could also help ease the constraints imposed by climate warming over wheat yields and WPs. Although, $CO_2$ enrichment showed promises to counteract the adverse climate warming impacts but the interactions between climate warming and $CO_2$ concentrations were quite uncertain and required further examination.

  • PDF

Climate Change and Soil-Water Balance

  • Aydin, Mehmet;Yano, Tomohisa;Haraguchi, Tomokazu;Evrendilek, Fatih;Jung, Yeong-Sang
    • Proceedings of The Korean Society of Agricultural and Forest Meteorology Conference
    • /
    • /
    • pp.7-10
    • /
    • 2011
  • The semi-arid and arid regions comprise almost 40 percent of the world's land surface. The low and erratic precipitation pattern is the single most significant contributor for limiting crop production in such regions where rainfall is the source for surface, soil and ground water. In a changing climate, the semi-arid and arid regions would increasingly face the challenge of water scarcity. According to the relevant literature; under the assumption of a doubling of the current atmospheric CO2 concentration, irrigation demand was estimated to increase for wheat and to decrease for second crop maize in a Mediterranean environment of Turkey in the 2070s. Crop evapotranspiration would decrease due to stomata closure. Reference evapotranspiration and potential soil evaporation were projected to increase by 8.0 and 7.3%, respectively, whereas actual soil evaporation was predicted to decrease by 16.5%. Drainage losses below 90 cm soil depth were found to decrease mainly due to lesser rainfall amount in the future.

  • PDF

Combined Application of Pseudomonas fluorescens and Trichoderma viride has an Improved Biocontrol Activity Against Stem Rot in Groundnut

  • Manjula, K.;Kishore, G.Krishna;Girish, A.G.;Singh, S.D.
    • The Plant Pathology Journal
    • /
    • v.20 no.1
    • /
    • pp.75-80
    • /
    • 2004
  • In an attempt to develop effective biocontrol system for management of stem rot disease in groundnut, 57 bacterial isolates and 13 isolates of Trichoderma spp. were evaluated for their antagonistic activity against Sclerotium rolfsii. The antagonists were selected based on their ability to inhibit the external growth of S. rolfsii from infected groundnut seeds. Four isolates of Pseudomonas fluorescens, GB 4, GB 8, GB 10 and GB 27, and T. viride pq 1 were identified as potent antagonists of S. rolfsii. T. viride pq 1 produced extracellular chitinase and parasitized the mycelium of S. rolfsii. Under controlled environment conditions, P. fluorescens GB 10, GB 27, T. viride pq 1 and the systemic fungicide Thiram(equation omitted) reduced the mortality of S. rolfsii inoculated to groundnut seedlings by 58.0%, 55.9%, 70.0% and 25.9%, respectively compared to control. In vitro growth of P. fluorescens GB 10 and GB 27 was compatible with T. viride pq 1 and Thiram(equation omitted). Integrated use of these two bacterial isolates with T. viride pq 1 or Thiram(equation omitted) improved their biocontrol efficacy. Combined application of either GB 10 or GB 27 with T. viride pq 1 was significantly effective than that with Thiram(equation omitted) in protecting groundnut seedlings from stem rot infection.

Effects of Windbreak Planting on Crop Productivity for Agroforestry Practices in a Semi-Arid Region

  • Jo, Hyun-Kil;Park, Hye-Mi
    • Journal of Forest and Environmental Science
    • /
    • v.33 no.4
    • /
    • pp.348-354
    • /
    • 2017
  • Agroforestry has been practiced in arid and semi-arid regions for the purposes of preventing desertification and to increase income for locals. However, the intended effects of such practices have been limited due to strong winds and aridity. This study undertook multi-year monitoring of the productivity of income crops associated with windbreak planting in a semi-arid region of Mongolia, and explored strategies of windbreak planning to enhance the multi-purpose effects of agroforestry practices. The tree crown density of windbreak planting was on average 40% in one year after planting and 65% 2-3 years after, and thereby windspeeds were reduced by about 30% and 54%, respectively. Average windspeed reductions at leeward distances from the windbreak planting were approximately 60% within 3H (H=tree height), 50% at 5H, and 42% at 7-9H, presenting a pattern in which the farther the distance the less the reduction in windspeeds. The windbreak planting increased crop productivity by up to 6.8 times, compared to the productivity absent of windbreaks. Increases in the crown density as stated above resulted in increases of crop productivity by up to 3.6 times. Based on such results, this study proposed a model of windbreak planning as a typical land-use system of border windbreak planting or alternate windbreak planting of combining trees and income crops. The model also included tree planting with a crown density of 60% and allocation of income crops within a leeward distance of 5 times the height of the trees to reduce windspeeds by about 50%. The results from this study are applicable to practicing agroforestry not only at the study site but also in other regions worldwide where strong winds and aridity are problematic.

