scholarly journals Root Dynamics of Apple Rootstocks in a Replanted Orchard

HortScience ◽  
2006 ◽  
Vol 41 (5) ◽  
pp. 1149-1155 ◽  
Author(s):  
Shengrui Yao ◽  
Ian A. Merwin ◽  
Michael G. Brown

Root observations in situ with a rhizotron camera enabled us to compare the performance of apple (Malus ×domestica Borkh.) trees on 3 rootstock clones planted in a New York orchard with a history of apple replant disease. Visual observations were conducted in situ at monthly intervals during 2 growing seasons through minirhizotron tubes for trees grafted onto 3 rootstocks: M.7 (M.7), Geneva 30 (G.30), and Cornell-Geneva 6210 (CG.6210). There were 3 preplant soil treatments (fumigation, compost amendment, and untreated checks) and 2 tree planting positions (within the old tree rows or in the old grass lanes of the previous orchard at this site). Preplant soil treatments and old-row versus grass-lane tree planting positions had no apparent influence on root systems, whereas rootstock clones substantially influenced root growth and demography. New root emergence was suppressed during the first fruit-bearing year (2004) on all 3 rootstock clones compared with the previous nonbearing year (2003). A root-growth peak in early July accounted for more than 50% of all new roots in 2003, but there was no midsummer root-growth peak in 2004. The median lifespan for roots of CG.6210 was twice that of G.30 and M.7 in 2004. Also, CG.6210 had more roots below 30 cm depth, whereas M.7 had more roots from 11 to 20 cm depth. Trees on CG.6210 were bigger, yielded more fruit, and had the highest yield efficiency in the third year after planting compared with trees on G.30 and M.7 rootstocks. Crop load appeared to inhibit new root development and changed root-growth dynamics during the first bearing year, with a resurgence in new root growth after fruit was harvested in October 2004. Rootstock genotype was the dominant influence on root lifespan and distribution in this study, whereas preplant soil fumigation, compost amendments, and replanting positions had little apparent impact on root characteristics despite their influence on above-ground tree growth and yield.

2010 ◽  
Vol 37 (4) ◽  
pp. 304 ◽  
Author(s):  
Junhua Ao ◽  
Jiabing Fu ◽  
Jiang Tian ◽  
Xiaolong Yan ◽  
Hong Liao

Root morphology and architecture are believed to be important for plant phosphorus (P) efficiency, but their genetic information is relatively scarce. In the present study, a field and a specially designed minirhizotron experiments were conducted using two soybean (Glycine max L. Merr.) genotypes and their 88 recombinant inbred lines (RILs) to elucidate the genetic variability for root morph-architecture traits and root growth dynamics as related to P efficiency in soybean. The results indicated that the root morph-architecture traits were continually segregated in the RILs with a normal distribution, indicating which are possibly controlled by quantitative trait loci. Significantly positive correlations were found between root and P traits, suggesting feasibility of screening P efficient genotype through simple selection of root traits in field. Most root morph-architecture traits were closely correlated, showing a coordinating contribution to P efficiency. Furthermore, root morphological traits always had higher heritability than architecture traits, thus, could serve as more reliable index in field selection. The dynamic parameters of root growth from the minirhizotron experiment showed that the P efficient genotype established longer and larger root system with preferring distribution in surface layer and also kept more active roots, therefore, had a better growth performance in field, than the P-inefficient genotype. Taken together, this is the first report on in situ root growth dynamics and its relation to P efficiency using minirhizotron systems in crops. Our findings help to better understand the relationships between P efficiency and root traits and, thus, facilitate development of P efficient genotypes in crops.


1986 ◽  
Vol 16 (6) ◽  
pp. 1360-1364 ◽  
Author(s):  
S. K. Srivastava ◽  
K. P. Singh ◽  
R. S. Upadhyay

Temporal variations in the spatial distribution of fine root mass were studied in a 19-year-old teak plantation in a dry tropical region. The soil block method was used to investigate fine root dynamics. Quantification of fine root mass was achieved in terms of live teak roots (separated by diameter), dead teak roots, teak root bark, herb roots, and fragmented soil organic matter. The annual mean fine root biomass was 5420 kg•ha−1 and the net production was 5460 kg•ha−1•year−1. The bulk of the root mass was distributed at a depth of 10–30 cm and roots ≤2 mm constituted one-half or more of the total root biomass. Maximum live root growth occurred during the rainy season. All root sizes showed similar bimodal seasonal patterns, but the maximum:minimum ratio generally declined with greater root size.


