Editing Cassava (section)

== Cultivation ==

Optimal conditions for cassava cultivation are mean annual temperatures between {{Convert|20 and 29|C|F}}, annual precipitation between {{Convert|1000 and 2500|mm|in|abbr=on}}, and an annual growth period of no less than 240 days.<ref name="Del-Rosario-Arellano 2022">{{Cite journal |title=Zonificación edafoclimática de la yuca (Manihot esculenta Crantz) para la producción sostenible de bioproductos |journal=Norte Grande Geography Journal |eissn=0718-3402 |last1=Del-Rosario-Arellano |first1=José Luis |last2=Aguilar-Rivera |first2=Noe |last3=Leyva-Ovalle |first3=Otto Raúl |last4=Andres-Meza |first4=Pablo |last5=Meneses-Marquez |first5=Isaac |last6=Bolio-López |first6=Gloria Ivette |year=2022 |issue=81 |pages=361–383 |s2cid=249657496 |language=es |trans-title=Edaphoclimatic zoning of cassava (manihot esculenta crantz) for sustainable production of bioproducts |doi=10.4067/S0718-34022022000100361|url=http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-34022022000100361 }}</ref> Cassava is propagated by cutting the stem into sections of approximately {{cvt|15|cm|in}}, these being planted prior to the wet season.<ref name="Howeler 2007">{{cite web |last=Howeler |first=Reinhardt H. |year=2007 |title=Production techniques for sustainable cassava production in Asia |publisher=Centro Internacional de Agricultura Tropical, Bangkok |url=http://ciat-library.ciat.cgiar.org/Articulos_Ciat/07169_Production_techniques_cassava.pdf |access-date=3 May 2016 |archive-url=https://web.archive.org/web/20161005114611/http://ciat-library.ciat.cgiar.org/Articulos_Ciat/07169_Production_techniques_cassava.pdf |archive-date=5 October 2016}}</ref> Cassava growth is favorable under temperatures ranging from {{convert|25 to 29|C|F|0}}, but it can tolerate temperatures as low as {{convert|12|C|F|0}} and as high as {{convert|40|C|F|0}}.<ref>{{cite book |url=https://www.eolss.net/ebooklib/bookinfo/soils-plant-growth-crop-production.aspx |title=Soils, Plant Growth and Crop Production Volume II |date=2010 |publisher=[[EOLSS]] Publishers |isbn=978-1-84826-368-0 |editor-first=Willy H. |editor-last=Verheye |page=273 |chapter=Tropical Root and Tuber Crops |access-date=29 December 2020 |archive-url=https://web.archive.org/web/20210511044506/https://www.eolss.net/ebooklib/bookinfo/soils-plant-growth-crop-production.aspx |archive-date=11 May 2021 |url-status=live}}</ref> These conditions are found, among other places, in the northern part of the [[Gulf Coastal Plain]] in Mexico.<ref name="Del-Rosario-Arellano 2022"/> In this part of Mexico the following soil types have been shown to be good for cassava cultivation: [[phaeozem]], [[regosol]], [[arenosol]], [[andosol]] and [[luvisol]].<ref name="Del-Rosario-Arellano 2022"/>

<gallery class=center mode=nolines widths=180 heights=180><!--arrange images to stop'em running into next section-->
[[File:Ladang Singkong Putat Nutug Ciseeng-Bogor.jpg|thumb|Healthy crop, Indonesia]]
File:Cassava stakes1 (4627297822).jpg|Stakes
File:Cassava grafting7 (4425027331).jpg|[[Grafting]]
</gallery>

=== Harvesting ===

Before harvest, the leafy stems are removed. The harvest is gathered by pulling up the base of the stem and cutting off the tuberous roots.<ref name="Howeler 2007"/>