Effects of Nitrogen Fertilization on Growth of Populus sibirica and Ulmus pumila Seedlings and Soil Properties in a Semi-Arid Area, Mongolia (몽골 반건조지에서 질소 시비가 백양나무와 비술나무 묘목의 생장 및 토양 특성에 미치는 영향)

  • Chang, Hanna;Han, Seung Hyun;Kim, Seongjun;Park, Min Ji;An, Jiae;Kang, Hoduck;Yi, Myong-Jong;Akhmadi, Khaulenbek;Son, Yowhan
    • Journal of Climate Change Research
    • /
    • v.6 no.3
    • /
    • pp.249-256
    • /
    • 2015
  • This study was conducted to investigate the effects of different levels and types of nitrogen fertilizer on seedlings and soil chemical properties in a semi-arid area, Mongolia. 2-year-old Populus sibirica and 4-year-old Ulmus pumila seedlings were planted in May 2014. Six treatments with three levels of nitrogen (low-level: urea $5g\;tree^{-1}$; medium-level: urea $15g\;tree^{-1}$, ammonium sulfate $33g\;tree^{-1}$, urea $15g\;tree^{-1}$ with potassium phosphate $10g\;tree^{-1}$; high-level: urea $30g\;tree^{-1}$) were applied and for the medium-level of nitrogen, different types of fertilizer were treated. Survival rate, root collar diameter (RCD) growth rate, leaf nitrogen concentration of seedlings, and soil chemical properties were determined in August 2014. The seedling survival rate of both species decreased as the level of nitrogen increased. This result can be explained by water stress caused by nitrogen fertilization in arid regions. The RCD growth rate of P. sibirica was significantly decreased by the treatment of high-level of nitrogen due to excessive nitrogen fertilization, and was increased by the treatment of ammonium sulfate due to sulfur which might promote nitrogen uptake. The leaf nitrogen concentration of P. sibirica did not change by the treatment of low-level of nitrogen, and was increased by the treatment of medium-level of nitrogen. There were no significant differences in the RCD growth rate and the leaf nitrogen concentration of U. pumila among the six treatments. None of soil chemical properties was affected by nitrogen fertilization. Overall, the low-level of nitrogen showed no effect on seedlings and soil chemical properties, except on survival rate of U. pumila and the high-level of nitrogen was considered excessive fertilization. Continuous monitoring of medium-level nitrogen fertilization including the ammonium sulfate, which increased early growth of seedlings, would be needed to elucidate the effect of fertilization on seedling growth and soil properties in a semi-arid region.

Mesquite (Prosopis juliflora) Pods as a Feed Resource for Livestock - A Review -

  • Sawal, R.K.;Ratan, Ram;Yadav, S.B.S.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.17 no.5
    • /
    • pp.719-725
    • /
    • 2004
  • Mesquite or Vilayati babul (Prosopis juliflora) is a drought resistant, evergreen, spiny tree with drooping branches and a deep laterally spreading root system. It grows in semi-arid and arid tracts of tropical and sub-tropical regions of the world and is spreading because the leaves are unpalatable and animals do not digest its seed. The mesquite has become a major nuisance; cutting or pruning its branches to form a canopy would provide shade for travelers, aid harvesting of pods, as well as make available wood for fuel. An average plant starts fruiting by 3-4 years of age and yields annually 10-50 kg pods/ tree, which can be collected from May-June and September-October. Availability of pods worldwide is estimated to be about 2-4 million metric tonnes. Ripe pods are highly palatable; on dry matter basis they contain 12% crude protein, 15% free sugar, a moderate level of digestible crude protein (7% DCP) with a high level of energy (75% TDN). The pods contain low tannin levels below those toxic to animals. Seeds contain 31-37% protein; pods should be finely ground before feeding to facilitate utilization of the seeds. Mesquite pods could replace costlier feed ingredients such as grain and bran contributing 10-50% of the diet. Phosphorus supplements need to be added when mesquite pod, exceeds 20% of animals' diet.

Review of Ancient Wisdom of Qanat, and Suggestions for Future Water Management

  • Taghavi-Jeloudar, Mohsen;Han, Mooyoung;Davoudi, Mohammad;Kim, Mikyeong
    • Environmental Engineering Research
    • /
    • v.18 no.2
    • /
    • pp.57-63
    • /
    • 2013
  • Arid areas have a significant problem with water supply due to climate change and high water demand. More than 3,000 years ago, Persians started constructing elaborate tunnel systems called Qanat for extracting groundwater for agriculture and domestic usages in arid and semi-arid areas and dry deserts. In this paper, it has been demonstrated that ancient methods of water management, such as the Qanat system, could provide a good example of human wisdom to battle with water scarcity in a sustainable manner. The purpose of this paper is twofold: Review of old wisdom of Qanat-to review the history of this ancient wisdom from the beginning until now and study the Qanat condition at the present time and to explore why (notwithstanding that there are significant advantages to the Qanat system), it will no longer be used; and suggestions for future water management-to suggest a number of new methods based on new materials and technology to refine and protect Qanats. With these new suggestions it could be possible to refine and reclaim this method of extracting water in arid areas. Also, a new multi-purpose water management model has been introduced based on rainwater infiltration management over the Qanat system as the model can be applied either in dry or wet cities to solve current urban water problems.