Mantis Tiller - Free Shipping

Posts Tagged ‘sympeoms’

Verticillium Wilt

Thursday, September 10th, 2009

(Verticillium albo-atrum, V. dahliae)

Verticillium wilts may be a serious problem in tropical and subtropical regions and irrigated deserts where water deficiency may be severe. V. dahliae is more severe during prolonged warm, dry weather in cooler regions of potatoes production.

Symptoms of Verticillium Wilt

This potato disease is characterized by leaf yellowing, which begins at the plant base and may develop unilaterally, restricted to the sides of leaves, the stem, or the plant.
verticillium-wiltLater, the plant may wilt. The vascular system of the lower stem turns brown. Potatoes plants frequently become yellowed and mature early without pronounced wilting (early dying).
Stems wilted by V. albo-atrum are blackened by the presence of a blackish resting mycelium.
However, when V. dahliae causes wilting, the lower portion of the stem becomes grayish because of the presence of microsclerotia.
The vascular ring of tubers may have light brown discoloration extending from the stolon end up to more than halfway through the potato tuber. Larger tubers often have light tan, discolored eyes (pink eye).
These fungi are long-lived in soil or plant debris and have a wide host range, including other solanaceous plants, cotton, and weeds.
Surface-borne inoculum on seed tubers is important in disease spread. Interaction with nematodes (Meloidogyne, Pratylenchus, Globodera), fungi Rhizoctonia, Colletotrichum, Fusarium), and bacteria (Erwinia) can increases damage.

Management

Use crop rotations with nonsusceptible cereals, grasses, or legumes. Resistant or tolerant potato varieties are available.
Treat potatoes seed tubers with disinfectant fungicides to remove soil-borne inoculum. Prevent water stress by irrigation.
Systemic fungicides are useful while growing potatoes.

Go Green with ECO FRIENDLY landscaping tools from GreenGardenTools LOWEST PRICES on the Internet.


Mantis Tiller - Free Postage and Free Kickstand

Reblog this post [with Zemanta]