Root disease and fungal populations in organic crops under different tillage and cropping systems

Fungi regulate nutrient cycling, decomposition, symbiosis, and pathogenicity in cropland soils. However, the relative importance of generalist and specialist taxa in structuring soil fungal community remains largely unresolved. We hypothesized that generalist fungi, which are adaptable to various environmental conditions, could potentially dominate the community and become the basis for fungal coexisting networks in cropping systems. In this study, we identified the generalist and habitat specialist fungi in cropland soils across a 2,200 kms environmental gradient, including three bioclimatic regions (subtropical, warm temperate, and temperate). A few fungal taxa in our database were classified as generalist taxa (~1%). These generalists accounted for >35% of the relative abundance of all fungal populations, and most of them are Ascomycota and potentially pathotrophic. Compared to the specialist taxa (5–17% of all phylotypes in three regions), generalists had a higher degree of connectivity and were often identified as hub within the network. Structural equation modeling provided further evidence that after accounting for spatial and climatic/edaphic factors, generalists had larger contributions to the fungal coexistence pattern than habitat specialists. Taken together, our study provided evidence that generalist taxa are crucial components for fungal community structure. The knowledge of generalists can provide important implication for understanding the ecological preference of fungal groups in cropland systems.

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Devising fertiliser recommendations for diverse cropping systems in a region: the case of low-input bean/maize intercropping in a tropical highland of Haïti

Agronomie ◽

10.1051/agro:2003046 ◽

2003 ◽

Vol 23 (7) ◽

pp. 673-681 ◽

Cited By ~ 9

Author(s):

C. Clermont-Dauphin ◽

J. M. Meynard ◽

Y. M. Cabidoche

Keyword(s):

Cropping Systems ◽

Low Input

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Biscogniauxia (Hypoxylon) Canker or Dieback in Trees

EDIS ◽

10.32473/edis-fr407-2017 ◽

2017 ◽

Vol 2017 (6) ◽

Author(s):

Claudia Paez ◽

Jason A. Smith

Keyword(s):

Water Stress ◽

Tree Species ◽

Soil Compaction ◽

Urban Areas ◽

Root Disease ◽

Poor Health ◽

Green Spaces ◽

Opportunistic Pathogens ◽

Wide Range ◽

Quercus Spp

Biscogniauxia canker or dieback (formerly called Hypoxylon canker or dieback) is a common contributor to poor health and decay in a wide range of tree species (Balbalian & Henn 2014). This disease is caused by several species of fungi in the genus Biscogniauxia (formerly Hypoxylon). B. atropunctata or B. mediterranea are usually the species found on Quercus spp. and other hosts in Florida, affecting trees growing in many different habitats, such as forests, parks, green spaces and urban areas (McBride & Appel, 2009). Typically, species of Biscogniauxia are opportunistic pathogens that do not affect healthy and vigorous trees; some species are more virulent than others. However, once they infect trees under stress (water stress, root disease, soil compaction, construction damage etc.) they can quickly colonize the host. Once a tree is infected and fruiting structures of the fungus are evident, the tree is not likely to survive especially if the infection is in the tree's trunk (Anderson et al., 1995).

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Observations on root disease of Container whitebark pine seedlings treated with biological controls

Native Plants Journal ◽

10.2979/npj.2008.9.2.92 ◽

2008 ◽

Vol 9 (2) ◽

pp. 92-97

Author(s):

R. Kasten Dumroese

Keyword(s):

Root Disease ◽

Whitebark Pine ◽

Pine Seedlings

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Growth and Economic Profitability of Castor Cultivation in the Semi-arid Zone of Haryana

Indian Journal of Economics and Development ◽

10.35716/ijed/ns20-011 ◽

2020 ◽

pp. 300-305

Keyword(s):

Arid Zone ◽

Cropping Systems ◽

Descriptive Analysis ◽

Market Price ◽

Transportation Cost ◽

Castor Seed ◽

Production Constraints ◽

Net Profit ◽

Semi Arid ◽

Extract Information

The present study was carried out in three districts viz; Rewari, Sirsa and Hisar of Haryana state. A survey of 60 sampled farms was conducted to extract information pertaining to various expenses incurred in cultivation of castor and output attained as well as to ascertain the perception of farmers for various problems encountered in production and marketing of castor seed. The descriptive analysis was employed to draw valid inferences from the study. The results revealed that net profit accrued from cultivation of castor seed was ₹ 46331 ha -1 in the study area. The value of B: C ratio of castor cultivation was more than one and also higher as compared to prevalent cropping systems indicated that cultivation of castor seed is economical viable entity. However, production constraints like retention of F2 seed in the field over year, grain scattering, shortage of irrigation water, frost effect on crop yield and marketing constraints like absence of MSP, higher transportation cost sale of castor seed in distant markets, frequent fluctuation in market price, non-availability of processing units were observed.

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Comparative Effect of Groundnut (Arachis hypogea l.) Genotypes on Yield and N Fixation in Sudan and Northern Guinea Savannahs of Nigeria

10.36265/njss.2019.290208 ◽

2019 ◽

pp. 61-67

Keyword(s):

Agricultural Research ◽

Cropping Systems ◽

Block Design ◽

Dry Weight ◽

Field Trials ◽

Yield Potential ◽

N Fixation ◽

Maize Crop ◽

Significant Interaction Effect ◽

Pod Yield

Recognition of high yielding and nitrogen (N) fixing groundnut genotypes and desegregating them in the cereal-based cropping systems common in savannah regions will enhance food security and reduce the need for high N fertilizers hence, minimize the high cost and associated environmental consequences. Field trials were conducted during the 2015 growing season at the Research Farms of Bayero University Kano (BUK) and Institute for Agricultural Research (IAR), Ahmadu Bello University, Samaru-Zaria to assess the yield potential and Biolog- ical N fixation in 15 groundnut genotypes (ICG 4729, ICGV-IS 07823, ICGV-IS 07893, ICGV-IS 07908, ICGV- SM 07539, ICGV- SM 07599, ICGV-IS 09926, ICGV-IS 09932, ICGV-IS 09992, ICGV-IS 09994, SAMNUT-21, SAMNUT-22, SAMNUT-25, KAMPALA and KWANKWAS). The groundnut genotypes and reference Maize crop (SAMMAZ 29) were planted in a randomized complete block design in three replications. N difference method was used to estimate the amount of N fixed. The parameters determined were the number of nodules, nod- ule dry weight, shoot and root dry weights, pod, and haulm yield as well as N fixation. The nodule dry weight, BNF, haulm, and pod yield were statistically significant (P<0.01) concerning genotype and location. Similarly, their interac- tion effect was also highly significant. ICGV-IS 09926 recorded the highest nod- ule dry weight of 2.07mg /plant across the locations while ICGV-IS 09932 had the highest BNF value of 140.27Kg/ha. Additionally, KAMPALA had the high- est haulm yield, while ICGV-IS 07893 had the highest pod yield across the loca- tions with a significant interaction effect. The result shows that ICGV-IS 07893 and ICGV-IS 09932, as well as ICGV-IS 09994 and SAMNUT – 22, were the best genotypes concerning BNF, haulm and pod yield in the Northern Guinea and Sudan Savannahs of Nigeria respectively with the potential for a corresponding beneficial effect.

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