=== Handling and storage ===

Cassava deteriorates after harvest, when the tuberous roots are first cut. The healing mechanism produces [[coumaric acid]], which oxidizes and blackens the roots, making them inedible after a few days. This deterioration is related to the accumulation of [[reactive oxygen species]] initiated by cyanide release during mechanical harvesting. Cassava shelf life may be increased up to three weeks by overexpressing a cyanide-insensitive alternative oxidase, which suppressed ROS by 10-fold.<ref>{{cite journal |last1=Zidenga |first1=T. |display-authors=etal |year=2012 |title=Extending cassava root shelf life via reduction of reactive oxygen species production |journal=[[Plant Physiology (journal)|Plant Physiology]] |volume=159 |issue=4 |pages=1396–1407 |doi=10.1104/pp.112.200345 |pmc=3425186 |pmid=22711743}}</ref> Post-harvest deterioration is a major obstacle to the export of cassava. Fresh cassava can be preserved like potato, using [[thiabendazole]] or bleach as a fungicide, then wrapping in plastic, freezing, or applying a wax coating.<ref>{{cite web |title=Storage and processing of roots and tubers in the tropics |url=http://www.fao.org/docrep/x5415e/x5415e04.htm |access-date=4 May 2016 |publisher=[[U.N. Food and Agriculture Organization]] |archive-date=22 April 2016 |archive-url=https://web.archive.org/web/20160422120308/http://www.fao.org/docrep/x5415e/x5415e04.htm |url-status=live }}</ref>

While alternative methods for controlling post-harvest deterioration have been proposed, such as preventing reactive oxygen species effects by using plastic bags during storage and transport, coating the roots with wax, or freezing roots, such strategies have proved to be economically or technically impractical, leading to [[plant breeding|breeding]] of cassava varieties with improved durability after harvest, achieved by different mechanisms.<ref name="Venturini-2016">{{cite journal |last1=Venturini |first1=M.T. |last2=Santos |first2=L.R. |last3=Vildoso |first3=C. I |last4=Santos |first4=V. S |last5=Oliveira |first5=E.J. |year=2016 |title=Variation in cassava germplasm for tolerance to post-harvest physiological deterioration |journal=[[Genetics and Molecular Research]] |volume=15 |issue=2 |doi=10.4238/gmr.15027818 |pmid=27173317 |doi-access=free}}</ref><ref name="Morante-2010">{{cite journal |last1=Morante |first1=N. |last2=Sánchez |first2=T. |last3=Ceballos |first3=H. |last4=Calle |first4=F. |last5=Pérez |first5=J.C. |last6=Egesi |first6=C. |last7=Cuambe |first7=C.E. |last8=Escobar |first8=A.F. |last9=Ortiz |first9=D. |last10=Chávez |first10=A.L. |last11=Fregene |first11=M. |display-authors=3 |year=2010 |title=Tolerance to Postharvest Physiological Deterioration in Cassava Roots |journal=[[Crop Science (journal)|Crop Science]]|volume=50 |issue=4 |pages=1333–1338 |doi=10.2135/cropsci2009.11.0666}}</ref> One approach used [[gamma ray]]s to try to silence a gene involved in triggering deterioration; another strategy selected for plentiful [[carotenoid]]s, [[antioxidant]]s which may help to reduce oxidization after harvest.<ref name="Morante-2010" />

<gallery class=center mode=nolines widths=220 heights=180><!--format prevents images becoming very large at some window widths-->
File:NP Cassava Processing 7 (5867707684).jpg|Starch processing
File:NP Cassava Starch Processing (5867152719).jpg|Starch flour 
File:Vietnam cassava processing3 lo (4070319057).jpg|Starch wet-processing
File:Secando casabe.JPG|Spreading ''Casabe burrero'' (cassava bread) to dry, Venezuela
File:Vietnam cassava processing24lo (4070342389).jpg|Starch being prepared for packaging
File:Vietnam cassava cellophane noodles.jpg|Starch noodles packaged for shipping
File:Frozen cassava leaves.jpg|Frozen leaves in a Los Angeles market
File:Cassava buds (4733912948).jpg|Picked buds<!--used in some dishes-->
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