Biology Agriculture Aquaculture Horticulture Postharvest Forestry Geography Environment Health

Black leaf streak disease and plantain fruit characteristics as affected by tree density and biomass management in a tropical agroforestry system

submitted by notaripradacts 1 year and 11 months ago
Black leaf streak disease (BLSD) affects both bananas and plantains. Anecdotal evidence suggests that when plantain is grown under shade in agroforestry systems, there is less damage from BLSD. In this study, BLSD severity and agronomic fruit characteristics of plantain were compared under high and low timber stand densities (TSD), and also under different crop management systems (mulching, burning, intercropping). By 11 months after planting, in high TSDs, plants had 1.2 more standing leaves, 1.5 more symptom-free leaves and a lower percentage of total leaf area attacked than in low TSDs. At harvest, plants in high TSDs had, on average, 1.4 more standing leaves than those in low TSDs. Percentage leaf area attacked by BLSD was 43.0 % in high TSD treatments, significantly lower than the 57.2 % in low TSD treatments. There was a significant and positive relationship between the number of leaves at flowering and dry fruit bunch mass for plantains grown under low TSD. However, there was no correlation between the number of leaves and fruit mass for the high TSD. The beneficial effects of shade in the high TSD, such as reduced severity of BLSD, were established. However, as there was bunch mass loss associated with reduced leaf production rates under the high TSD, a reduction in BLSD only partially compensated for this yield loss. Thus overall, at the high TSD, there was no yield gain from reduced BLSD.

Topic: Agriculture

Add your comment

Please Login or Signup to leave a comment

Related stories

Allele-specific loss and transcription of the miR-15a/16-1 cluster in chronic lymphocytic leukemia
submitted by toareno 2 months ago - Topic: Health
Deregulation of the miR-15a/16-1 cluster has a key role in the pathogenesis of chronic lymphocytic leukemia (CLL), a clinically heterogeneous disease with indolent and aggressive forms. The miR-15a/16-1 locus is located at 13q14, the most frequently deleted region in CLL. Starting from functional investigations of a rare SNP upstream the miR cluster, we identified a novel allele...

Phorbol myristate acetate, but not CD40L, induces the differentiation of CLL B cells into Ab-secreting cells
submitted by moysen 2 months ago - Topic: Health
In this study, we investigated the capacity of chronic lymphocytic leukemia (CLL) B cells to undergo terminal differentiation into Ig-secreting plasma cells in T cell-independent and T cell-dependent responses. We used a two-step model involving stimulation with phorbol myristate acetate (PMA) and CD40L, together with cytokines (PMA/c and CD40L/c), for 7 days. We describe immuno...

Black Leaf Streak Disease Affects Starch Metabolism in Banana Fruit
submitted by 8miladiis 1 year and 1 month ago - Topic: Agriculture
Black leaf streak disease (BLSD), also known as black sigatoka, represents the main foliar disease in Brazilian banana plantations. In addition to photosynthetic leaf area losses and yield losses, this disease causes an alteration in the pre- and postharvest behavior of the fruit. The aim of this work was to investigate the starch metabolism of fruits during fruit ripening from plants infected ...

Deadwood Density of Five Boreal Tree Species in Relation to Field-Assigned Decay Class
submitted by sarish 1 year and 1 month ago - Topic: Forestry
Aboveground deadwood, consisting of downed woody debris (DWD), snags, and stumps, is an important component of boreal forest ecosystem structure. Accurate deadwood density estimates are essential for evaluating ecosystem biomass and carbon stocks. The objective of this study was to examine the relationships between deadwood density, tree species, and decay status, identified in the field by mor...

Structural development of vegetation on rehabilitated North Stradbroke Island: Above/belowground feedback may facilitate alternative ecological outcomes
submitted by sajotho 1 year and 1 month ago - Topic: Biology
This study depicts broad-scale revegetation patterns following sand mining on North Stradbroke Island, south-eastern Queensland, Australia. Based on an ecological timeline spanning 4–20 years post-rehabilitation, the structure of these ecosystems (n = 146) was assessed by distinguishing between periods of ‘older’ (pre-1995) and ‘younger’ (post-1995) rehabilitation practices. The gener...

Tackling black leaf streak disease and soil fertility constraints to enable the expansion of plantain production to grassland in the humid tropics
submitted by vrachebh234 2 years and 1 month ago - Topic: Agriculture
In Central Africa, plantain is traditionally grown after a forest fallow. Given increasing urban demand and a lack of forest fallows near urban centres, as well as poor roads and environmental concerns to reduce pressure on forests, research is needed to identify suitable shade, fertility management and cultivars to shift production of plantain to grasslands and to reduce losses to diseases suc...

Clinical and Regulatory Features of Drugs Not Initially Approved by the FDA
submitted by sarish 8 months ago - Topic: Health
US Food and Drug Administration (FDA) denials of New Drug Applications (NDAs) are often controversial, yet little is known about the basis and characteristics of these decisions. We reviewed new drugs and biologics evaluated by FDA advisory committees between 2007 and 2009 and found that half (27/52, 52%) were unapproved in the first cycle. By 2013, 63% had been approved. Products with initial ...

Intragenic integration in DLC1 sustains factor VIII expression in primary human cells without insertional oncogenicity
submitted by brejsdi 5 months ago - Topic: Biology
Techniques enabling precise genome modifications enhance the safety of gene-based therapy. DLC1 is a hot spot for phiC31 integrase-mediated transgene integration in vitro and in vivo. Here we show that integration of a coagulation factor VIII transgene into intron 7 of DLC1 supports durable expression of factor VIII in primary human umbilical cord-lining epithelial cells. Oligoclonal cells with...

A decision-support system for forest density management within upland black spruce stand-types
submitted by pandhiiponkor 1 month ago - Topic: Environment
The objective of this study was to develop an enhanced modular-based structural stand density management model (SSDMM) and associated algorithmic analogue for upland black spruce (Picea mariana (Mill) BSP.) stand-types situated within the central portion of the Canadian Boreal Forest Region. For a given density management regime, site quality, rotation age, stock-type, cost structure and set of...

Therapeutic DNA Vaccination Using In Vivo Electroporation Followed by Standard of Care Therapy in Patients With Genotype 1 Chronic Hepatitis C
submitted by rechisib 1 year and 1 month ago - Topic: Health
Clearance of infections caused by the hepatitis C virus (HCV) correlates with HCV-specific T cell function. We therefore evaluated therapeutic vaccination in 12 patients with chronic HCV infection. Eight patients also underwent a subsequent standard-of-care (SOC) therapy with pegylated interferon (IFN) and ribavirin. The phase I/IIa clinical trial was performed in treatment naive HCV genotype 1...