2017 ◽  
Vol 15 (2) ◽  
pp. e0803 ◽  
Author(s):  
Isabel Abrisqueta ◽  
Wenceslao Conejero ◽  
Lidia López-Martínez ◽  
Juan Vera ◽  
M. Carmen Ruiz Sánchez

 The objectives of the paper were to study the pattern of root growth (measured by minirhizotrons) in relation to trunk, fruit and shoot growth and the effects of crop load on tree growth and yield in peach trees. Two crop load (commercial and low) treatments were applied in a mature early-maturing peach tree orchard growing in Mediterranean conditions. Root growth dynamics were measured using minirhizotrons during one growing season. Shoot, trunk and fruit growth were also measured. At harvest, all fruits were weighed, counted and sized. Roots grew throughout the year but at lower rates during the active fruit growth phase. Root growth was asynchronous with shoot growth, while root and trunk growth rates were highest after harvest, when the canopy was big enough to allocate the photo-assimilates to organs that would ensure the following season’s yield. Shoot and fruit growth was greater in the low crop load treatment and was accompanied by a non-significant increase in root growth. High level of fruit thinning decreased the current yield but the fruits were more marketable because of their greater size.


2020 ◽  
Vol 11 ◽  
Author(s):  
Fauziatu Ahmed ◽  
Emmanuel Arthur ◽  
Hui Liu ◽  
Mathias Neumann Andersen

HortScience ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 1026C-1026
Author(s):  
Shengrui Yao ◽  
Ian A. Merwin ◽  
Michael G. Brown

Rhizotron observations enabled us to compare the performance of three apple (Malu ×domestica) rootstock clones following different pre-plant soil treatments in an apple replant study at Ithaca, NY. Trees were planted in Nov. 2001, with one minirhizotron tube per tree in three replicate plots of three rootstocks (M7, CG30, and CG6210), three pre-plant soil treatments (fumigation, compost amendment, and untreated controls), and two planting positions (within the old tree rows, or in the old grass lanes). Monthly root observations were conducted during the 2003 and 2004 growing seasons. There were substantially fewer new roots observed in the first bearing year (2004) than the previous nonbearing year (2003), for all three rootstocks. A root-growth peak in early July accounted for more than 50% of all new roots in 2003, but there was no midsummer root growth peak in 2004. Neither pre-plant soil treatments nor old row or grass-lane planting positions had much influence on root growth. The median lifespan for roots of CG6210 was twice as long as that of CG30 and M7 in 2004. Also, CG6210 had more roots below 30-cm depth, while M7 had more roots from 11–20 cm. Trees grafted on CG6210 were bigger and yielded more fruit in the third year after planting, compared with trees on CG30 and M7 rootstocks. Crop load severely inhibited new root development and changed root-growth dynamics during the first cropping year, with a surge in root growth after fruit harvest in Oct. 2004. Rootstock genotype was the dominant influence on root lifespan and distribution, compared with pre-plant soil fumigation, compost amendments, or replanting positions within the previous orchard rows or grass lanes.


Author(s):  
Alicia Balbín-Suárez ◽  
Samuel Jacquiod ◽  
Annmarie-Deetja Rohr ◽  
Benye Liu ◽  
Henryk Flachowsky ◽  
...  

Abstract A soil column split-root experiment was designed to investigate the ability of apple replant disease (ARD) causing agents to spread in soil. ‘M26’ apple rootstocks grew into a top layer of Control soil, followed by a barrier-free split-soil layer (Control soil/ARD soil). We observed a severely reduced root growth, concomitant with enhanced gene expression of phytoalexin biosynthetic genes and phytoalexin content in roots from ARD soil, indicating a pronounced local plant defense response. Amplicon sequencing (bacteria, archaea, fungi) revealed local shifts in diversity and composition of microorganisms in the rhizoplane of roots from ARD soil. An enrichment of OTUs affiliated to potential ARD fungal pathogens (Ilyonectria and Nectria sp.) and bacteria frequently associated with ARD (Streptomyces, Variovorax) was noted. In conclusion, our integrated study supports the idea of ARD being local and not spreading into surrounding soil, as only the roots in ARD soil were affected in terms of growth, phytoalexin biosynthetic gene expression, phytoalexin production, and altered microbiome structure. This study further reinforces the microbiological nature of ARD, being likely triggered by a disturbed soil microbiome enriched with low mobility ARD-causing agents that induce a strong plant defense and rhizoplane microbiome dysbiosis, concurring with root damage.


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