Glassy-winged sharpshooter a continuing threat to grape industry
Anaheim boasted a thriving wine industry in the late 1800s, before an unnamed affliction killed 40,000 acres of the grapevines and put 50 wineries out of business. The problem was later found to have been Pierce’s disease of grapevines. Would Anaheim be wine country today if it weren’t for Pierce’s disease? Probably not, but the sad fate of this Southern California wine industry underscores the importance of controlling the disease and the insects that spread it in California’s thriving grape growing regions.
GWSS has turned out to be a very efficient vector of Xyella fastidiosa, the bacterium that causes Pierce’s disease in grapes. When GWSS made their way to places where scientists believed the bacterium didn’t exist, such as Kern County, grapevines began to express symptoms of the disease. The county agricultural commissioners in the San Joaquin Valley have been working tirelessly over the last 10 years to keep glassy-winged sharpshooters out of grape growing regions to protect a very valuable economic driver. In Fresno County alone, where grapes are the No. 1 agricultural commodity, the crop was worth $961 million in 2011.
Despite the efforts to contain GWSS in Fresno County, the pest is spreading very gradually south and east of the Fresno-Clovis metropolitan area into commercial vineyards and orchards.
“Cooperation by urban residents where we find GWSS has been great,” said Fred Rinder of the Fresno County Agricultural Commissioner’s office. Nevertheless, in 2012, GWSS was found spreading out in Kerman, Parlier, Sanger and Kingsburg.
Stephen Vasquez, UC Cooperative Extension advisor in Fresno County, fears local grape farmers have become complacent about glassy-winged sharpshooter and Pierce’s disease, even though all grapes are susceptible. The best way to control its spread, he said, is to monitor and manage sharpshooter vectors and remove and replace vines that have tested positive for Xylella fastidiosa.
“Be vigilant. Learn the symptoms and train crews and workers,” Vasquez said. “Pierce’s disease has been around for a long time and GWSS has been here more than a decade, but we still haven’t had that marriage of the two. That is potentially devastating.”
Anaheim alikuwa na sekta ya divai yenye kusitawi mwishoni mwa miaka ya 1800, kabla ya ugonjwa usiojulikana kuua ekari 40,000 za mizabibu na kuweka vyumba vya divai 50 nje ya biashara. Baadaye iligunduliwa kwamba tatizo hilo lilikuwa ugonjwa wa mizabibu wa Pierce. Je, Anaheim ingekuwa nchi ya divai leo kama haingekuwa na ugonjwa wa Pierce? "Hakuna shaka, lakini hatima ya kusikitisha ya sekta hii ya divai ya Kusini mwa California inasisitiza umuhimu wa kudhibiti ugonjwa na wadudu ambao hueneza katika mikoa ya California ya kukua zabibu. """ Kwa mfano, kuna bakteria inayoitwa Xyella fastidiosa, ambayo husababisha ugonjwa wa Pierce katika zabibu. Wakati GWSS ilifika mahali ambapo wanasayansi waliamini bakteria haikuwepo, kama vile Kaunti ya Kern, mizabibu ilianza kuonyesha dalili za ugonjwa huo. Wakurugenzi wa kilimo wa kaunti katika Bonde la San Joaquin wamekuwa wakifanya kazi bila kuchoka kwa miaka kumi iliyopita ili kuwazuia wapiganaji wa mrengo wa kioo kutoka maeneo ya kuzaliana zabibu ili kulinda dereva wa kiuchumi wa thamani sana. Katika Fresno County pekee, ambapo zabibu ni No. Kwa mujibu wa takwimu za mwaka 2011, mazao ya mimea ya kilimo yaliongezeka kwa dola milioni 961. Licha ya juhudi za kuzuia GWSS katika Kaunti ya Fresno, wadudu wanaenea polepole kusini na mashariki mwa eneo la mji mkuu wa Fresno-Clovis katika mashamba ya mizabibu na bustani za matunda. "Ushirikiano wa wakazi wa mijini ambapo tunapata GWSS umekuwa mkubwa", alisema Fred Rinder wa ofisi ya Kamishna wa Kilimo wa Kaunti ya Fresno. Mwaka 2012 ugonjwa huo uligunduliwa katika maeneo ya Kerman, Parlier, Sanger na Kingsburg. Stephen Vasquez, mshauri wa UC Cooperative Extension katika Kaunti ya Fresno, anaogopa wakulima wa zabibu wa eneo hilo wamekuwa na wasiwasi juu ya shellfish yenye mabawa ya kioo na ugonjwa wa Pierce, ingawa zabibu zote zinaathirika. Njia bora ya kudhibiti kuenea kwake, alisema, ni kufuatilia na kusimamia vector sharpshooter na kuondoa na kubadilisha mizabibu ambayo imepimwa chanya kwa Xylella fastidiosa. Kuwa mwangalifu. Jifunze dalili na mafunzo ya wafanyakazi na wafanyakazi, <unk> Vasquez alisema. "Ugonjwa wa Pierce umekuwapo kwa muda mrefu na GWSS imekuwa hapa kwa zaidi ya muongo mmoja, lakini bado hatujafanya ndoa hiyo ya wawili. Hilo linaweza kuwa lenye kuangamiza. <unk>