The most important disease of woody dicotyledonous plants in Arizona is Phymatotrichopsis root rot (Cotton or Texas root rot) caused by a unique and widely distributed soil-borne fungus, Phymatotrichopsis omnivora. This article talks about the diseases distribution, symptoms/signs, biology, identification, sampling, and control.
Cotton root rot, caused by Phymatotrichopsis omnivora, is the most destructive disease of dicotyledonous plants in Arizona. There are no known reliable control methods for this disease, and the difficulty in its management is most often directed at its survival deep in soils and its wide host range. Genetic diversity in P. omnivora and its potential role in disease are unknown. Isolating the fungus and reproducing the disease in the greenhouse or laboratory are problematic, making it difficult to assess the efficacy of potential treatments.
Pest Abundance on Desert Produce and Melon Crops in 2014
This document contains a number of charts and graphs detailing information relating to the abundance of Whitefly, Bagrada bugs, Beet Armyworm, Cabbage Looper, and Corn Earworm. There are also a few figures relaying temperature information.
2014 Management of Whiteflies and CYSDV on Fall Melons
CYSDV has caused significant reductions in fruit yields in the past, mainly due to the whitefly. This article gives some management guidelines for the whitefly including cultural management and chemical management.
Nutrient deficiencies can be identified in field through visual observations. However, additional analysis, either plant or soil testing is often necessary to confirm nutrient stress. The following is a quick-reference flow chart that can be used in field to identify potential nutrient deficiencies. Each nutrient has unique deficiency symptoms. Deficiencies will appear in many ways. It can be confused with other plant problems like pathogens or spray damage. But nutrient deficiencies can often be recognized because they tend to form symmetrical patterns, where both sides of leaf or plant parts show the same pattern.
“Summer slump” is a decline in growth of alfalfa usually beginning in July in areas where maximum daily temperature exceeds 100 °F, such as the low elevation deserts of Southwestern U.S. This article discusses some of the causes behind this and potential impacts.
Pest Abundance on Desert Produce and Melon Crops in 2013
This document contains a number of charts and graphs detailing information relating to the abundance of Whitefly, Bagrada bugs, Beet Armyworm, and Cabbage Looper. There are also a few figures relaying temperature information.
Area wide Incidence of Whiteflies and CYSDV In Fall Melons in Yuma County, 2007-2012
Authors: John C. Palumbo, Kurt Nolte, Yves Carriere
This is a summary of a recently completed project that was designed to survey the area wide incidence of Bemisia whiteflies and Cucurbit Yellow Stunting Disorder Virus (CYSDV) in commercial melon fields throughout the Yuma Arizona growing region.
Authors: Mary Olsen, Mike Matheron, Mike McClure and Zhongguo Xiong
Many diseases of citrus have been described world wide and have colorful and descriptive names such as: blue mold, green mold, gray mold, pink mold, pink nose, brown rot, black spot, black rot, black pit, yellow vein, yellow spot, rubbery wood, lumpy rind, curly leaf, corky bark, slow decline, spreading decline, and stubborn. This article secribes some of the diseases common to Arizona
Verticillium wilt may cause wilting of all or only parts of plants. Leaves become mottled or chlorotic and turn brown, often in interveinal parts of the leaves only. This article covers signs/symptoms, environmental conditions, the disease, and control.
Nematodes are microscopic round worms found in many habitats. There are several plant parasitic nematodes that cause problems on landscape and garden plants in Arizona. This article discusses the root-knot nematode, some of the symptoms is causes, disease, and prevention and control.
Factors Contributing to Development of Salinity Problems in Turf
Professional turfgrass managers in many parts of Arizona are confronted with a growing number of management challenges related to excess levels of salinity and/or sodium in soils. The consequences of excess salinity and/or sodium are poor turf performance, reduced water infiltration and the appearance of a new turf disease, rapid blight (Labyrinthula terrestris).
Grain sorghum (milo) is a warm season, annual grain crop. It is more resistant to salt, drought, and heat stress than most other crops. Nevertheless, highest yields are obtained when stresses are minimized. This Article give some suggestion on planting, fertilizing, irrigation and other aspects of growing.
After a few ears of widespread use, some growers have noticed that some fungicides have become less effective. The objective of this field trial was to evaluate disease control efficiency of various fungicide treatment sequences, utilizing products with different modes of action that are registered for use on melon crops.
Alfalfa Weed Control in the Low Deserts of Arizona
Alfalfa is a vigorous crop that is very competitive with weeds. However, chemical weed control is often necessary even in well managed alfalfa since the marketplace has a low tolerance for weeds in alfalfa hay.
The alfalfa stem nematode, Ditylenchus dispsaci, is a soilborne plant-parasitic nematode that infects alfalfa. Different races infect other hosts such as onion, oats and strawberries, but the alfalfa race reproduces only on alfalfa in Arizona. This article discusses symptoms, disease cycle, management and identification.
Water is essential for citrus trees.This article discusses some of the symptoms of stresses caused by lack of water and gives suggestions on how to estimate and time water applications on citrus trees.